Axiom Home Page Forums General Discussion Technical Questions Impedance graph for m80's?

Sigh... more confusion.

Fogetta 'bout it!

On the other hand I feel vindicated that I am not the only one to experience trouble with the combo of the XPA2 and M80s (with precisely the same characteristics, reference volume in a big (?) room during HT sound effects); I had begun to suspect that my unique system was somehow the culprit. Although I feel better to know it is not just me, I would be much happier, especially with regard to future component purchases, if I understood exactly what the problem was in the handshake between the two components, although I suppose the rational response at this stage would be to continue to avoid what MAY NOT WORK at the level of concrete components, even if at this stage no one can explain why they don't work/play well together, except to point fingers.

Well studying the thread further I am not sure how to explain, flyboy909 experienced a similar problem in a room about half the size (4300 rather than 7300 cu ft) and also during time of moderate playback volume; the only real commonality was not reference volume but rather HT sound effects (given my experience and commonsense logic presumably LFEs). I give up!!! Nah, never, I love a mystery!

so someone is fibbing???

Hi turbo16v,

As JohnK and others have pointed out this is pure BS. In fact, the M80 is a relatively easy 4-ohm load. I have said all along that Emotiva has a problem with its amplifiers and 4-ohm compatibility--whether that's due to inadequate current in the Emotiva power supply or wonky protection circuitry is unknown.

One thing is certain: Emotiva's engineer called Tom Cumberland, Axiom's chief R&D engineer, and acknowledged that there was a problem in the Emotiva XPA-2's protection circuitry and that he thought it could be solved.

If one closely examines the M80 impedance curve, it is much closer to a 5-ohm impedance. The curve is quite smooth and only touches 4 ohms at a couple of points in the spectrum. Much of the time, the impedance is well above 4 ohms.

If the M80 was a difficult 4-ohm load, why is it that entry-level $300 Denon and Sherwood Newcastle AV receivers can drive the M80s to loud, clean playback volumes with no shut-down or problems?

Regards,

I remember when Emo's engineer sent me instructions on how to remove the protective waveform limiter circuit from the amps motherboard, I think NOT.

Yes,it is strange that a regular reciever can run M80s without shut down issues and that Emotiva amps can run other 4 ohm speakers without shutdown issues.I hope whatever the issue is gets sorted out because they are both decent companies and do sound great together.

Suddenly I'm feeling really leery about that UPA-2, and more than about whether it would make a difference or not.

Rotel+M80s=no problems