[Caminatr]

My Home Theatre setup is powered by a Marantz SR-18 with Definitive Technologies BP2000's (L/R), CLR 2500 (Ctr), BP2006's (LS/RS), and the subwoofers are the one's built into the BP2000's. The other night, while listening to BT's "This Binary Universe" DVD in DTS mode at my usual volume level (Pretty consistent 100 dB level with peaks about 110 dB), the receiver started going into protection mode repeatedly. Protection mode mutes all channels for several seconds. I could only play the disc if I dropped the volume levels to the 80's. I started tinkering with the channel levels and noticed that the RS was significantly lower in level now than it had been before. I recalibrated the channels and resumed playback but it started having problems again as soon as I raised the levels. I recalibrated again and dropped the level of the RS to as low as it could go and started play again. This time I was able to play at the normal level (100-110 dB). I though I had found the cause of the problem and assumed it had to be the RS channel on the SR-18. The next day, I started thinking about the problem again, and decided to test the RS speaker. I recalibrated the channels again to normal and sure enough, protection mode clicked in again. Next, I disconnected the RS speaker. Doing so allowed me to play at full level. This made me think that it was the speaker and not the SR-18. To further test my theory, I swapped the surround speakers (LR was now RS and RS was now LS) and with the normal levels, protection mode engaged if that speaker was connected. So, I figured I had confirmed that the speaker was the problem. I disconnected the LS (Originally RS) and was able to play the DVD at my wonderful 100-110 dB levels. Unfortunately, after recalibrating the levels and resuming playback, protection mode again engaged. This should not have happened since the "Damaged" speaker was no longer connected. Testing confirmed that the previously healthy surround speaker now had the same problem that it's brother had. Now, with both surrounds not plugged in, the system plays at normal levels. I relocated the damaged surrounds and plugged them into my computer system and they both play, but at seemingly lower levels than before. Also, there is an odor that comes from them while playing.


I'm thinking that both speakers were damaged by a problem with the RS channel on the SR-18 and that both BP2006's and the SR-18 have to be repaired. Anyone else care to give me their $0.02?

 

[louthewiz]

The wire has a short in it so check it carefully ,if it was the speakers the avr would not even turn on .

 

[Caminatr]



Quote:
Originally Posted by louthewiz /forum/post/0


The wire has a short in it so check it carefully ,if it was the speakers the avr would not even turn on .

So you're thinking that the amp is ok, but there's a short in the speaker wire? I would LOVE for you to be correct as new wire would be less than repairing the SR-18.

 

[lexa695]

Check the wire for any partial breaks or if a nail or tack is going through them. Also check what the load (Ohms) and make sure your receiver is set accordingly. If you have in the wall wiring and you have recently hung anything with a nail, remove it and see if you still have the same issues. Running too low a load would trigger the auto protect. I am taking a guess, but I think you were probably pushing the tiny amp in your PC so hard to drive the surrounds, that you were sending a square wave to them (distortion) and that will fry speakers faster than anything I can think of. Also, 100 dbs is really pushing the speakers probably beyond there limits. Most speakers are built and tested to around 90 dbs. You may want to consider pro speakers and amps if this is the level you want to run. They can take a lot more abuse than consumer eq.

 

[Caminatr]



Quote:
Originally Posted by lexa695 /forum/post/0


Check the wire for any partial breaks or if a nail or tack is going through them. Also check what the load (Ohms) and make sure your receiver is set accordingly. If you have in the wall wiring and you have recently hung anything with a nail, remove it and see if you still have the same issues. Running too low a load would trigger the auto protect. I am taking a guess, but I think you were probably pushing the tiny amp in your PC so hard to drive the surrounds, that you were sending a square wave to them (distortion) and that will fry speakers faster than anything I can think of. Also, 100 dbs is really pushing the speakers probably beyond there limits. Most speakers are built and tested to around 90 dbs. You may want to consider pro speakers and amps if this is the level you want to run. They can take a lot more abuse than consumer eq.

The PC test was after the speakers had already been damaged and they were being driven by a Sony STR-GX10ES (150w X 2) receiver. The Home Theatre is powered by the Marantz SR-18 (140w X5) and it and the speakers are standard 8 Ohm equipment. The speaker wire for the RS is loose and runs along the carpet and fireplace (The fireplace hasn't been used in years). I'll check it but it is unlikely I'll find a culprit such as a nail, but maybe a crimp or something. As for the volume levels, the speakers in question can easily handle them aside from whatever has caused this problem.

 

[davdev]



Quote:
Originally Posted by Caminatr /forum/post/0


The PC test was after the speakers had already been damaged and they were being driven by a Sony STR-GX10ES (150w X 2) receiver. The Home Theatre is powered by the Marantz SR-18 (140w X5) and it and the speakers are standard 8 Ohm equipment. The speaker wire for the RS is loose and runs along the carpet and fireplace (The fireplace hasn't been used in years). I'll check it but it is unlikely I'll find a culprit such as a nail, but maybe a crimp or something. As for the volume levels, the speakers in question can easily handle them aside from whatever has caused this problem.

Instead of futily tring to find a short in your wire, just get a short run of some new wire and connect it and see what happens


Also, are you connecting with bare wire? Make sure you don't have any stray strands that could be shorting the system out

 

[Caminatr]



Quote:
Originally Posted by davdev /forum/post/0


Instead of futily tring to find a short in your wire, just get a short run of some new wire and connect it and see what happens


Also, are you connecting with bare wire? Make sure you don't have any stray strands that could be shorting the system out

Ooouuuu, good idea! I'll definitely give that a try. Thanks.

 

[bryan.carlson]

You mentioned a smell, this may be of concern. I don't know if you've ever smelled a burned winding but if this is what you're smelling then the voice coil is likely shot.


When electrical stuff burns up, generally you are left with an open circuit - no current flow, hence no sound. You have sound, so you're fine here. If you have a multimeter, check the speaker resistance.


Listen carefully to the bass, voice coils tend to overheat under high volumes which can melt the glue holding them to the speaker cone. If this is the case you may hear a crackling or scraping sound while playing the speaker.


Another thing to check is amplifier power output to produce the 100-110 dB sound levels you're used to. The 2006 is rated at 92dB at 1W/1m. This means 1 watt of power will produce 92 dB sound volume. Each time power is doubled, the volume increases by 3dB so at 110 dB you're only pushing 64 watts, speaker is good to 250.


Sounds to me like you could have a problem with the amp.

 

[Caminatr]

Never posted this, so thought I'd finish off the thread. Although I was never able to confirm visually that the wire had shorted, replacing the wire cured the problem. Both surround speakers had blown their sub-woofer amps, no doubt due to the wire short, but fortunately for me, Definitive Technologies repaired them for no cost (Even though they were outside of warranty.)

 

[Blasst]

Damn! We get closure after 3 1/2 years.

Glad you were able to figure it out without much of a dent in the wallet.


Nice setup of DT's by the way.