CAN Bi-Amping been done Correctly?

Mark:
The answer is yes, it can be done. You will need an active crossover and need to bi-pass the internal cross-over of your MLs when using two different types of amps. Undoubtedly the gain will be different. I have a pair of ML monolith IIs which I bi-amp--to great success. I'm using solid state on both top and bottom--but your idea is a good one. I have tried using a tube amp on top and it didn't work, but that was because of the great mis-match (in power) in the amps I was using. Your tube amp needs to have close to the same output and needs high current delivery to handle the panels (this is generally not a problem for most good quality tube amps). I would recommend no less than 100 watts per channel (per driver as well). In terms of cross-overs, Bryston 10B and the Marchand are both excellent. The Marchand is a bit more economical.

Lastly, if you are using a class A SS amp and the tubes--better have a good air conditioner or live in Canada--you are going to generate some heat.

Bi-amping is great for sound. The problem is that it is more expensive. Don't confuse it with bi-wiring which is mostly not worth the effort. It is far to complicated to deal with well in this forum. One of the best discussions on bi-amping that I know of on the web is Rod Elliot's website, www.sound.au.com. The article is caled "Bi-amplification-Not Quite Magic, But Close." The article is located exactly at www.sound.au.com/index.html. If you browse around the website you will find it. The entire site is fairly good and there are some other good articles on amplification too. He is mostly solid state. Give me an e-mail if you have any questions after reading the article. Biamplification is great and it is easy to do. Easier (and better) than passive crossovers if you are into that.
Good Luck,
Craig Klomparens

email address: [email protected]

I have a pair of B&W 802 series 3's that are bi-amped with a pair of Parasound amps. The difference was nothing short of amazing.

I don't know if it can be done "correctly", as I don't know what "correctly" is. But if you are asking, if you can have glorious sonics, by bi-amping Martin Logans, yes.
I use Curcio modified MKlll's, on the panel, and solid state, on the bass. With 60 watts, on the stats, and 200 watts, on the bottom, I think it sounds grand. The Martin Logans are Sequel ll. I did a lot of interconnect cable, and speaker cable swapping, before arriving at what I liked.

I work with pro sound reinforcement a lot and multi amping is a way of life. Use a big solid amp for the bottom and you can get away with a smaller amp for the highs and mids because the big power suck is the bass. I don't know why you would need the same amp for highs and lows, especially if you are mixing two different speakers, though you may need to experiment to find an amp combination that suits you. The difference i see in the pro side verses what i see here is that we use a cross over to split the signal out of the board (i.e. the pre-amplifier) where as it seems that in hi-fi applications the full range signal goes to both the mains and the subs with a cross over in the sub controlling what the sub reproduces. The mains are also trying to reproduce that low signal and that may be where the clash comes from...just a guess. In pro set ups you also need to tune the cross overs and eq for the room, it's not a simple plug and play operation. The cable swapping noted above seems to be a dialless method of EQing the system.