I love the Ren 90's, the best I heard them was bi-amped with two big solid state Krells.
The Ren 90’s have a load presented to the amp very much like the Kappa 9’s (I was told by Trevor who measured this graph linked below).
Saying that to get the very best out of them, your Krell on the bottom is the right amp to drive that low impedance, but I think the upper mids around 5khz which is the same kind of nasty load as the low bass, and maybe an amp more like the Krell (a current pusher), only smaller (as you wouldn’t need 400w) would do better up there also for the mids and highs.
http://www.rageaudio.com.au/modules/gallery/albums/Kappa9/img/090801082656_kappa9.jpg
Cheers George
The Ren 90’s have a load presented to the amp very much like the Kappa 9’s (I was told by Trevor who measured this graph linked below).
Saying that to get the very best out of them, your Krell on the bottom is the right amp to drive that low impedance, but I think the upper mids around 5khz which is the same kind of nasty load as the low bass, and maybe an amp more like the Krell (a current pusher), only smaller (as you wouldn’t need 400w) would do better up there also for the mids and highs.
http://www.rageaudio.com.au/modules/gallery/albums/Kappa9/img/090801082656_kappa9.jpg
Cheers George