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.