Speaker Imaging - Do you hear a line, or do you hear an arc??


Hi Everyone,

I am not trolling, I genuinely am interested in your experiences.


When listening to a system you feel images well, how do you perceive the sound stage? Do you perceive it as a rectangular space on which the speakers sit, or does it sound like an arc, going further back towards the middle?


Please give examples with music and speakers if you have the time.


Thanks,
Erik
erik_squires
A fair number of LPs/CDs contain a photo of the group/orchestra playing while being recorded.
When listening to the recording, have you been able to correlated what you hear with what you see?
Only valid if the recording is mic'd stereo. If the session has several microphones, all bets are off there is any correlation, but some multi-mic sessions could be correctly panned and mixed to reflect player positions.

Mic-per-chair orchestra recordings don't usually image well and suffer the additional defect of 'strolling' wherein the perspective changes when a player or section is featured.
While I agree with the room and speaker placement within it doesn't explain the differences in imaging from different speakers placed in the same place. The revel salon 2's were the most particular in my room, imaging was always recording dependent, but the soundstage was elusive with them. the big ushers imaged wide and deep but very little height. the revel f52 were the most intimate imaging speakers i've ever had in this room placing singers and instruments solidly in space while capturing panning effects intensely. There's been several quality speakers down here with their own personality,   the current residents manage to erase the walls and put me in the middle of the performance.  Roger waters, amused to death for example the phase thing had different results with each speaker. A speakers ability to capture my imagination and allow me to create the image can hide many other shortcomings and I don't know if there's a measurement for it yet.
The basics are pretty simple, in my experience and based on audio science.  I've been fortunate to be able to experiment with a wonderful array of spaces:

*  Sidewalls -  the closer they are to the speakers the more your image is anchored on the speakers while forming a "U" between the speakers (speaker output is reinforced with short delay reflections).  For best imaging, you should for all intents and purposes have no side walls within many, many feet of the speakers.

*  Wall behind speakers:  The further away, the more "depth" you will perceive when it is recorded on the recording.  The closer behind, the less depth.  (Of course, you have also to pay attention to room nodes for accurate bass reproduction.)

*  Prevention of center "cross-contamination".  Experiment with center reflections from the wall behind the speaker.  To experiment, put a six foot high stack of empty boxes with one corner ("v") centered and facing out behind the speakers.  This breaks up reflected diffusion from between the speakers.  In a real room, this can be approximated many ways, including a "v" shaped two panel screen if needed.

This is the simplified basic.  It can be approximated different ways with room treatments.  If you are lucky, you can even arrange a living room this way.
Harrylavo made some excellent recommendations, if I may paraphrase:

- We want to minimize the early sidewall reflections, ideally with distance.

- We want to minimize the early reflections off the wall behind the speakers, again ideally with distance.

- We want to re-direct the early reflections off the wall behind the speakers so that they don’t bounce directly towards the listening area.

If I understand correctly, the idea is to manage early reflections in a way that reduces what might be called "small room signature". By that term, I mean the aural impression of being in a small acoustic space, rather than in the acoustic space (or "soundstage") on the recording. (Notice Harry is not advocating absorbing these potentially detrimental early reflections - I’ll come back to why his is such a good idea in a minute.)

There is in effect a competition between the acoustic signature of your listening room and the soundstage on the recording. The acoustic signature of the room is primarily conveyed by the first reflections, and the acoustic signature of the (typically much larger) recording venue is primarily conveyed by later-arriving reflections. Notice this key aspect of harrylavo’s recommendations: He is NOT using absorption, so he is PRESERVING the beneficial late-arrival reflections! (In particular, he is preserving the SPECTRAL BALANCE of these late-arrival reflections).

How is the ear/brain system able to pick out these soundstage-signature reflections on the recording from the later-arrival reflections that come from all around the room?   By matching the spectral balance of these reflections with the spectral balance of the first-arrival sounds.  Thus it is important that these reflections be spectrally correct, or nearly so. To the extent that absorption alters the spectral balance of reflections by selectively absorbing shorter wavelengths, it is weakening the soundstage signature we’d like to enjoy.

I’m not saying that absorption is always a bad idea, and often it makes a worthwhile net improvement, but if we can find a benign acoustic solution to detrimental early reflections - like harrylavo’s recommendations - ime that facilitates hearing the soundstage on the recording. Not to mention the richer timbre we get from a well-energized reverberant field.

So imo the more we can do to minimize small room signature without degrading beneficial late-arrival reflections along the way, the closer we can hope to approach that elusive "you are there" kind of presentation.

Duke
the closer they are to the speakers the more your image is anchored on the
speakers while forming a "U" between the speakers (speaker output is reinforced with short delay reflections).



That's probably at least partly my issue.  << sigh >>