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 San Antonio, TX. There's where you'll find Bjorn's (just Bjorn's) (http://www.bjorns.com) and their Ultimate Home Theater Experience demo room, with the only 10.2 system in a retail space. And it's a very special room and system, designed personally by Tomlinson Holman (inventor of THX, and the one who named 5.1 channel surround), and calibrated by him. In fact, he supplies the demo material, complete with his own personal introduction. The demo includes a marching band, orchestra (from both the audience perspective, and from a perspective within the orchestra) and a demonstration of the systems ability to reproduce the acoustic space of a large hall. One orchestral segment is the final few minutes of Aaron Copland's 3^rd Symphony…an presentation so involving, so immersive, that it brought us to tears…quite literally. The final segment is a very fun 10.2 mix of a Herbie Hancock piece, with lots of electronic pings, fast multichannel pans, all to a lively bit of jazz. For storing the 10.2 material, there was a computer with Firewire audio interfaces, and a bit of software for playback.

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 San Antonio. Bjorn's is a short cab ride from the airport, and downtown San Antonio is only about 10 minutes away from the store, with its picturesque River Walk, dinner cruises around the narrow canals, restaurants with live jazz, and world class hotels. Make a weekend of it…but the highlight, I promise you, will be 10.2.

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!

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?

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.

The Re-Equalization Debacle…The "Industry" shoots itself in the foot…again!

If the term "Re-Equalization" is new to you, hang on for a minute...it's something you need to know, and we'll explain it, and the problems surrounding it as a feature in your receiver or Pre/Pro.

Simply, re-equalization is a tonal correction that needs to be applied to film soundtracks that are mixed for a large theater, but played in the home. Large theaters are equalized to the industry standard "X-Curve", which deliberately rolls-off the high end in an attempt to correct for the problem of speakers sounding to bright in large rooms. However, the "X-Curve" is actually in error, and applies too much roll off. Dubbing stages used to mix film soundtracks are equalized to an extended X-curve, and sound mixers push highs to compensate for the overly aggressive roll-off. As a result, when film soundtracks are played back on home systems with reasonably flat response, they sound too bright. Re-Equalization compensates for this anomaly. Re-equalization is part of the THX specifications for home theater equipment, and was developed by Tom Holman as part of the original Home THX specification set.

Today there are several variants on the idea (Denon has "Cinema EQ", for example) but the concept remains misunderstood. Even Denon's description of the reason their own Cinema EQ is needed is incorrect. They claim it is required because theater speakers are placed behind the screen which causes high frequency loss, but home speakers are not. In reality, 'screen loss' is compensated for elsewhere in theater sound systems, and does affect the mix. The real reason Re-Equalization is needed in home theater systems has to do with acoustic differences between large and small spaces, and the effect they have on sound systems. Recall that film soundtracks are mixed in large "dubbing stage" theaters, and thus the soundtrack is created specifically for the characteristics of that size space.

Some form of Re-Equalization is necessary in home systems if film soundtracks are to sound properly balanced and not overly bright. However, other material such as TV programs are mixed in smaller control rooms, which match the home environment more closely. Re-equalization isn't required for that material. So, on the surface, if you only watched movies on your DVD player, selecting it on your AV receiver or Pre/Pro could also automatically select re-EQ, and you might think you'd have the problem licked…but you'd be wrong.

In its inimitable style, the entertainment industry has pointed their shotgun once again at their own feet and pulled the trigger. With tens of thousands of films on DVD now, and with the normal procedure being to directly transfer the original soundtrack without modification, re-EQ would seem to be required for every one of them. But in the last year or so some DVDs have produced with re-EQ already on them. Applying re-EQ in the receiver would apply it a second time, which would result in a very dull presentation of the soundtrack. Some of these DVDs indicate in a set-up menu that re-EQ has already been done, but some do not. Even some high def discs have been re-equalized, some have not. How are we supposed to know? A fine-print notice buried in a set-up menu will hardly grab most viewer's attention, even if they did know what it meant. That means the average consumer won't know there is any action they need to take for optimum presentation. Then there's the DTS soundtrack…which has the reputation of being "re-mastered for home video", whatever that means. If directors only knew what was happening to their finely crafted soundtrack, they'd surely spontaneously combust.

We had a de-facto standard…re-EQ for all film soundtracks, no re-EQ for everything else. Now we have growing ambiguity, and as time marches forward, little chance of a fix. And it's even more frustrating knowing that the Dolby Digital audio format has within it a status bit designated for a re-eq indication…which by extension, could be used for an automatic re-equalizer trigger. But it's never been implemented, possibly due to industry rivalry between Dolby and THX…but that's conjecture…I think…but it doesn't matter really, because the result is the consumer is the one taking the beating in the form of sub-standard audio. And all of this continues in the new high-definition soundtracks found on HD disks. The Re-EQ debacle is, in fact, worse than ever.

What do we do? Assume that up until a year or so ago, re-eq is required for film soundtracks. For recent disks of any type, you need to research each one to discern if Re-EQ is required on your part, or if it has already been done on the disk…that's if you can. And finally, use your ears. If it sounds dull, turn of re-EQ. If it sounds bright, turn re-EQ on. And to that statement we do mean to imply that you need to get out the manual to your receiver or Pre/Pro, find the Re-EQ (or similar function) feature, and learn how to quickly turn it on and off, and at least find out how to tell if it's on or off.

Once again, along with the aspect ratio mess, the entertainment industry has done a major disservice to the very people that support it…us.

More HD Disc News - Watching the War

The one thing that is needed in the HD Disc Wars is for the remaining film studios supporting HD-DVD to switch sides to Blu-ray. And that may have just happened.

Universal Studios, staunch supporters of HD-DVD exclusively, just announced they plan to continue to support HD-DVD for now, but no longer exclusively. And Paramount is no longer locked to HD-DVD either. While not the definitive final blow, this is significant news. It means both studios have recognized they are in the minority, and since studios are all about making money, they have realized their profits lie on the BD side, more so than HD-DVD.

What really swayed the war? We think the Blockbuster announcement of last spring may of done it. While you might still find a few HD-DVDs in a hand full of Blockbuster stores, they aren't a growing number (probably shrinking, due to Blockbuster's 'you don't have to return it' policy). If you want to rent an HD Disc, you have to have a Blu-ray player. And if you buy a Blu-ray player, you'll only buy BD discs. So the chicken/egg problem is solved.

What's interesting is, contrary to what Universal Studios has been saying, the consumer's choice of low-cost hardware didn't drive the war. HD-DVD players are still a couple of hundred less than BD players, but what good is that if you can't get the movie you want? In fact, it seems this was not a decision driven by the market, as much as by the studios. As consumers, if we had two equal quality choices, we'd always pick the cheaper. But we didn't have tha choice. It was made for us by the studios, and it wasn't the less expensive option.

We still advise our clients to wait just a bit longer to buy their Blu-ray player, though. Players we've tested all make wonderful pictures and sound, but operationally are disasters. Not just flakey, true disasters. It's a firmware/software issue we know will be fixed. But if you want to avoid frustration, and wait for the war to end, get one of the Oppo up-converting DVD players, see your current DVDs in near-high def, and wait for manufacturers to polish up their BD players. You'll soon buy one for $200 that will be great.

High Def Disc News!

Here's a clipping from USD Today:
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In a stunning announcement Warner Bros. Studios announced today that they will be releasing High Definition DVD Discs exclusively in the Blu-Ray Format. They will continue to release titles in the HD-DVD format thru May, but those releases will come after the Blu-Ray and Standard Definition releases.

"The window of opportunity for high-definition DVD could be missed if format confusion continues to linger. We believe that exclusively distributing in Blu-ray will further the potential for mass market success and ultimately benefit retailers, producers, and most importantly, consumers," Warner Bros Chairman and Chief Executive Barry Meyer said in a statement.

Warner Bros is the biggest seller of DVD's with an 18 to 20% market share. in the United States. They were one of the few studios that backed both formats.


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Note also that Blockbuster only rents Blu-Ray.

Comments: While both HD-DVD and Blu-Ray provide excellent HD picture and sound, it seems sort of dumb that consumers face a 'choice'. We quote 'choice' because the choice of which player to buy will be mostly driven by two things: price of the player itself and availability of your favorite movies. If you want the new Bladerunner Collector's Edition 5 disc set, you'll be buying a Blu-Ray player, for example.

But don't forget these cautions: Neither HD-DVD nor Blu-Ray players work very well. Yes, they play videos well, but both take up to 2 minutes to load a new disc, and menu systems continue to be clunky and glitchy with reported lock-ups on both systems. If you are like us, we expect fast response from pressing remote control buttons, and that spells frustration for a new user of either HD disc format player.

Don't forget the "third option"! A good up-converting standard DVD player. Our favorite are those by Oppo (sold direct). They are inexpensive, and convert standard DVDs to stunning, if slightly less than true HD, 1080p signals. Don't underestimate the power of these units! If you have a 50" HD screen, a well up-converted standard DVD will amaze you to the point you will forget it's not true HD. That means your existing library of standard DVDs is fully enjoyable on your HD screen. If you have a really large screen, like 80" or more, or sit very close, you may notice that a up-converted DVD isn't as good as a true HD disc. But for most viewers, it's quite good enough. At least, we expect it to hold us over until whatever format wins has players that are reliable, responsive, and not frustrating to use. At least we know of no standard DVD player that, after a firmware update from its manufacturer, refuses to play a particular HD disc at all! That's what happened to one of our clients with a Panasonic Blu-Ray player and one of his early BD movies. Yes, there's a lot of work to be done.

More Resolution Confusion…

In an earlier post I alluded to the fact that the human eye may be the limiting factor to the combination of screen size, resolution and viewing distance. And while that is true to a large extent, we need to clarify that when choosing a display, and working your mind over the question of if you need to spend the extra cash for full 1080p resolution, or if 720p at a cost savings will be adequate, or indeed, an imperceptible difference. Well…things are never simple.

Fortunately, the question of 1080p vs 720p may never come up with a growing number of home theater enthusiasts. It’s simply a question of future-proofing your purchase. If you buy a 1080p display today, it’s going to be the flat-out highest resolution display you can buy for a while, at least for the near future. There are already higher resolution projectors in the works, but as far as displaying pixel-for-pixel any HD source available, 1080p will do it. So why even concern ourselves with something less? Oh yea, money. That again.

As I wrote earlier, the average 20-20 vision eyes can only see things as small as 1/60 of a degree of arc wide or tall. That means that if a single pixel of your display is smaller than that, you can’t see it as an individual pixel. And that would seem to indicate that if a 720p display is small enough or far away enough, you wouldn’t be able to see the pixels of either it, or a similar sized 1080p display, so what’s the diff? Ok, sit down.

The first problem with the 20-20 vision limit is that while that is considered “normal” vision, it is now apparent that many more people either have better than 20-20 vision, or have had their vision corrected (notably via contact lenses) to somewhere closer to 20-10. In other words, they can see 1080p pixels much farther away than a person with 20-20 vision. So perhaps 720p won’t be so non-visible to as many people as we thought! A 1080p display would offer those eagle-eyed viewers a noticeably better picture.

Second, you have to realize that since a lot of broadcast, cable, satellite and HD discs contain 1080i or 1080p material, something has to happen to scale that image down to 720p. And, to add insult to injury, most plasma TVs aren’t actually 1280 x 720 pixels at all, but rather 1365 x 768 meaning that even native 720p material must be scaled a bit. Scaling downward is a tricky business, and not for the squeamish. Obviously, if you didn’t have to scale at all, you’d be better off, and that’s what 1080i or 1080p material is like on a 1080 display. Any other resolution means scaling. And scaling means artifacts that can be much bigger than the pixels themselves, and more easily seen by even our mediocre 20/20 eyes. So, again, advantage 1080p.

So, three reasons to opt for 1080p:
1. The 20/20 vision argument isn’t really about 20/20 vision, but should be more appropriately the 20/10 argument. That pushes minimum viewing distance based on acuity out farther.

2. Scaling artifacts may be more visible than the pixels of a 720p display, so why scale if you don’t have to?

3. It's about as "future-proof" as you can get. 1080p is likely to be the flat-out highest resolution that source material will be available in for quite a while.

Got it? 1080p is better, so if you can, get it.

Whew! I now wish to take aim at a misconception that is so prevalent that one of our distributors (who should really know better) casually said to me in conversation that 1080i is half the resolution of 1080p. I now take aim squarely down my telescopic site at that one. So listen up.

The resolution of anything called 1080 (i or p) is 1920 x 1080 pixels. There are two other important aspects, though, the frame rate (60, 30 or 24) unfortunately, also noted as a number with a p behind it (i.e. 24p), and the method of scanning, either Progressive, or Interlaced (1080p or 1080i). So the full specification of a video format should include the resolution, interlace or progressive indicator, and frame rate, as in "1080p 24p". If you don't have both parts, you don't have the whole story. There are actually many different possibilities. The Advanced Television Standards Committee has published these recommended standards:

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Vertical Lines	Pixels	Picture Rate
1080	1920	60i 30p 24p
720	1280	60p 30p 24p

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That's how the ATSC defined it, and I was surprised how hard it wast to find, buried in their technical specification documents. Somehow the consumer electronics industry has managed to re-write these figures in a much more confusing way (what a shock). Here are the same formats again:

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1080p 30p
1080p 24p
1080i
720p 60p
720p 30p
720p 24p

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And to make it much worse, the second figures are typically left off. The result is:
1080i (which is really 1080 lines by 1920 pixels at 60 fields, interlaced)
1080p (which is really 1080 lines by 1920 pixels at either 30 or 24 progressive frames)
720p (which is really 720 lines by 1280 pixels at 60, 30 or 24 progressive frames)

So when we ask "Is 1080i better than 1080p?" we are really asking "Is 1080i 60i better than 1080p 30p?" And we can reduce that to the difference between scanning an image with an interlaced pattern twice as often as a single progressive scan. And there it is: once every 1/30th of a second, or twice, interlaced, every 1/30th of a second. It amounts to what happens between scans. In the case of a progressive scan, the camera shutter snaps the image, and the entire image is scanned in one pass. In the case of an interlaced image, the camera snaps an image, and odd lines are scanned, then the camera snaps an image 1/60th of a second later, and the even lines are scanned. There is a 1/60th of a second time offset between interlaced scans. That does two things. First, motion may appear smoother (more scans per second can do this) and second, objects in motion may appear to have jagged edges (caused by half the scan resolution). But all is not lost. Motion adaptive interpolation within the video processor inside the display device can (and should) re-assemble all this interlaced mess using a process called 'interpolation'.

How adept the display’s interpolation circuits are determines how much motion jaggy artifact you see, and less artifact is better, but usually more expensive to obtain. But we’re only talking about 1080i video here, which is a 60Hz based frame rate. What about film, which is 24 frames per second?

Just to get a 24fps film to work at all on a 60hz based display system takes a process ‘telecine’. Going back to the early days of TV, engineers found that just projecting a 24fps film onto a camera image tube scanned at 30fps results in a rolling flicker bar due to the mismatched frame rates. Normal film projectors use two-blade shutters that expose each frame to light twice for an end flicker rate of 48Hz. That just simply doesn’t play well with the 60Hz field rate of NTSC TV. Early telecine machines were projectors that focused their image on a TV camera image tube, with five-blade shutters that were synchronized to the TV station’s house sync signals. The five-blade shutter means each frame is “exposed” to the image tube five times, resulting in a flicker rate of 120hz, which is a multiple of 60Hz. That got rid of the rolling bar, and left us with an odd way of converting film's 24fps frame rate to 30fps TV. Ultimately, what took place was a process called 3-2 pull-down, pull-down referring to a projector pulling the film down one frame at a time into its gate. 3-2 pull-down means that as a 24fps film gets transferred to video, a cadence, or pattern of 3 video fields, then two fields, then three, and so on. The resulting video is 30fps with 24fps embedded. Some displays are able to detect and undo this 3-2 cadence, and make it back into 24fps. Not very many displays can deal with the resulting 24p video, so it has to then be converted, sometimes again with interpolation, to a frame/field rate the display can handle. The short story around all of this is that for material that originated on 24fps film, the differences between 1080i and 1080p drop into irrelevance.

What is relevant is how well a display deals with all of these interlace/progressive and various frame rate issues. It’s all about interpolation, image processing, and display refresh rates. So the simple answer is (get ready, this is what you've been waiting for…) the differences between 1080i and 1080p are irrelevant for some material, and depends on how elegant the video processing is for others.

At this point you may be asking for a simple answer. There isn’t one, except this: for critical applications, like home theaters, media rooms, or your large primary screen, stick to 1080p displays. For the 42” TV in the bedroom or rec-room, you could save a little money on a 720p set. It’s highly likely that in a few years, 720p sets will be largely off the market, because the cost of 1080p displays will have dipped to match them, and most of the market wants the bigger numbers. After all, once you open your check book, doesn't 1080p sound better than 720p? I thought so.

There's much more to picking out the right display for your home theater or media room. Call the experts at Platinum Home Theaters for professional assistance and competitive pricing!