If 1% of the sound is absorbed at each reflection then the more often the sound impinges on the surfaces the faster it will decay. Its so obvious that I cannot believe you continue to argue this point.
RT60 == V/Sa where V = volume, S = surface area. Consider a square room. V = L^3, S = 6 x L^2, RT60== L/6a. Smaller rooms have shorter RT60.
(Note: == means goes like)
(Note: == means goes like)
But the smaller (domestic) room will almost always have a greater amount of absorptive furniture, drapes, rugs, human bodies than a larger room. The reflections off boundaries are more likely to run into absorptive objects. Empty rooms are pretty much of no interest.
Did a few runs, my impression:
1. The voice seemed a bit clearer than the previous.
2. The overall pans seem more obvious than the previous.
3. Pan to the right side did not seem as much as to the left.
4. The all pan seem to pan widest, the hi pan second, the low pan third. Since I was not listening in this order, I checked which files they were as I was writing this.
Wonder what others heard.
That calculation assumes a diffuse sound field which doesn't exist in acoustically small rooms.
Thanks for your feedback.
Possible. These files were split with a 48dB/octave filter. Previous files used 60dB/octave. I worked in 24 bit this time until reduction to MP3
They should be. More panning, delay added to the far track and it's a static pan, no sliding pans.
Yes, done on purpose to see if anyone noticed. You did. 🙂
The "all pan" should sound widest, because the entire spectrum is panned.
The other two may depend on your system, your room and your ears. I leave this for further comments.
So your saying that larger rooms decay faster than smaller rooms - the same false claim that John is refuting? Otherwise what point are you trying to make?
Earl,
Given a sound source with a fixed output spl wouldn't the square of the distance from the source have much to do with the attenuation of sound? So in a smaller room the distances would be shorter and the volume of air allowing for dissipation would be lower wouldn't that still hold true. This would be apart from the losses into the membranes, the walls and floor, or do we consider in a room that only the membrane absorption is causing attenuation?
Given a sound source with a fixed output spl wouldn't the square of the distance from the source have much to do with the attenuation of sound? So in a smaller room the distances would be shorter and the volume of air allowing for dissipation would be lower wouldn't that still hold true. This would be apart from the losses into the membranes, the walls and floor, or do we consider in a room that only the membrane absorption is causing attenuation?
The only way that sound power is disipated in a room is at the boundaries. (There is a small amount of air absorption at HFs but this is not significant and would be a constant independent of room size anyways.) If no energy is removed at the boundaries then the sound power is constant and the room SPL will not decay. The faster energy is removed at the bondaries the faster the decay. For a given absorption rate the more often the boundary is impinged upon the faster the energy is disipated. The smaller the room the more often the walls are hit in a given period of time. This is fundamental room acoustics - there is nothing complicated or magical about it. Simple math.
Thank you Earl,
I understand what you are saying. I was trying to equate this with a unbounded situation with attenuation outside with no walls. I see what you are saying and it makes sense that the boundary layer is the attenuation source in a room at lower frequencies.
I understand what you are saying. I was trying to equate this with a unbounded situation with attenuation outside with no walls. I see what you are saying and it makes sense that the boundary layer is the attenuation source in a room at lower frequencies.
Pano, when I said "panning is more obvious", my point was it was more focused to the side. In the previous files, they were not so well focused.
Yes. I made the panning much more obvious by using more amplitude difference and added delay. I thought the first batch of files was too subtle.
Thanks for clarifying your previous statement
which was at least misleading if not simply incorrect.
But that is simply incorrect. Sound power in a room can be dissipated (as Bill pointed out) by "contents", be they furnishings, people, or deliberate "traps". And air absorption is function of path length, and thus not "independent of room size".
What you have done here is shifted from a (questionable) statement about "absorption" to one about "decay time". Maybe that's what you meant in the first place . . . but it's not what you said.
There is no diffuse sound field in acoustically small rooms. That's not criticism but physics, no?
Lets compare an acoustically small room with an acoustically large room. Perfectly air tight and perfectly rigid walls. How does decay at each frequency look like?
But this has nothing to do with the question. And diffuse is not a yes or no situation, it is a continuum. There are some frequencies at some locations in any room that are more diffuse than others. Reverb chambers can be quite diffuse and quite small.
"At each frequency" doesn't matter, they would all be the same in this hypothetical ideal situation. There would be no decay and both rooms would reach a completely diffuse situation (except in the modal regime) at a constant SPL.
The reason that a small room is less diffuse than a big room is precisely because it decays faster - it can't become diffuse.
Did you use the same delay for pans both ways? In my memory, right side focus was not as well as the left side. I could not be sure whether it was the music original or not because the same part was always panned to the same side.
Really!? Are you serious? I am not the one who has shifted position here. You are seriously backpedaling to try and justify a dumb position. Go back and read what you said.
I'm done with this argument its too ridiculous to warrant any more discussion.
I am afraid listening capability may be too personal for people to handle here.😀
Let's see what happens bumping it again.