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

I can't believe it. My Onkyo M-504 dual monoblock....just dose NOT lIKE the M80's. It gose into protect mode. Never happened before, on any other speaker. It dose NOT like the 4 ohm load.

What kills me is for the few min i had them playing..they sounded great.

Anybody on here have a Hafler or Adcom 555 that they would like to get rid of..?????

At what level were you playing? Try a lower volume setting. It shouldn't go into protect unless it is pretty loud, any amp should be able to do 4 Ohms at lower levels.


But first, check your wiring. It's more likely that there is a short somewhere. Look for one strand out of place on one end or the other.

Second, try one speaker at a time. Just in case there is an internal defect.

Ditto on checking the wiring.

you better find the source of the problem because you will NOT get my Hafler!

;-)

Unfortunatly I checked all that. I use banana plugs..all i did was unhook the Polks and plug in the M80's. I checked the ohms on the M80's..both were the same. The Onkyo just dose not like 4 ohm loads...pretty much. There is no other reason for the amp to shut down, It has never done that in 20 years...this is the first time. The amp puts out massive power...it shut down at maybe 50 watts. It just dose NOT like the load from the M80's.
So to make these work...I need a different amp.

The Adcom 555-II would be my first thought on this.

If the M80's didn't sound good for the first few min's i heard them....I would pack them back up. But they did. But i'm not about to blow my Onkyo to keep playing them. So i will look for a used Adcom 555 to replace it.

To say i'm not a happy camper at this point..would be an understatement. But if the amp can't cut it...not much else i can do.

What about at low volume?

Oh man, I feel your frustration, Bob.

Do you have an Ohm setting on your amp? If you do, and it sounds backwards to do so, but switch it to 8 ohm.

I know there is a clear setting for 4 ohm, companies are required to do that, but it limits the amount of power.

Edit: Seeing as how it is a stand alone amp, it probably won't have that ohm setting. I tried looking for a picture of the back of it, but couldn't get anything to come up.

Do you have a friend with an amp or even a receiver to borrow?

Really, I still think something is wrong. There aren't many amps that can't drive the M80s at moderate levels.

Well this is a 1980's amp. Probably never made to do 4 ohm loads.
It works great for 6 ohms as what the Polks are. But 4 ...it dose NOT like. There is nothing wrong with the setup...I've run this for 20 years. I double checked everything. Its basically the amp dose not like the 4 ohm load..period. This amp never shut down running 2 speakers, the Polks at 6 ohms and a set of old large Advents at 8 ohms....pushed to the max.

The amp, no matter how good it sounds..just dose not like the 4 Ohm load.

Yeah it will work if i don't push it too hard....but the point of the speakers was to push them. Basically anything over 50 watts the amp shuts down. Not about to blow up the amp...so it needs a new amp. At least for these speakers.

Were you running the 6 and 8 Ohm speakers in parallel? That is the + of the amp running into two wires going to the +s on both speakers, and then the same with the -?

If so the amp was seeing a 3.4286 Ohm (nominal) load at that time.

The amp is set up to run 2 sets of speakers...2 sets of connectors. You can shut them down from the front of the amp.

To be honest....i don't think the amp likes 4 ohm loads.

At this point...either i return the speakers, or get an amp that can handle the 4 ohm load...at volume!

Wait, do you have a second set that you're trying to power with the M80s?

That could be either parallel or series. If you set it to A+B and there's no B does sound still come out of A? If yes, then it is parallel, and impedance will be lower than either speaker. If no, then it is series, and loads will be added together.

Thanks guys..but i'm just running the M80's on this amp nothing more. I Tried to find info on this amp..All i got was 165 watts at 8 Ohms. Ran thru a bunch of stuff.....what i did find was 1 guy who said...dose NOT work for 4 ohm stuff.

Which now i beleive 100%.
So either i send them back, or find an Adcom 555 to power them.
In any case NOT what i really wanted.

Play them at low volumes and put your ear up to each driver to make sure each of them is working. I know of at least one case on here who had a pair of M22's that would shut down a receiver at a certain point which was caused by a defective woofer. After the woofer was replaced, no more protect mode.

You might as well give Axiom a call and explain your problem, they might have an idea. They're answering calls on the weekend.

Well i can try that. I already talked to Axiom...they could not find any info on this amp. no problem with sending them back, if i want to. I just have a bad feeling this amp will not do 4 ohm loads..the one guy put it point blank pretty much...don't try to run a 4 ohm load on this amp..NOT going to work. So at this point..i beleive the guy.

The question now is do i spend another 500 bucks or so to find out if these speakers really work or they don't....LOL

I don't know why anyone is surprised by an Onkyo shutting down with the M80s. Ether buy a different amp or get the M60s. I know it has to suck but it is what it is.

It is what it outlaw, oops, I mean is.

Or the flavor of the day.

M60's might be an excellent choice.

The Onkyo M-504 power amp...is a great amp. It had great reviews and works perfectly..for 20 years. The problem here is it dose not work with a 4 ohm load. Which it was never designed to do i guess. But high end stereo speakers of the time, were not 4 ohm either. Don't fault the amp. It is the best amp Onkyo ever made.
This is nothing but a power amp..hugh, weighs a ton.
Stereo hi end speakers of the time were never 4 ohms. The amp works perfect, with all the others.

Just a while ago, a Denon receiver would have been enough.

I run M80s at reasonable volumes off a 75 WPC Harman/Kardon receiver. I think there's something else going on here--either a problem with the speakers or a short in the wiring.

I thought you only needed 2 WPC!

Speaking of Outlaw, this looks interesting:
http://www.outlawaudio.com/products/7900.html

An amp that requires dual 15A breakers is quite a beast...

I know of one speaker from the past that has always been 4 ohm, Magnepan. I doubt it was unheard of.

That was exactly my thought as I read this. AFAIR when I first started reading this forum several years ago only new Onkyo’s were being recommended for the M80s as previous models were not cutting it. That was exactly why I torture tested mine when I bought it just to make sure it could handle the 4 ohm load.

I agree.

Ken.C. is right.

I use an Onkyo Integra M-504 to drive a pair of Thiel CS 3.6 towers. They are 4 ohm rated speakers and reportedly a difficult load to drive. The Big ONK has no problem whatsoever driving the Thiels to high volumes with no discernable distortion and no problems, all day long.

There were many 4 ohm speakers available in the 80's, including Dahlquists, and KEFs - I'm sure there were more, but those are 2 that come right to mind.

Something is wrong with your speakers, cabling, or your M504.

Good luck.

PS

I just pulled out the manual for the M-504. They are rated at 165 wpc at 8 ohms at 1KHz, 0.003% distortion. They do not give an output rating at 4 ohms.

Worse, the manual indicates that the fault protection circuit may initiate when excessive current appears at the terminals as when speakers of lower impedence are being used.

Looks like I am lucky with mine and the Thiels.

I also have a bunch of old Yamaha M80 amps. They are rated stable to 2 ohms.

I THOUGHT I had heard that amp name floating around before. Thanks for backing me up.

But, have you tried M80s? It could just be they drop to low at a certain point for the amp. Maybe your Thiels are a more consistent load.

Ooops. Sorry if I misled you Ken.

Generally speaking, vintage 2 channel amps should do well with lower impedance speakers as that is what they were asked of is to power 2 speakers. Like most things, the build quality of vintage units can be superior (though I don't know anything of this Onkyo). With today's electronics there is the tradeoff with features over power and build quality. With modern units it really boils down to features, purchasing power and (increasing) economies of scale of production.

2X6spds....if your running the 504 on Thiels at 4 ohms.
I don't get it. This amp has never shut down until today. With the M80's.
The Polk SDA 1C' run at 6 ohms..i can run them to extreme volume
Its like blow up the speakers before i get anywere near the amp has a problem.

There is no diference in cable or anything..monstercable, Banana plugs....just moved 1 speaker for the other.

Then I'm at a total loss on this... if you can run the Theils at 4ohms..at high volume..and you have no problem. I don't get it.

So, the Onkyo Integra M506, M507, 508, 509, 510 amps are all rated at 4 ohms, some at 2 ohms.

The M504 is only rated at 8 ohms. Wid may be right that the Thiels are an easier load to drive than the M80s.

Audio may be like golf - full credit for luck.

OK...I buy the fact...may not do 4ohms real well

If i buy an Adcom 555 II is there any reason on the face of the planet...why these M80's will not produce really loud sound..like exteme, my ears can't take it..and the power amp would shut down. Would this power amp shut down for any reason at all???? with these speakers?????

Few people have suggested that there might be a problem with the speaker itself, maybe you should investigate that route before investing on another amp.

Try driving ONE speaker on one channel. Then, try that same speaker on the OTHER channel. Then, do the same sequence for the other speaker.

It might not tell you anything. But it might tell you something.

There might be something wrong in one channel, or in one speaker.

Hook the Polks back up. You might have fried something in the amp when you transitioned from one set of speakers to the other.

I'm VERY surprised that amp is having a problem with the M80's.

OK..I "assume" you mean a number of people have had a problem and i should look elsewere. Like the Thiel, which seems to work with this amp.

I think Bruno means that there might be a physical defect in one of the speakers.

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.

if you'd want to test with 8 Ohm load, connect both M80s in series on one channel and then test again by connecting on the other channel.
2 x 4 Ohm speakers in series will make 8 Ohms.

Can you clarify the conditions in which the amp is shutting down.

I am under the impression that you turn up the dial to a certain point and the amp shuts down. In which case like what a few people experience in the past sounds like exposed wire being damaged by an animal, vacuum (cleaning lady) etc or something going on like a whisker at the connection point. Since you are using banana plugs, check the banana plugs on the onkyo and at the speaker terminals that they are not touching either. This can cause the amp to shut down. The Polk terminals might have a bit more space for the plugs than the Axioms.

If there is a short inside the speaker itself then the amp would react the same way.

Tom's idea of trying the speakers one at a time is very valid. There may be a problem with one of the speakers, and that test would root it out. Also, trying them at low levels is another good idea. If the amp trips at low levels there is most defintiely a short somewhere.

If you don't know how to do this the wiring goes:

+ from the amp to + in speaker 1
- out speaker 1 to + in speaker 2
- out speaker 2 to - to the amp

Hello bobt,

Sorry you're having problems with your M80s and the Onkyo power amp. Like 2x6spds, I believe the old Onkyo M-series of power amps are very robust and it shouldn't have any problems with a 4-ohm load like the M80s. By the way, there were lots of 4-ohm high-end speakers back in the 1980s, including models from Acoustic Research, Infinity (the Kappa series), B&W, Acoustat, Axiom, Apogee, Duntech, JBL, Linn, Boston Acoustics, Dahlquist, Altec and so on.

Back then, at the AV magazine in Canada that I edited (Sound Canada, then Sound&Vision), we tested a fair number of big power amps, including several Onkyos, some Yamahas (M1000, M800), Perraux, Bryston, Macintosh, and others from SAE,. In fact, in that time, lots of stereo receivers would drive 4-ohm loads with no problems because there were just two internal amplifiers to heat sink and keep cool (not seven!).

Although I never owned an M-series Onkyo power amp, I always admired them and recommended them. I owned several Yamaha power amps with big-ass power output meters, one of which continues to power the M80s on my switching system. It has never shut down, nor has the the mid-level H/K AV receiver I have on the M80s. At the Axiom plant, we have an entry-level ($300) Sherwood Newcastle stereo receiver that drives the M80s to extremely loud levels and has never shut down.

2x6's note about the 504 having protection circuitry that may shut it down with large current flow makes me apprehensive, but still, like others here I think there must be a short or a stray wire in the connections or perhaps a defective driver in the M80s (it's rare, but it happens).

It's only in the last decade that some Onkyo receivers had real problems with ultra-sensitive protection circuitry and the 4-ohm M80. Recent higher-end Onkyos seem to be much more stable.

The M-504 in the mid 1980s was expensive in Canada--$1500--and it's mystifying to me that it's having shut-down problems.

Regards,
Alan

Despite Bob insisting that his wiring is fine, the first thing I would have done is remove the wires and banana plugs and do it all from the get-go. Then verify the speakers by using them one at a time. If one fails, switch it to the other channel to see if the problem remains with the speaker or the amp channel.

For all the posts in this thread, I don't see evidence that Bob has ruled out these basic possibilities.

OK guys, sorry i wasn't around yesterday, did not have time to do any other tests. Just a note, the speakers will play at lower volumes, only when you turn it up dose the amp shut down.( so i "ASSUME") the M80's just drop too low, ohm wise then this amp wants to see.

I will go thru all the connections again..double check everything. The first thing i will do is connect the old large Advents up, and run them at volume. Just to make sure i didn't damage the amp.
By the way, dose anybody run QSC, or Crown amps to power the M80?
Altho not really considered "Stereophile" amps, they do put out the power and can drop to 2 ohm's without a problem. I could get one of those shipped to the house in a few days. If one of those amps shuts down...then it's for sure a problem with the speakers. Those amps i can just send back, no questions asked.

I still don't get why you don't want to run these simple tests suggested in order to rule out or confirm a defect with the M80s before investing money on another amp. But hey, whatever floats your boat!

If he can run the M80s at lower volume and the Advents balls out then I would bet the amp just doesn't like the presented load of the M80s. It sure wouldn't be the first amp that shut down trying to run these speakers.

Pro amps from Crown, QSC, Behringer, Yamaha etc will be stable with low impedance speakers and you will also have an abundance of power at your disposal as well.

But before you get a new amp, do make sure there is no short in the chain somewhere - either the speaker or cabling because if there is your next amp will have similar fate and try to protect itself and shut down if it senses a short.

Like i said, I will check all the wireing, pull it all apart and redo it. Then i will test with the Advents. I'm rather hesitant, to test anymore with the Onkyo, for fear of doing damage.

If the M80's both work at a lower volume...say about 50 watts or less(acording to the meters) I'm not sure, what good it would do to test 1 speakers at a time, plus probably do the amp no good.

i run a QSX GX5 with my M80's; the GX5 is designed for 4 Ohms minimum, but not for 2 Ohms, unless you use it at low power levels.

As far as i can hear, my GX5 sounds exactly the same as the Hafler 500 i have been using for 25 years (never suffered from "upgraditis" before 2011).

if you want to buy a pro amp, just be wary of the Crown XLS 1000; the noise floor is not low enough.

If the amp trips always at a certain point on the dial, that sounds more like a short.

An amp shutting down because it can't handle the reactive load of the speaker, I think would be more random and depend on the source material, volume and how long the material was being played for.

It's not going to hurt the amp to run one speaker at a time.

Something is very wrong there bob. I've never seen 50 watts on the output meters of my M504. 50 watts would be enough power to blow your eardrums, cause the neighbors to call the police and prompt the wife to leave with the kids.

A little off this thread but there is a TFM 55 Carver on e-bay.
380 W at 8ohm
600 W at 4ohm
650 W at 2ohm
Sorry to go on about these amps but they are clear & powerfull.

Well the 50 watts was a guess, about were the meters are,(which are probably not that acurate) but it is pretty ramdom, and source dependent, not really volume dial dependent, per say. You just can't push the source TOO much.

J Bellemare, that was the exact amp i was considering. If you say it will push the M80's...to LOUD volumes,(like concert volume) with no problems. Plus you really don't hear a difference between it and your old Hafler..works for me.

I will double check all the wires. In fact i will not change them, just check and put the Advents on there. If there is a short, the Advents should shut down the amp also. But i don't think that will be the case.

2X6..like i said that was a guess...those meter readings get very compressed, so there hard to read. Yeah it was pretty loud. But the amp has been played ALOT louder with no problems.

If there is a problem with the M80's, playing your advents will not rule out a short but only that of the cabling.

Being that you are unwilling to see if there is an actual problem/defect with the M80's buy another amp to test with them.

The only reason i picked the QSC, is i can get 1 new from Musicains Friend, have it in a couple of days. 30 day try out. I've done alot of buisness with them before. If for some reason it is the M80's, and they toast the QSC... I can just send it back to them, say it was no good out of the box. They will just send my money back no questions.

Better to blow the QSC, then my Onkyo.

Doesn't exactly win on the morality front, though, does it?

You're not taking a few minutes to try the suggestions people are taking the time to offer to you, and you have no problem buying a piece of equipment, frying it, then lying about it when you return it?

There's IS something defective here, but I'm no longer sure it's the wiring of the speakers.

the reason we are asking to check one speaker at a time is to determine if one of the speakers is causing the problem, or one of the amp channels.

It looks like you're not understanding some of the previous posts and how your equipment works. Why do you think Onkyo designed the amp to shut itself off? To protect the speakers?

Exactly, you will not blow that amp up. It will protect itself.

Quote: "J Bellemare, that was the exact amp i was considering. If you say it will push the M80's...to LOUD volumes,(like concert volume) with no problems. Plus you really don't hear a difference between it and your old Hafler..works for me."

if you do the maths, you will see that an M80 fed with a GX5's full power will do extremely high SPL's and if you try it, it might make your ears bleed.
The GX5 can put out about 700-800 Watts in a 4 Ohm load; way more than you will ever need in a room.

room efficiency for the M80 is 95dBSPL/1W/1m
10 Watts = 105dBSPL @ 1 meter
100 Watts = 115dBSPL @ 1 meter.

At 2 meters, subtract about 3 dB from those numbers above; and
at 4 meters, subtract another 3 dB.
using 2 speakers, add 3 dB to those numbers.

Remember that movies have a max SPL of about 105.
115 dBSPL is the max. for the LFE channel (low frequencies).

Very loud peaks in classical music will reach about 112-115 dBSPL.

OK...just tried the Advents...at insane volume.(well over 50 watts easy) Played the same source CD. Same songs. Everything works fine.

The reason, i chose the QSC, number 1. I really expect it to work. My gut says the old Onkyo, just can't handle the 4 ohm load right. But also the QSC has better protection circuits, then a 1980's vintage amp. IF the M80's throw the QSC into protection, and shut down. Then for sure there is a problem with them, and need to be sent back. That amp was designed from the ground up to handle 4 ohm loads. Any REAL chance of frying the QSC, is pretty much nil. But to do anymore tests with a vintage amp, that in fact could damage it, i'm just not willing to do.

Normally 1 bad driver in a speaker, will just POP. A shorted one or one with a bad voice coil, will just not play. But thats not the case here. At least from what i can see. All drivers are moving, except for the tweeters, which i can't tell. They will play on the amp, There is no dead short, as the amp would shut down right away. The chance of the speakers shorting out at high volume levels....i would think is pretty remote. I've never seen that before, but dosen't mean it could not happen.

No, i understand what your saying completely. But again, this is a vintage amp..how many times can you throw it into protection mode with out some type of damage.

Good luck with your new amp.

OK, my 2cents
And to go along with quack, MJ and such it could be a bad speaker try, testing one at atime
Put a Voltage tester on the terminals see if there's continuity, see if thees a short internally. Maybe, one of the wires came loose, maybe it even fell off and is now shorting out within.
Maybe they we're drinking the night before and hooked it up in Serial. there's only four screws per driver nothing to it to check them out

I "assume" you mean check the ohms? As to check the continuity?

This is comical......

He refuses to check the speakers and it just keeps going on and on and on

(Well I admit I got bored after a few pages and didn't read every response)

There must be an end to "the help"

Mine ended.

yeh, continuity, there should be as they are working but, the ohm's reading should not be infinity should it ?
it there's a short internally, I believe the reading should go to infinity and if they are ok a normal reading around 4 - 8 if I can remember correctly.
That would drive the amp to protect pretty quick.

If it's an open, then an Ohm meter will read infinite, or overload, or out or range. If it is a short, it'll read 0 Ohms.

If there is a defective component in the speaker that allows more current through at a specific frequency, the Ohm meter will tell you nothing.

So did mine.

Really?...I don't see anything funny about it. I've checked the speakers ohm wise. they both read the same. there is no short, testing them that way. I've checked all the wireing. NO problems.

The fact that the amp will power an old set of Polks and Advents, either 1 at a time, or both at the same time...to extreme volume would say the amp works..at least with those speakers which are rated at 8 and 6 ohm.

Now you tell me. What is the point of testing 1 speaker at a time. If the amp dose not like the 4 ohm load...it's going to shut down. So your asking me to do what. Test to see when the amp shuts down? The M80's will play...just don't try to crank them.
If the amp dose not like the load, it's going to shut down...on both speakers, or tested 1 at a time.

Basic Logic would say the amp can not deal with the 4 ohm load. But you keep harping on testing the speakers. Dose that mean there is some known problem that these speakers short out or something?

I don't find anything funny about this at all. It will cost me another $400 to find out if the speakers work or they don't.

I would recommend sending the M80s back and get the M60s. Your amp will work (8 ohm load) and you will still get a set of outstanding speakers and save money.

What they are saying with testing one at a time is; it could be only one of the speaker shutting down the amp. Therefore the speaker, which ever one, would be defective and be replaced by Axiom. This very well could be.

No manufactured product has 100% perfection. Your speakers may have been wired wrong internally. All manufactures count on a certain % of defects/not right.

Do us a favor and check each speaker, not the connection to your rcvr/amp, the speaker connections at terminals, but the speakers themselves. They "MAY HAVE" been wired internally wrong. It happens!

DISCLAIMER: I know nothing about anything!