Monoblocks and Marchand

I have ordered a Marchand powered crossover and plan on using it with my Cary 500MB monoblocks. One monoblock for the high mids on my Maggies and the other monoblock for the bass. A friend says that will not work. Anyone out there have experience with this set up?
You have 4 monoblocks? Even if that's so, doubt it would work the way you expect.
A single monoblock handles a single channel; stereo has two channels. That's why you need two monoblocks for stereo, in a regular setup.

You might say that stereo splits up the music into left and right.

An active crossover like the ones that Marchand makes splits the music into high frequencies and low frequencies.

So you are trying to split the music in four slices. You are going to need four monoblocks to handle that.

There is one exception: you can play the low frequencies in mono. You sum the low frequencies of the left and right channel into a single mono channel. This actually works below 100 hz or so (probably 80 hz if we get picky about it) because stereo information tends to get washed out by then; the reason, basically, is that the wavelength of an 80hz sound wave is quite a bit longer than the separation between your speakers. This reasoning becomes more dominant as the frequencies get lowered. You may still prefer to have two (or more) subwoofers, but it will not be because the stereo effect suffers, rather because of low-frequency sound propagation through the room; but at least you can begin with one subwoofer and add more later as you see fit.

btw I recommend that you talk directly to Phil Marchand about any of this, as he is knowledgeable, straightforward and honest. If he tells you you need something for your setup, you most probably do. :)
Thank you Trebejo for this great insight. I'm still at the lower end of the learning curve but I'm gettin there thanks to people like you.
I will have to explore using my Cary 120S tube amp on the top end and the Cary monoblocks on the bass. I'm not sure how this hooks up but will explore this possibility.
500MB: 1.4 V sensitivity, 27 dB gain
120S: 1.24 V, 28 dB

Relative to full output.

Received the Marchand XM44 powered crossover yesterday and spent a few hours to install it last night. I've got my Cary 120S, EL34 tube amp on the highs and mids and Cary 500MB monoblocks on the base powering my Magnepan 20.1's. The sound is incredable. Night and day difference between the Magnepan passive crossovers and the Marchand. Everything just seems more coherent and the base is excellent. If you have 20.1's, you are missing out using stock crossovers.
I have a very similar setup on my 20's.

I went with the Marchand's tubed version with stepped attenuators, becayse it was only a little more.

The nice thing about the Marchand crossovers is that they are modular. If you later decide to have it made into a 3 way, the parts inside get reused.

That way, you can cut 50Hz down out of the maggies, and send it to a subwoofer or 2.

I found that with the crossover in the system the 20's sound better with the speaker wires to both tweeters reversed so they are out of phase with the bass panels.

John C.

John C.

What frequencies did you find worked best in your set up. I'm still experimenting but don't think I've found the ideal ranges yet.