Bi-amping and Bi-wiring variations

Some help please from those who are experienced or can remember more physics than I can.

Bi-amp..... Does one use a 3 or 5 channel amp and have 1 amp each go to the speaker or in the case of bi-wiring too.... 2 amps to each speaker (1ea for high and low on each speaker) Are single amps better or worse than one multichannel amp ?????

Bi-wiring.... 2 leads from amp going to 4 per speaker or better yet... 2 wires each from amp to speaker accounting for 2 wires each (4 leads) from speaker to amp.

Does any of this make sense ????

Bob J

BobJ,
I think you have the idea. I did a similar setup with one amp and 2 sets of outputs to my speakers. One "pair" was for the panels and one "pair" was for the woofer.
All things being equal two amps would obviously be better because there would be less "strain"(?) in comparison to one amp. This is in theory. I would imagine if you had a strong enough amp, in my case I did, you would not see any real heat. You do not want your amp/receiver to get hot enough to cook a grilled cheese sandwich.
It depends on how much you have to spend. I think you may be ok with a 5 channel amp. It depends on what you are driving and at what volume.

Jeff

Here are a few links to bi-amping basics:
http://sound.westhost.com/bi-amp.htm
http://www.audioholics.com/FAQs/biampingvsbiwiring.php
http://www.audioasylum.com/audio/ge...ages/57210.html

This topic has been discussed elsewhere in the previous pages of this forum.


Spike

Jeff Zaret said:

BobJ,
I think you have the idea. I did a similar setup with one amp and 2 sets of outputs to my speakers. One "pair" was for the panels and one "pair" was for the woofer.
All things being equal two amps would obviously be better because there would be less "strain"(?) in comparison to one amp. This is in theory. I would imagine if you had a strong enough amp, in my case I did, you would not see any real heat. You do not want your amp/receiver to get hot enough to cook a grilled cheese sandwich.
It depends on how much you have to spend. I think you may be ok with a 5 channel amp. It depends on what you are driving and at what volume.

Jeff

Click to expand...

The benefits of bi-amping with hybrid ML's is greater than with conventional speakers because of the different type of loads placed on the amp by the panel and cones. Have a seperate amp for the cone and panel lets each driver do its thing without interference from the other.

Follow up .....

Follow up on the biamping issue. Has anyone actually biamped a set of Ascents? How did you deal with disconnecting the passive crossover in the speaker?

I discussed biamping with ML, to get information on the crossover and they constantly said it could not be done and should not be done due to the "equalization" circuitry.

Any hints?

Yes, I'm bi-amping my reQuests

Follow up on the biamping issue. Has anyone actually biamped a set of Ascents? How did you deal with disconnecting the passive crossover in the speaker?

Click to expand...

I'm (passively) bi-amping my reQuests with tubes on the panels and solid-state on the bass. Does that count?

I discussed biamping with ML, to get information on the crossover and they constantly said it could not be done and should not be done due to the "equalization" circuitry.

Any hints?

Click to expand...

Yep, I've talked to ML regarding active bi-amping where the crossover circuitry is bypassed and came to the conclusion that it could not be done easily. However, I am passively bi-amping my reQuests (without an active cross-over) in order to keep the components in the signal chain down to a minimum. The reason for my wanting to bi-amp is to have tubes on the panels for more...midrange bloom. I could have an electronic crossover in addition to the ML built-in crossover, but that would mean many more components the signal has to go through. Hope I've answered your question.

Spike

Spike

Thanks, I think I understand what you are doing, essentially running two sets of amplifiers (tubes and solid state) from your preamp or processor to the two sets of posts on the speakers (without the connector bar)? Essentially using common input feeding the amps with separate outputs to the panels and bass, but still using the internal speaker passive cross over.

I am trying to actually use a Bryston active crossover and wanting to eliminate the passive crossover connection internal to the speaker. This is where ML says the issue gets complicated due to some internal eqaualization circutry for the panels that are part of the croossover network. They used to actually make some ML speakers that could be actively biamped, but the newer models are not capable. At least that is the info I received.

The advantage seems to me to be that the impedance of the panels, especially at higher frequencies gets very low and is tough on the amplifiers (lots of drive current). Thus, a lot of press about using tube amps for the panels and solid state for the bass.

Thanks for the discussion and if I find how to disconnect the crossover network I will post the info.

dilithium said:

The advantage seems to me to be that the impedance of the panels, especially at higher frequencies gets very low and is tough on the amplifiers (lots of drive current). Thus, a lot of press about using tube amps for the panels and solid state for the bass.

Click to expand...

Don't worry too much about the (impossible) low impedance of 1.2 ohms on the spec. It only dips that low around 20Khz where there isn't much musical data, translating to little energy required from the amplifier. You do need to worry about the wide impedance swing from 200hz to 20Khz the panels have to support. This can be addressed given a reputable amplifier with a beefy power supply section like BAT, ARC, Cary, etc... This is what led me to the AES SixPacs from Dennis Had.
Regarding the electronic crossover, I had actually considered the Marchand tubed unit but backed out of the idea since I'd still need to have the passive one inside the speakers in the signal path. If you're really considering the Bryston unit, you should read up on the Marchand unit where you could combine preamp functionality into the same unit (volume knob & selector). All in the interest of minimizing the active components along the signal path. Give Phil Marchand a call and see what can be done.

Spike

Spike said:

Regarding the electronic crossover, I had actually considered the Marchand tubed unit but backed out of the idea since I'd still need to have the passive one inside the speakers in the signal path. If you're really considering the Bryston unit, you should read up on the Marchand unit where you could combine preamp functionality into the same unit (volume knob & selector).
Spike

Click to expand...

Thanks for the info. I am currently using a Bryston SP1.7 processor / preamp and would like to use the active crossover. But .....

Seems like you and I have the same overall issue, how to disconnect the passive crossover in the speakers. Not much info from anyone else. I am again going to talk to ML as another friend with ML speakers has the older models without the crossover issue. I will continue my discussions with ML until I gat either an answer or the actual schematics for the crossover. Seems like they used to consider biamping but have decided not to any longer. The reasons are what I am looking for