McIntosh MC901's internal active crossover & speaker's internal passive crossover

I own these amps, and they are all you think they would be. Extremely versatile and easy to work with. When I purchased them, I ran Infinity IRS Betas. The mid/high panels with the tube section, and the bass towers with the solid state. I did not use the internal crossover since the Betas have a servo box for the Woofers and adjustable level crossovers on the mid/high panels. These amps sounded much better than a half a dozen or more previous arrangements with the Betas.

Now they are running a set of Analysis Audio Orion Mid/High panels using the internal crossover on the amps, with no passive crossover in line to the speakers. This is the best way to run these amps and sounds incredible. Another option is to run the monos as two separate amps for two separate types of speakers if you’d like to change up your flavor. You can run a more sensitive pair of speakers off of the tube section, and drive more power-hungry speakers with the solid-state section switching between based on your mood, but this will need two outputs from your preamp.

Can’t say enough good about the MC901’s. I watch the used market daily and have yet to see a used set for sale since their introduction.

@cleeds 

What exacy do you think a speaker made for bi wiring does?  What do you think happens when you remove the external jumpers?

A biwirable speaker provides a separate path for lo and hi frequencies, but they are still joined electrically at the xover. A biamplified speaker provides electrically isolated paths for the two frequency bands. That's the difference between the two.

A biwirable speaker provides a separate path for lo and hi frequencies, but they are still joined electrically at the xover.

@cleeds 

Would you post some example what make and model of speakers that is bi-wirable but not bi-ampable?

TIA

A biwirable speaker provides a separate path for lo and hi frequencies, but they are still joined electrically at the xover.

@Cleeds In my experience that’s’ almost never the case, but I have seen it happen. Almost all speakers I’ve seen with 2 sets of inputs and external jumpers separate the crossovers internally.  Otherwise, why have jumpers??

You can easily check this in a couple of ways. Remove the jumpers and plug in the woofers. See if anything comes out of the tweeter.

Next, do an impedance check between hot to hot and ground to ground. Should be infinite.

The one case I remember being posted about the speaker only had ground shorted internally. Normally this would be OK unless your amp was fully balanced.