room modes

[Basil Rush]

My room sound ... i've got a gaping wound at 100hz :/ Think I might need to fix it ... this was white noise recorded from the mix position. If I play a 100Hz sound and walk around the room there are places where I can't hear it and places where it's screamingly loud.

The next big dip is 500hz then two at 850hz and 950hz in close proximity.

Gonna have to fix this now i've looked into it in enough detail to know how bad it is. Any top suggestions? Otherwise I might try some auralex bass traps for starters...

http://www.myfirste.com/whitenoise.JPG[/img]

[DJZeMig_L]

bro definatly take these plots 2 some1 who know abotu this stuff also a pic/ drawing of yer studio...

basstraps tuned 2 100Hz seem necessary, maybe some scatterboxes for the rest of the problematic freq. or just find ways 2 break the eveness in yer room... I used some drapes that dryed it out a bit but totally helped!

Z

[sash]

throw everything soft u have into the corners of your room (pillows, blankets, cats n rabbits etc..). that'll help.

[Basil Rush]

my neighbours have some rabbits ... mmmm ....

[sash]

basil rush - Yep...they will do. I was just wonderin how you brought up that graph in sound forge. im using sound forge 6.0. I've seen that page b4 but i can't bring anything up on it, even when ive got an audio track on the main page.What do u mean 'white noise'? Room ambience?

[Basil Rush]

white noise as in i just played back some white noise really loud out the speakers, stuck the microphone where my head usually is and recorded 10 seconds into sound forge. Then (Sound Forge 7) I choose the spectrum analyser from the View menu and selected a bigish section of the recording.

[Patrick DSP]

did you try to take readings 1 meter to the left or right or front and back

my guess is you have some wicked reflection/phasing/cancelation going on. bass traps would help with 100hz but not as much on the 500 and 897hz areas.

try re-arranging your room better. what are the dimentions/materials of the room?

do you get the same spectragraph reading at lower volumes? my guess is no.

[Basil Rush]

mm, not tried lower levels why do you suspect it'd be different?

the 100hz problem changes insanely dramatically as you move around the room tried playing a 100hz sine wave and walking around and stanging on things.

i'm guess the wiggly line is to do with early reflections comb filtering at higher freqencies

[Barely Human]

This may sound like a dumb question, but what microphone did you record it with??? It can have a huge affect on the results...

[Patrick DSP]

it sounds like reflections to me,

the cheapest way around it, is to make it sound good to you and where you work. so try moving your studio around the room. it only needs to sound good where your head is, so why waste money trying to make it sound good in a bad spot? unless you have clients coming in and you're being hired a lot.

[Basil Rush]

bit restricted by things in the room for much movement.

I'm wondering if the silly dip at 100Hz might be something to do with boundary interference from the sound off the wall behind the speakers.

I can probably move the speakers about 6" in any direction without having to do 6 hours work dismantling things. Will see if this affects it. Can't imagine its' going to have much effect on the ragged top end of my graph but be interesting to see the bottom end.

On the other hand I'm hearing the 100hz change dramatically around the room so that sounds like room modes to me. maybe i've just got the speakers at a position that's particuarly good for exciting my room...

I hate room acoustics, shame i can't just shift all the kit outside...