Arthur- I agree with John and the only disadvantage I know of is the amount of space 5,6 or7 monoblocks can take up. I currently own two stereo amps and three mono's which is a slight compromise over having all monoblocks. Personally, I would absolutly never purchase a 5 or 7 channel amp. A nice compromise might be a good 3 channel complimented with mono's to fill out the remaining channels. If you have the room and enjoy the very "cool" look of stacked monoblocks, go for it.
It's all about the power supply. A monoblock does not share it with other amplifiers so loading by low impedance loads will not cause the rail voltage to sag as much from a high impedance load since amps are rated at 8 ohms for all channels driven and for most multichannel amps the increased current demand on the power supply will affect all the amplifiers. There are some multichannel amplifiers that have independant power supplies for each channel.
Doesn't the fact that multi-channel amps share a power supply only applicable when you play them at super loud volume? If so, 99% of the time, mono's vs multi's wouldn't make much difference.
Well - you can always go w/ Sherbourn. The 5/1500A's design is 5 monoblocks inside the main chassis. No shared power section w/ the space of a traditional amp.
Several multi channel amps have individual power supplies for those looking for this feature however, my preference for the monoblock is in their versatility. Much easier to move around 25-30 pounds vs. 70-100lbs or more. This would just be my preference and I'm sure many would prefer the one box multi-channel design.
Todd named the lower cost monos commonly found in use.
I use 5 IRD MB-100's for my HT and recommend them highly.
Once known as Le Amp, the IRD's designer and owner recently pulled the Le Amp from nOrh and now sells his unit exclusively through his website.
At $269. ea. shipped you will NOT find a better monoblock that can even get close in this price range, let alone in performance.
www.audiocircle.com hosts IRD's forum and site link. 23lbs per mono, 3 year warranty, and an overbuilt mono that will easily push 175W when needed.
my .02.....and IMHO...... (the MB-100's are made in Thailand and ship from Charlotte,NC--- i.e free shipping to your door).
Service is above and beyond, as evidenced when Curt, the owner, fixed and brought up to spec, a mono I had bought used and which was damaged. He fixed it NC and sent it back to me, again, no charge. It was out of warranty too. A great company and a super product. I sold off my Marantz MA6100 monos after listening to the MB-100's. No contest... the Marantz got squashed.
And they easily bested the amp section of my Yamaha DSP-A1 integrated amp. Yes, flexibility is a plus, but clean, steady power (and then some) for long, sustained, and highly demanding HT audio scenes is where they earn their followers.
Hard to push monos too hard if they are built to an overkill spec.
Arthur, what about buying 5 rackmount prosound power amplifiers? If you bridge them mono, you can get 800+ watts for each. It would essentially be the same as having 5 mono amplifiers.
You can get the QSC RMX 1450 for $399 each and it does 900 watts rms into 8ohms mono and 1400 watts rms into 4ohms mono.
They do have a downside though, the fans can be kinda loud...
The IRD MB-100's run cool to the touch.... even after Das Boot and U-571 ...back to back... in truth.. LOL.. the heat sinks weigh at least 10 lbs ea. No fans included. I never turn them off in fact-- 24/7.