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!

You understand that the speaker is only 4 ohm at certain frequencies, and in fact much higher for most of the range?
What we are saying is if one of the speakers are bad, which is unlikely, this way you will know this. If the amp shuts down only driving one speaker, and not the other, you will have your answer, I don't really care what the multimeter is talling you.

Most likely, your amp just can't handle the m80's for whatever reason. Kinda like when my old Emotiva MPS 1 kept shutting down driving my M80's. On paper they say it will, but in reality it wasn't designed to what the paper said. During wide dynamic jumps in dB's they would puss out.

The reason they are asking you to test each speaker individually is to rule out anything that may be wrong with one of the speaker’s drivers or electronics components that is not detectable by the meter. If one speaker shuts the amp down and the other doesn’t then you’ve narrowed the problem down to the one speaker. If both speakers shut the amp down individually then IMO the amp and M80s just don’t play nice together, though there is a slight chance both the M80s could be bad, but not likely.

Certainly you can buy another amp that you know can handle the M80s and if it also shuts down then you know that one or both (not likely) of the M80s are bad. Testing the speakers individually with your existing amp or borrowing a receiver from someone to do it will just let you know sooner.

My suggestion is that you return the M80s and just buy something else since your initial hesitation and this experience have likely tainted your opinion of them to the point that if you do get them working properly cognitive dissonance will stop you from wanting to keep them.

Hi,
All and each Axiom speakers pass a final performance test prior to being boxed which eliminates wrong internal wiring. A hard and severe shock while in transit might have caused internal damages. Because of the memory foam type used by Axiom for superior protection ; such an occurence might not be apparent.
I agree that each M80 should be powered individually helping at determining if one of the two speakers was roughly handled durng transit.

Well maybe I pushed that one ..... but all manufacturers count on things going "south" ..... in the field, after delivery ... the world is not a perfect place and things happen during delivery or with users ..... and ocassionally after product testing in house by a human....a fight with the wife, a bad day, etc............. just saying

they are actually tested by an android that is incapable of error.

Their QC is a phone or tablet?

No Lieutenant Commander Data, he needed a job after he retired from the Federation and outlived his crew. Here is is running frequency sweeps on Bob's 80's before they left the shop.

OK, any manufactured product can be bad. Nothing is 100%.
But the problem is more like what sirquack said. It just can not handle the M80's. Since i can find no real info from Onkyo on this amp,plus have no idea what this protection circuit is.
I'd rather go with the QSC, which has a big protection circuit, which is not likely to blow up. Rather then risk a vintage amp.
Basically if the M80's shut down this amp...then the speakers are at fault, and i can send them back. To be honest, i'm not in the mind set to pull all the drivers out of these speakers, to check stuff. At least at this point.

I tried to find any and all info on the Onkyo amp. The only thing is i did find a review, where the guy said, great amp, but don't try to run 4 ohm speakers on it. I now have to believe the guy 100%.

That one guy does seem to have the credentials. I'm all for it.

Bob, why are you so reluctant to run one M80 on your amp at a time as many have suggested?

It would seem this would be the easiest and fastest way to determine if it is in fact a single M80 that has a bad crossover component etc. If the amp shuts down driving either one M80 then you will know it is that speaker causing the problem, if it shuts down for both, as grunt mentioned, it is most likely your amp and the M80s do not like each other at which time I would then go ahead and purchase the QSC amp as I highly doubt you would have 2 speakers damaged in transit.

Big ONK, Integra M504 with Onkyo TXNR 1007 driving the Thiel CS 3.6 towers. Surrounds left to the receiver's amp sections.

I like the compressed air. What speaker is that behind your equipment?

No problems. Big ONK never even gets warm. Output is huge and clean... or, soft and clean, or mid volume and clean. The meters are large and 50 watts indicated 3/4 or more to the right of the scale.

I knew someone would ask. The speaker to the left of the rack is a Michaura M55. Downright gorgeous and sound quality to match. Oh, that's a 3/4" Axiom made titanium tweeter, and ooh, there's a pair of Axiom 5.25" drivers, but the cabinet is a beautiful, hex shaped, heavy, SOLID, piece of work. Sound quality is wonderful.

If you were asking whether there is a speaker behind the rack, no, that's the rack, with holes for cabling.

I'm not sure what the problem is with this? i'm willing to spend an extra $400 to test out the speakers, rather then damage a vintage amp which i know works.

The QSC will handle the shut downs....IF that happens. The old Onkyo...I'm not sure about. Plus i'm not willing to risk a vintage amp that at the time cost as much as the M80's. So what seems to be the problem?

It's pretty basic...if the M80's shut down the QSC.....there are broke. Period. The amp was built to run 4 ohm speakers.
If they work...great...problem solved.

Old Portuguese saying:
Vira o disco e toca o mesmo
http://translate.google.com/#pt|en|

Well, I understand your affection for the big ONK, but it has fault protection ... circuitry which is well established and proven for more than 6 decades. The fault protection protects both your amp and speakers. Don't be afraid. Test it.

Save yourself $400!

BTW, do you have a picture of your M504?

I had a old Kenwood M2A that was able to run the M80s, no problem.

That looks a lot like the Yamaha M80 monster amplifier which also had no problem driving the Big Thiels.

It still runs a set of Bose 901s. I gave them to a very good friend of mine.

The problem with testing like that is...basically, the amp is going to go into protection and shut down. Either with 1 speaker, or both. Lets face it..if it dose not like 4 ohms...just dose not like it. This power amp is OLD...I don't know how good this circuit is , or what it is. If you do this enough...something is going to break. Just not worth the risk to me.

bobt, the word you're looking for is "does", not "dose". That is driving me effing crazy.

MMmm Hmmm.

2X6 the 504 looks just like yours. But again i'm not willing to risk blowing it up. Basically with these old amps..you keep throwing them in protection...NOT good.

The QSC will work..or not..in any case will not blow up the QSC..which i can send back....if it dosen't work with the M80's..then there is a problem with the M80's and i can send them back.

Not real rocket science here...just strait logic. Just not willing to risk the 504, thats all.

Using them at all is going to wear on them, too. As old as it is, it's already well into its life. Protecting your equipment from its own protective measures is fine, but as you mentioned, you don't mind frying a new one that you can then return as faulty. Straitjacket logic, indeed.

Of course, I feel like we're bullying him into trying this test, and we could be jinxing it into blowing up the amp. On second that, I don't mind him buying a new amp and testing it that way, since if it were me, I'd buy a new amp, anyway, even if testing it proved one of the M80s was at fault. I just wouldn't want my nice speakers being powered by such old equipment.

Wow, is all I can say. Good luck on that.

Well the QSC amp, has little or no reason to blow up. It is brand new has way more protection then a 1980 amp. It was built to handle 4 ohm loads. If it shuts down at all...then the speakers are the problem. That amp will put out 700watts at 4 ohms..way more then i would ever need, or anybody could be in the room to hear. The chance of this amp getting toasted...is pretty much nil.....has WAY better protection circuits then the old amp.

Like i said..this is NOT rocket science. It either works or it dosen't.

NOT that I don't think your tests are valid.....just not willing to risk the 504 amp. The M80's are NOT going to damage the QSC...if that amp shuts down...the speakers are at fault..period.

I hope it works out for ya Bob, good luck.

Well, let us know the results
I am not going to suggest to try one speaker, but if they do ( when ) they shut down on the QSC, try the one speaker test and see which one it is Doesn't Axiom pay for free shipment back and return if it is faulty?

And I think somewhere there was a list Axiom recommends for Recievers that work great with thier products, I am sure the 504 wasn't listed.

Sometimes great products need tried, tested and proved great products to give ultimate performance. This maybe an example of a F1 car running a race on gasoline and trying to figure out why he never won ?

LOL!!!

Since your so knowledgeable of the circuit protections used in the 80s and the ones used nowadays, maybe you could share some with the rest of the forum, all of us here are always willing to learn. Schematics (if you could find the board layout and the number of layers used, that would be nice!), circuit block diagrams, IEC 60950 results, fuses (resettable and non-resettable) and sidactors schemes, overvoltage and overcurrent measurement circuitry (an IC part number would be nice!),etc, etc... anything that would be useful, like I said, we love to learn new stuff.
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Sorry guys but I just can't take it anymore.

No the M504 is not listed anywere. Infact the only "valid" info I can find from Onkyo or pretty much anyplace else...just lists it as an 8 ohm amp.
So i will order the QSC on monday. May take a week to get here. but I'll know in 10 min's or less if it works or not.

If you were close to the Chicago vicinity I'd bring over a Rotel amp.

I just hope once the shutdown issue gets resolved, we don't have to go through the speakers are "bright" routine.

NO bdpf....I can NOT find the drawings for this 1980's amp,Or very little else, number 1. Number 2, if a 2011 amp, dosen't have a better protection setup, then a 1980 amp...there is pretty much something wrong.

Why in hell would you think circuits from 1980, would work all that dam well?????

I said ...I DON'T KNOW..what they used...SO I can't TELL how many times you can throw it into protection mode, without damageing the dam thing. What the hell is your problem????

I have said NOTHING wrong about the M80's......All i stated was this amp, dose NOT seem to work well with a 4 ohm load.

No Kidding!
Next to this, the discussion between 2x6, Lampy, Peter and Randy looks like a breeze... At least, these people know what they're talking about.

Nice head-palm with sucking in of breath through pursed lips, for the stupidity of it all, Blue Jays.

Couldn´t agree more!!

I say get off Bobs ass and let him do his thing. He'll find out what's what in his own way, nothing wrong, or stupid, for him doing so.

LOL! Can´t tell anything about the M80´s but the speakers being bright idea never crossed my mind. My new KEF Q300´s have a very similar sound to my Axioms IMO.

Yes, wid. I should have thought more before commenting on Blue Jay's picture. bobt, I was not referring to you, I just wandered off topic a bit.

Good luck to you bobt. I not only really like my M504, but I picked up new wood side panels because one of mine came scratched and some veneer peeled off the top.

AFAIR, nobody in this thread said that Bob's idea of trying another amp was stupid. In the end, there might be nothing wrong with the M80s and his Onkyo might just not be able to drive them.
What's outstanding is is rejection for 13 pages to try something extremely simple based on some reason that makes no sense at all.

What I realized is that in this forum we're only good to convince people spend more money, not less Usually, people come to the forum asking if M22s, VP100 and QS4s are enough and they end up with M80s, VP180 and QS8s. Here we're trying to save Bob $400 for an amp in case the problem is with the speaker and we're not able to

Anyway, Rick is right. Bob, good luck in solving your problem in whatever way makes sense to you.

Well, everyone is different from others and also think differently. If not what would be the joy of being a human being if we were all equals and think all equally? Sometimes fear of losing something that you like can blind you from seeing things they were supposed to be. Guess that he is so afraid of frying his AMP ( that he loves so much ) that this is blocking him from trying out the suggestions. For people who are sure of the outcome of what will happen if they try to use the amp and will simply shut down it is easy to accept the suggestions, but if he is blinded by fear in any way...

This might be something going down deeply in his conscious, so it will never change.

Bob, if you consider the Onkyo M-504 manual to be "valid info" and if you bother to take the time to read it, as I have, you'll find at p.4: "Only use speakers with an impedance rating of 4 ohms or more with this unit". The reason that the M-504 doesn't show an "official" 4 ohm power rating is that in order to do so under FTC amplifier power regulations it would have to drive a 4 ohm load at the full rated power for at least 5 continuous minutes, which few units are designed to do without overheating. In real use, you may find, as have others, that the M-504 not only "likes" 4 ohms, it loves it!

Oh my... why is this thread so long!

After having John confirm, I just think the amp is too old for the ohm load as things do wear out and you better buy another.

I wouldn't get rid of the M504. Find someone who can work on electronics, swap out some of the power capacitors and enjoy the Honking Onkyo Integra. It's a great amp, and its huge power meters are downright beautiful at night.

You have spent more time arguing on this forum than it would have taken to try one speaker at a time to see if there is a short somewhere. As an EE (and ClubNeon can back me up), one more test would not cause your amp any harm especially since the trip is there to protect your amp.

Stop being so defensive, there have been a lot of good suggestions here. It's better to spend a little time to see if you have one bad speaker than to spend more money to buy another amp you may not need.

I understand where you are coming from bobt and I hope the Qsc works for you. I also hope you will stick around long enough to let us know how it works out.

(Note: the M80 tower's impedance is 4 ohms. Big rooms call for a separate power amplifier for the M80 towers. An A/V receiver rated to drive 4-ohm loads without overheating or shutting down is recommended. Call Axiom for recommended receivers or amplifiers that will drive the 4-ohm M80s.)


From a link on Axiom's main page

Hi,

As per Axiom . . .

What brand of AV receiver should I consider to drive the 4-ohm M80 loudspeakers?
For rooms up to 4,000 cu. ft in volume (length x width x height), Axiom has found that receivers from:

•Denon,
•NAD,
•Outlaw Audio,
•Sherwood Newcastle,
•Harman/Kardon,
•Rotel,
•B&K,
•Pioneer Elite,
•high-end Onkyo ($800 and up)
•and high-end Yamaha ($1000-plus)
are the most stable and will make these speakers sing. Buyers who have "great rooms" or those with cathedral ceilings or who want movie-theater-loud playback levels in such rooms should consider using separate outboard power amplifiers for at least the M80s.

Hi,

Jc, i don't see Emotiva's in your list, which I was considering for m80's. Any known issues with them??

Sarang, I use 3 Emotiva UPA-1's for my M80's & VP180, and have not had any issues. My Integra did a fine job as well which technically JC covered with high end Onkyo.

Emo must have resolved their past problems, but there was a time when they were very iffy driving the easy to drive m80's, rockets, etc. Personally, now that I've owned both, the Outlaws are much better quality/performance, and built right in the US per Outlaw specs is iceing on the cake.

Sarang,
Emotiva is not on the list because of reported issues awhile back. As you will be able to read on the forums, some owners are using Emotiva without any issues.

hmm, wonder if the amp arrived and how good the M80's sound.

Yeah, see this thread:
http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showflat&Number=347757#Post347757