Binaural Barricade Against The Audio Police
by John Sunier
Being heavily into headphones, I couldn’t resist having my curiosity aroused by Tom Corbin’s first column [in a past issue] announcing that he will suggest circumstances under which one may want to wear two pairs of headphones simultaneously. Well, I can’t imagine what circumstances those may be and am waiting with bated breath to find out, but in the meantime I can tell you about some circumstances you probably had not thought about in which you might want at least to wear one pair of headphones.
Tom’s “Audio Police” business also caught my eye and I couldn’t agree more. I’ve railed against some of the Audio Police dogma for years, such as the “hair shirt” approach to component features, especially dispensing with headphone jacks (since I’m into headphones) in preamps, not to mention tone controls. I’m going to do a bit of creative, lateral thinking such as Tom was encouraging, and among other things I’ll also give you a rock-solid reason why you should buy a graphic equalizer.
Room Treatment & the Sweet Spot
Rumors are that one of the leading very high end speaker exhibitors at Hi-Fi ’97 bragged about how great his speakers sounded without any acoustical treatment in the small and sonically-deprived room of the San Francisco hotel where it took place. Yet a little snooping after the demo revealed Tube Traps in the front corners and a bunch at the rear wall.
While both the Audio Police and those of us who prefer to think and hear for ourselves stress the importance of the listening room in the high end equation, it is the former, not the latter, who have escalated the ritual of room treatment to new complexities and expense. Many audio buffs buy more room treatment materials than they need, or entirely the wrong ones, because they don’t sit and listen while trying simpler, less ugly and cheaper means such as rugs, drapes, furniture, or CD/LP storage shelves.
Another problem connected to the room treatment emphasis is the narrow sweet spot encountered with many of the larger and most expensive tower and panel speaker systems. Loss of 50% of the sonic achievement of a typical large high end speaker when standing up from a seated position is not at all an unexpected occurrence. Even moving from side to side a few inches destroys most of the superior imaging and soundstaging of many two-speaker setups. How many of us can sit next to a friend or spouse and be assured that the other person is hearing exactly what we are hearing in our carefully-aligned sweet spot? OK, so the majority of the audio unwashed out there has never heard of the idea of sitting equidistant from the two speakers in an equilateral triangle and thus has one speaker horizontal at floor level in one corner with the other vertical high up on another wall. The Audio Police have gone too far the other way – resulting in some of the listening room diagrams appearing in some audio pubs looking like a prison cell with a kitchen chair two-thirds of the way back, two speakers one-third of the way into the room, one little equipment cabinet to one side, and nothing else.
And in these ruminations on the sweet spot I’m not even addressing those approaches that REALLY have a narrow sweet spot – namely processes attempting to cancel some or all of the left speaker signal from reaching your right ear and the right speaker signal from reaching your left ear. (There used to be a specific name for this but it is now trademarked so I can’t use it). Among these are Carver Sonic Holography, Polk SRDS speakers, Lexicon Panorama circuit, and many new computer-related speaker-processing approaches that attempt to give a “3D” feeling to stereo sources heard through them.
In the computer area, I’ve never understood why all the research and effort are being expended to getting a 3D effect with dinky little speakers (and often a third little box laughably referred to as a “subwoofer”) when the computer user isn’t going anywhere and doesn’t require any freedom of movement. This is a perfect situation for headphones! Even inexpensive models can achieve better sound than the undersize speakers being sold for multimedia use; but better than that, headphones plus Binaural sound can precisely locate sounds anywhere in a full 360-degree sphere around the listener.
Everything You’re Listening To Is Wrong!
More than 200 million headphones were sold over the past decade, yet everything that nearly everyone is listening to on headphones was never designed nor intended for headphone playback – it was designed for loudspeaker playback! Stereo purposely mixes some of the left channel signal into the right and vice versa, and then when your pair of speakers are speaking in your listening room they do the same thing.
The result on headphones is what’s sometimes referred to as the “musical hat” effect – all the sounds happen inside your skull. Not only that, but half of the musicians seem to be clustered over just inside your left ear and the other half of them over just inside your right ear. Some people also hear another cluster in the middle of their cranium. The HeadRoom circuit offered by that headphone-oriented mail order service tries to connect these clusters via cross-feeding of the two signals to more closely emulate the effects of loudspeaker listening when wearing headphones. For many listeners and some types of music this subtle circuit enhances the listening to stereo material.
Biophonic Response Chart
[Vertical Scale = relative level in dB; Horizontal Scale= frequency.
Ron Cole feels this EQ can make listening to standard stereo sources on headphones
less bizarre-sounding to most persons, though not equalling true binaural.]
Here is a less subtle enhancement for listening to all these recordings and broadcasts that were never designed for headphones. Binaural recordist Ron Cole came up with this chart which corrects for ear canal resonance and other differences in the spectrum between speaker listening and headphone listening. It can be set up on a parametric equalizer or almost any multiband equalizer (those accessories which the Audio Police tell us should never have been invented). You don’t have to hit the various boost points right on the button — even getting close makes an amazingly more natural headphone listening experience when using stereo source material. While I have yet to try this in combination with the HeadRoom circuit, the two should be a synergistic duo. Remember though that neither of these band-air approaches locate the music outside of one’s head nor do they impart a “you-are-there” feeling in listening on headphones.
The Binaural Rap
There’s only one way to do that. That’s using true binaural recordings and any headphones. [Editor: Auralization processors will also image outside the head.] Here again we are at odds with the Audio Police, since absolutely no additional components are needed. Plus the ultimate in fidelity is not required to experience binaural recordings. The very first public experiments with it, in fact, took place at the Paris Opera in 1881, using primitive carbon transducers both on the stage and a pair of them hooked to two separate telephone lines at each subscriber’s home.
Even with a $25 walkman-type cassette portable and the ear-buds that came with it, one can have a jaw-dropping sonic experience with a good binaural cassette. One that I frequently suggest to binaural virgins is Stephen King’s “The Mist,” available at the Simon & Schuster audio book rack of most chain bookstores for about $9. It’s more hair-raising than any King movie. With a cast of about 30, original sound effects and music, you’re part of the horror drama. Monsters creep up on you from behind and drop down from the ceiling on you.
But it is with music that binaural can almost literally Take You Away. Isn’t the primary purpose of high end audio to Get Into the Music More? (The Audio Police may say that but their actions often contradict that.) Well, with binaural one is in the same venue where the musicians originally performed. One is aware of the room size and shape, and all the reflections that are such a major part of the musical experience are preserved instead of being turned into a general mish-mash of reverberation without any directional information, as with stereo.
The basics of binaural couldn’t be simpler, but recent improvements have brought it to such a level of viability and functionality that if recording engineers would only wake up to it they would be recording everything binaurally. It is now completely compatible for mono or stereo speakers as well as matrix surround sound playback.1 The heart of binaural is a dummy or artificial head which replicates the human head. The most vital features on it are the two outer ears or pinnae. They are usually formed out of soft rubber or plastic and often cast from actual human ears. Ridges and valleys in the pinnae reflect the sounds differently into the inner ears and therefore they are vital to recreating precise localization of sounds. The current interest in spherical mike systems for stereo preserves many elements that are part of binaural reproduction, but without the pinnae to reflect the incoming sounds to the omni mike capsules, the localization cannot be very specific.
The two channels from the dummy head must be kept absolutely separated all the way in the chain to the two drivers of the listener’s headphones. And the left mike on the dummy head must feed the left driver of the headphones and vice versa; the backs of our heads lack the features of the front and reversing the channels gives a confusing sonic image much as does reversing the left and right-eye images of a stereo photograph.
While even a $3.98 pair of ear buds will deliver good binaural, the better quality your headphones, the better will be your experience. We already know that it’s possible to get better sound with some of the high end phones2 than one could get with many of the most expensive speaker systems. Add binaural to that equation and you have a really amazing sonic experience. Add one of the many dedicated headphone amps now being produced3 and you’ll be hearing the ultimate. Add a longer cable and you’re no longer glued to that sweet spot! You can now take it with you, within reason.
The Audio Police have decided that FM radio, audio cassettes and binaural are all not worth our consideration as far as high fidelity sources. I could expound at length on the idiocy of the first two, but that’s off the subject. Their beef with binaural is the claim that it sounds perfectly awful played back on loudspeakers. In the distant past that was somewhat correct; binaural recordings sounded a bit thin and distant. Part of this was the very poor bass end sensitivity of the consumer mikes, which were often built into headphones and had to have a low cutoff to avoid feedback! Even the recently-discontinued Sennheiser MKE 2002 binaural mikes lacked extended low end.
Today, however, the two commercial binaural mike systems used in 99% of existing binaural recordings are completely equalized for excellent speaker playback. After the first of the two gold binaural CDs from Newport Classics was released, a press event was held in the same auditorium in Pasadena where the recording was made. Speakers placed on the lip of the stage played back the binaural CD and all agreed it sounded as good or even better than the best standard stereo CD. 4 (Of course most of the “you-are-there” feeling is lost in speaker playback.)
The other binaural misconception is that there are no recordings available. Not true. They were extremely difficult to find, and when I began regular All Binaural Broadcasts on my local AUDIOPHILE AUDITION program about 17 years ago listeners reported that they asked in shops about binaural recordings but only got blank stares. So seven years ago I decided to start THE BINAURAL SOURCE, which is a web-based mail order business currently stocking over 125 different true binaural CDs and cassettes. Most of these are imported exclusively by us from Germany, France, Britain, Bulgaria, Japan, not to mention a growing number of small U.S. labels who lack distribution in the stores. The sounds cover classical, pipe organ, jazz, crossover, new age, pop, audio dramas (such as “The Mist”), nature sounds, and special sounds to enhance sleep and relaxation.
An extensive FAQ and more detailed information about binaural reproduction are found at THE BINAURAL SOURCE. Actual binaural demos for free downloading will be available there by the time you read this! A flyer describing 28 new binaural CDs and listing all 125+ recordings in the current catalog is available by calling 800-934-0442 (PST), emailing your street address to firstname.lastname@example.org or by writing to THE BINAURAL SOURCE, Box 1727, Ross, CA 94957.
1 = I realize most LISTENER readers are staunch two-channel/two-speakerists, but if you buck the Audio Police by owning any sort of matrix surround sound processor (no DSP reconstructions, please), you will find that binaural CDs provide a superior surround soundfield to any Dolby Surround-encoded music CD.
2 = Among my personal favorites for binaural are the AKG K 1000, the Jecklin, Sony CD-3000 and any of the Grados.
3 = Headphone amps have been available from HeadRoom, McCormack, Audio Alchemy, AKG, Melos, EarMax, Creek. New headphone amps have been introduced by Musical Fidelity, Parasound, VLS, Sennheiser, Holmes·Powell, Moth Audio, Celeste, Pure Audio, Mesa Engineering, Naim and Bowman.
4 = Fellow audiowriter Martin De Wulf said this about the second Newport gold binaural CD in a recent Bound for Sound issue: “…while this recording does do some amazing, almost unbelievable things when listened to on a set of headphones, it sounds every bit as good when listened to through a pair of speakers.”
c. 1997, John Sunier.
From The Binaural Source. (Republished with permission.)
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[…] In Taking Audio in Another Direction, John Sunier and Ron Cole suggest following a “biophonic” curve for setting equalizers to correct for ear canal resonance and other differences in the spectrum between speaker listening and headphone listening: […]