Secrets Q & A

TVs? We Don't Need no Stinking TVs - Third Generation Multi-channel Audio - Part 1

ARTICLE INDEX

Placement

High-resolution discs are mixed in the recording studio with very specific speaker placement as specified by the International Telecommunication Union (ITU). The document goes by the name ITU-R BS 775. The ITU placement of the speakers is shown in Figure 2.

Five speakers are shown in this plot. No standard exists for seven channel music. It is generally agreed that the worst place to put them is in the back as the videophiles do. Some recommend they be used as height channel in the front of the room. Others recommend they be used as wide front speakers. Some recommend these wide speakers by as much as 60 degrees from the center. At this point I do not know of anyone mixing in seven channels for music alone. Audyssey developed a system to synthesize the signals for up to 11 speakers from a 5 or 7 channel source called DSX.

part-1-figure-3

DTS has a similar system called Neo X. No music recording mixed with 9 or 11 channels exist. Within a fixed budget it is likely that better sound will be achieved purchasing 5 excellent speakers instead of 11 average ones. The ability to place all these speaker optimally in a regular sized listening room will also work against adoption of these systems.

Currently, when music is mixed in a studio, the speakers are placed in the configuration specified in ITU-R BS 775. All speakers in the recording studios mix room are identical and are aligned at the same vertical plane. Audiophiles seeking the best sound should replicate the floor plan. With an identical center channel placed at the same vertical height as the left and right channels, video is not practical. If the center is placed above or below the left and right speakers to accommodate a TV, the image will bend up or down. A so-called matched center-channel speaker with different speaker alignment introduces additional problems that result in tonal balance shifts.

Expensive front projection system with an acoustic screen hide an identical center channel placed at the same vertical height (obviously the 40+ lb LCR speakers must be mounted in-wall, with significant professional construction to support the speaker. In wall speakers that are limited in size and weight to allow for a DIY installation without disturbing existing construction are not be capable of producing high end sound in my opinion. A large flat-screen panel display on the wall defeats the purpose because the center speaker in front of the screen and blocks the view.

The Trinnov optimizer system, available at an affordable price in the Sherwood R-972 AVR, can adjust the apparent height of a center channel speaker so it aligns with the left and right channels. Trinnov also improves the sound from speakers not placed in the ideal angles as shown in Figure 4.

part-1-figure-4

Obviously any type of electronic processing can never create a sound field as good as correctly placed speakers. I find Trinnov system on the R-972 to be very effective. Other subjective impressions of the Trinnov system on the R-972 are available in the many professional reviewers of the unit in print and on the web. The system in which I tested the unit had no video.

The R-972 has been available for longer than most AVRs. Accordingly, the R-972 does not have the feature set of recently-released AVRs in the same price class. However, the issue with multichannel audio reproduction is minimal. The required feature set for an AVR to operate without video is outlined below. To my knowledge, the low-cost TI DSP implementation will remain unique to the R-972 past CEDIA 2011. The next step up is the $8,000 ADA TEQ-8 room correction system (pre/pro also required). The price is justified for reasons which run outside the scope of this piece.

The effectiveness of the R-972s optimizer is influenced by speaker deployment and voicing. Base your purchase decision on a home test; given the unit is price controlled (you have the Supreme Court to thank for this) your dealer should be willing to offer this option. The ADA uses Trinnov's third generation code, has enhanced compute power, and a wide array of parameter adjustments allow the system to be effectively deployed over a broad range of systems and rooms. That said my measurements show the R-972 should provide many audiophiles who cannot follow ITU-R with an improved multichannel experience.

A TV is required for a music-only multichannel system to enable setup of the Blu-ray player and AVR; otherwise, there is no means to view the setup menu. Even some DVD-A and Blu-ray Audio discs have on-screen displays that allow you to move to different tracks quicker and gain access to special modes such as an on-stage mix versus the standard in-hall mix. Blu-ray players sometimes display CD title information on the monitor, not on the front panel like a CD player.

A small TV on the equipment rack should be sufficient to navigate the setup menu. Consider a thirteen-inch panel TV with HDMI. These have fallen in price. Another alternative – and one that is costless -- might be a small NTSC (original analog color standard for the US) TV that stored in the attic. The Blu-ray player and AVR must have composite video outputs that are on all the time if you go the NTSC route. Some Blu-ray or AVRs units may blank composite video when they sense an HDMI connection, which is bad news because the HDMI cable passes the high-resolution digital audio signals to the AVR.

Needless to say, when one is in a setup screen with a Blu-ray player that does not keep composite video, no visual cues are available should the composite signal be accidently muted. Most units have reset modes to return to square one. A small HDMI monitor may not be a panacea if the composite video output is not present at all times. The same setup screens can cause your HDMI monitor to go blank when selecting formats incompatible with the monitor. HDMI copy protection handshaking problems are also common. The instruction manuals for Oppo units, which do not mute the composite video signal, suggest the user connects both the composite video and HDMI to a digital TV in the event the HDMI blanks.

Now Go to Part 2 - Desirable and Mission-Critical HDMI Functionality for Blu-Ray and Universal Players

FEATURED COMMENTS

Good summary, you forgot one BIG option
Written by Jason C , June 17, 2011

Smyth Research (www.smyth-research.com) has an approx $3,000 processor that will enable headphones to perfectly reproduce any multichannel system that it can sample, with custom algorithms to match with the user's hearing, and then speakers and amps are no longer necessary, except possibly if one wants the physical sensations of a large subwoofer (there's a huge savings on expensive speakers, speaker cables, and amps. If you want different speakers and/or amps for your virtual system, buy some new samples, or sample a system for storage that you like yourself to ease your audiophile upgrade urges). The price also includes a pair of very good Stax electrostatic headphones, although you're not supposed to have to use a set that is of that quality for excellent sound quality-for additional listeners. You will also need a surround processor to work with the Smyth unit. I'm certain that the price will plummet as the generations of the processing chips increase.

So if you have a small cart to put the surround processor and Smyth unit on, you can wheel your virtual surround system (and a large number of surround system samples can be stored in the Smyth unit, enabling you to have dozens of virtual systems with different speakers, amps, virtual rooms, etc stored in the unit) around to any room that will hold you and your "system cart". Of course, all this could probably be condensed into a Walkman-sized unit if enough people wanted it, possibly with a touch-screen interface, maybe even with the multichannel music stored on it just like an iPod on steroids (hint, hint manufacturers).

And guess what? You can keep your big screen because the headphone virtual audio won't interfere with it one bit. Now, with a good set of virtual glasses that can do 3D and HD, perhaps you could have an entire virtual Skywalker reference audio/video system (THX approved, of course) to take anywhere very soon. I could see a HUGE amount of profit for the company that can make that happen. A whole new industry, in fact, with the successful example of the iPod/iPad to serve as help for financing.

Perhaps Secrets could get together with Widescreen Review (whose editorial policy has never shied from promoting a solution that they see benefiting the consumer) to push for such an option from manufacturers.

The increase in numbers of audio and video-philes could take an enormous leap from such a device/entire new industry. And a huge amount of fuel and pollution would be saved from not having to ship much more massive equipment all over the planet. Not to mention all the energy that would be saved from just powering headphones instead of a 5.1/6.1/7.1/etc system. And of course make it compatible with game systems, to further increase cost reductions from economy of scale. Why not tie it in with education abilities, and we could get rid of a lot of the costs of education and do it in a way that would excite young learners and do it more efficiently.

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Hear here...
Written by Jim M , June 17, 2011

JC- What if you can not stand wearing cans? How can your family enjoy a movie together if you all have to wear headgear?

Oh...I get it...you are being "cheeky". ;)

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Saving some dough
Written by Jason C , June 18, 2011

If you have an average teenager today, they are already wearing headgear anyway; phone/music device headphones, etc. If you have an older listener whose hearing is below-par, they could be wearing headphones/hearing aid already to help hear without blasting the others.

There are lots of open-back phones so one can talk with others if that is what one wants to do during the movie (I don't). And if one doesn't like phones, go ahead and spend the multiple thousands or tens of thousands that the headphones would replicate, along with the space they would take up (or cost to install in-wall), the extra cost to the environment in materials/shipping, and the extra electricity used.

The author appears to be approaching the subject comprehensively, and I want the market for surround music to be greatly enlarged, so making the entry fee as small as possible will hopefully accomplish that. Now, if they could only get laser front-projection ready for the consumer, at 4K resolution.

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    Smyth Realiser for Virtual Surround on headphones
    Written by David Rich , June 19, 2011

    Jason

    Thanks for your comments.

    I evaluated the Smyth Research headphone at CEDIA 2010. It appeared to do a good job of simulating the sound of the room but, under show conditions, it's tough to be definite. Customization of the signal to the headphones, via digital signal processing, to the characteristics of the user's ears is innovative. The quality of standard Binaural systems have been restricted by match of the shapes to the dummy head and ears. The details of the calibration are on the Smyth Research website. It will be interesting to see if the company can bring the price down to a level for it to sell in volume.

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    Its about bloody time
    Written by AllanG , June 24, 2011

    For the last year or so. It has been my contention that all music going forward should be released and re-released on Blu-Ray disc. We have the ability to put out one disc with 196/96 and stereo. One of the reasons I recently purchase a Sony S560. Only to learn six weeks later it clips whiter than white. Going to Oppos BDP-93. Buy one player BOOM. All format wars over. At least until someone clever comes up with some thing better.

    By the way I am addicted to Blu-ray movies...help Not really....lol For all reviewers when reviewing music on Blu-ray. Please state if it is studio (i.e no video) or concert(i.e video included)

    AG

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    Wave of the future?
    Written by Howard Ferstler , June 27, 2011

    Excellent introduction to the topic. I have found that some home-based surround synthesizers can do a pretty good job with standard two-channel CDs, at least if what one is after is hall ambiance pulled further out into the room. A good center-steering function also can help stabilize the normal phantom-center soundstage.