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Perceptual Effects of Room Reflections

Jack B

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It's entirely possible that I've become so senile that I remember it backwards. :)
Hello all! Just discovered this discussion a coupla days ago, been reading and ruminating on it in my own way (being a Bear of Very Little Brain). I want to thank everyone for their contributions. So far I'm in the camp of liking early reflections in my small (and overly-live) room, but I agree the trade-off is losing pin-point imaging. Don't mind, cause I'm the guy who sits halfway back in the concert hall to hear the "hall sound".
 

pozz

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Interesting question, isn't it? The brain is pretty good at filling in dips above the Schroeder Frequency (and to some extent, even below). It has to be, because room reflections cause all kinds of comb filtering. It's known that peaks are more audible than dips, and high Q filters more than low Q ones. But I don't know how deeply your question has been studied. If anyone does, I'd be curious to know.
The brain doesn't fill anything in. Seriously it doesn't. It averages the power response across some time period per auditory filter.
 

dasdoing

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I have been wondering, if you run music through two filters like this and then ABCX those, which will sound closer to the original?

a.jpg


"obviously the red is closer", you might think.
BUT the same filters on var smoothing look like this:

b.jpg


so acording to the perceptional smoothing theory the blue filtered one should be closer to original
 

srrxr71

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Humm, I wonder if we could get some room measurements on some of these. :eek:
http://www.highendnovum.de/en/
Paul McGowan wrote in his blog: "...placed between your speakers, it stares back at you like some piece of Asian dinnerware or ornament. But holy cow, it works! Immediately, vocals get more lifelike, the sound sweeter and easier to listen to..."

Slide11s.jpg
Oh my gosh. You found the brass bowls that my acoustician mentioned. Haha what a great laugh these. Paul is a true clown.
 

fpitas

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Hello all! Just discovered this discussion a coupla days ago, been reading and ruminating on it in my own way (being a Bear of Very Little Brain). I want to thank everyone for their contributions. So far I'm in the camp of liking early reflections in my small (and overly-live) room, but I agree the trade-off is losing pin-point imaging. Don't mind, cause I'm the guy who sits halfway back in the concert hall to hear the "hall sound".
It's certainly down to preference. I have tons of absorption in my room, including ceiling absorbers and acoustic panels to each side of my speakers. Even just walking into the room gives a "hushed" feeling. I like it.
 

srrxr71

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It's certainly down to preference. I have tons of absorption in my room, including ceiling absorbers and acoustic panels to each side of my speakers. Even just walking into the room gives a "hushed" feeling. I like it.
I’ve got the same going on. So quiet in my listening space.
 

fpitas

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I’ve got the same going on. So quiet in my listening space.
Even Toole's data using audio professionals was equivocal. When I've been in control rooms, I greatly enjoyed the ambience. That clued me in.
 

MRC01

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It's certainly down to preference. I have tons of absorption in my room, including ceiling absorbers and acoustic panels to each side of my speakers. Even just walking into the room gives a "hushed" feeling. I like it.
I’ve got the same going on. So quiet in my listening space.
Same here. As soon as you walk into the listening room you can hear the difference. And measurements, especially CSD, show it. I've always loved how such a room presents music with such clarity. The room disappears and you hear the recording itself. If the recording is medium distant miced capturing room effect, you can hear whether they're in a stone cathedral, a symphonic hall, a smaller room, etc. If it's close miced and dry then you hear a completely different perspective.

I also like what you don't hear: your own room's reflections superimposed on the recording. I understand many people prefer this but it's not for me.
 

dasdoing

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the whole lower plane of my room is 80%-ish absorbive. above 1,20m it's mostly live though. never had that creepy feeling. my girlfriend complained in the beginning though claiming she feels "deaf" when coming in. that lasted for a week or so only though.
 

fpitas

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Same here. As soon as you walk into the listening room you can hear the difference. And measurements, especially CSD, show it. I've always loved how such a room presents music with such clarity. The room disappears and you hear the recording itself. If the recording is medium distant miced capturing room effect, you can hear whether they're in a stone cathedral, a symphonic hall, a smaller room, etc. If it's close miced and dry then you hear a completely different perspective.

I also like what you don't hear: your own room's reflections superimposed on the recording. I understand many people prefer this but it's not for me.
Yes, I'm trying to reproduce the recording, not introduce special effects of my own.
 

fpitas

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the whole lower plane of my room is 80%-ish absorbive. above 1,20m it's mostly live though. never had that creepy feeling. my girlfriend complained in the beginning though claiming she feels "deaf" when coming in. that lasted for a week or so only though.
Some people get it bad. No idea why.
 

srrxr71

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Same here. As soon as you walk into the listening room you can hear the difference. And measurements, especially CSD, show it. I've always loved how such a room presents music with such clarity. The room disappears and you hear the recording itself. If the recording is medium distant miced capturing room effect, you can hear whether they're in a stone cathedral, a symphonic hall, a smaller room, etc. If it's close miced and dry then you hear a completely different perspective.

I also like what you don't hear: your own room's reflections superimposed on the recording. I understand many people prefer this but it's not for me.
Yes exactly. Each recording brings its space to me.

I will be adding some absorption/diffusion to the rear wall. But the front and sides are all absorptive. I might play with the left wall a bit just to compare. There is already enough leaking out even with a a heavily absorptive room. The panels might -10dB at best. That’s actually perfect to cut early reflections down -10dB. It’s not all getting absorbed. Just the right amount.
 

dasdoing

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Yep. And to hear dialog in movies, even at low levels or when sounds in the movie mask it. And song lyrics, for that matter.

also works wonders changing to the treatred room while having a loud argument with a girlfriend/wife lol
I always called her in order for the neighbours to hear less, but I percieved that we automaticly got less loud, too....and therefore less agressive, too
 

Sal1950

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It's certainly down to preference. I have tons of absorption in my room, including ceiling absorbers and acoustic panels to each side of my speakers. Even just walking into the room gives a "hushed" feeling. I like it.
Mine's close to that. I'd like to get a little more in here but places to put it are limited.
 

srrxr71

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also works wonders changing to the treatred room while having a loud argument with a girlfriend/wife lol
I always called her in order for the neighbours to hear less, but I percieved that we automaticly got less loud, too....and therefore less agressive, too
I solved that problem at the source. Haha.
 

srrxr71

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So basically according to Genelec early reflections should be down 10dB. Late reflections half of that about -3dB down. That creates a sufficient quality room for dialog intelligibility. Definitely made a difference as I got to that number. You cannot imagine it until you try it.

I have seen reports with far more absorption than that. Pretty incredible. I’m just aimed for slightly more than the minimum. Balance and all that.
 
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