If you want to bi-amplify, there are many good reasons to do so VERTICALLY. Vertical bi-amping means using one stereo amp for each speaker. Every different marquis of amp has different current rise times (slew rate), different input impedances, different distortion levels, different clipping thresholds, different timbral presentations and more. If you use one type of amp (say, tube) for the mids and highs, but another for the lows (say, the DNA), your music will not mesh. If you use two identical DNA's, one for each side, you will not have differing presentations of, say, a single cello (which could be played through woofers or mids/his), or harps, or piano, etc. - you will achieve a seamless whole in your presentation with vertical bi-amping. As far a cross-over mods are concerned, contact the manufacturer. They may be willing and able to help. Avoid additional external circuitry - there is significant loss with each additional resistor, capacitor, inductor, circuit board and the like. In your case, if you split the signal at the speaker inputs, you would run two speaker cables to each speaker (woofer and mid/hi). Back at the amps, you would either fit a Y-connector to your amp inputs, or (better yet)take off the top cover and solder two short sections of wire across the inputs: hot to hot and ground to ground. Use good wire from an old, unused interconnect. Each piece need only be about 2 inches long. I run an audiophile surround with FIVE McCormack DNA amps operating in just this configuration. All five speakers are rigged for vertical bi-amp. I pulled the crossovers and positioned them outboard for easier upgrading and service, but this is not required. Contact me with further questions at AUDIO OPTIMIZER@CS.COM. Bruce Kopitz
Bi-Amplification advice
Hello, I have some questions about this process. I am getting quite a lot of different opinions on this subject and hope that anyone reading this can give me some advice. I have: McCormack DNA-1 Dlx. McCormack ALD-1 Dlx. w/ E.S.P. Resolution Audio CD-55 Von Schweikert VR4 Gen. II Rega 25 All interconnects are by Luminous Audio Tech. Power Cords by T.G.Audio. I have been told numerous ways of achieving this set-up. Some have said that an external electronic crossover would need to be introduced into the equation thus necessitating the need to diconnect the internal crossovers from low to mid-high, directing one Amp. for lows the other for mid-high. Others have said to use one Amp. for the lows and the other for the mid-high's without an external crossover. Still others have said to use one Amp. for each side, as in a Mono set-up, without bridging. There is the added scenerio of Tubes for the mid-high and S.S. for the lows. What began as a project of fun and curiosity has grown into full scale confusion. I have been an avent audiophile for some time and have owned a lot of equip. over the years. I have a chance to purchase another DNA-1 Dlx. at a good price and I have wanted to try Bi-Amplifying. Any "sound advice" out there?