My Experience Bi-Amping Khorns

[pen_man]

There has been alot of discussion lately about biamping. For some time I had been considering taking the plunge into biamping and the recent postings convinced me to do so. The first thing I did was dust off an Audio Research EC-4 crossover that I had sitting on the shelf. It is a tube based analog crossover that can be used as a 2 or 3 way crossover depending on how one sets it up. Unfortunately, the crossover frequencys are not easily adjustable. To do so one must change several sets of capacitors which are not easily accessible. I decided to use it as a two way and set the crossover point at 400hz for the low pass and high pass. I used the existing ALK Universal passive crossover to then divide the mid and high frequencies. For amps, I dug out a Crown DC-300 that I recently had rebuilt for the LF and continued to use my Marantz 9's for the MF/HF. One thing that I liked about this amp combo was that the amps had a gain control for each channel. Hence, I set the crossover output to its maximum output for each channel and controlled the relative gain using each amp's individual gain control. For a preamp, I continued to use my Fisher 400CX-2.

After a few minutes of listening, I dialed the gain between the LF and the MF/HF in to my liking using only my ears as a guide. I had always felt that my Khorns were lively with plenty of HF sparkle and LF umph, but biamping took them to a new level, especially on the LF. Now, there is plenty of tight controlled bass response which I discovered was missing on most of the source material that I listened to. Overall, the speakers are now much more well-rounded with tight, responsive LF's an even airer MF/HF. The MF/HF sound reminded me of the sound from Greg's VTRAC which I demo'ed and liked very much. I must admit that I am sold on the idea of using an active line level crossover and urge anyone considering it to give it a try.

The one drawback is that on about 10% of the source material, I feel a need to readjust the gain for the LF response to tone down the bass so as to maintain a proper overall balance between LF and MF/HF. Frankly, this is a mild annoyance that I am willing to deal with given the positive benefits.

I would be curious if anyone has used Greg's VTRAC with an existing bi-amp, active crossover setup? If so, what did you think? How much of a benefit did the VTRAC provide over your biamp setup? Finally, has anyone gone to Jubilees from active biamped Khorns, with or without the VTRAC modification? If so, would you please provide some feedback as to the differences in the sound of your setup before and after the Jubilees. I am in the south suburbs of Chicago if anyone is able to stop by for a listen.

[theluggman]

Hey penman are you still using this setup? I just acquired the EC-4 and was looking into what capacitors/capacitance to get to cross at 400 hz from what I can gather the caps should be about 4000pF is this what you used? Currently I am using a Rane crossover a lot better than no bi amping but I am anxious to use the AR