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Did Fleetwood Mac's "The Chain" blow up my woofer?

System: Ortofon 2M Red > Musical Surrounding Phonomena II > PS Audio Stellar preamp > M700 monoblocks > Buchardt S400 

Phonomena is set to 46db of gain, 200pF capacitive, 50k Ohms resistive

The other day I was playing "The Chain" off of Rumors, and one of the woofers stopped entirely during the bass guitar interlude. It just went completely silent, no pops, crackles or distortion. The tweeter is fine, and I reversed the L and R channels to confirm this problem is in the right woofer. The volume level was a "strong" listening level (30 out of 100 on the Stellar), but not loud. We were still able to converse just fine without raising our voices much at all. I have certainly listened to these speakers much louder with other sources.

I understand the power amps are overkill, but I figured my ears would bleed far before I was in danger of blowing anything up. Was this distortion? Subsonics? Woofer pumping due to poor TT isolation? Or a simple defect in the driver?


jayy42

Showing 4 responses by jayy42

jayy42 OP
4 posts
 
No filter - just strait from the TT > Phono stage > Preamp. I have heard this suggestion before. I am reluctant to add a filter. I have never needed one before but this system combo is new. 
jayy42 OP
4 posts
 
I suspect woofer pumping is the culprit here, but I am seeking advice. Right now the components are stacked on the floor while I wait for my new media console. 

I didn't see any burn marks on the woofer or the stuffing around the crossover. I have a new woofer unit on the way. 

I am thinking about a maple shelf with sorbothane feet on which to place the TT along with a KAB RF-1 filter. Hoping that will eliminate the potential for rumble/pumping in the future. I already have sorbothane pucks between the speakers and the stands. 
jayy42 OP
4 posts
 
I swapped the L and R speaker wires to confirm the problem exists within the speaker. 
jayy42 OP
4 posts
 
No smell that I could detect and no loose leads on the woofer.

Interesting that the DD turntable stopped the woofer pumping issue. Do you think it was truly the DD motor that made the difference, or just a different tonearm/cartridge pairing? 

How do I tell if I have woofer pumping without risking blowing up the driver? I think I will have to go the KAB rumble filter route for now and I will continue to work on TT isolation. 
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