I suggest speaker cables with MUCH LESS capacitance! Anywhere from the cheapest (Paul Spletz anti-cables) to the very pricey (Purist Audio Provectus) or something in between (Virtual Dynamics.)
Speaker Cables
I have used MIT Terminstor 2 biwire and Monster Z series biwire for my Apogee Stages, but they seem to be lacking something. I am using a Carver 500 T amp. What do you suggest, Thank you.