I use harmonic tech pro 9 bi-wire with 2.9's and a Classe CA200. They go for around $450-$500 used so may be a little more than you want to spend. Before I got these I was using original monster cable. The improvement with the new cables was huge. Much more detail, depth, and tighter base.
Recommended cables for NHT 2.9
I'm looking for smooth, mellow speaker cables ($200 and under - used) that would work well with the NHT 2.9. I've read that the MIT Terminator is good (and I may get the T2 biwire), but I'd like more opinions. Presently I'm using cheap, old $1.75-ft Monster Cable in a bi-wire configuration from a Counterpoint SA-220. The cables are 4ft long on either side. Thanks for your help ;-)