Envelopment of sound is an important subjective variable which clearly enhances the sound experience in optimized rooms.

[Neuro]

The fact is that the envelopment of sound is an important subjective variable which clearly enhances the sound perception in optimized rooms. Without envelopment a dry boring sound.
Envelopment is related to a mix of a few physical facts.
The reflections of the direct sound created in the listening room are the primary variable for creating envelopment. The reflections envelop the listener.
In headphones and in a free field/echoic chamber, there are no audible reflections of the direct sound => no perceived spatially related envelopment of the direct sound.
Not all reflections contribute to envelopment.
In the subbass dimension below 80 Hz there are reflections. The reflections create standing waves without perceived direction => no perceived spatially related envelopment of the direct sound.
If the reflections are stronger than about 12 dB than the direct sound, no direct sound is perceived. Similar to the perceived sound in a narrow cave. => maximum perceived room-related negative envelopment without perceived direct sound.
Above 500 Hz, a colored direct sound is perceived with a some envelopment.
Toole/Olive and to some extent Griesinger have shown when the envelopment is maximally positive. The dimensions of the large listening room at Harman optimize the envelopment in the listening position. Griesinger with LATS hinted at important variables.

Optimal envelopment is created by the reflections in the room.
1 Angle relative to the 0-axis of about 60 degrees.
2 Attenuation of about 8 dB.
3 Delay of about 20 ms depending on the sound type.
4 Frequency curve similar to direct sound.

In an echo-free room, reverb gives an artificial, not ok envelopment according to consensus research. No perceived optimal direction.
Stereo in an echo-free room gives no envelopment.
Mono sound in an optimal room gives good envelopment.

 

[Keith_W]

Griesinger with LATS hinted at important variables.

Optimal envelopment is created by the reflections in the room.
1 Angle relative to the 0-axis of about 60 degrees.
2 Attenuation of about 8 dB.
3 Delay of about 20 ms depending on the sound type.
4 Frequency curve similar to direct sound.

Thank you for your post. I am interested in the reference for above. I did a search for it and could not find it, but I did find a lot of other publications by Griesinger on envelopment. Here is one.

By the way, I have experimented with placing small speakers around the room and then DSP'ing them so that they have the same frequency spectrum as the main speakers. I then measured the delays, and adjusted the speakers so that the delay was 20ms and only just audible when the main system is playing. The illusion that you are in a much larger room with sound coming from all around you is quite compelling.

 

[bmc0]

I am interested in the reference for above.

I think "LATS" is supposed to be LARES, developed by David Griesinger and Steve Barbar at Lexicon.

Optimal envelopment is created by the reflections in the room. [...] 60 degrees [...] Delay of about 20 ms

You must have a very wide room

 

[Timcognito]

Seems like getting envelopment into the recording session and stored analog/digital would more important than playback? Please comment.

 

[Anton S]

Thank you for your post. I am interested in the reference for above. I did a search for it and could not find it, but I did find a lot of other publications by Griesinger on envelopment. Here is one.

By the way, I have experimented with placing small speakers around the room and then DSP'ing them so that they have the same frequency spectrum as the main speakers. I then measured the delays, and adjusted the speakers so that the delay was 20ms and only just audible when the main system is playing. The illusion that you are in a much larger room with sound coming from all around you is quite compelling.

I've come across a paper by Octávio Inácio that you may find interesting with respect to this topic. It includes a bit about envelopment in a section titled, "Room Acoustical Quality Evaluation."

> HERE < is a link to the paper on Research Gate.

 

[Flaesh]

the perceived sound in a narrow cave

Caveman Speakers. The Troglodytes.

Speakers so easy - even a caveman could build them! Prehistoric sounds. Flint knives and bearskins - almost. Here is pair of speakers I made this afternoon to go in my cave. My man cave is a real cave. This is good, as my DNA is at least 3% Neanderthal. See, a real cave right behind my...

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[ZolaIII]

Full sum +6 dB is 60 Hz and under and it's low bass not sub bass. I am sure you are aware it's possible to emulate different spaces and you can use real model and complex mathematical one's to make it feel more real. However main reason for doing that in studio is to check how it will sound in different environments not archiving some ultra realism. Some things you simply can't get in a average (small) room and almost no one has reference sized one. Main thing is back to front refractions ratio (that you can't get right). This is becoming pointless.

Erins Review of the Yamaha NS-10

What does 'decay time' actually mean to a human subject, do you have data on preference as to establish a discrimination between 'long' and 'short'? I'm not pretending to be an expert on loudspeakers, but the measurements shown in the paper I posted indicate that this speaker may have some...

www.audiosciencereview.com