New Video Technology Rings the Bell(curve)
At this year’s NAB convention, there were two new video technologies that dominated the show: 3D and 4K. They are soon to be touted at CEDIA as well. Let’s look at both and see if we can pick a winner for Home Theaters.
You remember the “bell curve”, right? It’s low on the right and left, with a bell-shaped peak in the middle, and is used to show that the average always falls between extremes. While we home theater owners and fans like to stay to the right of the curve, industry basics, like video formats, distribution methods, and even TV screen sizes, fall right in the center peak of the curve. With that in mind, look for a moment at the new technologies.
3D could hardly be called new, though. It’s been lurking around since at least the 1950s (way before, if you’re picky), when it and wide screen processes where the desperate grappling hooks the film industry was using to try to snag the audience already wandering away from the box office to TV. There are so many 3D and wide screen processes, that each has filled its own rather substantial hard cover book (click HERE, and go to Technology Books to buy a copy). While widening the screen was fairly easy to do, and even worked better in existing theaters, 3D has the nasty and annoying demand of having two of everything, except the screen. And that’s where the problem has always been: how do you project two images on one screen, then separate them so that only one image is seen by each eye? Those darn glasses. Nobody likes them. They are usually cheap, scratched, don’t fit right, darken the image, and make you look silly.
Today’s 3D has come a long way. The issues of intraocular angle, alignment and convergence have largely been solved, and once you get past the camera, editing and post production are now computerized, making 3D easier to create. Even digital projection solves the issue of two projectors, as one can do double duty. And for all the advancements all the way up to the light leaving the projector, you still have that problem of two images on one screen, and glasses to separate them. But that’s not really what kept 3D from being a success historically. Sure the old processes were less than ideal. But it’s not a technical issue. 3D lends itself well to a very few films, mostly big action or animated features, and becomes a distraction in simpler films. Star Trek films might be great, but imagine what benefit or annoyance 3D would have been in “The Notebook”, for example. Or even “Benjamin Button”. The technology can actually get in the way of the story, and as we all should know by now, the success of entertainment is always content. It can be aided and abetted by technology, but take away the content, you’ve got a demo piece only, not an involving story.
When producing a 3D film, it’s very hard to resist exploiting 3D. Shots with extreme perspective, things flying at the camera, the camera whizzing forward over a set or landscape, etc., all because you’re working in 3D, but wouldn’t use otherwise. It’s a hard line to walk, and very few films are able to do it right. 3D must add to the shot, not dictate the shot. But why would you down-play 3D when it’s a marketing strategy? The results are mixed, but the more 3D work is done, the better they’ll be at it.
Special effects are the same. You can load a film with them, but that doesn’t mean you’ll have a blockbuster. And the films that achieve average success mostly are not effects films. 3D is more an effect, than a format. It’s great to see it, but those images are NOT reality, no matter how tangible they may seem, and our brains know this. 3D will probably never support the bulk of all films, for the same reason that film narratives are better supported by 24 fps than something higher. 24p puts a distance between the entertainment and reality. Something in 60p, for example, is too real, too smooth for fantasy, though technically more able to accurately capture motion. Hyper smooth, hyper sharp 3D may always be “too much reality” for story telling.
Then throw in the darn glasses, and you’re asking a lot from a casual viewer, much less a home theater owner who must now spend more money to play 3D content, which makes up growing, but as yet still tiny fraction of the available content.
3D is fun, but it’s not for everyone or every type of entertainment. Watch for it to establish a solid niche market, but probably not penetrate the main stream for quite some time, if ever.
4K is another story. Right now, our highest available display resolution is really 2K, otherwise specified as 1920 x 1080 pixels. Keep in mind that this refers only to screen resolution, the displayed content may be lower. Flat-screen TVs and monitors as well as projectors for home theater use come in two basic resolutions: 1080p and 720p. Depending on the size of your screen and how far away you sit, you may not notice the difference between a 720p and 1080p screen, given both are fed from a real 1080p source . And that’s not as easy to come by as you might think. Some TV stations limit themselves to 720p so they can jam more channels into their allotted spectrum. Others max out at 1080i, the right number of pixels to fill a 1920x 1080 screen, but not the maximum progressive frame rate. TV will likely be stuck there for the foreseeable future. They simply don’t have the bandwidth to fit a 1080p signal on the air, cable, or satellite. So far, the solitary source of 1080p content is found on Blu-ray discs. That’s un-scaled content, now. It’s possible to up-scale other resolutions to 1080p quite successfully. The excellent and affordable DVD players from Oppo, for example, do such a good job of up-scaling standard video to all flavors of HD that they might quench your desire to own a Blu-ray player at all.
Other sources, like downloaded or streamed video might be called HD, but land at 720p or even less. But this is not necessarily a bad thing. The convenience and impulsive nature of download systems more than makes up for slightly under 1080p, and still looks great. But let’s return to the screen for a moment.
If you’re “average”, your new flat-screen TV is a 42” LCD, 720p set that internally scales up to some other real screen resolution. That’s what most folks purchased in the last year, both because of cost and size. If you have a 50” plus screen purchased in the last year, it stands a fair chance of hitting a native 1920x1080 (1080p) resolution, but if it’s a budget model, might end up a native resolution of 1366 x 768, with internal scaling to make up the difference. And, unless you sit closer than 6’ away, it looks darn nice. A native 1080p set might look a shade better in optimal conditions, but the difference won’t blow your sox off. If you have a front projection system, you will benefit from a real 1080p projector, though, and you’ll be most sensitive to other than 1080p material, scaled or otherwise. Sadly, you’re in a very small elite group of viewers, though.
So along comes 4K, more than double the horizontal resolution of the best we have now. And what does this get us? Sharper movies? Better contrast? Higher detail? A bigger more thrilling entertainment experience? Well, yes and no. We’ll put an emphatic “NO” on the contrast thing right now. 4K projectors so far can’t beat a good 2K for contrast, though in all but the darkest rooms where everyone watches movies wearing head to toe black leotards and tights (sorry for the mental image), you can’t ever hit the current contrast specs anyway, because your clothes reflect to much stray light back to the screen. Sorry, there’s no 50,000:1 in real life. Commercial cinemas are quite happy at 2000:1, and most don’t do even that. So “no” to contrast.
What about sharper movies? If, and this is a big “if”, film production becomes completely digital so that the entire chain right down to you remains digital and at high resolution, then yes, you’ll have sharper movies (assuming the focus puller has done his job, and they sometimes don’t!). So far, the film industry is clinging to film as the acquisition media. But analysis of the resolution of a “release print”, the film they show in theaters, shows it down around 700 – 900 lines, with losses occurring in film, negatives and printing the release print. However, film resolution is not the same as digital resolution. You in fact need nearly double the digital rez to match a given film rez, because film’s resolution falls off slowly, where digital’s just stops. 700 lines in film will actually still show a bit above that, where 700 lines in digital takes 1400 pixels, but that’s a hard limit. So, we’re kind of at “film” now, with 1920x1080. To exploit 4K, we need to shoot in 4K digital (just staring now in some productions, but not common), digitize the original camera negative (being done now), or do some deft up-sampling. So sharper movies is a qualified yes.
So why the interest in 4K at all? It’s huge in terms of data size. A 4K feature, even with today’s compression algorithms, won’t really fit on a Blu-ray disc, so 4K features might be a download-only proposition, except for the already overloaded Internet infrastructure. But what if we started with today’s 1080p and up-scaled to a 4K display? Hmmm! Now that could work nicely. It sure does right now, scaling from 480p standard to 1080p HD, so why not? Up-scaling is tricky, but if done well, is spectacular. After scaling, the bottleneck is the projector. We’re going to blow right past flat-screen technologies here because if you don’t sit 6’ from your 50” set now, you can’t even appreciate 1080p, and we have to assume nobody’s going to sit closer than 6’…ever. So, back to front projection systems that fill the peripheral vision. Big requires bright. Bright requires power, and big and bright requires money. Big lenses, lamps and image chips. 4K won’t be cheap, but will it be worth it?
I think you see where we’re going here. Ideally, money is no object. If it isn’t in your case, call me at once, we’ll work up a home theater for you like none other. But if money is an object, and you’re on a budget at all, you’ll want to weigh the cost of 4K home projection (when it’s available) against other budget line items that have equal or higher impact on the total experience. Things like acoustics, light control, sight lines, speaker placement and choice, etc., and make an informed choice. All the while keeping in mind that you probably aren’t seeing 4K in a film theater, and even in a 4K digital theater you may not see the full 4K resolution. Duplicating a theatrical experience at home is less about 4K, more about basic image and sound quality.
4K projection is a fine goal to aspire to. But don’t limit your enjoyment now because you’re waiting for 4K to become available or affordable! Today’s projectors are amazing devices capable of immersive entertainment. Tomorrows 4K projectors will be even better, but the step is a small one, not a quantum leap. And of course, if you haven’t though of it already, stand by for 4K, 3D! Yikes!
As always, our recommendation is: “Hurry up and wait”. But remember the “bell-curve” at the beginning of this post? The center of that curve is what really drives things, particularly content. Very few, mostly indie producers, ever make a movie intended for a small audience. It’s counter to the financial constraints of the movie making process. The only reason 3D has made recent in-roads animated and action films is that it’s become easier to make it downward compatible with 2D for the bulk of the audience. And, while we probably will see 3D capable TVs at big box stores soon, the content is limited, and you still gotta wear the goggles. That all places 3D at one end of the bell-curve.
4K home theater projection will get here, and eventually penetrate the projector market well. But 4K flat screen TVs may never become a reality for the center of the curve, because the benefit won’t be visible enough to justify the cost.
If you’re up on the top edge of the curve, you’re in for some fun. If not, don’t feel bad. We can still build a system for you that will be visceral and imersive with current technology. Remember, this is all about the fun!
Monday, August 17, 2009
Tuesday, May 19, 2009
Why We Love Our Home Theaters
Beyond the obvious “cool” factor, why exactly do we own home theaters? Convenience, sure. Your own “theater” ready when you are. But isn’t it really about being able to fall into a movie, become absorbed, taken away for a while, the “suspension of disbelief”? And these days, it’s getting harder and harder to tolerate the experience of a commercial movie theater, largely because so many things can interfere with that “suspension of disbelief”.
Here’s a short list of what commercial theaters do wrong, that home theaters do right:
1. The cost. OK, truth be told, it is actually cheaper to go to the theater than to buy a really high-end home theater. But on a per-event basis, $10 or more for a ticket to a show is pretty high, especially when they expect you to also buy the most expensive food in the world – popcorn! Anyone ever figure out exactly what that big bucket costs? It’s worth about 25 cents, but you paid $6 or more for it. And it’s ever so chewy, slathered with all that imitation butter. What do you get at home? Really fresh popcorn you just microwaved, with real melted butter. No sour after-taste there. Yes, if you divide the cost of your HT system up by each movie you see, it is more costly, but isn’t it worth it?
2. Trailers by choice. Not in the theater, though. You are told the film starts at 8, but really it’s more like 8:15, after you get force-fed the trailers, ads, and two or three warnings to turn off your cell phone, which you do of course, but that idiot behind you is living a highly important life, and needs his left on, ringer and all.
3. Picture quality. Oh, you say, your home theater will never have a screen that size. True, the size is impressive, though if you watch a plasma screen, you may actually see a better contrast ratio, and a brighter picture. But in a theater, equally impressive are the stains on the screen, the drink straw stuffed into one of the screen perforations, and the seam down the middle. You may not be treated to all these visual amenities at every theater, and hopefully not all at the same time, but there’s usually something to distract. Perhaps it’s the exit sign lighting up the screen, or the bad framing. Or focus, though that one’s so basic it should simply NEVER happen, but does. How about the low-rez digital projection of the ads before the show? 1080p it ain’t. Not even 720p. The last one we saw was probably 480p, with some scaling, but mid-theater seats could clearly see every pixel. And it was dim, and washed out. Yes, it was only the pre-show "ads", but come on, guys. This is a "professional" theater, isn't it?
4. Sound quality. Yes, again, size matters. But it’s only one part of the story. There’s usually something to annoy everyone; the blown woofers, defective tweeters, fried subwoofers, and out of balance surrounds, or missing channels. Yes, even the all-important center speaker is often damaged. The last show we went to added a sharp snapping click every half second or so, all through the film. Complaining did no good, their alternative was to “bypass the system”, and play the track in mono, with no noise reduction, resulting in lifeless, compressed, non-dynamic sound. State of the art, circa 1940. Thanks, but I’ll just live with the ticks. And we did. Sort of. It took three chats with the manager. Talk about getting pulled out of the film. Not at home, though. Sound will be predictable, consistent, and adjustable by you should you need more or less.
5. Do you dash to make the show on time, or just push “start” when you’re ready? The best theaters around here are at least 15 minutes drive away, then perhaps a wait in line, a wait in the concession line, then you sit through the above mentioned inane trailers, then you watch what you paid to see. At home, you sit down, relax, and start the show at 8:23, or whatever time you are ready for it. Oh, and if the worst happens, and you need to take a break, you can, and never miss a single frame.
Our family paid $30 to see Star Trek at the Yorktown Theaters, Lombard, IL, and put up with bad sound for the entire feature. One of us paid even more per ticket to see the same film at the Navy Pier IMAX theater, replete with a bad subwoofer, and low volume. When we stay home and pop in a disc, none of that happens. We just watch the film undistracted, uninterrupted, and when we want.
Need more reasons to own a Home Theater? Just go out and see a movie, you’ll have your own list in no time.
Here’s a short list of what commercial theaters do wrong, that home theaters do right:
1. The cost. OK, truth be told, it is actually cheaper to go to the theater than to buy a really high-end home theater. But on a per-event basis, $10 or more for a ticket to a show is pretty high, especially when they expect you to also buy the most expensive food in the world – popcorn! Anyone ever figure out exactly what that big bucket costs? It’s worth about 25 cents, but you paid $6 or more for it. And it’s ever so chewy, slathered with all that imitation butter. What do you get at home? Really fresh popcorn you just microwaved, with real melted butter. No sour after-taste there. Yes, if you divide the cost of your HT system up by each movie you see, it is more costly, but isn’t it worth it?
2. Trailers by choice. Not in the theater, though. You are told the film starts at 8, but really it’s more like 8:15, after you get force-fed the trailers, ads, and two or three warnings to turn off your cell phone, which you do of course, but that idiot behind you is living a highly important life, and needs his left on, ringer and all.
3. Picture quality. Oh, you say, your home theater will never have a screen that size. True, the size is impressive, though if you watch a plasma screen, you may actually see a better contrast ratio, and a brighter picture. But in a theater, equally impressive are the stains on the screen, the drink straw stuffed into one of the screen perforations, and the seam down the middle. You may not be treated to all these visual amenities at every theater, and hopefully not all at the same time, but there’s usually something to distract. Perhaps it’s the exit sign lighting up the screen, or the bad framing. Or focus, though that one’s so basic it should simply NEVER happen, but does. How about the low-rez digital projection of the ads before the show? 1080p it ain’t. Not even 720p. The last one we saw was probably 480p, with some scaling, but mid-theater seats could clearly see every pixel. And it was dim, and washed out. Yes, it was only the pre-show "ads", but come on, guys. This is a "professional" theater, isn't it?
4. Sound quality. Yes, again, size matters. But it’s only one part of the story. There’s usually something to annoy everyone; the blown woofers, defective tweeters, fried subwoofers, and out of balance surrounds, or missing channels. Yes, even the all-important center speaker is often damaged. The last show we went to added a sharp snapping click every half second or so, all through the film. Complaining did no good, their alternative was to “bypass the system”, and play the track in mono, with no noise reduction, resulting in lifeless, compressed, non-dynamic sound. State of the art, circa 1940. Thanks, but I’ll just live with the ticks. And we did. Sort of. It took three chats with the manager. Talk about getting pulled out of the film. Not at home, though. Sound will be predictable, consistent, and adjustable by you should you need more or less.
5. Do you dash to make the show on time, or just push “start” when you’re ready? The best theaters around here are at least 15 minutes drive away, then perhaps a wait in line, a wait in the concession line, then you sit through the above mentioned inane trailers, then you watch what you paid to see. At home, you sit down, relax, and start the show at 8:23, or whatever time you are ready for it. Oh, and if the worst happens, and you need to take a break, you can, and never miss a single frame.
Our family paid $30 to see Star Trek at the Yorktown Theaters, Lombard, IL, and put up with bad sound for the entire feature. One of us paid even more per ticket to see the same film at the Navy Pier IMAX theater, replete with a bad subwoofer, and low volume. When we stay home and pop in a disc, none of that happens. We just watch the film undistracted, uninterrupted, and when we want.
Need more reasons to own a Home Theater? Just go out and see a movie, you’ll have your own list in no time.
Saturday, December 13, 2008
Are there audible benefits from higher-priced AVRs?
The premise that all AVRs sound the same, or that the differences are vanishingly small is a bit too generalized to be accurate. There are several reasons an expensive AVR could sound better than a cheap one. Here are some of them.
Power output. It’s not just the rated power per channel, it’s the rated power, dynamic headroom (the ability to handle peaks above the rated power) and the ability to drive multiple channels at the high dynamic peak level simultaneously. The most expensive single section of an AVR is the power supply. An inexpensive 7.1 channel AVR (8 channels), rated at 100W/channel is incapable of producing 100W from all channels at once. That would require an 800W power supply, minimum, and they don’t put those in cheap AVRs. The cost of such a power supply might easily exceed the total cost of some of those receivers. As the price of receivers goes up, one thing that improves is the power supply. Even $2000 AVRs sometimes can’t deliver full rated power to all channels simultaneously, but the better and more expensive the power supply, the closer to it they get, and can do so in at least the front 3 channels. It’s rare that a film soundtrack would require that ability in all 8 channels, especially if you have efficient speakers, or play at low volumes, but with less efficient speakers in a larger room, and playing sound at ‘reference levels’, the ability to drive all channels with full power becomes an issue.
Using the preamp outs and separate power amps can accomplish this goal. Any two channel power amps of decent quality is capable of delivering full power to both channels simultaneously, so using 4 external power amps results is higher simultaneous peak capability.
As a point of reference, THX Ultra2 Certified receivers are tested with all channels driven, and you won’t find one with less than 100W per channel, typically more like 130. THX Ultra2 is a certification that includes all audio components in a room of up to 3000cu ft. By contrast, THX Select2 receivers are power tested with only one channel driven at a time, and must meet lower peak current ratings. Select2 products are intended for rooms up to 2000cu ft, and are meant to be more affordable.
Could you hear the difference between an Ultra2 and a Select2 receiver? That depends on the size of your room and your speaker efficiency, but if played to THX reference levels, the answer is yes. More importantly, could you hear the difference between a THX Certified product and one that isn’t? Remember, it costs real money to design, develop and certify a THX product, money you wouldn’t have to spend otherwise on a similar product. Again, the answer is “yes”, and that would be not only for reasons of good and certifiable design, but also for reasons of THX processing in the line level stages.
Another power-amp factor, which is usually not specified, is output impedance, which directly relates to the amp’s ability to drive a complex load such as a multi-driver speaker. Low cost amps may have higher output impedance, and if the speaker’s load impedance is complex (most are), they will sound different than if driven by a higher cost, lower output Z amp stage. The relationship is not strictly cost, but in general, lowering output Z increases unit cost. Damping factor is directly related. Higher damping factor results in more ability of the amp to control the speaker, a generally desirable trait.
The line level stage in a receiver has little to no audible effect, and that includes the DACs. With the exception of exotic over-sampling techniques, noise shaping, etc., the fundamental limit to performance is the digital word length and sampling frequency. At 24 bits, a digital system is about at the limits of what can be done in the analog domain, in terms of noise and distortion, but at 16 bits, analog circuitry can easily surpass the performance of the digital system. By the way, noise is not a subjective quality. It is clearly audible, and the audibility of noise is well known. The audibility of harmonic distortion is also well known, but the threshold of audibility is not widely known to consumers. We are used to seeing audio devices with distortion figures in the .01% range, yet the typical listener only begins to hear odd-order harmonic distortion well above 1%, and that depends on the signal type. Even-order harmonic distortion remains inaudible up to 10%! Inter-modulation distortion (IMD) is perhaps more obvious that THD, but then it still has to be in the single whole-number digits to be heard, and is also signal dependant. Given all those figures of the threshold of audibility of distortion, no receiver should have distortion that would affect the sound subjectively. And you can include TIM in that too, it just shouldn’t be a problem.
This reduces the possible audible differences in receivers to three areas. First, the power supply’s ability to supply power to all channels under high demand, second, the amplifier’s ability to interface with a complex speaker load, and third, DSP functions in the line stage, like special processing, EQ, Audyssey, THX processing, and so on. Those functions depend on DSP programming, which is not at all fixed or even similar brand to brand, beyond standardized functions like Codecs and ProLogic, etc., and are all DSP functions are likely to be audible, most by design. DSP firmware of higher sophistication is more expensive to produce, and could potentially raise the price of an AVR. And, personal preference for certain DSP functions could drive a receiver choice.
So I surmise that you can get audible benefits from more expensive AVRs. Cost justification is the subjective part. For me, I hate to replace audio gear. I own my audio stuff for at least a decade at a time, barring radical changes in function (like the advent of 5.1, for example). I like my stuff to be built well, and to be as reliable as a wood-burning stove. That saves me money in the long run, but costs me money in the short-term. Sort of like buying a Toyota over a Ford. Sure it costs more, but if it lasts twice as long, it’s actually cheaper.
Power output. It’s not just the rated power per channel, it’s the rated power, dynamic headroom (the ability to handle peaks above the rated power) and the ability to drive multiple channels at the high dynamic peak level simultaneously. The most expensive single section of an AVR is the power supply. An inexpensive 7.1 channel AVR (8 channels), rated at 100W/channel is incapable of producing 100W from all channels at once. That would require an 800W power supply, minimum, and they don’t put those in cheap AVRs. The cost of such a power supply might easily exceed the total cost of some of those receivers. As the price of receivers goes up, one thing that improves is the power supply. Even $2000 AVRs sometimes can’t deliver full rated power to all channels simultaneously, but the better and more expensive the power supply, the closer to it they get, and can do so in at least the front 3 channels. It’s rare that a film soundtrack would require that ability in all 8 channels, especially if you have efficient speakers, or play at low volumes, but with less efficient speakers in a larger room, and playing sound at ‘reference levels’, the ability to drive all channels with full power becomes an issue.
Using the preamp outs and separate power amps can accomplish this goal. Any two channel power amps of decent quality is capable of delivering full power to both channels simultaneously, so using 4 external power amps results is higher simultaneous peak capability.
As a point of reference, THX Ultra2 Certified receivers are tested with all channels driven, and you won’t find one with less than 100W per channel, typically more like 130. THX Ultra2 is a certification that includes all audio components in a room of up to 3000cu ft. By contrast, THX Select2 receivers are power tested with only one channel driven at a time, and must meet lower peak current ratings. Select2 products are intended for rooms up to 2000cu ft, and are meant to be more affordable.
Could you hear the difference between an Ultra2 and a Select2 receiver? That depends on the size of your room and your speaker efficiency, but if played to THX reference levels, the answer is yes. More importantly, could you hear the difference between a THX Certified product and one that isn’t? Remember, it costs real money to design, develop and certify a THX product, money you wouldn’t have to spend otherwise on a similar product. Again, the answer is “yes”, and that would be not only for reasons of good and certifiable design, but also for reasons of THX processing in the line level stages.
Another power-amp factor, which is usually not specified, is output impedance, which directly relates to the amp’s ability to drive a complex load such as a multi-driver speaker. Low cost amps may have higher output impedance, and if the speaker’s load impedance is complex (most are), they will sound different than if driven by a higher cost, lower output Z amp stage. The relationship is not strictly cost, but in general, lowering output Z increases unit cost. Damping factor is directly related. Higher damping factor results in more ability of the amp to control the speaker, a generally desirable trait.
The line level stage in a receiver has little to no audible effect, and that includes the DACs. With the exception of exotic over-sampling techniques, noise shaping, etc., the fundamental limit to performance is the digital word length and sampling frequency. At 24 bits, a digital system is about at the limits of what can be done in the analog domain, in terms of noise and distortion, but at 16 bits, analog circuitry can easily surpass the performance of the digital system. By the way, noise is not a subjective quality. It is clearly audible, and the audibility of noise is well known. The audibility of harmonic distortion is also well known, but the threshold of audibility is not widely known to consumers. We are used to seeing audio devices with distortion figures in the .01% range, yet the typical listener only begins to hear odd-order harmonic distortion well above 1%, and that depends on the signal type. Even-order harmonic distortion remains inaudible up to 10%! Inter-modulation distortion (IMD) is perhaps more obvious that THD, but then it still has to be in the single whole-number digits to be heard, and is also signal dependant. Given all those figures of the threshold of audibility of distortion, no receiver should have distortion that would affect the sound subjectively. And you can include TIM in that too, it just shouldn’t be a problem.
This reduces the possible audible differences in receivers to three areas. First, the power supply’s ability to supply power to all channels under high demand, second, the amplifier’s ability to interface with a complex speaker load, and third, DSP functions in the line stage, like special processing, EQ, Audyssey, THX processing, and so on. Those functions depend on DSP programming, which is not at all fixed or even similar brand to brand, beyond standardized functions like Codecs and ProLogic, etc., and are all DSP functions are likely to be audible, most by design. DSP firmware of higher sophistication is more expensive to produce, and could potentially raise the price of an AVR. And, personal preference for certain DSP functions could drive a receiver choice.
So I surmise that you can get audible benefits from more expensive AVRs. Cost justification is the subjective part. For me, I hate to replace audio gear. I own my audio stuff for at least a decade at a time, barring radical changes in function (like the advent of 5.1, for example). I like my stuff to be built well, and to be as reliable as a wood-burning stove. That saves me money in the long run, but costs me money in the short-term. Sort of like buying a Toyota over a Ford. Sure it costs more, but if it lasts twice as long, it’s actually cheaper.
Wednesday, June 11, 2008
The Misunderstood Aspect of your Screen Shape
Nearly everyone has been into a store and seen the new, huge HDTV sets. At some point, we probably notices that the screen is more rectangular than square, and while this fact may have made a small impression, the reasons why, and the impact of the new shape may have gone right on by us. Here’s some help.
So what do we call it? To call it rectangular is not very specific. Just how rectangular is it? To define its shape in a number to two, it’s been reduced to a ratio of width to height. A standard TV has a width to height ratio of 4:3, which can further be reduced to 1.33:1. Sometimes this is just stated as 1.33, assuming the “:1” part as understood. That aspect ratio came from the early days of movies, when the screen size was picked. It was standardized as 1.33:1 nearly 100 years ago, in 1907, when the fledgling film industry recognized the need to set a standard film size and frame shape. Yet, even as early as 1897 there were experiments with wider screen shapes. But big changes really happened in the early 1950s, when TV began to supply to the consumer the bane of movies existence: free entertainment. To the TV boys it made perfect sense to make the screen the same aspect ratio as movies, since there would probably be a lot of film shown on TV. But size and shape aside, TV did one thing very well…it caused theater ticket sales to plummet. The movie industry was desperate to save itself in any way it could. It stepped up the production of color films, but TV responded by announcing that it too would soon be in color. The movies only real option was to build on the physical size of their screen, to emphasize that a movie was more of a special experience than just entertainment. So, out of desperation, the movie industry developed ‘wide screen’ movies. But since wide screen was more of a knee-jerk reaction than a well-planned strategy, there were many different systems, film formats, and aspect ratios tried. The names of these processes are entertainment in themselves: CinemaScope, Cinerama, Panavision, Super Panavision 70, Technirama, Todd AO, VistaVision, and more. (My favorite one is “Cinemiracle”…just the name, not the wide screen process). Enough to fill a book! And in fact, it did. You can buy “Wide Screen Movies – A History and Filmography of Wide Gauge Filmmaking” by Robert Carr and R. M. Hayes on Amazon.com for the full story. It’s an exhaustive studio of the wide screen movie concept, the variations, screen sizes and shapes, and the people that invented them (or in many cases just copied from others!) While much of the book is an extensive filmography of each wide screen process, the stories of the development of these formats is nothing short of fascinating, though possibly not quite worth the hefty price of the book.
But back to wide screen movies. Since each process was somewhat different, and movies had to show on thousands of theaters, there had to be at least some standards. Two methods proliferated above all others. Generically known as “Scope” (from CinemaScope), but used to refer to any film made with an anamorphic process, the screen became 2.35:1. The film is shot through special lenses that squeeze the image horizontally by 2X, then re-stretch it during projection to take a 1.18:1 film frame (yes, it was more square than even 1.33) out to 2.35. The various squeeze/stretch amounts were eventually standardized, and we now have “Panavision”, a company that makes equipment used to produce the current most popular “Scope” format. But, since 2.35 was quite wide, and some theaters couldn’t even show the full width properly, and since there are limitations in cinematography imposed by the special lenses, the Academy of Motion Picture Arts and Sciences chose to standardize an in-between aspect ratio of 1.85:1 (known today as “flat” in the film world). It requires no special lens, and is achieved by masking off the upper and lower parts of a 1.33 frame by using an appropriate aperture plate in the projector. Cheap, easy, and at no additional cost…the film industry embraced it wholeheartedly. With very few exceptions, all films made today are either 2.35:1 “scope” (anamorphic) or 1.85:1 “flat”, and shot on 35mm film.
Fast-forward to HDTV. The TV industry had long experienced the difficulty of showing a 2.35 scope film on its 1.33 screen. You’ve seen “letterboxed” versions, panned and scanned versions, and just plain bad cropping where one of the key actors is on screen in the theater, but off screen on TV. Since every theatrical film made in the last 40 years was at least 1.85, but TV was standardized at 1.33 over 50 years ago, broadcasters had a problem, and with new standards being developed for HD television, they had a chance to solve it. But the problem proved more thorny than anyone though. Introducing a new standard aspect ratio in TV would alienate old TV viewers. You’d have the cropping and pan/scan issues all over again, but this time on every program all day long, not just movies. It would have made sense to pick an HD aspect ratio that matched Hollywood’s 1.85 standard, right? But broadcasters know about compromise, and being worried about letterboxing a standard image within a 1.85 frame, they chose a compromise of 16:9, which reduces to a rather inconvenient ratio 1.7777777:1 (the 7’s go on forever). Now, you have to wonder what drove this. And the simple answer is, it's related to the problems of scanning the front of a picture tube with an electron beam, and getting it to work into the corners of the tube. Yes, it's rooted in a display technology that virtually vanished once 16:9 flourished. Sure, as HDTV slowly penetrated the market, for a time there would be two side bands when a 1.33 image was shown on a wide screen TV, but soon every TV made would have the new wide screen, and eventually 1.33 sets would go away. But rather than match the prevailing 1.85 standard, they picked the 1.77 compromise because it results in a little letter box to show 1.77 on a 1.33 set, and a little vertical letterbox (pillarbox) to show a 1.33 image on a 1.77 set. Neither is optimized, and when you see a real wide screen ‘scope film, it’s always a large letterbox. Actually, my personal theory is that Broadcasters picked 16:9 because it matches the aspect ratio of the original Star Trek series View Screen. Hey, it's as valid a reason as any other given.
Simply put: they goofed, big time. They compromised the long term aspect ratio by catering to a short term problem. It turns out nobody likes to see a letterboxed image, and constant display of a letterboxed image will actually burn a letterbox into a TV screen, so TV manufactures developed their own compromise: stretching. If you have a new HD set and have a standard image to show, the set can stretch it to fit the new wide screen…and in doing so add 30 pounds to every actor or actress, distort the image, and mess up the cinematographer’s composition. You’d think this would be something any viewer would object to, but go into any TV store and you’ll see one stretched image after another. Go into any sports bar and you’ll see more of the same. In fact, we were shocked recently to go into a Sushi bar and see a nice non-stretched 1.77 HD image TV program with 1.33 aspect commercials, just as it was meant to be…at least in the world of broadcast television.
So that’s the story. It’s a compromise, and a poor one. But there are solutions! You can still see a 2.35 wide screen movie letterboxed inside your 1.77 screen. Several projector manufacturers are now making equipment designed to utilize the anamorphic images found on some DVDs and make them fit a real 2.35 screen. When this is done with HD DVD or BluRay DVDs, the result should be real, honest to goodness, 2.35, ‘scope, Panavision, CinemaScope, Technirama images on your home screen. That’s your own, home, 2.35:1 aspect ratio screen! And what to do about 1.85 or 1.33 material? How about motorized masking curtains that make your screen the right shape for every format. It’s available. Today. From Platinum Home Theaters.
If you’re interested in taking the ‘wide view’, give us a call, and we’ll help you do it. In fact, we look forward to it!
For more information on wide screen projection in the home, call Platinum Home Theaters at 708-588-0880.
So what do we call it? To call it rectangular is not very specific. Just how rectangular is it? To define its shape in a number to two, it’s been reduced to a ratio of width to height. A standard TV has a width to height ratio of 4:3, which can further be reduced to 1.33:1. Sometimes this is just stated as 1.33, assuming the “:1” part as understood. That aspect ratio came from the early days of movies, when the screen size was picked. It was standardized as 1.33:1 nearly 100 years ago, in 1907, when the fledgling film industry recognized the need to set a standard film size and frame shape. Yet, even as early as 1897 there were experiments with wider screen shapes. But big changes really happened in the early 1950s, when TV began to supply to the consumer the bane of movies existence: free entertainment. To the TV boys it made perfect sense to make the screen the same aspect ratio as movies, since there would probably be a lot of film shown on TV. But size and shape aside, TV did one thing very well…it caused theater ticket sales to plummet. The movie industry was desperate to save itself in any way it could. It stepped up the production of color films, but TV responded by announcing that it too would soon be in color. The movies only real option was to build on the physical size of their screen, to emphasize that a movie was more of a special experience than just entertainment. So, out of desperation, the movie industry developed ‘wide screen’ movies. But since wide screen was more of a knee-jerk reaction than a well-planned strategy, there were many different systems, film formats, and aspect ratios tried. The names of these processes are entertainment in themselves: CinemaScope, Cinerama, Panavision, Super Panavision 70, Technirama, Todd AO, VistaVision, and more. (My favorite one is “Cinemiracle”…just the name, not the wide screen process). Enough to fill a book! And in fact, it did. You can buy “Wide Screen Movies – A History and Filmography of Wide Gauge Filmmaking” by Robert Carr and R. M. Hayes on Amazon.com for the full story. It’s an exhaustive studio of the wide screen movie concept, the variations, screen sizes and shapes, and the people that invented them (or in many cases just copied from others!) While much of the book is an extensive filmography of each wide screen process, the stories of the development of these formats is nothing short of fascinating, though possibly not quite worth the hefty price of the book.
But back to wide screen movies. Since each process was somewhat different, and movies had to show on thousands of theaters, there had to be at least some standards. Two methods proliferated above all others. Generically known as “Scope” (from CinemaScope), but used to refer to any film made with an anamorphic process, the screen became 2.35:1. The film is shot through special lenses that squeeze the image horizontally by 2X, then re-stretch it during projection to take a 1.18:1 film frame (yes, it was more square than even 1.33) out to 2.35. The various squeeze/stretch amounts were eventually standardized, and we now have “Panavision”, a company that makes equipment used to produce the current most popular “Scope” format. But, since 2.35 was quite wide, and some theaters couldn’t even show the full width properly, and since there are limitations in cinematography imposed by the special lenses, the Academy of Motion Picture Arts and Sciences chose to standardize an in-between aspect ratio of 1.85:1 (known today as “flat” in the film world). It requires no special lens, and is achieved by masking off the upper and lower parts of a 1.33 frame by using an appropriate aperture plate in the projector. Cheap, easy, and at no additional cost…the film industry embraced it wholeheartedly. With very few exceptions, all films made today are either 2.35:1 “scope” (anamorphic) or 1.85:1 “flat”, and shot on 35mm film.
Fast-forward to HDTV. The TV industry had long experienced the difficulty of showing a 2.35 scope film on its 1.33 screen. You’ve seen “letterboxed” versions, panned and scanned versions, and just plain bad cropping where one of the key actors is on screen in the theater, but off screen on TV. Since every theatrical film made in the last 40 years was at least 1.85, but TV was standardized at 1.33 over 50 years ago, broadcasters had a problem, and with new standards being developed for HD television, they had a chance to solve it. But the problem proved more thorny than anyone though. Introducing a new standard aspect ratio in TV would alienate old TV viewers. You’d have the cropping and pan/scan issues all over again, but this time on every program all day long, not just movies. It would have made sense to pick an HD aspect ratio that matched Hollywood’s 1.85 standard, right? But broadcasters know about compromise, and being worried about letterboxing a standard image within a 1.85 frame, they chose a compromise of 16:9, which reduces to a rather inconvenient ratio 1.7777777:1 (the 7’s go on forever). Now, you have to wonder what drove this. And the simple answer is, it's related to the problems of scanning the front of a picture tube with an electron beam, and getting it to work into the corners of the tube. Yes, it's rooted in a display technology that virtually vanished once 16:9 flourished. Sure, as HDTV slowly penetrated the market, for a time there would be two side bands when a 1.33 image was shown on a wide screen TV, but soon every TV made would have the new wide screen, and eventually 1.33 sets would go away. But rather than match the prevailing 1.85 standard, they picked the 1.77 compromise because it results in a little letter box to show 1.77 on a 1.33 set, and a little vertical letterbox (pillarbox) to show a 1.33 image on a 1.77 set. Neither is optimized, and when you see a real wide screen ‘scope film, it’s always a large letterbox. Actually, my personal theory is that Broadcasters picked 16:9 because it matches the aspect ratio of the original Star Trek series View Screen. Hey, it's as valid a reason as any other given.
Simply put: they goofed, big time. They compromised the long term aspect ratio by catering to a short term problem. It turns out nobody likes to see a letterboxed image, and constant display of a letterboxed image will actually burn a letterbox into a TV screen, so TV manufactures developed their own compromise: stretching. If you have a new HD set and have a standard image to show, the set can stretch it to fit the new wide screen…and in doing so add 30 pounds to every actor or actress, distort the image, and mess up the cinematographer’s composition. You’d think this would be something any viewer would object to, but go into any TV store and you’ll see one stretched image after another. Go into any sports bar and you’ll see more of the same. In fact, we were shocked recently to go into a Sushi bar and see a nice non-stretched 1.77 HD image TV program with 1.33 aspect commercials, just as it was meant to be…at least in the world of broadcast television.
So that’s the story. It’s a compromise, and a poor one. But there are solutions! You can still see a 2.35 wide screen movie letterboxed inside your 1.77 screen. Several projector manufacturers are now making equipment designed to utilize the anamorphic images found on some DVDs and make them fit a real 2.35 screen. When this is done with HD DVD or BluRay DVDs, the result should be real, honest to goodness, 2.35, ‘scope, Panavision, CinemaScope, Technirama images on your home screen. That’s your own, home, 2.35:1 aspect ratio screen! And what to do about 1.85 or 1.33 material? How about motorized masking curtains that make your screen the right shape for every format. It’s available. Today. From Platinum Home Theaters.
If you’re interested in taking the ‘wide view’, give us a call, and we’ll help you do it. In fact, we look forward to it!
For more information on wide screen projection in the home, call Platinum Home Theaters at 708-588-0880.
Tuesday, April 15, 2008
5.1 surround? 7.1 surround? Bah! 10.2!!!!
I've heard the future of audio, and it is 10.2!
We've all by now heard of 5.1 channel surround, and the greater percentage of home theater sound systems are capable of playing that format. Most of today's home theater receivers are capable of 7.1 channel surround, though very few films are mixed with 7.1 channels. But what I heard goes beyond 5.1, beyond 7.1, to 10.2 channels.
Before you groan thinking "I can't put 3 front speakers where I want them, how am I ever going to place 12?", we have to go through a little analysis.
The logic goes: everyone can hear the improvement that stereo has over a single speaker mono. Similarly, the improvement between 2 channel stereo and 5.1 channel surround is also unmistakable. If you follow that line of progression, you'll notice that every time the channel count is doubled, the improvement is unmistakable. So, the next logical step past 5.1 is 10.2 channels…not 7.1, which would be an incremental step.
The Sound
The goal of all surround sound systems, from early 4 channel (Quad) systems to present day 7.1 channels is to wrap the listener in an immersive soundscape. It could be for ambience sound support of picture, or it could be used to provide a new perspective, such as a "front row" position at a concert, or a prized seat within the band itself, a position simply impossible to purchase a seat for. To a considerable extent, 5.1 channel systems do that, and create a sound space that wraps the listener in 360 degrees of sound…in a horizontal plane. So long as the speakers are mostly aligned for that horizontal 360 degree wrap, the sound field will be a thing of its own, a creation of a sound field, not the re-creation of an acoustic space.
The System
Enter 10.2 channel surround. Research has shown that the more precise the directional content of sound is, the more we perceive it as "real". What that means is, if you want a sonic image in a particular location, you need a speaker there. Early research into what became "stereo" seemed to indicate that for a 360 degree sphere of sound, you need a 360 degree sphere of thousands of speakers. Lacking that ability, compromises could be made that achieve most of the effect with far fewer speakers. 10.2 is the next logical step. Rather than limit the sound field to a basically horizontal plane, it adds the element of elevation with two high front speakers, and adds two forward side channels between the listener and the L and R speakers, and adds a single rear speaker directly behind you, along with a second subwoofer channel.
That's how 10.2 differs over 5.1, but what about 7.1? Here's a comparison:
| 5.1 | 7.1 | 10.2 | |
| Left/Center/Right | yes | yes | yes |
| L-surr/R-surr | yes | yes | yes |
| L-rear/R-rear | no | yes | no |
| L-side/R-side | no | no | yes |
| L-high/R-high | no | no | yes |
| LFE-1/LFE-2 | no | no | yes |
Now, before you look at the chart and say "Look! 7.1 offers something 10.2 doesn't!", look closely. No, 10.2 does not have a Left and Right Rear, but keep in mind that Lr/Rr systems cannot reliably place a sound directly behind you. To do that they depend on a phantom image between two speakers, which only will exist if you are equidistant between two speakers playing exactly the same sound. That phantom image is fragile. Remember stereo? If you don't keep your head locked on the center-line between L and R, you won't have that firm center image of a vocalist. That means stereo has a small "sweet spot". Placing a center speaker between L and R creates a solid center, regardless of listening position. The rear speaker in 10.2 does exactly that, but behind you. The function of Lr/Rr from 7.1 is maintained by placing sound between Ls and Rear, for example. From a surround standpoint, 10.2 works like 7.1, but with a palpable rear image. That "no" in the Lr/Rr 10.2 column could really be a "yes".
What about two subs? Didn't you think subwoofers were omni-directional? Turns out, that's only true to a degree. Having two LFE channels adds dimensionality to bass while preserving the advantage of multiple subwoofers from an acoustic standpoint.
So, that's what it is. Impressed? Want to actually hear 10.2? You will have to take a little trip to
There is no video to go with 10.2 at this time. In fact, the material available in 10.2 is limited to the demo selections, and possibly others from Holman's TMH Labs, the sole supplier of 10.2 at this moment. Of course, the new Blu-ray Disc has all the capacity needed for HD picture and 10.2 channels of audio in PCM or DTS (which supposedly can support up to 2,000 channels!). There's a bit of a problem getting 10.2 out of a player right now, but providing a bit-stream output is a start.
So, you want one, right? So do I! And, quite honestly, if you don't mind waiting for more music, or even better, have the budget to commission 10.2 recordings, Platinum Home Theaters would be more than happy to build a system for you…right now. We'll also be happy to arrange for and produce those recording sessions for you. Of course, when we say budget, it's not for the squeamish. But if you REALLY want immersive audio, this is THE way to get it.
There is simply no way to describe the experience of 10.2 in words. I know, because I've been trying to for several years. You just need to pop for a weekend in
Stand by…10.2 will get here. It's already had a start of the best part of a decade. We just need to wait for those other 5.1 and 7.1 slow-pokes to get out of the way!
Thursday, March 20, 2008
Blowing a Brain Breaker
Every so often I read or hear about something that trips an internal circuit-breaker in my brain. That breaker is usually tripped by an urban legend, hoax, or flat-out un-truth. Something so off the wall, so out-there, so completely implausible that it overloads brain circuits and trips a brain breaker. You get what I mean.
Here’s the latest. I hesitated even writing about this, as merely doing so propagates the myth, but better to inform than not, so here we go. It’s called the HiFi-Tuning Fuse. That’s right, a fuse. The typically cylindrical object that goes into your gear on the power-line side of things that prevents the unit from catastrophic melt-down in event of some sort of failure. The same fuse that almost never blows, and if it does, can be replaced for about $1. Only this fuse costs a bit more: try $40-$50. For one. Of course, it’s a very fine fuse, hand-made in Germany with the finest of materials, ceramic, silver, and gold. That’s not the problem, no doubt it’s well made. It’s the claims that it makes a “night and day” improvement in sound!
A fuse is simply a piece of wire that is designed to melt when a certain amount of current is passed through it, encased in a protective package. There are variables that usually address how fast it blows when an over-current situation occurs. Slower is good if you get momentary intentional over-current conditions that you don’t want to blow the fuse. Fast is better if you only expect over-current conditions when there’s a critical failure, and want to quickly protect other devices in the circuit. By its very nature, a fuse must have a small resistance in it so that it gets hot enough to melt the conducting wire inside. The wire itself is usually that resistive element. However, the net voltage drop across a fuse is extremely small, usually equivalent to many feet of wire. And, it should be said that these days the time it takes to blow a fuse is an eternity compared to how fast solid state devices can blow up. The joke is, the transistor blows out to protect the fuse. It does happen.
That’s about it. Nothing more, nothing less. So how can this be a problem? I don’t rightly know. But the testimonials on the web site for the HiFi-Tuning Fuse seem to indicate an audible improvement when they are installed. For that to actually happen, the new fuse must have change something electrically in the circuit. It must have different electrical properties than a standard fuse. What could these be?
First is resistance. A fuse must have some resistance to work as a fuse. The current causes the fuse wire to heat and melt...and that happens because of a small amount of resistance. It’s very small, though. For example, a 2A fuse run at 2A will have about a half volt drop across it. Your power line voltage swings around more than that on a daily basis. Oh, and lets not forget that 60Hz power line voltage changes direction and thus instantaneous voltage continuously…at a 60Hz rate.
Next is inductance, again very small. In fact, the power transformer the fuse is in line with has much more. There are no published figures, but as you will see, even a few mH of inductance won’t matter in the long run. Read on.
Last is capacitance. There are also no published figures, but it can be assumed that it is quite low, or a fuse would produce AC leakage, not a good thing. Again, insignificant.
So much of electrical properties of fuses. What about the “audible effect” they have? Lets consider where they are in a circuit. A fuse is usually placed in line with the AC power cord, just ahead of the power transformer or power supply. No audio, video, or computer circuit uses 60Hz AC power line voltage directly. It must first be changed to one or more DC voltage power supplies. To accomplish this in a simple analog power supply, you need a transformer to step-down the power line voltage, then a rectifier to change the AC to DC, then a filter to smooth off the resulting ripple, then a regulator to further smooth and stabilize the DC voltage. What you’ve built in a power supply circuit is something that is, by nature, designed to ignore fluctuations of voltage on the power line, first as 60Hz, but beyond that, voltage variations, impulses, sags and surges. Within limits, a well-designed power supply will keep its equipment running even during a 20% brown-out. So whatever variation a fuse introduces is more than compensated for in the power supply. Switching power supplies are used in a lot of equipment today to eliminate or reduce the need for large power transformers, but they serve the same function…produce a stable, smooth, noise-free DC voltage regardless of power line frequency or voltage fluctuations. (Are you starting to question the need for power conditioners? Hmmm!) By the time the power line AC is converted to regulated DC, the miniscule effects of power cords, fuses, and hospital-grade AC plugs are long since swamped out.
That’s my electronics theory on it. A fuse can’t have an effect on the sound or picture of a piece of audio or video gear. Now here’s my challenge:
If someone, manufacturer or otherwise, would like to send me a sample of their fuse to test in my equipment and lab, I will do so and report on the results. If it is, as claimed, a “Night and Day” level improvement, I’ll not only say so on this blog, but I’ll also sign up to become a dealer for the product, and advertise it for free on my web site. However, if it does not live up to the claims, I’ll also say so here. I’ll even return the sample, postage paid. I will take every precaution during testing to insure the fuse is not blown.
To be completely fair, the manufacture’s web site on this high end fuse makes no direct claims as to what it does, only that it is a precision manufactured item, which not doubt, it is. The claims are in the form of testimonials from reviewers and users. Care to win over a skeptic?
There it is, the gauntlet is laid down. Not as dramatic as the “Amazing Randy’s” challenge about cables, but laid down none the less.
Any takers?
Here’s the latest. I hesitated even writing about this, as merely doing so propagates the myth, but better to inform than not, so here we go. It’s called the HiFi-Tuning Fuse. That’s right, a fuse. The typically cylindrical object that goes into your gear on the power-line side of things that prevents the unit from catastrophic melt-down in event of some sort of failure. The same fuse that almost never blows, and if it does, can be replaced for about $1. Only this fuse costs a bit more: try $40-$50. For one. Of course, it’s a very fine fuse, hand-made in Germany with the finest of materials, ceramic, silver, and gold. That’s not the problem, no doubt it’s well made. It’s the claims that it makes a “night and day” improvement in sound!
A fuse is simply a piece of wire that is designed to melt when a certain amount of current is passed through it, encased in a protective package. There are variables that usually address how fast it blows when an over-current situation occurs. Slower is good if you get momentary intentional over-current conditions that you don’t want to blow the fuse. Fast is better if you only expect over-current conditions when there’s a critical failure, and want to quickly protect other devices in the circuit. By its very nature, a fuse must have a small resistance in it so that it gets hot enough to melt the conducting wire inside. The wire itself is usually that resistive element. However, the net voltage drop across a fuse is extremely small, usually equivalent to many feet of wire. And, it should be said that these days the time it takes to blow a fuse is an eternity compared to how fast solid state devices can blow up. The joke is, the transistor blows out to protect the fuse. It does happen.
That’s about it. Nothing more, nothing less. So how can this be a problem? I don’t rightly know. But the testimonials on the web site for the HiFi-Tuning Fuse seem to indicate an audible improvement when they are installed. For that to actually happen, the new fuse must have change something electrically in the circuit. It must have different electrical properties than a standard fuse. What could these be?
First is resistance. A fuse must have some resistance to work as a fuse. The current causes the fuse wire to heat and melt...and that happens because of a small amount of resistance. It’s very small, though. For example, a 2A fuse run at 2A will have about a half volt drop across it. Your power line voltage swings around more than that on a daily basis. Oh, and lets not forget that 60Hz power line voltage changes direction and thus instantaneous voltage continuously…at a 60Hz rate.
Next is inductance, again very small. In fact, the power transformer the fuse is in line with has much more. There are no published figures, but as you will see, even a few mH of inductance won’t matter in the long run. Read on.
Last is capacitance. There are also no published figures, but it can be assumed that it is quite low, or a fuse would produce AC leakage, not a good thing. Again, insignificant.
So much of electrical properties of fuses. What about the “audible effect” they have? Lets consider where they are in a circuit. A fuse is usually placed in line with the AC power cord, just ahead of the power transformer or power supply. No audio, video, or computer circuit uses 60Hz AC power line voltage directly. It must first be changed to one or more DC voltage power supplies. To accomplish this in a simple analog power supply, you need a transformer to step-down the power line voltage, then a rectifier to change the AC to DC, then a filter to smooth off the resulting ripple, then a regulator to further smooth and stabilize the DC voltage. What you’ve built in a power supply circuit is something that is, by nature, designed to ignore fluctuations of voltage on the power line, first as 60Hz, but beyond that, voltage variations, impulses, sags and surges. Within limits, a well-designed power supply will keep its equipment running even during a 20% brown-out. So whatever variation a fuse introduces is more than compensated for in the power supply. Switching power supplies are used in a lot of equipment today to eliminate or reduce the need for large power transformers, but they serve the same function…produce a stable, smooth, noise-free DC voltage regardless of power line frequency or voltage fluctuations. (Are you starting to question the need for power conditioners? Hmmm!) By the time the power line AC is converted to regulated DC, the miniscule effects of power cords, fuses, and hospital-grade AC plugs are long since swamped out.
That’s my electronics theory on it. A fuse can’t have an effect on the sound or picture of a piece of audio or video gear. Now here’s my challenge:
If someone, manufacturer or otherwise, would like to send me a sample of their fuse to test in my equipment and lab, I will do so and report on the results. If it is, as claimed, a “Night and Day” level improvement, I’ll not only say so on this blog, but I’ll also sign up to become a dealer for the product, and advertise it for free on my web site. However, if it does not live up to the claims, I’ll also say so here. I’ll even return the sample, postage paid. I will take every precaution during testing to insure the fuse is not blown.
To be completely fair, the manufacture’s web site on this high end fuse makes no direct claims as to what it does, only that it is a precision manufactured item, which not doubt, it is. The claims are in the form of testimonials from reviewers and users. Care to win over a skeptic?
There it is, the gauntlet is laid down. Not as dramatic as the “Amazing Randy’s” challenge about cables, but laid down none the less.
Any takers?
Wednesday, February 20, 2008
Oh, and by the way, the War is over...
In what some now think was a very predictable outcome, HD-DVD has died, and Blu-ray is the winner. Since it's been covered elsewhere, here's a link:
Engadet Story
So what now? Are we done for good? Never!
Now that we know what disc based HD format we'll be using, there are still lots of problems to solve! Here are some:
1. Player control - most Blu-ray players are sluggish to respond to remote controls. In the old days (yes, way back!) early VCRs, particularly Betamax machines, responded instantly to a remote control button press, giving the user a feel of control. Scanning back for a missed piece of dialog was immediate. And the remotes themselves made sense...simple, and easy to understand, not like the current glob of black buttons on a black remote with dark gray lettering.
2. Picture improvement - What??? Sorry, folks, Blu-ray isn't the be-all and end-all. In fact, it's got quite a ways to go. For some time my personal reaction to HD of almost any flavor has been consistently "Why isn't this sharper, cleaner, lower noise, just plain better?" Whether it's been intentionally hobbled to limit the quality available to the consumer, or it's still a storage capacity thing, there are still many aspects of HD that 35mm film beats. And, digital theater projection is moving to 4K (1080p is essentially 2K). Down the road, might we see some sort of High HD consumer format? That's a subject for another post, though.
3. Lower the hardware cost, already! Blu-ray's two limiting factors to a hands-down win a year ago where second to market (can't help that now) and competitive hardware cost. An HD-DVD has always been less expensive to buy, and that's a problem still. When will we get the $149.95 Blu-ray player? Oppo, are you listening? How about the Oppo up-converting, all format playing (including SA-CD?) Blu-ray supreme player? I'd pay a lot more than $149 for that!
4. Then there's the non-disc HD content competition. Most of us still don't accumulate thousands of movies. We recognize that most of what Hollywood produces isn't worth owning, but we might subject ourselves to a one-time, low cost viewing, otherwise known as a rental. Yes, we can go to the video store and get a disc, but how much easier it would be to stay at home, not have to deal with the store's strange lack of organization, already checked-out discs, store personnel with piercings through every body part, huge check-out lines and late fees? Much. And that is rapidly becoming a viable option from Apple via Apple TV, and others. We won't have the quality of full 1080p for a bit yet, but that's a bandwidth thing, and bandwidth does seem to keep going up. If on-line rental via a set-top device is as cheap as a physical rental, almost as fast as a trip to the store, and has at least 720p quality, the convenience factors will win, and disc rental will eventually loose volume, stores will close (they are already closing), and physical rental will get harder which will avalanche on-line rentals forward. From a studio standpoint, if you don't have to produce physical materials, it's way less expensive to distribute your content. I see non-disc based distribution as being the way of the future, and your dedicated Blu-ray player becoming a dinosaur in as little as 5 years. And while that may not be enough to influence your purchase now, in a few years it will. Look for Apple TV or the like with increased capabilities like 1080p and multichannel sound and a built-in Blu-ray transport. You know it's coming...
All of that said, the Blu-ray win is welcome. We have a single standard, which we should have had all along. And HD is a definite improvement over standard video, both in picture and sound.
So, for the first time, we have a recommendation: buy a Blu-ray player, plug it into your HD home theater system, and enjoy.
Don't forget that to enjoy optimum picture and sound in your HT system of any size or type, you should have it professionally calibrated. Call Platinum Home Theaters for details.
Engadet Story
So what now? Are we done for good? Never!
Now that we know what disc based HD format we'll be using, there are still lots of problems to solve! Here are some:
1. Player control - most Blu-ray players are sluggish to respond to remote controls. In the old days (yes, way back!) early VCRs, particularly Betamax machines, responded instantly to a remote control button press, giving the user a feel of control. Scanning back for a missed piece of dialog was immediate. And the remotes themselves made sense...simple, and easy to understand, not like the current glob of black buttons on a black remote with dark gray lettering.
2. Picture improvement - What??? Sorry, folks, Blu-ray isn't the be-all and end-all. In fact, it's got quite a ways to go. For some time my personal reaction to HD of almost any flavor has been consistently "Why isn't this sharper, cleaner, lower noise, just plain better?" Whether it's been intentionally hobbled to limit the quality available to the consumer, or it's still a storage capacity thing, there are still many aspects of HD that 35mm film beats. And, digital theater projection is moving to 4K (1080p is essentially 2K). Down the road, might we see some sort of High HD consumer format? That's a subject for another post, though.
3. Lower the hardware cost, already! Blu-ray's two limiting factors to a hands-down win a year ago where second to market (can't help that now) and competitive hardware cost. An HD-DVD has always been less expensive to buy, and that's a problem still. When will we get the $149.95 Blu-ray player? Oppo, are you listening? How about the Oppo up-converting, all format playing (including SA-CD?) Blu-ray supreme player? I'd pay a lot more than $149 for that!
4. Then there's the non-disc HD content competition. Most of us still don't accumulate thousands of movies. We recognize that most of what Hollywood produces isn't worth owning, but we might subject ourselves to a one-time, low cost viewing, otherwise known as a rental. Yes, we can go to the video store and get a disc, but how much easier it would be to stay at home, not have to deal with the store's strange lack of organization, already checked-out discs, store personnel with piercings through every body part, huge check-out lines and late fees? Much. And that is rapidly becoming a viable option from Apple via Apple TV, and others. We won't have the quality of full 1080p for a bit yet, but that's a bandwidth thing, and bandwidth does seem to keep going up. If on-line rental via a set-top device is as cheap as a physical rental, almost as fast as a trip to the store, and has at least 720p quality, the convenience factors will win, and disc rental will eventually loose volume, stores will close (they are already closing), and physical rental will get harder which will avalanche on-line rentals forward. From a studio standpoint, if you don't have to produce physical materials, it's way less expensive to distribute your content. I see non-disc based distribution as being the way of the future, and your dedicated Blu-ray player becoming a dinosaur in as little as 5 years. And while that may not be enough to influence your purchase now, in a few years it will. Look for Apple TV or the like with increased capabilities like 1080p and multichannel sound and a built-in Blu-ray transport. You know it's coming...
All of that said, the Blu-ray win is welcome. We have a single standard, which we should have had all along. And HD is a definite improvement over standard video, both in picture and sound.
So, for the first time, we have a recommendation: buy a Blu-ray player, plug it into your HD home theater system, and enjoy.
Don't forget that to enjoy optimum picture and sound in your HT system of any size or type, you should have it professionally calibrated. Call Platinum Home Theaters for details.
Subscribe to:
Posts (Atom)
