What is known as passive biamping (I also like the description "dual amping") is certainly not difficult when using two identical amps. Anyone can do so; it simply takes more time and care to ensure that the connections are set up properly. You also need enough power receptacles, something which is often overlooked. It may be necessary to obtain a longer power cord for a component if you do not wish to use power bars or other power conditioning equipment.
It is unnecessary to scare people away from trying it with suggestions that it is very difficult. Diagrams for how to hook up two stereo amps are numerous (note that you can also use a multichannel amp with four channels, and if our speaker has three sets of inputs you can use a six channel amp). Going the other direction you can use four or six monos.
Al is right to suggest vertical dual amping. I have tried horizontal dual amping with all sorts of amps over the years and in every instance have preferred vertical. It has been so consistent that I would not even suggest trying horizontal. If you simply keep the amp's channels dedicated to a particular speaker, one channel to M/T and the other to Bass, you'll do fine. Make sure that you are using the proper settings on the amp; some, like the Cambridge Audio Azur 840W, allow for several combinations and have multiple switches for those settings for inputs and outputs.
As to sweeping conclusions regarding the usefulness of dual amping those who have never done so really don't have much to contribute. The fact is that there will be a noticeably different presentation whenever passive dual amping is tried as opposed to using amps in Mono mode.
I just finished a review of an approx. $15k speaker, one of the systems for which was dual amped integrateds, a most unusual approach. Dual amping brings its own particular "flavor" to the sound, and for some they may prefer it. It is generally true that a larger, more powerful and likely more refined amp does often sound better, and yes, often putting two stereo amps in Mono mode is superior. However, imo you will not get the full advantage of one stereo or two Mono amps unless you biwire the speakers. Note well: Switching to an entirely different brand of larger stereo amp is NO assurance that it will outperform the two more diminutive amps in dual amping mode. One simply has to conduct the comparison; a simple comparison of aggregate Watts is wholly insufficient to settle the matter of which is perceptually better.
Speaking to biwiring, after working with literally dozens of single wired (one pair of L/R inputs) speakers I strongly urge owners to try doubling up their speaker cables. No, I am not joking. You will get easily noticed superior results by doubling speaker cables, simply joining the proper leads as you would a single set. You must be absolutely sure you are not crossing wires; double and triple check. If you cannot hear the difference, then you will not really benefit much from chasing different brands of cables - just get something you like and be done. But if you love your speaker cables go get another set and slap them on, as you have not heard what a speaker can do when you have only single wired it. (And no, I have no intrest in arguing this.)
Obviously you can swap different brands of cables, but if you have found one you enjoy then double it. You have not begun to hear the capabilities of your speakers if you have not tried this. Sure, you can get a biwire pair of speaker cables, but many times the sum of conductors is split, versus having double the conductors when using two sets of speaker cables - a huge difference in total gauge, and sound.
I do concur that proper active (x-over) biamping is much more involved, but is well worth trying if you have the money and time, and are not afraid of more complex systems. With any given amp I have used in a passive mode versus active the active system has conferred upon the amp the ability to sound more powerful and with far more control over contouring the desired sound of the system.
Though I do not recommend mixing brands of speaker cabling, this also allows for some tuning of the rig's sound. If you do have different sets you will need to try all hookup options to know which will yield the best sound. Again, if you cannot easily hear any distinctions in sound when trying such things then it is less likely that you will be able to perceive distinctions betwen the two methods of amping.
Once you factor in the variable of cabling the audiophile has a lot of options for setting up even dual amping. :)
It is unnecessary to scare people away from trying it with suggestions that it is very difficult. Diagrams for how to hook up two stereo amps are numerous (note that you can also use a multichannel amp with four channels, and if our speaker has three sets of inputs you can use a six channel amp). Going the other direction you can use four or six monos.
Al is right to suggest vertical dual amping. I have tried horizontal dual amping with all sorts of amps over the years and in every instance have preferred vertical. It has been so consistent that I would not even suggest trying horizontal. If you simply keep the amp's channels dedicated to a particular speaker, one channel to M/T and the other to Bass, you'll do fine. Make sure that you are using the proper settings on the amp; some, like the Cambridge Audio Azur 840W, allow for several combinations and have multiple switches for those settings for inputs and outputs.
As to sweeping conclusions regarding the usefulness of dual amping those who have never done so really don't have much to contribute. The fact is that there will be a noticeably different presentation whenever passive dual amping is tried as opposed to using amps in Mono mode.
I just finished a review of an approx. $15k speaker, one of the systems for which was dual amped integrateds, a most unusual approach. Dual amping brings its own particular "flavor" to the sound, and for some they may prefer it. It is generally true that a larger, more powerful and likely more refined amp does often sound better, and yes, often putting two stereo amps in Mono mode is superior. However, imo you will not get the full advantage of one stereo or two Mono amps unless you biwire the speakers. Note well: Switching to an entirely different brand of larger stereo amp is NO assurance that it will outperform the two more diminutive amps in dual amping mode. One simply has to conduct the comparison; a simple comparison of aggregate Watts is wholly insufficient to settle the matter of which is perceptually better.
Speaking to biwiring, after working with literally dozens of single wired (one pair of L/R inputs) speakers I strongly urge owners to try doubling up their speaker cables. No, I am not joking. You will get easily noticed superior results by doubling speaker cables, simply joining the proper leads as you would a single set. You must be absolutely sure you are not crossing wires; double and triple check. If you cannot hear the difference, then you will not really benefit much from chasing different brands of cables - just get something you like and be done. But if you love your speaker cables go get another set and slap them on, as you have not heard what a speaker can do when you have only single wired it. (And no, I have no intrest in arguing this.)
Obviously you can swap different brands of cables, but if you have found one you enjoy then double it. You have not begun to hear the capabilities of your speakers if you have not tried this. Sure, you can get a biwire pair of speaker cables, but many times the sum of conductors is split, versus having double the conductors when using two sets of speaker cables - a huge difference in total gauge, and sound.
I do concur that proper active (x-over) biamping is much more involved, but is well worth trying if you have the money and time, and are not afraid of more complex systems. With any given amp I have used in a passive mode versus active the active system has conferred upon the amp the ability to sound more powerful and with far more control over contouring the desired sound of the system.
Though I do not recommend mixing brands of speaker cabling, this also allows for some tuning of the rig's sound. If you do have different sets you will need to try all hookup options to know which will yield the best sound. Again, if you cannot easily hear any distinctions in sound when trying such things then it is less likely that you will be able to perceive distinctions betwen the two methods of amping.
Once you factor in the variable of cabling the audiophile has a lot of options for setting up even dual amping. :)