Features

Stereophile Vol.17 No.8, August 1994

Bravo, JGH
Editor:
Bravo for J. Gordon Holt's review of the Fosgate/Audionics surround-sound system (April 1994, p.155). Since 1971, when I first experimented with David Hafler's Dynaco 4 Dimensional Sound System, I have been enjoying some of the benefits of surround-sound, depending, unfortunately, on the way the disc was recorded.

But since the advent of Nimbus Records, I have been enjoying surround-sound much, much more. Nimbus and the Dynaco/Hafler system go together like peaches and cream! All this without the pumping, breathing, and distortions of surround-sound processors---just the natural dynamics of music with the realism of hall ambience added.

Why the Hafler system has not been totally accepted is beyond my understanding. I challenge anyone with ears to listen for themselves. If Mr. Hafler is reading this, may I just say, thank you so very, very much.
---Paul G. Eppes, San Antonio, TX

I've lived for extended periods now with point-source surround and THX-type dipole surround speakers, and my vote is in. In my 16' by 24' audio/video room, I prefer the point-sources for music and for films. The reason? With ambient surround (music), the extracted difference signal, although mono, relates to the front side ambience well enough to give a good illusion of stereo surround. The surround has breadth, and there's no tendency for it to image inside my head.

Film surround, even of the ambient variety, is often pan-potted into the surround channel; this seems to strip it of much of its relationship to the front ambience. (Why don't more film-sound people record space in true stereo?) It doesn't appear inside my head, but neither does it surround me from point-source speakers as effectively as it does from the dipoles. On the other hand, discrete surround effects, such as a speaking voice from behind, are noticeably dulled from dipoles, because I'm listening at 90 degrees off-axis to speakers that are aimed parallel to the room's side walls. The point-source speakers sound much more alive---sometimes startlingly so. There have been times when I thought someone was actually speaking or moving around behind me.

Finally, my response to Mr. Eppes and to some other readers who wrote in about my surround article ("Space...the Final Frontier," Stereophile, March 1994, p.60):

Like Mr. Eppes, Justin Graves ("Bravo, J. Gordon Holt," June '94, p.17) chided me for not mentioning the simple L-R extraction hookup advocated by David Hafler. Yes, this does produce an impressive ambient soundfield---one actually capable of giving a semblance of rear stereo. But it lacks an essential element: rear delay. Delaying the surround channel by 25ms or so invokes the Haas precedence effect, which effectively keeps the direct sounds up front---where they belong. Without it, it's often impossible to get the surround level high enough without it becoming obvious that instruments are coming from the rear as well as the front.

Hrvoje Hrvokic ("Binaural Heard From," June '94, p.23) wondered why I didn't mention binaural sound. Because it has one serious flaw that I feel is fatal: It doesn't do frontal imaging. Yes, it reproduces space magnificently and gives marvelous imaging of sounds to the sides and all the way around the rear quadrant; but most listeners hear front-located sources as being inside their heads, not in frontal space. Binaural can sound impressively realistic...until you compare it with discrete surround.

Alan Rauchwerger ("Appalled by Gordon," June '94, p.15) accused me of once advocating what I now denounce: tailoring loudspeaker frequency-response to sound good rather than to measure flat. Guilty as charged. But in 1985, when I wrote that piece, there was no alternative way of getting musically natural sound. Now there is.

Jim Payne ("Due Respect?," June '94, p.21) objected to JA's carping footnotes and sidebars on the grounds that, because I'm the founder of Stereophile, I deserve respect. Respect was not the issue; intellectual rigor was the issue. JA has the right---the obligation, in fact---to question any published assertion that can't be supported by credible documentation. Some of my points were based on conjecture, which is always fair game for doubt.
---JGH

Stereophile Vol.17 No.9, September 1994

One more on the final frontier
Editor:
Regarding J. Gordon Holt's "Space...the Final Frontier" article (Vol.17 No.3, p.60) and the letters responding to it, I agreed, naturally, with Gordon on most of his points, but thought that JA had a good point about a speaker's high-frequency dispersion being primarily forward of the listeners and not reflected off the front wall. I was surprised that, in such a comprehensive article, Gordon left out both Ambisonics and binaural. There is more quantity and higher-quality ambience information on both than there is with SQ or QS. And there are a couple hundred CDs available today of those formats, while there are almost no QS or SQ available anymore. (I touched on this in my article on Nimbus and Ambisonics in Stereophile, June 1987, Vol.10 No.4.)

It was exciting to see that Onkyo had finally included an Ambisonics UHJ decoder in their SV909 receiver, but then disappointing to find that they left out the "Stereo Enhance" circuit which was a major part of the Minim decoders. This feature is a sort of blend of the Hafler L-R circuit with the more seamless surround of Ambisonics and results in the best surround-sound from two-channel stereo of anything I've ever heard. And no one is forced to buy special UHJ CDs. Unfortunately, the Minim decoders had, as you observed of most surround processors, disappointing electronics.

I've been waiting for Stereophile to review the Cogent Research SPI box; guess I'll have to review it myself in Bound for Sound to get them some needed exposure. Both binaural and Ambisonic recordings sound fabulous via the Cogent Research four-speaker frontal arc arrangement, with simple L-R ambience going to two more matched speakers in the rear (the Dynaco QD-1 passive box and a separate amp work better for this than any active surround processor). In fact, I now prefer that effect with binaural recordings to the Lexicon CP-3 binaural panorama circuit, which was previously the only way to maintain most of the binaural localization realism when using loudspeakers.

Problem was, the sweet spot was tiny; and with the Cogent Research, it's quite wide. Additionally, any ordinary stereo material with good L-R information decodes beautifully via the SPI box. That's why binaural sounds so great with the Cogent Research---it has plenty of clean, accurately phased L-R information! (Your letter-writer from Singapore in the July Stereophile ["Height Information, Please," Vol.17 No.7, p.11] is just one of our Binaural Source customers who has been telling us how much they enjoy their compatible binaural CDs on anywhere from two to eight loudspeakers!)

When Gordon wrote that when people familiar with live sound in a large space hear reproduced surround-sound, "...they'll never be satisfied with two channels again," he should have said "with two speakers again." First, two channels are all that are needed for binaural, and of all the most lavish surround systems---only B-format Ambisonics comes close to binaural on headphones. Second, the simple Hafler-type ambience retrieval from two ordinary stereo channels is sufficient on well-miked recordings for achieving a realistic-enough surround field for classical and jazz. I have personal reservations about all multi-channel systems so far except B-format Ambisonics, and, as you said, neither Ambisonics format is happening in the real world. [Meridian demonstrated Ambisonics playback at the recent Summer CES.)
---Ed.

(By the way, I trust that your poor record of never reviewing any of the binaural CDs I've sent to Stereophile is being corrected with an upcoming review of the Pasadena Symphony/Jorge Mester AUracle compatible ($50!) binaural CD that Larry Kramen of Newport Classics sent you.
---John Sunier, Audiophile Audition

Stereophile Vol.17 No.11

Nice one, Gordon!
Editor:
I think it is fascinating the variety of responses---from the paranoid to the enthusiastic---the J. Gordon Holt article ["Space...the Final Frontier," Vol.17 No.3, p.60] has wrought. I, too, would like to respond to this apparently wonderful essay; but since the back issues I requested (and paid for) four months ago have not come my way (ahem), I am going to have to wing it.

Until recently, I always thought that surround-sound was a dirty word. This position was reinforced by my experience as an audio retailer, in the early Dolby Pro Logic days when people would come in and ask if we had "surround-sounds." I would first desperately resist the urge to correct their grammar (there is no "s" at the end), and then I would launch into a demonstration and explanation using Home Theater movies as the key demo material. Very rarely would we have someone who wanted surround-sound for music-only purposes, but it did happen.

My argument against surround-sound was that, when I was sitting in a concert hall, I never heard sound coming from behind me; since the sound was coming from where the performers were, that's the way I wanted it when I heard it at home. This had to be the most realistic and accurate way of listening to the recorded event, right? Well, maybe not.

The key for me here is the acoustic of the situation. If I am in a concert hall listening to the first oboe player, then unless the oboe is playing in an anechoic chamber, I am really listening to two things: the musician and the hall---perhaps 50% of each. Now, it's when I listen to this instrument in my music room that things start to go amiss. I basically take the oboe and half of the concert hall and stick them in a room that is about 20 times smaller than the original recording venue; then, on top of that, we have this bizarre blending of the acoustic that the oboe player was playing in, and my room, which is totally irrelevant in relation to the original event. How could we even pretend that this is realistic or even accurate?

The solution to this acoustic nightmare is, however subtly, to reproduce the acoustic of the original event as I would hear it. This means re-creating the reflections of sound that "surround" me when I am there. Voilà, we have surround-sound.

Of course, we still have problems, such as how to record this properly, and how to properly integrate the center channel. (Why should we have to conjure up a center-sound source when we can just put a speaker there?!) Also, surround-sound per se is not always accurate. If a musician is recorded anechoically in a studio and you want to put him or her directly in your room, then not just any rear-channel sound would be appropriate, because you want your room to sound just as it would if he or she were playing right in front of you.

What does all this mean? It means that, even after almost a hundred years of recorded music, we are still trying to figure it out---which is good! Because it means that we keep developing, learning, listening, and advancing the state of the audio art.
---Sean Engel, Valladolid, Spain

More
Editor:
It seems the diehards for point-source stereo playback are losing some ground. Thank goodness. We need intense development of three front speakers if we are going to effectively re-create the live performance for more than one in a room. Or do we? Isn't that what Bose has been working to accomplish for years? Maybe Stereophile and other audiophiles should be more open-minded and supportive of Bose's research and application.

Those who commiserate over the failure of quadraphonic and "Hafler" four-channel systems contribute to the diffusion of concentrated better-sound development. Can we audiophiles agree to get behind, push, pull, or just get out of the way of this superior playback system?

Let's face it. The center speaker, the "three in the front," makes logical and perceptual sense. How stupid [audiophiles who stick with stereo] must look to today's layman, let alone the "new" audio engineer.

Let's hope Audio Research, Krell, Mondial, Vandersteen, McCormack, and the recording engineers, etc., (let alone Sony) move quickly to get a grasp of this storage/playback method.

The sooner every home in the world is "three in the front," the sooner the artists' music can be more properly conveyed.

J. Gordon Holt, thank you very much for your stubborn quest and support of musical truth.
---George Tyler, Illegible, MN