Axiom Home Page Forums General Discussion Advice from Axiom Owners The M80's just got here....the AMP will not work

Tom....I hope the hell not. The amp has been perfect for 20 years. I'm not going to try the m80's any more. I'll throw the old Advents on it...make sure it kicks ass.

You could go to Best Buy and get a Denon receiver and give it a try. Then take it back once you know the speakers are OK, or just keep the Denon.

Bob, what I meant is that sometimes things happen, it's part of life. A few people suggested for you to check the drivers to take the speakers out of the equation but I didn't see a reply that you did, it might be something wrong with them or not, but worth to have a look.
I think by now, people understand that your equipment is the same and that your Onkyo had no problem driving your Polks for 20 years. These are not the Polks and I think any suggestion to determine where the problem is, is a good suggestion, it might be that the Onkyo dose NOT like the 4 ohms load or it might be the speaker, who knows?.
I, myself had a bad driver on one of my QS8s, I called Axiom, they sent me a new driver right away. Like I said, things happen. Now, if you want to look elsewhere is up to you, Axiom will give you a full refund..

I got some info stating that the amp is 4 Ohm stable.

Power Output: 165 Watts Per Channel, min. RMS, at 8 ohms, both channels driven, from 20 Hz to 20 kHz, with no more than 0.003% total harmonic distortion.
165 Watts per channel, into 8 ohms at 1 kHz, 0.003% THD
Total Harmonic Distortion: 0.003 % at rated power. 0.003% at 1 watt output.
Intermodulation Distortion: 0.003 % at rated power. 0.003% at 1 watt output.
Frequency Response: +0, - 1.5 dB at 1Hz-100kHz
Input sensitivity: 1Volt
Input Impedance: 20 Kohms
Damping factor: 140 (8 ohms, 1 kHz)
Signal to Noise Ratio: 120 dB (IHFA, Shorted)
Outputs: Speakers 1&2. AC OUTLET UNSWITCHED X1
Inputs: L/R Input
Power Supply: AC 120V, 60Hz
Dimensions: 465(W)x185(H)x422(D)mm. 18-1/16(W)x7-5/16(H)x16-5/8(D) inches.
Weight: 22.5Kg, 49.5 lbs.

Features:
Power switch and LED indicator
Speaker A Switch and LED indicator
Speaker B Switch and LED indicator
Speaker A and B Relay
Protection Relay
Peak Meters. Large and easy to see with soft greenish blue lighting. These meters are Extremely precise and fast power meters.
Servo Operation indicator (When power is turned on)
4 ohm stable
Rear panel features RCA in put jacks.

Convenience outlet on back of unit.
Heavy Duty bind post speaker outputs.
Convenience outlet
Made in Japan

Bob, your frustration is understandable, and you've continually repeated that the the M-504 doesn't "like" 4 ohms. It's highly likely that this isn't actually the problem though, since the history of the M-504 indicates that it's a very powerful amplifier, including 4 ohm output.

As others have said, an intermittent short somewhere in the wiring appears to be a more likely problem. This might even be internal wiring in one of the M80s, so as Tom suggested, try driving then one at a time to see if only one of them causes a shutdown.

WOW..were did you get the info on this 504 amp? I looked all over the place but could not find the spec's.

I checked the Ohm's on the speakers..there the same.
The cables are perfect..no shorts or anything,,,work fine.
The problem would be i'm not about to blow up the amp..to see if the speakers have a problem. I could check 1 speaker at a time...but again.. i have to run it till the amp shuts down.

Not my Fav thing to do...as i could blow up the amp doing this.

What DB levels are you getting to before the amp shuts down?

Bob, relax; don't let your frustration cloud your judgment. Any competently designed amplifier, certainly one as fine as the M-504, has a protective circuit which shuts things down when there's a short(or overheating)without damage being done. You shouldn't hesitate to test further to see what the real problem is. Don't be frightened by the 4 ohm monster, but if you want, you can try the M80s at around 8 ohms by playing a 1000Hz test tone, where the M80 impedance is around 8 ohms.

I don't think hooking up an ohmmeter to speakers is necessarily a valid test. If you look at impedence graphs, speakers vary by frequency. You're likely testing a single frequency with an ohmmeter, so you may be missing something there. Trying out some of our advice would probably be more help to you than simply saying that the amp works fine or it doesn't, over and over again.

I'm not sure why you're stuck on Adcoms; there are plenty of other manufacturers out there, but that's a whole 'nother discussion.

Indeed, speakers are a reactive load. They change impedance with the frequency of the alternating current they are fed. An Ohm meter measures the resistance (not impedance) with DC. It is not a valid test.