Bi-amping versus Mono-blocks

Wondering if there are varying positive reasons for bi-amping versus mono-blocks. I know that bi-amping is usually hooked up horizontally (one amp for lows and one amp for lows) and that mono-blocks are one amp per each speaker. I also know that if you want to mix amps with a SS amp on the low end and Tube on the high end, you bi-amp. My question is ............ which method is best for an amp being able to drive the speakers (least pull on the amp)? Is it easier/better for an amp to handle the complete frequency range of only one speaker .... or better for an amp to cover only a portion (low frequencies or high frequencies) of the frequencies of two speakers? Does each have it's place because of certain reasons/circumstances? Thanks for any input.
What would you say if you could have both monoblocks and biamping in the same pair of monoblocks ?? Best of both worlds !!!! Here in Denmark there is a company called LC Audio ( and they make som very special amps. I use a pair of their ''The End'' monoblocks myself and they are real high end amp at a budget price. But let me explain how they work (hopefully it will not be to technical): Each monoblock contain a mainboard and 3 extension boards. The signal from the preamp is fed to the mainboard that contains the inputstage, driverstage and ONE pair of output transistors. This pair of output transistors is connected to a set of binding posts - you connect the mid/tweeeter from your speakers to these terminals. The 3 extension boards each contain an output stage similar to the one on the main board and the 3 extension boards are connected in parallel for maximum current delivery (that's what's needed in the basss). The extension boards are connected to a separate pair of binding posts - you connect the bass section of your speaker to these. The extension boards get their input signal from the driver stage on the main board, meaning that the input and driver stages in the amps are shared between the ''mid/tweeter'' amp section and the ''bass'' amp section. The above construstion is very unique and also answers many of your questions: Even though you level match your bass and mid/tweeter amps you will have phase shifts between the bass amp and the tweeter amps if you use different amps - not good. That's why many speakers designers doesn't offer the possibility to biwire/amp their speakers (Thiel, Avalon etc). The risk of making a complete mess of the sound from the speakers is to big and the chance of getting a good blend between the bass and tweeter amps is very small. If you use monoblocks (no biamping) you might loose some top end detail and sweeetness compared to the biamping set-up. But if you use the LC Audio amps (or similar if any) you get it all because you have a dedicated tweeter amp and a dedicated bass amp that share the same input and driver stages without any of the downsides mentioned above.
Biamping with two mono's per speaker would be best. Without doing that, the best way to biamp is to use one amp for each speaker(ie:right channel drives bass, left the tweeter). This makes the demand on each amplifier even, so one isn't doing all the work(like the bass) and the other the highs. Biamping is done for a few reasons. The main ones are increased transient response(they don't have to work as hard), and also it lowers distortion. When you biwire, or single wire with jumpers, the larger voice coil in the woofer is basically trying to cram a compy of the signal in the other direction, which can interfere with the tweeter and cause distortion. Biwiring helps lessen this effect, biamping avoids it altogether. The easiest way to go is to use the same four mono's or same two stereo amps, with the same type and length of interconnects, so you don't run into any input sensitivity/impedence problems etc. You do not need an external crossover to do this. It's nice if your preamp has two pairs of pre-outs(like my ARAGON), but you can use a Y-adapter just fine. Biamping is superior, but remember, one good amp, or two mono's, are always better than 2 lesser stereo amps in biamp mode. I don't recommend using a tube amp for the highs and solid state for the lows, unless the input impedence of both amps is the same. That would be unlikely, and you'd have to add more to the chain to adjust, never a good idea. Keep speaker cable the same length as well. The difference a good biamp setup makes is astonishing! Good luck.
Willi, I have experimented in this area, let me first say I am not an expert, but just a curious audiophile. I own 2 Musical Fidelity X-AS100 amps, 100w each, they have mono/stereo switch and input/output RCA connectors, this alllows for very flexible system! Most gurus prefer monoblock set-up as this is more balanced use of amps, one mono amp for each speaker, Stereophile mag Class A amps has several monoblock designs, also as you know high freq drivers need lower power than low freq drivers, so monoblock is most efficient use of total amp power. Bi-amp using two stereo amps, one for high freq both speakers and one for low freq both speakers, wastes some power but offers further isolation of bass from treble, in theory giving lower distortion in treble. Most experts prefer monoblocks but both ways sound good, also you should have bi-wire capable speakers to take advantage of either method, Shayner gives good summary of reasons to bi-wire and bi-amp....regards Sam
Willi, I would also point out my experience with my MF amps is the monoblock set-up produces a better 3D soundstage, deeper, wider etc. I also like the fact that it eliminates one pair of interconnects from the sound path, compared to two stereo amps used for bi-amping, monoblocks are more direct signal path........I have also run high freq drivers with one stereo amp and low freq with two monoblocks, but that is getting beyond this subject....regards Sam