I've used many receivers for Home Theater - a Harman Kardon AVR 65, an Onkyo TS DX797 THX for 7.1 channel HT and DVD Audio, a Sony STRDB1070 for 5.1. I've also used the big Onkyo and Sony as processors with outboard amplification. I heard a big difference. The issue is not whether an Onkyo 797 or Sony STRDB 1070 will push Axioms to high SPLs, the issue is how good does it sound. My Onkyo 797 sounded better with outboard amplification than it did using its internal amplifiers. I used an Onkyo M-504 2 channel for the front L/R speakers and an Anthem PVA-5 for the rest. I don't know whether or not the outboard amps would play louder than the internal amps, but they sure sounded much better. I used 3 Onkyo M282 2 channel amps with the Sony, and that set-up certainly sounded much better than the Sony's internal amps.
I have a really nice 2 channel system in my garage - a Kenwood KA9100 with twin power meters, and a pair of Dahlquist DQM905s. I was listening to some nice jazz at pretty high levels and noticed that the Kenwood's power meters rarely bumped past 3 watts and most of the time the amp was putting out under 1 watt!
Now, for HT (and symphonic pieces) you need head room - amps which have the power reserves to handle sudden transients to high levels, booms, bangs, roars ... or the cannons from the 1812 Symphony ... that means you need more than 3 watts per channel. So, if most of the material we listen to does not require more than (let's go crazy) 5 watts per channel, what can be the difference between the internal amps in our receivers and dedicated outboard high power amps? More ... the Anthem PVA-5 puts out 120 watts per channel - pretty much the same as the rating for the internal amps in the Onkyo 797. So, if it's not the number of watts, what's the difference between the internal amps and dedicated outboard amps?
There's a saying - if the first watt isn't any good who cares how many more like it are lined up behind it? If you believe there is no difference between amps of similar output, then don't bother getting outboard dedicated amplification.
I tested the proposition using my ears - and upgraded my HT systems by using the receivers as processors with outboard amps. I've since sold my receivers and picked up dedicated processors - an Integra DTC 9.4 for the 7.2 system, and a fabulous Sony TA E9000ES for my 5.2 system. (I've since passed the Onkyo M282s along, and replaced them with 3 Yamaha M80s). Do I hear a difference? You betcha! Do I play my movies or music any louder? I do not! Do these systems sound better than with internal amplification? Absolutely they do! Do I know exactly why? No.
Last edited by 2x6spds; 01/03/05 06:39 AM.
