Is it consistent with all records or worse on some than others? If its the same it could be a bad or dry platter bearing. Check the bearing and see if it needs lube or if there is play in it. Also check to make sure the TT is perfectly level, measured on the platter. Its also good to have a test record to check the performance and setup of the table. Spend some time checking the table for proper setup (or have a dealer help you). Its the only way to get the most out of what you already have. Some how very low frequency info is entering the system and a bad bearing is one posible cause. Better quality TT’s have better bearings. Good luck!
Unsolvable Woofer Pumping (Phono only)
I'm at a loss for trying to find the source of my "woofer pumping." It's most noteworthy when playing something that is mostly/all treble, and the woofers of my Focal Aria 906s are going nuts (inaudibly, of course). Turntable is a Debut Carbon with Ortofon 2M Blue.
Initially I was told it's an isolation problem, so I better isolated my TT, even put it right on the concrete floor to test! Next I thought maybe a problem with the TT itself, so tried a couple others, no change. So I figured it must be acoustic feedback, as with the TT stopped and stylus on a record, I could produce woofer pumping by tapping on certain parts of my stand...but it is also not this! I turned off my amplifier and recorded from the pre-out to a Tascam digital recorder and played that back afterwards and the pumping STILL happened! So I tried an Schiit Mani phono stage, no change in woofer pumping...I was sure it had to be my pre-amp...
So a local audiophile came over with a couple of pre-amps and we tried those. The only time the problem went away was when the subsonic filter that one had was engaged. So, I've ordered some Harrison Labs "FMODs" (20Hz high pass) to see if they will help. If they do, I may order a KAB RF1 one day...but don't want to spend that much if I don't have to.
Any other ideas on what could cause this?!
tl;dr: Woofer pumping not caused by isolation, acoustic feedback, phono/preamp or a compliance issue...what's happening?!
Initially I was told it's an isolation problem, so I better isolated my TT, even put it right on the concrete floor to test! Next I thought maybe a problem with the TT itself, so tried a couple others, no change. So I figured it must be acoustic feedback, as with the TT stopped and stylus on a record, I could produce woofer pumping by tapping on certain parts of my stand...but it is also not this! I turned off my amplifier and recorded from the pre-out to a Tascam digital recorder and played that back afterwards and the pumping STILL happened! So I tried an Schiit Mani phono stage, no change in woofer pumping...I was sure it had to be my pre-amp...
So a local audiophile came over with a couple of pre-amps and we tried those. The only time the problem went away was when the subsonic filter that one had was engaged. So, I've ordered some Harrison Labs "FMODs" (20Hz high pass) to see if they will help. If they do, I may order a KAB RF1 one day...but don't want to spend that much if I don't have to.
Any other ideas on what could cause this?!
tl;dr: Woofer pumping not caused by isolation, acoustic feedback, phono/preamp or a compliance issue...what's happening?!
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- 55 posts total
- 55 posts total