Recommendations for electronic crossover.


I am bi-amping my B&W 804 matrix speakers with a 50 watt per channel tube amp for the top and a 200 watt SS for the woofer. Any suggestions for reasonable priced crossover? I have been told Merchand (?) makes a good one.

Thanks!
jpahere


And I thought listening

Na, you already proved you can’t do that with this statement.
Every one of us preferred the sound of the bridged configuration, with some describing the sound as now being "more hifi"
The "can’t see the forest for the trees" was the technical aspect of what you know, and what happens to a stereo amp when it’s bridged, all you gain is watts EVERYTHING else takes a hit.
Bridging makes what was maybe a good amp, almost a P.A. amp.

Look, George, this merry-go-round of ours leads nowhere, so let's just agree to disagree.
God idea. 
At best having to bridge an amp is poor planning. I think the best posts her on the subject of biamping  are by mijostyn and avanti1960. If you are making your own speakers and want to approach the problem of a 2 or 3 way system that way there are certainly advantages. Bypassing the cross over network of a well designed  speaker made by a reputable company is a mistake unless the speaker was designed for it. 
Arguing about whether bridging is good or bad misses the point. Many base designs (such as those from Nelson Pass) are bridged inherently. They allow the use of lower power supply rail voltages and therefor reduce power consumption, particularly with Class A configurations. I don't think that a properly designed bridging configuration increases distortion any more than using fully balanced circuitry does. It is true that each amplifier that is bridged will see half the load impedance, and as such must be designed to drive that lower impedance.

Regarding the subject of active XOs, it is almost impossible to find one that is built without op amps. Bryston is the only company that comes to mind that produced HP and LP versions with discrete Class A circuitry, and I do not recall if these are still in current production. In any case they are not cheap, and if you need more than just a single XO point (two way system), the costs mount up fast.

For the poster who mentioned potential pitfalls of eliminating the factory passive XOs, almost all of these are removed by providing a dedicated amp/driver. Line levels are easy to match with gain controls on the amps, and most other impedance matching gymnastics are eliminated with a dedicated amp. The system is also much more efficient if the drivers have widely different sensitivities, because you do not have volume matching resistors wasting a lot of power. The passive components are a lot cheaper and you can use higher quality. For example, teflon film caps are almost impossible to get (or afford) as large values in a passive XO, but are affordable in an active design where they are a lot smaller in value. For more discussion on the advantages of dedicated amping, see Professor Linkwitz discussion on the matter.
@dhl93449

Regarding the subject of active XOs, it is almost impossible to find one that is built without op amps. Bryston is the only company that comes to mind that produced HP and LP versions with discrete Class A circuitry, and I do not recall if these are still in current production. In any case they are not cheap, and if you need more than just a single XO point (two way system), the costs mount up fast.

This stance is a quick way to discard active XO’s when in fact they could be beneficial to a passive solution - even with opamps and A/D to D/A conversion being introduced in the signal chain.

What’s the bigger picture; do the comparison and forget for a while the drawbacks mentioned to hinder the fuller realization of an active XO, if they’d even be that relevant compared to the negatives of a passive config., and then see. My take with an XP-series Xilica XO is that it trumps excellent passive XO’s in the three set-ups I’ve heard so far - quite easily. The sound in all cases went from slightly diffuse/smeared and soft to more clear, refined, transparent and dynamic going from passive to active.

A second suggestion of the First Watt B4 (designed and built by Nelson Pass). The factory-built edition is no longer in production, and used examples rarely come up for sale, so be prepared to wait. A kit version is about to be made available, I believe.

The B4 is a discrete design, no opamps, no ic’s. It listed for $1500, sold for about $1200. Really versatile: two channels of 1st/2nd/3rd/4th-order high and low-pass filters in 25Hz increments from 25Hz to 6375Hz, level controls for either the high-pass or the low-pass outputs, switchable.