Question Woofer / Permanent fix

[AJM1981]

I am not planning to collect speakers but couldn't resist a steal offer for a pair of second chance Wharfedale Diamond 11.2s from a trusted channel for around 100 euro's claimed to have come back and are fully checked and tested.

I think they are worth every cent since an online store here retails them for 450 euros a pair while the 12.2 going for 300 euros. Probably it is still a popular model and a classic in that it is about the half of the current Evo 4.1.

All was well but I noted that one speaker has a heavy resonance problem in the bass region that sounded like a broken woofer.

Luckily the quick fix was deadly easy to apply as to what seems a huge problem. I noted that when I kept my finger on the rubber ring around tbe kevlar woofer, the problem disappeared. So I mildly pressed and released the rubber ring around the kevlar woofer and now literally all resonance is gone and it sounds like it should sound for more than an hour by now.

However..this might work forever and the woofer might have behaved fine while they ran tests, since it is so easy to make it disappear. In an attempt to deliver something more permanent I wonder if there is anything I can apply if it happens again.

many thanks in advance

 

[musicmanO]

Funny, I have a completely different set of speakers but noticed the EXACT same problem coming from my left channel woofer. Issue ONLY happens when play tracks with upright bass. It drove me crazy and I thought it was my room at first, but then after some hunting I narrowed it down to the speaker and then the woofer. I guess it's instinct because I tried the same thing as you; applying light pressure with my finger. I'm also looking for a permanent fix because I'm quite happy with these boxes otherwise. If you find anything, please chime in.

 

[AJM1981]

Funny, I have a completely different set of speakers but noticed the EXACT same problem coming from my left channel woofer. Issue ONLY happens when play tracks with upright bass. It drove me crazy and I thought it was my room at first, but then after some hunting I narrowed it down to the speaker and then the woofer. I guess it's instinct because I tried the same thing as you; applying light pressure with my finger. I'm also looking for a permanent fix because I'm quite happy with these boxes otherwise. If you find anything, please chime in.

Maybe the following can help.

I was literally at the point of sending the speaker (box was ready, made a videosample) for repair when I decided to try them in another room and in a different position. I put them on my solid main speaker stands and turned the volume both up and down.. Problem was like it had never existed. Tested it for a whole weekend, nothing strange anymore.

For some reason I think it has been a external sound wave problem at some frequencies that they might have been bounced off by something nearby and fed back to the speaker creating resonance. Otherwise I could not explain why dampening helped those times. I have also tried applying a little pressure again "hoping" it would reoccur (if it would have been the rubber strip around the woofer) but not even a hint. So most likely nothing has been ever wrong with the speaker.

Now I have them back at the same place and everything is fine.

P.s. So What by Miles davis is an excellent testing track for its first minute.

 

[musicmanO]

I'll try repositioning as you suggest. Reflected resonance is an interesting theory for sure. I'm using Rapture from Shades of Jade vol 5. Huge bass notes straight through the first 30 seconds.

 

[AJM1981]

I'll try repositioning as you suggest. Reflected resonance is an interesting theory for sure. I'm using Rapture from Shades of Jade vol 5. Huge bass notes straight through the first 30 seconds.

Try free standing solid stands if not tried before and if available for testing purposes. My setup was on two shelves in the corner of our bedroom originally meant for the Diamond 12.0 s which are two sizes down. I think the interaction could have been with the iron framework from a bakery cabinet that is in the same corner of the bedroom creating the reflected frequencies that were probably fed back to the source. Another thing is that the bottom ported bass reflex could have been resonating with the shelves and somehow interacted with the woofer. Bottom ported speakers for sure do best at solid stands since the main pressure is generated downwards.

Whatever it has been, it seems to have been external