help me understand sound waves!

  • Thread starter Thread starter drossfile
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drossfile

drossfile

nope
my drum mics go through a mixer. with faders at unity gain, it seems that i use very little of the gain on the preamps before i start peaking, so my signal-to-noise ratio just sucks. my room is small, the walls are clay tile blocks, and the whole damn thing is untreated (except for the carpeted floor--whoopdy shit).

i'm wondering: because i have so many reflected sound waves flying around, do my mics receive these reflections as additional vibrations and are therefore getting "too much information?" if i treat the room so that reflections are being absorbed, will that actually make the sound that the mics are receiving "quieter" (and as a result cleaner), thus allowing me to add more gain and getting my signals further above the noise floor?

i'm planning on making several acoustic panels out of mineral wool insulation, but i'm wondering if my premise here is correct. i'd hate to pour all the time and effort into making the traps/clouds/etc and find i'm still in the exact same situation...

please help me understand this better! i've searched, i've read, i just want to verify that i'm on the right track. thanks!
 
Yes - treating the room should make the room sound better. Acoustic treatment done correctly leads to a neutral and balanced sounding space.

I'm not an expert by any means (look for posts by Rod Gervais for that), but here's my understanding:
If your room is all hard surfaces, is small, and the walls are all parallel to each other - then your probably getting a lot of standing waves at multiple low (and maybe some high) frequencies and possibly some flutter echo and/or comb filtering. The result is going to be a lot of indirect sound bouncing sound that is only miliseconds (or less) away from the direct sound, and certain frequencies (especially lower ones) are going to be enhanced or diminsihed as a result (neither in a good way).

Bass traps (see ethan winer's site for more info), some absorption (studio foam, rockwool, fiberglass, etc) and some diffusion (scattering the sound waves, non parallel surfaces) should help create a better sounding space in most untreated rooms. Knowing where to put the stuff is a little harder - but if the room is small - you don't have a lot of options.

Other important things to consider are properly tuned drums and close micing in a small space.
 
Yes - treating the room should make the room sound better. Acoustic treatment done correctly leads to a neutral and balanced sounding space.

I'm not an expert by any means (look for posts by Rod Gervais for that), but here's my understanding:
If your room is all hard surfaces, is small, and the walls are all parallel to each other - then your probably getting a lot of standing waves at multiple low (and maybe some high) frequencies and possibly some flutter echo and/or comb filtering. The result is going to be a lot of indirect sound bouncing sound that is only miliseconds (or less) away from the direct sound, and certain frequencies (especially lower ones) are going to be enhanced or diminsihed as a result (neither in a good way).

Bass traps (see ethan winer's site for more info), some absorption (studio foam, rockwool, fiberglass, etc) and some diffusion (scattering the sound waves, non parallel surfaces) should help create a better sounding space in most untreated rooms. Knowing where to put the stuff is a little harder - but if the room is small - you don't have a lot of options.

Other important things to consider are properly tuned drums and close micing in a small space.

well, i currently have pearl exports which are tuned as well as those pieces of crap can be. my spankin' new custom tama starclassic performer should be arriving in 2 months at the latest and will vastly improve the sound source, so there's a start anyway.

bubbagump wrote an article awhile back and this is what i plan on doing for bass traps:

http://audiominds.com/forums/index.php?showtopic=3320

plus i was going to make 2" versions for walls and celings.

but is my premise correct regarding my signal levels?
 
my drum mics go through a mixer. with faders at unity gain, it seems that i use very little of the gain on the preamps before i start peaking, so my signal-to-noise ratio just sucks.
Not having to use a lot of gain will make your signal to noise ratio better, not worse.


i'm wondering: because i have so many reflected sound waves flying around, do my mics receive these reflections as additional vibrations and are therefore getting "too much information?" if i treat the room so that reflections are being absorbed, will that actually make the sound that the mics are receiving "quieter" (and as a result cleaner), thus allowing me to add more gain and getting my signals further above the noise floor?
Absorbing the reflections will clean up the signal because you will only be picking up what you are micing, not all the other garbage in the room. You will not be able to turn up the gain-and you wouldn't want to.

i'm planning on making several acoustic panels out of mineral wool insulation, but i'm wondering if my premise here is correct. i'd hate to pour all the time and effort into making the traps/clouds/etc and find i'm still in the exact same situation...

please help me understand this better! i've searched, i've read, i just want to verify that i'm on the right track. thanks!
What you are planning to do will make the recordings sound better, just not for the reason you thought. It's not a waste of time.
 
thanks farview!
so, ideally i want my faders as close to unity gain as possible and my preamps all the way down? is there any difference between gain at the fader stage (above 0) and gain at the preamp pot? i suppose that depends on the design of each stage...
 
so, ideally i want my faders as close to unity gain as possible and my preamps all the way down?
Yes. In this instance, anyway. You want your fader at unity so that you can set your preamp control so the signal is at line level. how much gain that will take depends entirely on the volume of what you are recording and the sensitivity of the mic.

is there any difference between gain at the fader stage (above 0) and gain at the preamp pot?
Yes, the preamp control sets the level for the rest of the chain. This includes the insert, EQ, and aux sends. The fader is meant to adjust the relative level between tracks.

You want the preamp control to set the signal to line level (whatever that setting needs to be) so that the rest of the signal chain is running in it's sweet spot, where the signal to noise is the best and the distortion is the lowest. Then, when you are mixing, you adjust the faders to get everything to sit right.
 
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