Wildly fluttering woofer


Without any kind of warning the left woofer of my Thiel 7.2 speaker started fluttering-the excursion was at least two inches. Won't happen with a CD. Tried another record and the same thing happened again. I have not switched speaker cables.
System: VPI Mark IV turntable with Graham Phantom arm and Dynavector XX2 cartridge, McCormack DNA 500 amp, Audible Illusions Modulus 3B pre-amp, Thiel 7.2 speakers, all wires are Audience. HELP!
katz1
Katz1,

Sometimes you don't have to do anything major to improve the sound. Changing stock speaker crossover capacitors is one thing that can be done easily and reversed if not satisfied.

My favorite thing about changing capacitors (any capacitor) is listening to them as they break in. At first, new capacitors usually sound horrible. After about 15 minutes they bloom as though someone opened up the door to make things clear, it's really dramatic for me, like someone raised the lights. After that, as they continue to stretch out and break in, the sound continues to get clearer, more subtle and detailed.

Rolling tubes is a little easier, no soldering involved. Different tubes have their own sound. My preamp uses three 12ax7 types in the line stage. I started out with three Telefunkens but it seemed like the sound was over-driven and sometimes too loud. So I changed the first tube to a 5751 (70% of the gain of a 12ax7) thinking I might be over-driving the second stage and the sound became less congested and more subtle. I left the tele in the second position and put a nice low distortion 7025 in the third position to smooth over and finish the sound. Kind of like finishing scotch in a sherry cask. The sound took on a different flavor. That's what rolling tubes is like for me.

I'm not as big of a tinkerer as you might think. Once I like what I hear, I'm done and just enjoy the music. It's only when I get no pleasure from listening that I wonder if it's my ears or the equipment. I can't do much about my ears, so I check the equipment or go to a friend's house to compare.

I do have an extra set of speakers that I might experiment with. They're an extra set of Large Advent's and I'm thinking of removing the internal capacitors and passing the wires to the outside of the cabinet to some terminal strips. That way I can practically change capacitors on the fly till I find my favorite. Then, using another amp, I might "stack" them to see what all the fuss is about.

How's the leg coming along? I can empathize with you're plight because I broke my neck 10 years ago and was stuck in a halo for 3 months. Thank God I had Star Trek recordings to watch, I was so bored. After that, I got hooked on The History and Discovery channels and made it a point to watch all of Clint Eastwood's movies that summer.

One day at a time..each day over is a day closer to getting the cast off.

Good luck.

Rich
I haven't checked my posting in a while hence the delayed response to your last post. Without sounding like a sycophant, your communication skills blow me away.
My left leg which has a Jones fracture of the fifth Metatarsal bone got another cast yesterday for another month. Don't know if I mentioned that I retired on April 17, bought a Honda Civic Si with six speed manual transmission two weeks later, and fractured the bone two weeks after that. So, the car sits!
According to Art Ferris at AI, my pre-amp checks out O.K. and will be returning soon. Meanwhile I can listen to music thru a Yamaha C-60 pre-amp with interestingly MM &MC(with variable loading).
Changing caps on my Thiel 7.2s is way beyond me and tube rolling sounds interesting but I'd still be hesitant to experiment. Maybe I'll run the idea past Art, although I can predict the answer. I will however engage the sub sonic filter om my 3B.
Since the pre-amp seems O.K., I have to consider that excessive tracking force may have caused the woofer flutter. Hope to hear from you again...
Thanks for taking the time to care, Katz1
That kind of fracture can take a while to heal, as you are coming to realize. Sucks about the car, I can relate. I broke my neck 7 days after purchasing a new Subaru Outback and wasn't allowed to drive it for 4 months. A couple of times I sat in it just to take in that "new car smell".

Check the capacitance setting that you're using for your cartridge, too much and it can boom. Wherever you moved your turntable may coincidentally happen to be the worst spot in the room for a turntable. Corners, for example can be boomy.

You'll figure it out. Now's the time to relax and be thankful for what you have and make the best of your situation. I felt like listening to Michael Jackson one night and recorded the playlist. I called that CD "The Halo Session". Good CD, very reflective of my mood that night.
Dear Heyraz, you might have fit another piece of the puzzle-the turntable is in a corner, I have always listened with the TT cover up/open. I too sit in the car and start the engine-it's better than nothing.
What happened to your neck and did you need surgery?
By the way, have you ever heard of the "Ukulele Orchestra of Great Britain"? Check them out on you tube.
Regards, katz1
I am going to check out Ukulele Orchestra. The name alone has my interest. Have you ever heard Vaughn Williams "Concerto for Tuba"? I couldn't resist that title.
When I landed on my head the force broke C1 into three pieces. It's called a Jefferson Crush Fracture and it's similar to what would happen to a pretzel ring if you slapped it on a table. C1 can only absorb so much force, after that it splits. A bad bop on the head is all it takes.
The C1 fracture wasn't as life threatening as the subdural hematoma, in fact the C1 issue wasn't realized for two days. I told the doctor that my neck hurt but not in the usual way (I had C5-C6-C7 fused the year before because of herniated discs). In fact, during the car ride to the ER I supported my head in my hands because it felt like it might fall off of my neck. I walked into the ER supporting my head, covered in blood looking like Carrie at the prom, and passed out shortly after.
After I awoke from the brain surgery, the doctor asked me if I had a runny nose, to which I replied "funny you should ask". He shot a picture of C1 through the roof of my open mouth which showed the C1 fracture as well as a fracture to the spenoid bone, which is behind the ocular orbits, one of which was also fractured. My "runny nose" was my cerebral spinal fluid leaking out.
Fortunately for me, I needed no further surgery, just rest and a halo to keep my head on straight so C1 could mend. Because of the trauma, the retina in my left eye also detached, but laying in bed for a few days gave it the opportunity to lay back down and re-attach by itself. That issue was realized many months later during an eye exam. I complained of blurry vision while I was in the hospital, but by the time they got an ophthalmologist to examine me, the retina had already settled back, my vision cleared up, and nothing was seen till scar tissue formed later on. The runny nose stopped by itself, and thank god my body did a great job of healing itself. I just needed food, rest and time. I was forced to take the summer off, so I adapted and made the best of the situation. No complaints, I could have easily died, or worse.
As a bonus for my pain, I got a great torque screwdriver out of the deal. It's very precise and calibrated so the halo can't be over tightened to the skull. The halo is in my shed hanging from a hook.
So take it easy and try to enjoy the down time. If you're like me, you'll come out of the gate fast once you're medically cleared. You just have to be patient.
Rich
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