Weird Harmonic Resonance

[Snoo]

This is a bit of an odd one. Been recording my girls band of late and found that my monitors display a horrid resonance with the bass guitar. Can't reproduce it with anything else (bass synth etc) but makes the instrument stick out like a sore thumb. At first we thought it was the instrument so we changed that for a better one but it was still there. Then after listening on headphones and hi-fi speakers I realised it only seems to manifest with my monitors (M-Audio BX5a).

Anybody got any suggestions how I can get rid of this?

[Block Party]

Have you tried a hi pass filter or notching out the resonant frequency?

How are you recording the bass? DI or via an amp?

Do other commercially released tracks cause the same problem?

[Snoo]

The only thing I get this with is live recorded bass guitar. Will try to notch it out.
It's DI'd.

[Block Party]

Ok, so it's not the room it is being recorded in. It may be your monitors, but it doesn't matter because you want the mix to translate well on any system, including your own! Try a bit of subtractive EQ to see if you can find the offending frequency. Try sweeping a parametric EQ with some gain first to help spot the frequency and then cut it. Change the width of the Q to fine tune it and see if that resolves the problem.

[resinate]

if it is only apparent on your monitors then its probably a room resonance in your mixing space.

Try some acoustic treatment, dn't have to pay for it, just getting books up around the corners if your room or thick drapes across the walls will help. Cardboard boxes piled up will help too, anythign to dampen the room a bit.

[Snoo]

I swept it with the parametric and it seems to be at 124Hz. I'm thinking it's my monitor placement though. I thought they were sealed but they are actually rear ported and both kind of backed into a corner.  I guess there's a bass trap forming.
Can't do much about that at the mo but should be moving house soon and can hopefully give them a bit more space to breathe. Thanks for the tips.