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Help me choose an active crossover

I need an extremely high quality 3-way crossover for a high resolution system (see virtual system). The midrange/tweeter unit will be crossed over at 600Hz, and will use a Cary CAD-211AE amplifier. The woofer will be bandpassed between 80-600Hz, and will be powered by a solid state amp. Everything below 80Hz will be sent to stereo subs.

I have narrowed down my selection to two models in the Marchand catalog - the XM44, and the XM126.

The XM44 is a solid state crossover, which can be ordered with any frequency slope from 6dB/oct - 48dB/oct. You can specify optional daughter boards, including notch filters, baffle step compensation, delay sections, and Linkwitz transform. It is relatively affordable - specified for my needs it would cost $1350. Link is here: http://www.marchandelec.com/xm44.html

The XM126 is a valve based crossover, only available at a maximum 24dB/oct slope (although 1st, 2nd, and 3rd order slopes are available). The website does not list any optional daughter boards. My understanding is that the XM126 does not use any op-amps, and all the circuitry is discrete. Which probably accounts for its whopper of an asking price - $4700 (with attenuator, balanced option, and 3 way). Link is here: http://www.marchandelec.com/xm126.html

As far as I can see, the extra money for the XM126 buys you a better volume control (i.e. a stepped attenuator instead of a potentiometer), and it buys you discrete circuitry instead of op-amps.

Now, I do not have a philosophical objection to op-amps per se. I would not exclude a product simply because it uses op-amps, as long as the result is what I want - clean, dynamic, with a low noise floor and extremely high resolution. I do not care so much about the superior tonality of valves, because I have already achieved the tone I want elsewhere in the system.

Obviously I would prefer to spend less, but I am prepared to save for a better crossover if need be. I also wonder whether I should consider a crossover from Nelson Pass or Bryston instead of the Marchand. Your opinions?
amfibius
eldartford
4,262 posts
 
I have used active crossovers for decades. I am presently using an Ashly XR2001 (pro sound) crossover and find it very good. It can do four channels 2-way, or two channels 3-way. Crossover frequencies are easily adjustable (with knobs) which I believe is very important, particularly for the SW/Main frequency where the optimum depends on the kind of music being played.

It will cost far less than the units you mention, so you might want to give it a try. Its flexibility would be useful to you as a tool for determining crossover frequencies for your speakers. It is built well, and input/output is balanced XLR.

Performance of OP amps depends greatly on how they are used in circuitry. High gain aplications, as in a phono preamp brings out their less than good characteristics. In a crossover aplication they are basically unity gain devices and their characteristics have little impact on overall circuit performance.
amfibius OP
282 posts
 
Thank you, Eldartford for your comments. I failed to mention that I have a DEQX and a Behringer CX2310 crossover. Neither are good enough for my needs, although the DEQX was helpful when it came to taking measurements and choosing slopes. The little Behringer is far more transparent, but the Behringer still isn't good enough.

"Performance of OP amps depends greatly on how they are used in circuitry. High gain aplications, as in a phono preamp brings out their less than good characteristics. In a crossover aplication they are basically unity gain devices and their characteristics have little impact on overall circuit performance."

Thank you for that little insight! That helps to tip my decision towards the XM44.

I have emailed someone asking which crossover would be better suited to performance enhancing modifications further down the track.
darkmoebius
900 posts
 
I have narrowed down my selection to two models in the Marchand catalog - the XM44, and the XM126...I also wonder whether I should consider a crossover from Nelson Pass or Bryston instead of the Marchand. Your opinions?
I think the better places to ask this question are Audio Asylum's High Efficiency forum and Madisound's speaker builder forum. You might find more multi-way horn owners at the first and more crossover designers and specialist at the second.
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