[Trevdeb]

I have a Denon AVR-2307 surround receiver with Mirage Omnisat V2 Series floorstanding front and Centre speakers, plus Niles HD6 in wall surround speakers.


For the second time, the receiver has gone into protection circuit mode. The first time this happened the resistors and diodes were replaced in the front left and centre output stages under warranty.


Since this has happened for a second time I have been investigating and now wonder whether I have an impedance mismatch issue with the receiver and speakers.


The receiver is rated front A,B at 100w + 100w (8 ohms, 20hz-20khz), centre is the same. The Surround is the same.


According to the manual the impedance on all the speakers should be in the 6 to 16 ohms range.


The Mirage front and centre speakers are rated at 175 watts and their impedance is 8 ohms nominal and 4 ohm min. The Niles surround speakers are rated at 10 to 125 watts per channel and their nominal impedance is 6 ohms.


Both times when the receiver has gone into protection circuit mode, it has been whilst playing music DVD's at high volume, but not extreme. So, I am wondering if the amp has been pushing too much power over the period and it has clipped and hence damaged the circuitry? Does anyone know if this might be the case?


My second question relates to what comback would I have on the authorised Denon dealer who sold me and installed the entire package in the first place?


Hope someone can help.


Thanks,

 

[arnyk]



Quote:
Originally Posted by Trevdeb /forum/post/15451460


I have a Denon AVR-2307 surround receiver with Mirage Omnisat V2 Series floorstanding front and Centre speakers, plus Niles HD6 in wall surround speakers.


For the second time, the receiver has gone into protection circuit mode. The first time this happened the resistors and diodes were replaced in the front left and centre output stages under warranty.


Since this has happened for a second time I have been investigating and now wonder whether I have an impedance mismatch issue with the receiver and speakers.


The receiver is rated front A,B at 100w + 100w (8 ohms, 20hz-20khz), centre is the same. The Surround is the same.


According to the manual the impedance on all the speakers should be in the 6 to 16 ohms range.


The Mirage front and centre speakers are rated at 175 watts and their impedance is 8 ohms nominal and 4 ohm min. The Niles surround speakers are rated at 10 to 125 watts per channel and their nominal impedance is 6 ohms.

I found an independent measurement of the true impedance curve of your mirage speakers at http://www.audioholics.com/reviews/s...t-v2-fs/page-4


I would call them 4 ohm speakers.


Is there a possibility that the receiver is in a poorly-ventilated cabinet and overheading for environmental reasons?


How about the speaker cables? Any chance that they are shorting at either end or in-between?

Quote:
Both times when the receiver has gone into protection circuit mode, it has been whilst playing music DVD's at high volume, but not extreme. So, I am wondering if the amp has been pushing too much power over the period and it has clipped and hence damaged the circuitry? Does anyone know if this might be the case?

The purpose of protection circuits is to stave off damage to the receiver. Going into protect mode a few times should not permantly damage it.

Quote:
My second question relates to what comback would I have on the authorised Denon dealer who sold me and installed the entire package in the first place?

If the receiver is getting plenty of fresh air, then it would appear that the dealer is at fault.

 

[Trevdeb]

Thanks for that. The receiver is on a shelf with plenty of fresh air surrounding it. Also, I have taken all of the speaker cables out and ensured that they are correctly connected.


I agree too that the speakers are 4 ohm, so tomorrow I am heading off to the store to discuss it with them.


Thanks for your reply and the link to the ohm curve.