Is bi amping worth it ?

I have been puzzling through your bi-amp instructions as posted.  Bi-amping means using separate channels of amplification for the high and low frequencies on each speaker.  Inherently this requires four channels of amplification for a stereo pair of loudspeakers.

A monoblock contains only one channel of amplification.

In the connection steps listed, it says to run two interconnects into the input of each monoblock.  I don't know of any monoblock amplifiers that have two inputs, both balanced, that would accommodate this setup.  Monoblocks have one input and one output for their one channel of amplification.

Also, in the area on speaker connections, it states that for the right speaker, to use the other two McIntosh 601 monoblocks.  That implies that there is a second pair of monoblocks.

I don't know the origin of these instructions, but my interpretation is that they are in error.

Four channels of amplification are required, be they two stereo amps, four monoblocks, or one stereo amp and one pair of monoblocks (which is what I use).

Bill

FWIW, the big advantage to passive bi-amping is being able to match amplifiers to speaker requirements.  In other words, you can run a big honking amp to power your power hungry woofers to bring out their capabilities and use an amp that you love for it's midrange and high frequencies to power the mids and tweets.

If you vertically bi-amp you are using identical amplifiers on both highs and lows (oftimes a stereo amp).  This can work well if you are somewhat compromised in power requirements in the first place.  It also allows for short speaker cable runs and maybe more convenient placing of the amplifiers.

In your case, I wouldn't use a second pair of 601s for the mids and highs because your speakers are efficient and you would only be using a fraction of their power.  A much smaller amplifier would work just fine and possibly be much less $ than a second pair of 601s.

The biggest issue when using different amplifiers for the highs and lows is matching the outputs.  In my case I had to tame down the bass to match the highs, by using an attenuator between the preamp and the monoblocks.

As always, YMMV.

Bill

Knotscott said it pretty well.  A stereo amplifier is two one-channel amplifiers in one chassis which happen to share one power supply (usually).  There is an input and an output for each channel.  Really not different than setting two monoblocks next to each other.

The stereo part comes from the left and right outputs from your preamp.  If you use two sets of outputs from the preamp you have two lefts and two rights and as long as you don't mix them up they are still stereo.

Bill 

Passive bi-amping is fine to try if your speakers have two sets of binding posts, one for high frequencies and one for low frequencies, as long as the two sets of posts are completely isolated electrically from each other.

There have been speakers (and may still be) that share grounding between the two sets of posts and shouldn't be passively bi-amped.

This can be easily determined with an ohmmeter.

As far as active bi-amping is concerned, the internal crossover needs to be bypassed entirely and the speaker must be modified to that effect.

I cannot imagine any speaker manufacturer would happily recommend advising to do that.

Bill

@billpete 

Hi other Bill

I was just pointing out that if two identical stereo amplifiers are used, one channel of each amp could drive the woofers and the other channel could drive the mids and highs.  Configured in this way each speaker could have it's dedicated stereo amplifier positioned near the speaker.  And, it would be a lighter load on the amp's power supply than if both channels were driving woofers.

The comment about shorter cables is mostly esthetics.  Personally, differing speaker cable lengths don't bother me.

Bill