135 Hz Bass management

Hey people,

 

I measured my studio with Room Eq Wizard, a couple of times. i don't have a measurement mic so i used one I have, in this case it's a Violet Designs Dark Knight. I know, it will add some coloration but for the low frequencies it should give me some idea of possible problems. It resulted in the following waterfall diagram.

 

 

I see 3 problems: a peak with long decay at 41 Hz and 132.5 Hz, and a big dip at around a 100 Hz. I recognize the 132,5 one, that's a frequency I regularly cut while eq'ing my bass guitar, and with kick drums. If I do a frequency sweep the peaks and dip are clearly audible.

 

The wavelength of 132,5 hz is 343 m/s (speed of sound at 20 deg) / 132,5 hz = 2,59 meter, about the height of my studio. The sidewalls of my studio are angled but my ceiling is not, so this could be the reason for a standing wave. I could tackle this issue in 2 ways: by making an angle in my ceiling (could do this with plywood) but that's a pretty radical solution, I would have to make a pretty solid construction. The other one could be absorbing this wave. So I would need to make a narrow band bass trap. Can anybody give me some direction in how to calculate this trap?

 

100 Hz dip is harder for me to explain, it could be a result of other standing waves interfering, so getting rid of the 132 one would be my first step.

 

Any help is much appreciated!

it most certainly is a result of standing waves.

What are the dimensions of your room?

fwiw, im working with an acoustic engineer, same height as you have, and tackling low end will involve 30cm thick membrane absorbers.

so the room is 440 cm long, with a partly angled back wall (it's an attick). the width is 330 cm at listening position, going to 360 in an angle.

 

so I would like to make an absorber you mention. There are several bass traps around the room, the typical Auralex corner traps and some homebrewn 6cm rockwool traps in the different cornerers. bUt these are all broadband and won't manage frequencies in the lower range.

 

How do I calculate a membrame trap for 132,5 Hz?

I bought ARC from IK multimedia, because I don't think I will be able to tame the frequencies below 100 Hz. First results are pretty good, my mixes become more transparent. the top end 'opens up' because there is more room in the spectrum somehow. I am going to work on the 135 hz peak but for now I am mixinf

hi, sorry i worked with an acoustic engineer. these things are hard to DIY.

 

fwiw, i'm not a big fan of speaker correction software such as Sonarworks or ARC.

I don't think they really work, and when you learn your headphones/speakers you will probably get more faithful mixes than some EQ mushing it up on the output.