Idiotic Vertical Biamping Question

Hi Aggielaw,

Yes, monoblocks would be connected so that each block would drive a singe speaker, or channel. This is also how it would "look" if you were to run two amps in bridged mode with each amp acting as a monoblock and running a single speaker. Both of these configurations only require a single IC connection from the pre to the amp for each channel, so it is simpler to connect. What I have experienced with the amps that I have tried running in bridged mode is that the soundstage would lose depth even though there was plenty of power. Now, monoblocks are different because their power supplies are built and integrated as a single unit. They are build for the express purpose of driving a single channel. Of the 4 or 5 amp builders who I have asked about running their stereo amps in bridged mode, all have said that while their amps had the current supplies to do it they recommended running them in stereo mode to get the best sound. (Send an email to Steve, I bet he says the same thing.) I have found it fairly easy to confirm this after listening to both configurations using the same amps. So it really is a matter of what amps you're using and what you're preferences are, assuming the amps you're using have the current capabilites that may be required from driving that 4 ohm load that is now seen as 2 by the bridged amp.

Bi-wiring is completely different and is dependant only on how your speakers are built. I suppose the cables used could also be a factor. There can be a benefit from bi-wiring, but in my experience the gains made from biamping (or dualamping for Eldartford) are much greater than the gains from bi-wiring. Also, with biamping you can get the amps very close to the speakers using longer ICs and keep the speaker wires very short. Another sonic benefit I have experienced. As always, YMMV.

Dan

The above discussions of bridging SS amps are pretty good, but to make a point--bridged amps are NOT 'high-current' amps. Only if an amp has a 4-Ohm rating that's double its 8-Ohm rating will it be able to drive FOUR times the power into 8 Ohms--and four times is the theoretical amount. So if your speakers are 4-Ohm rated or are relatively insensitive...say below 90dB...don't look for a bridged amp. However, the channels of any SS amp can be paralleled, just as the channels of a tubed amp can. Simply drive both inputs with a Y-connector and wire the output terminals in parallel and you have a mono amp with the combined power of the 2 channels. IOW, if you had a 125-into-8 stereo amp, when paralleled it becomes a 250-into-8 amp.

I think passive biamping makes sense only when you intend to use amps that are (more or less) well suited to driving parts of the audio spectrum. Let's say you have a overall sweet-sounding amp that just doesn't have enough power to produce the bass 'slam' diddeeboppers love. Connect it to the MR/treble part of your 3-ways and buy a SS amp noted for its bass performance. After level matching, you have what MAY turn out to be a QUITE-fine-sounding amp system.

IMO, biamping AND biwiring benefit equally from using speakercable selected to carry parts of the audio spectrum, same as amps. If driving bass only, select a cable with lots of material for low resistance but that's still inexpensive, such as AQ's Type 6. For MR/treble, select a cable that has excellent material and geometry for critical listening but that's not too high in gage or expensive. For this, I'd use AQ's DBS-type CV-6 or KE-6, both using 4 pairs of 4-different-size conductors. If driving treble only, I'd use AQ's all-silver, DBS-type KE-4 at half the price of KE-6.

All of this is controversial, but my experience over the decades supports it. As always, listen carefully and be cautious.
.

Eldartford

"dualamping"? Come on...

The term biamping is an industry standard. Any speaker with two sets of binding posts and a truly divided internal passive crossover is "biampable", no? In this situation, far more common than "actively" biamped systems, no external electronic crossover is involved. The term "actively" is what distinguishes the two.

Dan,

Interestingly, when I asked Steve yesterday about biamping vs. monoblocking (or monobridging, since his monblock conversion bridges the channels of the amp, which he describes on his website at www.smcaudio.com), he stated that he finds better performance with the monoblocks because the amps (his amps, anyway) control the speakers better in that configuration than they do in a biamping setup. He said this results in even better imaging. He is absolutely not a fan of active biamping, because the active XO before the amps inserts its own "personality" on the sound. Steve did say some people have reported not liking biamping or monoblocking, and he didn't really understand why.

I was almost ready to sell my current DNA-0.5 Rev. A to buy the monoblocks that came up for sale last night, but now I'm not so sure - the number of comments of experienced users who say monoblocking or monobridging is a step backward seems to outnumber those who hear the benefits. I don't think I want to fork out the money to find out for myself quite yet. Of course, the negative comments I've heard about monoblocking have not been directed at McCormack amps, either. Might be time to email Swampwalker...

Jeffreybehr...I always heard that connecting two power amp outputs in parallel was a NO-NO. Frankly, I never tried it, as the caution seems reasonable.

Creeper...The "industry standard" when I started biamping in the mid 50's always involved a low level crossover, and I think this terminology remained for many years. Only lately have I heard about using two power amps with passive crosovers. Indeed, until fairly recently loudspeakers did not come with separate terminals for woofer and tweeter (a feature intended to facilitate bi-wiring).

Aggielaw...A low level electronic crossover has far less "personality" than a passive crossover. Of course, the "personality" of the passive crossover may be deliberate, to overcome certain known deficiencies of the drivers.