I'm losing my mind...

BKphoto

I have the dreaded speaker pump subsonic craziness going on....Its only on the left speaker, speakers are same distance from TT (about 3 feet) I have the project tube box s phono pre that is supposed to have a built in subsonic filter...no switch, on all the time...the cart is set up from factory on this TT (maybe wrong...?) when I use the low filter on my Maantz 1060 it seems to go away but the music suffers...

I'm using Blue Jeans IC's could this be making it worse...?

not sure why only 1 speaker, the right is fine and its closer to the arm...

I thought maybe speaker was out of phase but if that was the case using filter on amp wouldn't change it...

its not a warped record issue because i use a clamp...

At the moment I'm having a miller light and sitting in silence trying to figure this out...

mhardy6647

If it's only in one channel makes me think its LF oscillation in the amplifier...

Otherwise, the most likely culprit is acoustic feedback - a good test for acoustic feedback. With the platter not turning, amp on and set to phono and at zero volume, set the stylus down in the groove of a record and slowly increase the volume. If, as the volume increases, the woofer(s) start to boogie and/or you hear the low-frequency howl; bingo!

If your're actually playing a record and the problem goes away at lower volume levels, that would also be symptomatic of acoustic ffeedback.

Acoustic feedback is usually due to poor isolation of the tt from vibration and/or ill-advised matching of cartridge and arm (e.g., high-compliance cartridge in an arm with medium to high effective mass, or low-compliance cartridge in low-mass arm).

BKphoto

gonna try that test thanks...

BKphoto

gonna try that test thanks...

if it is feedback I'm not sure what to do....there is no vibration in the base and the cart and arm are put together at the factory...

sorry posted before completed....

see, I'm going crazy...

steveinaz

I'm thinking "airborn" vibration/harmonics.

ZLTFUL

Stupid question, but does your TT have a dust cover? Mine was exhibiting similar symptoms (the subsonic was in both channels but significantly worse on the left than the right) and it turned out the cause was from playing with the dust cover shut...
Just spitballin' here.

steveinaz

ZLTFUL wrote: »

Stupid question, but does your TT have a dust cover? Mine was exhibiting similar symptoms (the subsonic was in both channels but significantly worse on the left than the right) and it turned out the cause was from playing with the dust cover shut...
Just spitballin' here.

Good call, never a good idea to play a TT with the cover closed.

BKphoto

i either raise it all the way or completely take it off when listening...

BKphoto

steveinaz wrote: »

I'm thinking "airborn" vibration/harmonics.

to the left speaker only...?

steveinaz

Sure, ever move around your room and hear bass peaks in different locations?

BKphoto

did the test and same result...left speaker drivers going crazy....there is supposed to be a subsonic filter in the tube box s phono pre, so I'm even more confused....its on a sturdy platform with stone under the TT....using Bluejeans IC's, Herbies matt, record clamp....etc...speakers are 3 feet away....they were closer with my old table and never had this issue

BKphoto

its not the amp...just hooked up an iPod and everything is normal...

voltz

Brent

have you re-tried your NAD Phono stage? just reaching here since you have cover almost all the bases for what people here & on other forums have suggested to do based on your problem.

pitdogg2

Sorbothane feet under TT will stop most all vibration from making it to the table.

One of the reasons I gave up the TT just too finicky for me.

BKphoto

voltz wrote: »

Brent

have you re-tried your NAD Phono stage? just reaching here since you have cover almost all the bases for what people here & on other forums have suggested to do based on your problem.

could it be a bad tube in the phono pre...?

BKphoto

I bought the TT online from a store called ListenUp...

Awesome people, sent me out a replacement today...

voltz

I remember you have to adjust the TT from the start, fingers crossed the new one cures you problems.

BKphoto

If it doesn't I might make the news....

Man freaks out and throws records all around neighborhood...

westmassguy

BKphoto wrote: »

If it doesn't I might make the news....

Man freaks out and throws records all around neighborhood...

Wow, I just had a flash-back from an old Bond Movie, Goldfinger

BKphoto

Ha...

good one...

audiocr381ve

steveinaz wrote: »

Good call, never a good idea to play a TT with the cover closed.

Don't want to derail the thread but why is this?

Toolfan66

audiocr381ve wrote: »

Don't want to derail the thread but why is this?

It picks up vibrations and feeds it to the tone arm..

mhardy6647

Toolfan66 wrote: »

It picks up vibrations and feeds it to the tone arm..

'zackly so - although, in fairness, there are two schools of thought on this :-)

That said, up here in the Northeast - in the winter time - there's another, compelling reason not to play with the cover down... when the relative humidity is low, the static field that can build up can quite literally lift the arm up off the record when an album is playing! In fact, it's fun to gently rub one's fingertips across a closed dust cover (in Northern New England, in January) when a record is being played, and watch the arm gently levitate[\i]... better'n David Copperfield...

FWIW, I've actually taken to the simple step of just sitting the acrylic dustcover atop my ol' dump-find Technics -- and I just remove it completely when spinning a licorice pizza.

DSC_8946 by mhardy6647, on Flickr

BKphoto

new TT same problem....although this table had no vibration problem and is completely quiet its still freaking out my speakers....used the Pre in my amp instead no difference...looks like i'll get a http://www.ebay.com/itm/390858460436?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

voltz

Dang let us know if it does the trick.

I think they are who I got my stainless record clamp from.

madmax

Can the table be placed somewhere else in the room? It may be sitting in a space where there is a big bass peak. Someone else eluded to this but didn't actually say it. Even as a test it would be worthwhile changing its location.

pitdogg2

I'd try some pangea sorbothane feet first before i went to 100.00+ route. I have used them for years from audioquest but these are cheaper. Here's a link that you can get sheets from might be cheaper don't know.

http://forums.audioreview.com/audio-lab-tweaks-mods-diy/pangea-mega-feet-38200.html

voltz

^^^^^^

I do have some under my TT that I got from Audio Advisor, after pitdogg2 talked about them earlier in this thread and with the problems you been having I thought they would be a good idea to pick some up, & I picked up the smaller ones for my sources.

http://www.audioadvisor.com/Pangea-Audio-Mega-Large-Sorbothane-Foot/productinfo/PGMEGA/#.U7MMvLEd2Ys

Dawgfish

Ok, I got a few things to try. Whenever I had woofer pump issues with my turntables in the past it was nearly always due to the turntable not being level. If your left side of the table is low the momentum of the table while spinning will make the left speaker pump. I would check the level on the table first. But a level on top of your clamp directly over the spindle. The next thing is what kind of stone platform do you have it sitting on? Believe it or not most stone bases,especially granite ring like a bell. If you are going with stone, limestone is your best bet. Wood bases work good, but they need to be at least 2inches thick if going with maple, 3 inches thick is even better. Like the others have mentioned experiment with sorbathane half-domes under the table, or under the platform, or both and see what works best. Herbies tenderfeet or isoballs are actually much better, but the prices for those can add up quick compared to sorbathane. I've experimented with many different footers with my table and isolation platform and found what works the best is the stock feet of the table being under laid by a 3" thick maple platform with wood footers between the platform and rack. Ymmv. If after trying all this you still have issues, I would look at either changing the location of your table or move your speakers further from the table like the others have mentioned.

Btw, just because you are using a clamp, doesn't mean your vinyl is completely level. I use a TTWeights heavy 3.5lb center weight combined with an outer weight that ways over 2 lbs and even this setup will not completely flatten all records. Ive tried clamps also with worse results than the weights with moderate to badly warped records. My gut feeling what you are dealing with is an unlevel table based on my experience with the same issue in the past. It nearly drove me crazy also.

mhardy6647

indeed - granite is awful for turntable bases/plinths - soapstone's an option.

BKphoto

ok....all awesome stuff...

no other place in room for TT...table is 4 feet from each speaker...

its on an inch of wood with thick slate tile under it left over from our bathroom remodel, about 6 inches in the air, wood legs with rubber pads......phono pre is under it...

going to check level again, and look into feet upgrade...

could a nice par of IC's make this actually worse...? using Blue Jeans cables, was going to try the cheap things that came with it...

speaking of pre amp i was under the impression that a subsonic filter was built into it and always on...but it also did this when i took it out of the loop and used the one on the amp...its a Pro-ject tube box s...