Hi all,
Does anybody have any useful info on how to test the audio in your room please? I'd like to do a bit of room treatment as a DIY project, but I'm having difficulty tracking down good testing files. Not much point in rushing into trying to solve the problems without getting a clear idea of what they actually are first. I also need a tool to keep assessing how successful the attempts are, otherwise I risk fixing one thing whilst simultaneously screwing up another... :wink: .
I know that my attic room - like any home recording situation - gives erratic responses across different frequencies, but I'm not sure how to accurately assess exactly where and when. I can find plenty of suggestions about how to build bass traps, and panels to absorb or otherwise tinker with the sounds, but very little on how to test what you've done.
If I use the LFSineTones file found here Some test files at the site for Mike Senior's book I can hear quite clearly that some of those low frequencies appear to drop down or build up in volume. But the effect is due entirely to the room accoustics. If I play the file over headphones it's dead even.
Obviously there's a huge range of possibilities - just imagine the difference between a bass guitar and a banjo for instance - but I don't know how to test the full range. Some sort of file like the bass one seems logical, but where to find such a thing? Would they be hard to make for yourself using something like a synth, or actual instrument samples, or....????
Anybody had any experience of doing home room treatments?
Thanks,
Chris
Based on what I've heard of and seen (apply salt as necessary), I would expect using a spectrum analyzer and a high quality microphone to measure various locations in the room, while playing a broad-spectrum sound, usually white or pink noise.
The setups I have seen have the noise generator and analyzer in the same device.
I've seen it done for live PA systems, where they play the noise thru the PA, and measure with the mic near the sound board, then adjust the system's graphic EQ to flatten out the display on the analyzer.
This makes the room sound "flat" at the location where the measurement mic was.
For a studio application, I suspect you'd play the sound thru a "known flat" speaker, at the location the musician would stand, then measure ... somewhere nearby. Or in various locations... (here's where the grains of salt should be applied to my advice)
There are software noise generators and spectrum analyzers that you can download.
Or as another option, analyzers and calibrated mics can be rented from better PA rental shops (not the places that rent to party DJs, but rather to larger touring acts)
I wrapped a newspaper ’round my head
So I looked like I was deep
Thanks very much mate. :)
Good to get some more relevant terms to Google.'Spectrum analyzer' sounds like the shot. I put a similar post up at a studio designer's forum and one of the members directed me to a utility called REW (Room EQ Wizard) and I think it does something very like what you suggested.
I was advised to set a mic up on a stand exactly where my head would be if I were mixing, and then to run some of the tests. The further advice was to mark the precise spot (maybe with a plumb bob) so that I could put it all back exactly for testing again after I've tried installing something. Sounds like a good way to go.
I've also found some 'pink noise' test files, so I think that my next step is to move the desk round so that it faces the right way down the room, and then spend a day or two reading instructions...
Cheers,
Chris
Ethan Winer has some good stuff on tuning a room.
Playing guitar and never playing for others is like studying medicine and never working in a clinic.
Thanks for the link Moonrider.
I've been checking out Ethan Winer's site, and a few others, and can find lot of advice on the construction and design aspects, but not very much on audio tetsing. At least not that I can actually comprehend yet! :wink: More study required...
Cheers,
Chris
