Quad 989 vs Martin Logan CLS IIz?

Suggest you look for a pair of the original CLS's or earlier Quads. Both are far superior to later models. Crosby mods on the Quads are very desireable. IF you can find a Quad 57 (very doubtful)go for it. Both like tubes. Your ARC should be great with either. Best of luck.

Although Quad 57's have about the best midrange you will ever find, the ESL 63's do it all, including better power handling capabilities.Imaging and room spaciousness are much better as well. Do not screw them up by putting them with subwoofers. I own both types of Quads, so I know. Never heard the 989's but it is not the same company that produced the earlier models. Martin Logan was never in the same league as Quad.

If you can find Quad ESL 63's with latish serial numbers, Nick Gowan of True Sound, Campbell, CA does a fabulous upgrade that involves replacing 62' of internal wire, among all the more obvious things. Without knowing the famous Crosby mods, I shouldn't say which are best--but I can't imagine that the Gowan upgrade can be beaten or even matched by them. Web address: www.tsound.com. It might be worth looking into. (I should add that Nick upgraded my Quads, and it was one of the biggest improvements in my sound.)