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Discussion Starter #1
I posted about this the other day, but I am completely stumped and at my wits end. I have three BG Radia PD6LCR 4ohm in wall speakers which I intended to use as my fronts and center channel.

I finally got the L/R speakers installed so I could test them out, and that's when the problems started. Basically, the left speaker keeps cutting out, and the volume goes down to basically where you can't hear it unless you put your ear up to the drivers. The right speaker continues to play fine at normal volume. HOWEVER, if I shut everything down, then try again a little later, the speakers sometimes play fine before once again, dropping volume. It's completely random.

It's not the cables, I changed them.
It's not the connectors on the back of the AVR.
It's not the banana plugs on the speakers, I checked them.

I have tried all three of the PD6LCR's and two of them exhibit this same issue. I've tried THREE different AVR's--two of which were not rated for 4ohm output and the other which had a 4ohm selector switch on the back.

Still, at least two of the PD6's exhibit the issue with all three receivers.

Now, I consider myself reasonably intelligent. The fact that different speakers of the same model are doing the same thing on three different receivers leads me to the following possible conclusions:

A) two of my speakers have bad crossovers, and this is what causes the random volume drop.

or

B) While trying to test out the speakers on my "8-ohm safe" receiver, I somehow damaged the speakers by clipping or providing them with insufficient current. (?)

or

C) Being 4ohm speakers, the PD6LCR's are hard to power, and the AVRs I've tried to far have simply not been up to the task.

I simply don't know enough about speakers to be able to diagnose this. I thought if an AVR was pushed by 4ohm speakers it would go into thermal shutdown. Not continue to play with one channel at reduced volume.

Could the crossovers be damaged, even though the speakers play fine for brief periods before the volume drop happens? If something on the crossover was blown, wouldn't the speaker "sound bad" all the time, not just intermittently?

Which is more likely: two bad crossovers, or three AVRs that can't handle the impedance?

I just ordered a new "4-ohm certified" receiver so that, I once and for all, can test the speakers out on an AVR that SHOULD drive them. But I have a sickening feeling that the two speakers are the culprit and I just wasted $700 on a new AVR.
 

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Buying a 4 ohm receiver for 4 ohm speakers is NOT a waste of money. In fact, it's what should have been done from the beginning. I'm gonna guess that the speakers actually dip below 4 Ohms at some point and the receivers you have been using are just not capable of handling it and some sort of internal protection circuits are being engaged. If you can shut everything down and have it work again does not point to the speakers, but to the receiver(s) as the culprit.

Try the new receiver. If you can't get it to work, then you probably need to replace your speakers with something more receiver-friendly. Contacting BG with your issues may also yield some info.
 

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Do you have an Ohm meter? Do all the speakers measure the same? Should be around 3.2 Ohms. Just after the speaker goes quiet measure the resistance to see if something is warming up and loosening.

Have you opened the boxes to check if anything is loose?
 

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Discussion Starter #4
Buying a 4 ohm receiver for 4 ohm speakers is NOT a waste of money. In fact, it's what should have been done from the beginning. I'm gonna guess that the speakers actually dip below 4 Ohms at some point and the receivers you have been using are just not capable of handling it and some sort of internal protection circuits are being engaged. If you can shut everything down and have it work again does not point to the speakers, but to the receiver(s) as the culprit.

Try the new receiver. If you can't get it to work, then you probably need to replace your speakers with something more receiver-friendly. Contacting BG with your issues may also yield some info.
Thanks for the reply... The reason I dont have a 4ohm stable receiver is because my previous speakers were 8ohms, and I had no desire or intention of going the 4ohm route. Things changed, and my search for in-walls led me to the Radias. All the research I did online about running 4ohm speakers with 8ohm rated AVR suggested it was common practice and no big deal.

Anyway, so you think the fact that the speakers still sound fine at times somewhat rules out a damaged crossover? In other words, if the speakerss were damaged, then they would always sound bad from here on out, not just intermittently?
 

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The crossover parts are most likely fine. There could be a loose solder joint or crimp connection that is getting warm with some useage and loosing up causing the voltage drop. If you have an Ohm meter you can check the parts.
 
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