Axiom Home Page Forums General Discussion Advice from Axiom Owners SC-07 / SC-05 with M80s

Mike, you got excellent info from Peter C. and Chris in the other SC-07 thread, so you should be more confident now that you can get the M80s. To add still a bit more however, you should realize that although the M80s carry a 4 ohm rating, they're actually quite a bit above that for most of the frequency range(see NRC measurements )and could justifiably have been given a rating of at least 6 ohms, following the common practice of using an average, rather than minimum, number. Both speaker and amplifier manufacturers tend to be cautious(overly so, in my view)on the 4 ohm matter so that they don't get trashed in audio forums or possibly incur legal liabilities. This is rarely a significant problem.

As far as the SC-07 goes, yes Gene DellaSala's measurements at Audioholics did show distortion problems into a 4 ohm load above about 5KHz, but as the NRC measurements linked above show, the M80s have an 8 ohm impedance throughout that range. The class D switching(not "digital")amplifiers have had some problems with distortion at high frequencies into 4 ohm loads(e.g., Gene's SC-07 tests)or frequency response at those frequencies into 8 ohms (e.g., his Axiom amplifier tests), but the M80/SC-07 combination should have no problem. Calculations indicate that peaks of about 110dB or a bit more can be handled, and this should be more than enough for any reasonable home audio use. Relax and enjoy.

Chris, I'd think that simply using M80s "small" with the 80Hz crossover(as several here do)would work well, with no need to consider any "plus" type of setting.

Thanks, John. That's probably what I'll do when I get there. Just cutting the M80s off at 80 Hz, when they reach an octave or more lower just seemed wasteful.

Not that I'm in the situation right now, but my thinking was like Chris's that I'd be giving something up with M80's and global crossover. I bow to greater experience than mine! If I am ever lucky enough to join the M80 club I will try that 1st. Thanks John.

"Excellent info"? From me? I'm flattered.

Enjoy that SC-07. The SC-05 that I had was a lovely AVR. Its amp section is phenomenal, and the MCACC worked really well for me too. However, when you run the auto MCACC setup, it will detect M80's (and VP150's) as 'large' speakers. If you have a decent sub, this probably isn't what you want. In that case, I overrode the MCACC setup and did 'small' speakers all around with a 60 or 80 hz crossover. Tinker with it to make it sound the best to you - in your room and with your gear.

The only real drawback for me was the lack of independent crossovers. While I know some intelligent folks say that it's actually better to have just one global crossover, I really want to be able to run my front M80's at a lower xover than the center and rears. The SC's don't allow that.

But it was a heck of a nice AVR, in just about every other way.

Oh, no independent crossovers, ferget it.

Was away for a few days, but hadn't expected more answers. Besides more answers I got excellent information. Yeah I am convinced that the M80s will work great and going to get those speakers and the 150 Center. I am separately complaining to Pioneer since the receiver is THX Ultra certified it should be able to handle down to 3.2ohm.... either way I am comfortable with my purchase of the speakers.

My HT is going up over the next 4 weeks so will order the speakers shortly. Thanks all for the advice and thoughts!