Two Amplifiers Connected in Parallel?

If you do not use an electronic crossover, this approach has limited usefulness. It works better with transistors than it does with tubes though, as most speaker crossovers are high impedance when they are blocking the unwanted frequencies. This causes a transistor amp to make less power. It may not reduce the power of a tube amp all that much.

If you use an electronic crossover, the introduction of the crossover itself will have an audible artifact. How much has to do with the design, but no crossover will be completely transparent or neutral. In addition, most speakers have nuances of driver behavior which most electronic crossovers don't take into account.

So it can be tricky! My advice is to try it but be careful- the top amplifier outputs cannot in any way have connections to the bottom amplifier (for example- through the speaker's passive crossover), else you could damage something.

I tried it last year .My set up was Aerial acoustics 10T with Rogue Zeus 200W driving bass on both channels and Rogue M150's 150W monoblocks on mids/highs with Rogue Magnum 99 pre dual outputs.I REMOVED the bridging straps at the back of the Aerials.I used this set-up for about 2 months and then tried then Mark Levinson 27.5 connected on the same speakers and I prefer the sound this way better.I am planking in the future to get an active crossover like the Bryston 10B and try it as Atmasphere describes.I was told that the Aerials have a well designed crossover specific to the design so I am sceptical if an external crossover will achieve better results.Your milage may vary,but try and see for yourself.
Best
George

Thanks everyone for the replies. Comments so far leave me on the fence regarding this. I don't have much experience in this sort of thing but intuitively, somewhat makes sense.

If I do try this, here is will do:

Equipment: Pioneer Elite VSX-32 Preamp/Receiver, Two Rega Maia amps, R & L Spendor SP7/1 speakers

Single line L and R outputs from the preamp and connect to L and R inputs on amp1. Use amp1 L and R link outputs and connect to amp2 L and R inputs. This is the parallel connection.

Amp1 R speaker outputs to R speaker tweeter, amp1 L speaker outputs to L speaker tweeter.

Amp2 R speaker outputs to R speaker mid/bass, amp2 L speaker outputs to L speaker mid/bass.

Make sense?

Stevensctt
I am not familiar with the Spendors,so assuming that they are bi-wire capable,that is they provide TWO inputs at the back ,then remove the bridging straps.Your connection seems wright.
If you want go to youtube and search for "virtualdynamics" "QnA bi-amping" there you can find a 10 minute tutorial from Rick who explains it further.
Regards
George