Reply to help required re: buzz in dj set-up!

Hi folks - first post, so be gentle with me

I have a DJ set-up consisting of 2 x CDJ's, 2 x turntables, a mixer and 2 x speakers.

Although the speakers themselves are giving me no issues during playback, when recording onto my computer I am left with a noticable high-pitched buzz.

Having removed all components one-by-one, recording all the while, I have isolated the problem as being the two powered monitor speakers, which are connected to the mixer via XLR cables.

The moment I plug the speakers into the power socket (the mains itself doesn't even need to be powered on) the buzz appears....

I bought a seperate two-way adapter for the speakers plugs to go into, and have even tried running the plug from a seperate socket in the other room, but to no avail.

Obviously, with the speakers being an integral part of the set-up, I can't loose them for recording purposes.

I've done a bit of google-trawling and the only thing I can find of any relevance was a suggestion to use a "ground lift adapter"... Having googled this, I notice you can get XLR adapter ground lift's - would this do the trick?

If not, any other ideas?

It's driving me mental