Omnidirectional speakers. The future?

Interesting thread, sorry I just joined in. Only a few comments, which I'll keep brief.

1. I agree in theory that the fewer room reflections the better, IF one only wants to hear what the microphones heard. However, many people want to hear more than that, and that is their prerogative. Subjectively, if added room reverb makes it sound more 'live' to you, then that's what you should be after. It's still a free country, after all.

2. The closer the listening room is to the size of the recording venue, the more 'real' the reverb is going to sound, because the reverb delay times match. Trying to recreate a full-blown concert hall sound in a den is not going to work, no matter what speakers you're using. Unless you happen to have a den the size of a concert hall, in which case you can use whatever speakers you damn well please.

3. Most people haven't ever studied room acoustics, and think that adding absorption to a room willy-nilly will make it sound 'better'. Not the case, unless you just happen to be very lucky, and often it will make it sound worse. What is really important is to (1) diffuse the reflected waves, and (2) make the in-room decay time the same at all frequencies. A much harder task, and one which requires some actual measurements and math before pasting acoustic foam all over the walls.

4. In typical small rooms, one of the biggest improvements you can make is to kill the first reflections from the side walls, back wall, floor, and ceiling. It isn't nearly as good as a dedicated room, but it's a lot better than nothing at all. Anyone who has done it will agree-- it makes the soundstage open up dramatically and vastly improves the clarity as well. Strong, early reflections are a very bad thing, far more so than diffuse, later ones.

5. As a longtime fan of the Ohms, I would say that IMO, what makes them so special is not necessarily their radiation pattern, but that they approximate the theoretical ideal of a full-range monopole transducer. Their natural spatial coherence and time/phase alignment is likely the main reason they sound so "right", far more so than their radiation pattern.

Best,
Karl

As others have stipulated, the listening room's added reflections are distortions. But we need to always keep in mind that "what the mics heard" was insufficient to represent what a human listener at the event would have perceived, and that what they did hear was judged largely based on the engineer's experience of monitoring and mastering in control rooms that are neither performance spaces nor anechoic chambers, and about what type of finished product will sound best played back in a typical home listening room through typical home speakers. A recording is not an objective 'verite' account of what happened, but a subjectively molded account derived from certain common assumptions intrinsically embedded in the production and reproduction processes - one of which is that there will be some liveliness to the listening room.

This also goes to my point about a speaker's radiation pattern and the acceptance pattern of the mics not necessarily being commensurate, but quite possibly incompatible, if we want to minmize listening room reflections by limiting dispersion (and often even if we don't). The simplistic assertion, made by some speaker manufacturers, that speaker radiation must somehow mimic microphone acceptance is further undermined by the implicit, but false, assumption that all recordings will be minimally mic'ed and that we can even know the acceptance patterns of the mics used, much less their positioning. For recordings assembled from multi-mono multi-mic'ing, and of course for electrical direct-injection into a recording console, the relationship simply doesn't exist at all. A more pertinent relationship might be that of the radiation pattern of the mixing and mastering monitors to that of the home speakers, but of course that can't be a consistent thing. In the final analysis, the best way to assess speaker radiation pattern must be subjective auditioning in the room in which they will be placed, using the kind of music which will be played through them, by the person who will be doing the listening.

About Karl's point #2, although it's true to a certain extent that if the listening room could match the recording venue, then the overlayed refections would be more "consistent", they would still be just as distorting. And the problem would be worse the larger and livelier the two rooms were. However, for smaller and relatively 'dead' rooms, I think we have some evidence in favor of this hypothesis, however unimportantly. Many of us will own some of Rudy van Gelder's vintage Blue Note jazz recordings (mono or stereo), hundreds of the earlier ones of which were taped right in his New Jersey home's furnished living room, employing minimal mic'ing. Despite the facts that these recordings are bandwidth-limited, afflicted with dynamic distortions, and subject off-axis and less-proximate instruments to premature roll-off, nevertheless many can display a scary amount of the familiar quality of sounding especially 'real' when listened to from another part of the house outside the listening room, where their flaws are not only less obvious, but where the direct and reflected room sounds have melded into one indirect sound deviod of specific spatial cues, regardless of the speakers used. In this narrow sense, these records can rather easily exceed higher-fidelity concert hall or studio recordings. My theory has long been that this is precisely because they were recorded in an acoustic environment presumably very similar to most people's playback environments. Try it sometime...

Very interesting thread with a nice range of opinions.

I'm wondering if anyone can comment on how an omni-like speaker such as a Shahinian or an Ohm might be expected to fare in a very large space- say 1200 square feet with 16' ceilings- with reflective walls and floors. Is this kind of space more or less likely to take positive advantage of the design principals behind an omni.

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.