Omnidirectional speakers. The future?

Binaural Recording Baby! - If you want to feel like you are there! So how come nobody does it? Jazz At The Pawnshop, clearly one of the most successful recordings of all time, was done with a binaural setup. From the Proprius website:

"Palmcrantz rigged the main microphone pair facing the stage, about two metres above the floor. These microphones were Neumann U47 cardioids, spaced 15-20 cm and inclined at an angle of 110-135 degrees.

This ORTF stereo technique - named after the French radio which introduced this simplified dummy head technique at the beginning of the sixties - was, according to Palmcrantz, the best method for optimal stereo effect and spatiality.

- Real stereo effect can only be achieved by placing the microphones in a similar way to the disposition of the ears.

Such a pair stood in front of the stage at Stampen and another pair was placed to the right of the stage, facing the audience in order to recreate the right "live" feeling. Some auxiliary supporting microphones were also necessary. One microphone was placed next to the grand piano standing on the right-hand side of the platform with its lid open, and Palmcrantz hung two cardioid Neumann KM56s over the drums on the left side of the stage. The bass, standing in the middle, and connected to a little combo amplifier on a chair, was supported by a Neumann M49, also in omnidirectional mode. The microphone was placed in such a way that it caught sound both from the instrument and from the amplifier's loudspeaker. "

I had a feeling this thread would get around to this end of things eventually. One of the biggest problems for us trying to reproduce music at home is inconsistent recording technique/methodology.

If all recordings were done this way I don't think you'd want/need Omni speakers to give you that feeling of presence.

To me a true binaural recording uses a dummy-head mic, although again, in the end the playback system positioning remains a rather arbitrary and subjective thing by comparison.

Hi Billhound,

In general, a large room is desirable because it introduces a greater time delay between the first-arrival sound and the onset of significant reverberant energy. This is probably more true for directional speakers than for omnidirectional ones, but both types would probably benefit from a large room in this respect.

The larger the room, the more the power response (summed omnidirectional response) tends to dominate the perceived tonal balance. This is because as you move farther away from the speakers, the loudness of the direct sound falls off more rapidly than does the loudness of the reverberant energy. With conventional speakers, the tonal balance is likely to be audibly degraded once you move back far enough for the power response to dominate. With omnis or other consistent-pattern speakers, the tonal balance will hold up better in a large room.

To given an extreme example, once upon a time I hauled my then-pair of big home-brew speakers (1" tweet, 7" mid, two 15" woofers) to an informal dance held in a church's activity room. To my shame and horror, my beloved behemoths sounded sluggish on bottom, harsh in the mids, dull on top, and overall quite fatiguing. I was mortified, as I'd been letting the locals know what a kick-butt speaker builder I was. Now I understand that those were the wrong speakers for that application, as the power response totally dominated the perceived tonal balance in that large space and their power response was quite poor, having never been given a second thought by their designer (ahem). That's why people use horns or horn/woofer hybrids at dances - they have a much better power response, even if up close and in the "sweet spot" conventional speakers would sound better. High output omnis like the Wolcott Omnisphere also work well in this sort of application.

Getting back to your 1600 square foot room with 16 foot ceilings, I would definitely argue in favor of a speaker that generates a tonally correct reverberant field over one that does not. You may or may not prefer a very wide-pattern speaker like the Shahinians; if you do, they'll sound great in there. In a medium-wide but still consistent pattern speaker, you have full-range planars like the Sound Labs and big Maggies, and dynamic dipoles from Gradient and Audio Artistry. If you like a narrower pattern speaker, then for a large room you might consider horn-based systems like the offerings from Edgarhorn, Classic Audio Reproductions, eXemplar, Pi Speakers, Zingali, SP Technologies, and the Klipsch Heritage line. [disclaimer - I sell two of the brands mentioned here]. But dealing with a 1600 square foot room with 16 foot ceilings is a nice problem to have.

Well, them's my thoughs.

Duke

Billhound,
1200 s.f. is absolutely huge. about as big as my whole house. I'm listening to my Shahinian Diapasons in a 12x15 room with 9 ft ceilings and they sound great- wicked bass node however. I know Richard Shahinian has his Diapasons set up in a very large room with high ceilings- kind of a factory type setting from what i have been told. By all accounts his setup sounds spectacular.
They must sound pretty darn good outside as well. A fellow by the name of Carl Salerno who used to sell Shahinians near Kenosha Wisconsin had a pair playing outside of his home on Lake Michigan. The neighbors stopped by thinking he had live musicians in his back yard.
The Diapasons have massive power handling. something like 800 watts I believe. These things really can approach the energy created by a live band.
As far as the reflective walls and floors go, I would suspect this room could have problems. Rooms that are too highly reflective can be a pain. In my experience, if peoples voices become muddled due to all the reflections, then your speakers are going to have problems also.

Hi Guys, Just dropped in to see this thread still going.

Lot of interesting ideas floating around, but the concept of "dispersion" mimicking instrument size, or cone size making an instrument sound larger is slightly off the mark.

Must be a visual thing. That is, we are comparing it to how we "see" things.

That is not how recorded stereo sound works at all.

Recorded sound is more like a three gun projector that has three beams that have to be perfectly converged to form a visual image. In the case of stereo, it is two "sonic projecting guns" that have to be converged to form a sonic image for the ear brain.

It the "projectors guns" are diffused and dispersed, the visual image is blurry and washed out. If they are clear and focused, they form a highly resolved and detailed image on the screen.

Wide dispersion from a speaker does not have anything to do with the way you hear it unless your ears are 3 feet wide on each side of your head.

Spreading the sound out 90 degrees, 180 degrees or 360 degrees, will not cause it to sound like the real instrument since your ears only sample TWO "very small" samples. And that image is formed by sampling 2 signals that combine to make the image.

The illusion or "confusion" is related to perceiving that we somehow hear recorded sound from stereo, as we do a live event.

We don't.

In real life, we have millions of sound sources coming in from any and all angles. In stereo, we have 2. Trying to make (disperse) the 2 into that million is not only futile, but impossible.

This is an attempt to "disassemble" the two signals, by sending them all over the place to somehow be reassembled at you ear.

Taking these two samples and trying to make them disperse into some sonic spray, and expecting that this spray will then gel into a soundstage, won't happen.

Now don't get me wrong, it can sound beautiful, but it really won't do what most are thinking.

The Bose 901s developed by Dr Amar Bose in the late 60s, tried to perform this by firing all that info into a reflective surface (wall) and using that dispersion and about 17-22% direct sound to give the mirage of a "sonic projection with direction".

Few use them any more.

Regarding Anechoic Chambers.

I have built and used many anechoic chambers, and was thinking at one time about building a small 7' x 7' x 6' chamber to sell to audiophiles who might find them fun to assemble and use in apartments or other applications where they wanted to listen at concert levels, without disturbing neighbors or whatever.

They could be placed in large closets, garages, basements, attics or where have you and the sound would be unbeleivable. Even modest equipment yeilded some very impressive, realistic, listening.

The sonic virtues of this type of listening has not been experienced by many, and I can only say the you can place yourself into a live recording far deeper than any other listening environment.

I have been there many times. I currently use a "modified" LEDE type room which also works well for most purposes.

Don't make the mistake of visiting JBL or some speaker company's chamber, (designed to measure speaker sound only) and think you know what anechoic listening really is.

But in any event, I just wanted to "sound off" on the dispersion issue. The point being that any dispersion any wider than your ear is not used in the ear/brain recreation, unless it has hit a surface and becomes a reflection, and then as someone else has stated it is a "distortion". A distortion is any thing other than the original signal that has be added to or subtracted from the original.

In the standard listening room we probably have a "very high" % of reflected sound/distortion. I mean it could be 40% or so. Imagine buying an amp that had 40% distortion!!

And as a final thought, many seem to read the scientific literature written by well respected Acoustic Engineers and researchers and "mis" interpret the info, and worse yet many well credentialed Acousticians,and experts do the same thing.

While physics and acoustics are "in stone" as to their properties and principles, their applications to venues and reproduction environment are "VERY" different.

The largest and main difference is that in a "performance venue" the space is designed or treated to "USE" the environment. Devices like diffusors and such "are" valuable to acheiving a good even covering of the original space.

In the "reproduction environment" that is not the case.

Anyone who confuses the two will never hear what is on the recording from the original venue.

Again, this is not a problem if you like the "sound shaping" you are doing. I certainly used to.....Until I heard about 90% of the real thing, and I haven't been the same since (OK no jokes)

I hope that all makes sense, and I also trust that those who are ecstatically happy with their sound do not take offense. It is just physics and acoustics, and beleive it or not, you're as much an expert as the next guy, cause you know what you like.

And that is what counts.