These are cheap and very functional. Made for computers they can be used with amplifiers as well. Other models there as well (thermo, color etc) if you browse some through the site.

You will need to do something with the power source though since they are 12 V DC and have some funny plug-ins. On the other hand, AC ones I have heard to be very noisy.

Axiom M60s, QS4s, VP100 Onkyo TX-SR804 Oppo 970HD Rotel RB-1080/RCD-1072 REL Q150E sub, PS 3