"They are here" vs. "You are there"

Hi Bryon,

As someone who listens primarily to classical music, my goal is to duplicate as closely as possible the experience of hearing a live performance from a good seat in a good hall (less extraneous sounds from the audience or other sources, of course). Therefore I am in the "you are there" camp.

I particularly second the comments by CWLondon, and, for the most part, the excellent analysis in your previous post.

The one exception I would take concerns item no. 2. I doubt that it is typically possible for the acoustics of the listening room to resemble those of the recording space in any meaningful way (assuming the recording space is a hall), because the dimensions (and hence the delay times between direct and reflected sound) are so vastly different.

I would therefore comingle your references to listening room characteristics (under item 2) with the thoughts you expressed regarding equipment, under item 3. In other words the overall combination of room acoustics and equipment should be as neutral as possible, to make the listening experience as "you are there" as possible.

Best regards,
-- Al

Hi Newbee,

Interesting questions.

My understanding has been that "forward" vs. "backward" is essentially a different issue than "they are here" vs. "you are there."

My understanding has been that "forward" and "backward" are primarily matters of emphasis or de-emphasis of mid-range frequencies, relative to highs and lows. That is why in the old days mid-range tone controls were commonly labeled "presence" controls.

While "they are here" vs. "you are there" is primarily a matter, as Bryon indicated, of the proportion of direct vs. reflected sound, which brings time relationships (as opposed to frequency response) heavily into play.

Therefore I agree with the ideas that have been expressed about mic placement and mic characteristics. Those factors, and their relationship to the hall size and its acoustic characteristics, would figure to be the key factors in how realistically hall ambience is reproduced. Assuming, that is, that subsequent processing is not overdone to the point of messing up what the mics have captured.

Best regards,
-- Al

Rather than relying on equipment colorations to enhance ambient cues, it seems to me that there is far better way to hear the ambient cues on a recording, and thus to contribute to the illusion that “you are there,” and that is by increasing RESOLUTION.

Increasing resolution is not the same thing as increasing “perceived detail,” since the latter may be increased, as you pointed out, by changing a system’s frequency response (i.e. making the system brighter). Increasing resolution is a matter of increasing either (1) format resolution, or (2) equipment resolution. Which brings me back to my view on the relation between equipment colorations and ambient cues...

I believe that equipment colorations tend to reduce equipment resolution, and hence to obscure ambient cues. Conversely, the reduction of colorations tends to increase resolution, thereby increasing the perceptibility of ambient cues and contributing to the illusion that “you are there.”

I am in basic agreement with this, and with respect to the reproduction of classical music as recorded in a hall, I would add more specifically that a very key factor seems to me to be what might be referred to as resolution in the time domain.

A notable example would be a speaker having sloppy transient response, whose output tends not to stop as immediately as it should when a sharp transient concludes. Such a speaker will tend to obscure the reflected energy that had been picked up by the microphones some tens of milliseconds after the arrival of the directly captured sound.

Which leads me to suggest, with respect to this comment:

Imagine for the moment that your preference in classical music were confined to orchestral music. In that case, I believe that you would be more likely to create the illusion that “you are there” with a large listening room with a high level of diffusion and a medium to long-ish reverberation time.

... that perhaps the reason such a room would enhance the "you are there" illusion for classical music is not because its large dimensions produce room reflections that begin to mimic those of the hall (which in turn is far larger still), but rather because its large dimensions REDUCE the amplitude of those reflections, as heard at the listening position, thereby reducing the degree to which room acoustics obscure our ability to hear the reflected energy that the mics had captured.

In principle the same thing might be accomplished by heavily damping a small room. However, that would seem likely to result in a very different overall frequency response than would result from the large room approach, possibly introducing or affecting colorations other than the time domain effects that my comments have focused on.

Best regards,
-- Al

As a practical matter very few recordings actually have real ambient cues. This is true even in classical recordings.

That's probably true for many or most releases by the larger classical labels, whose recordings are generally heavily multi-mic'd and heavily processed. However in my experience it is usually not true in the case of smaller labels that are either audiophile-oriented or are otherwise high quality. See my post in this thread for a list of some of these labels.

As a system's resolution increases you'll hear more soundstage information, but in and of itself that information isn't really important to the enjoyment of listening to music.

FWIW, my own experience suggests otherwise. Whenever I attend a classical concert in a good hall, I am IMMEDIATELY struck by the ambient "aura" that surrounds each note, for many if not all instruments. (Perhaps "aura" isn't the best word to use, but it seems to capture what I'm trying to relate). And its absence on many recordings, or inaccuracies in its reproduction, are major factors that distinguish live music from reproduced music, in my experience.

Best regards,
-- Al

Thanks very much, Bryon. With the clarifications, qualifications, and further exposition you have provided, I find little or nothing to disagree with. Although as we both agree, a lot of what has been said remains in the realm of hypothesis, that is conceivably refutable or subject to further qualification.

When you have time to return here from the real world :-) please take a look at item 3 in my previous post, which I added in some time after initially submitting the post. I believe you may not have seen it when you composed your response, and I'd be interested in your comments on it.

Best regards,
-- Al

Thanks Bryon. Yes, you interpreted my point no. 3 as I intended it, that the inclusion of what was direct sound in the recording space in an omnidirectional listening space presentation represents a significant inaccuracy, which must be traded off against the benefits of the omnidirectional listening space presentation.

The reason you didn't see no. 3 previously is simple -- it wasn't there when you started composing your previous response :-). As I mentioned in my subsequent post, I added it in sometime after initially submitting the post to which it was added, and by that time you were obviously working on your response (as shown by the fact that you referred to the headphone part of my post as item 3, rather than item 4 which it subsequently became).

I suppose that the bottom line in the tradeoff we are referring to comes down to matters of degree, which in turn are dependent on the speakers, the constraints imposed by the particular listening space, the types of recordings that are listened to, and the preferences of the listener.

The only exception I would take with respect to your last post would be the statement that:

I believe that headphones (in the absence of a binaural recordings) illustrate that, in that headphones will give you the most ACCURATE sound of the ambient cues of the recording, but not an OMNIDIRECTIONAL presentation of those cues.

I am doubtful that on non-binaural recordings headphones can be said to give an accurate reproduction of ambient cues, or anything else, because of the fact that they bypass the pinnae, and inject the sound from the sides instead of from the front. Although of course they can be extremely revealing and analytical. And once again a tradeoff is involved, because their accuracy (in the sense that you are using the term here) is aided by the absence of room effects.

Best regards,
-- Al

I wonder whether, as a generalization, speaker designs that emphasize time-alignment are better at presenting ambient cues, all other things being equal. Do you think so?

I'm not certain, but my suspicion is "no." I would guess that lack of time alignment would not obscure ambient cues, it would just change their sonic character, in a manner comparable to its effects on the sonic character of the initial note.

I say that because of the different time scales that are involved. Given that sound propagates through air at roughly one foot per millisecond, the arrival times at the listener's ears of wavefronts that are launched from non-aligned speaker drivers would most likely differ by less than a millisecond. While reflected sound in a hall typically arrives at the microphones many milliseconds after the direct sound.

Lack of time alignment would change the timing or phase relationships between the "fundamental frequency" of a note and its overtones/harmonics, thereby affecting its sonic character, but I believe that effect would apply similarly to both directly captured and reflected sound (although of course the frequency balance of the reflected sound may differ from that of the directly captured sound).

It's interesting to note in these Wikipedia writeups on the Haas Effect and the Precedence Effect that our hearing mechanisms have thresholds demarcating different kinds of responses when similar sounds arrive at our ears with timing differences of approximately 1, 2, 5, 10, 30, 50, and 80 milliseconds.

Best regards,
-- Al

Hi Bryon,

Your last post, while of course highly thoughtful, I would have to very respectfully say strikes me as being essentially a set of hypotheses, which are subject to challenge and skepticism in several ways:

1)Along the lines of some of our discussion earlier in this thread, there is little reason to expect, in general, that omnidirectional presentation in the listening room will augment or better present the omnidirectional information that was captured in the recording space, because of the vastly different delay times that are involved. Those timing differences will cause our hearing mechanisms to respond in completely different ways, per the Haas Effect and the Precedence Effect (for which Wikipedia links are provided in one of my earlier posts).

2)There would certainly seem to be ample empirical evidence, such as in the system descriptions posted here at Audiogon, that high quality directional speakers are not necessarily at a disadvantage, relative to speakers with broad or omnidirectional dispersion characteristics, in creating a reasonably good "you are there" illusion.

3)Omnidirectional presentation in the listening space presents in an omnidirectional manner not only the reflected sound that was captured in the recording space, but also the sound that was captured in the recording space via the direct path between instrument(s) and mics. The directly captured sound, of course, having a significantly earlier arrival time at the mics. Intuitively that would seem, at best, to invoke a significant tradeoff. Among other reasons for that is the fact that the frequency response curves of our ears vary considerably as a function of the direction of the sound source.

4)It seems to me that the major problem with headphones is not that the sound is presented bidirectionally. Per my item 2 above, speakers that present bidirectionally can, at least in many circumstances, present a reasonably good "you are there" illusion. The major problems with headphones are two-fold, as I see it:

(a)The sound we hear from them essentially bypasses the pinnae, thereby altering both frequency response and directional cues.

(b)Nearly all recordings are not mic'd to be compatible with headphone listening. A recording mic'd to be properly compatible with headphone listening needs to be recorded binaurally, which as you probably are aware means it is recorded via microphone capsules inserted in the ears of a dummy human head.

I have two or three binaural recordings, and they can be truly spectacular in their "you are there" realism, when listened to with headphones. Although the degree of that realism can be expected to vary somewhat from listener to listener, corresponding (I believe) to the anatomical differences that may exist between the heads and ears of each listener and the dummy head that was used.

FWIW, I'll add that on normal stereo recordings of classical music, if they are well recorded, minimally mic'd, and minimally processed, I can clearly hear ambient cues and hall effects on my Stax headphones. They do seem somewhat less prominent than when I listen via speakers, but I suspect that is due mainly to the relatively lean sonic character of these particular headphones.

5)

So why don’t we just say that BOTH the listening room and the equipment are important factors in creating the illusion that “you are there,” though neither is as important as the recording. Or we could leave that last bit out, and just say that ALL THREE are important.

I agree with both sentences. By which I mean to imply that in general my feeling is that the recording is the most important of the three variables, at least with respect to the role that ambient cues play in "you are there" realism.

So in conclusion, I have no conclusion :-). At least, beyond what I've said earlier. But those are some thoughts that come to mind in response to your latest post.

Best regards,
-- Al