....

srb · « **Reply #2 on:** 8 Dec 2015, 11:02 pm »

You can edit the Subject: field in the original post and correct woffer to woofer and it will appear that way in the topic lists.

I'm familiar with volume control positions as related to clock face hours - 12, 1, 2, etc. but what is 1:05 or how could that 1/12 possibly be quantified?

Edit: Aaah - got it. Between 1 and 2 (1:30) !

pmcd · « **Reply #3 on:** 8 Dec 2015, 11:08 pm »

pmcd · « **Reply #4 on:** 8 Dec 2015, 11:29 pm »

James Tanner · « **Reply #5 on:** 9 Dec 2015, 12:05 am »

Gee's sorry to hear about this.

It sure sounds like the speakers were over-driven. They should be able to tell when they look at the drivers. If the voice coils are burned (look black) it indicates they have been over-driven and received too much power.

The 1-2 o'clock position on the preamp seems very high and I will ask Mike what power level that would indicate.

james

pmcd · « **Reply #6 on:** 9 Dec 2015, 12:17 am »

////.

G Georgopoulos · « **Reply #7 on:** 9 Dec 2015, 12:32 am »

if woofers are blown,mids, tweeters are dead for sure!...

werd · « **Reply #8 on:** 14 Dec 2015, 03:43 pm »

Leave the amps at 23 dB gain in the future. What was the sensitivity of the those B&Ws? It does sound like you were over driving them with what ever source you were using.

gdayton · « **Reply #9 on:** 14 Dec 2015, 09:36 pm »

Woofers can blow if there is DC leakage. Often, speakers will have series capacitors which protect midranges and tweeters from blowing. It's also possible that woofers can blow if there is way more bass energy in a song than mid or HF. It's also not always the voice coil that burns up. So, though it's not hard to determine the mode of failure for the woofer, it's often difficult to find the cause. You can mechanically overdrive a woofer without frying a voice coil.

1 to 1:30 on the dial is pretty loud for an amp set to 29dB and 90dB sensitive speakers. Though the gain setting switch has no effect on whether or not you'll blow your speakers. If the switch was at 23, you'd simply turn the volume knob further up. How large is your room including ceiling height?

7Bs have more than enough power for those speakers. Having blown multiple drivers, I suspect you just need speakers that will play louder than the 802s can handle.

Let us know the details!

-Gary

pmcd · « **Reply #10 on:** 15 Dec 2015, 01:39 am »

.....

*Scotty* · « **Reply #11 on:** 15 Dec 2015, 02:35 am »

If you don't know how or why this damage occurred and what to do to avoid a re-occurrence then history will repeat itself.
Personally, I wouldn't put a dime into a repair until I understood the cause of the damage.
Scotty

pmcd · « **Reply #12 on:** 15 Dec 2015, 03:37 am »

*Scotty* · « **Reply #13 on:** 15 Dec 2015, 03:45 am »

Sounds like its past time to apply a cure from Altec-Lansing, JBL or a modern equivalent.
Scotty

pmcd · « **Reply #14 on:** 15 Dec 2015, 04:24 am »

,....

HAL · « **Reply #15 on:** 15 Dec 2015, 04:29 am »

I would contact B&W.

Many years ago I had B&W 805 Matrix speakers. The woofer in one had a scraping voice coil after many years of use. Contacted them and they had me ship back the driver to rebuild. I just paid for shipping back to B&W. Everything was fine after the rebuild.

pmcd · « **Reply #16 on:** 15 Dec 2015, 04:57 am »

...

Rod_S · « **Reply #17 on:** 15 Dec 2015, 01:58 pm »

What's the size of your room? I've run B&W 802D2's for a few years on a single Bryston 4B-SST, then bi-amped with 2 4B-SST's and now a 6B-SST occasionally at ear splitting levels and never an issue and now I also have a pair of 28B-SST2's powering a pair of 800D2's for my fronts and again no issues, which as the 7's to your 802's my 28's have more power on tap than the 800's are spec'd at.

Reading yours posts make me think either you like to listen at ear splitting levels constantly or there is/was a problem in some of your equipment, be that the speakers or up stream components.

pmcd · « **Reply #18 on:** 16 Dec 2015, 12:29 am »

.....

redbook · « **Reply #19 on:** 16 Dec 2015, 04:16 am »

Quote from: *Scotty* on 15 Dec 2015, 03:45 am

Sounds like its past time to apply a cure from Altec-Lansing, JBL or a modern equivalent.
Scotty

There's much to be said about the power capacity of a JBL 12 inch woofer with a 4 inch edge wound coil