Rothwell In-Line Attenuators?

It's just a couple of passive parts so there is no reason it wouldn't be.

If it solves your problem (I'm assuming too much overall gain) and you otherwise are happy with your system then I think they are good way to go. If you can solder you can build your own for about $5 worth of stuff from Radio Shack.

I'm using a pair on one of my amps to lower the gain from the pre-amp. Can't tell they are in the loop.

I've used them with good results to lower gain.