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Woofer pumping WHY??

Hello All, I have an older REL B2 series. I love this sub. I recently received a new Project Xtension 10 with Clear Audio Maestro Ebony v2. After a couple days I noticed bad woofer pumping on several records I like to listen too. When I brought it up to Needle Doctor they told me it was my records and said it worked fine in there store. Now my REL is blown! I am so upset at myself for not taking this matter more seriously. Now I am purchasing a KAB rumble filter because I am not going through this again. Is this a cartridge mismatch?? Because on my REGA with Dynavector 10X5 It did not do this woofer pumping nearly as bad. AND I do remember putting a DENON DL103 on my RB301 and this same woofer crazy action occurred!! Immediately took it off that arm. I just spent $4100 for this Xtension10/CA Maestro and now I am scratching my head. Hmmmm.
128x128mattmiller
dougdeacon
3,338 posts
 
When I play any vinyl it goes 4 very quick beats then nothing then 4 very quick beats and so on... it even speeds up when I play 45's
Good observations, which lead one to suspect an irregularity in the new TT's drive or bearing system.

As a cheap experiment, you might try a different drive belt.

If you don't have a spare belt, try removing the one you have and feeling for irregularities. Sanding those lightly might help. Then reinstall the belt "other side up".

Try as many of these as you easily can and see if the woofer behavior changes.

wolf_garcia
6,708 posts
 
I found a few phono preamps with 20hz rumble filters and bought one (Cambridge). Problem solved, but I do wonder if a higher end turntable would be rumble free, as the ultra low frequencies inherent in modern phono playback (and the wide frequency range of modern gear) matched with bass reflex speakers seem to make rumble. There doesn't seem to be any acoustic feedback in my current turntable system (which sounds great), so I suppose I won't know until I change the table someday.
oilmanmojo
472 posts
 
i have never had a problem with Woofer pumping in any system. I have heard about this, but whether it was an entry rotel preamp and Dual 721, to my current RCM Sensor II Phono preamp, ZYX UNIverse II, Pass Labs Xp10 and XA 30.8 etc, just have never see this issue. Have you changed the cartridge to see if there is a special resonance you are coming up with?
mattmiller's avatar
mattmiller OP
1,497 posts
 
Well with the REGA it dosent make the cyclic pumping action ( I still get a little subsonic pumping but not to bad). Im going to try a block of granite under the table, to increase self mass. Going from the REGA to the PRO-JECT was like lifting a veil off my system, I cant go back. I think the Project is picking up music from my system because everything is so close together in my room. Does that make sense??
jperry
2,450 posts
 
"07-21-15: Dougdeacon
When I play any vinyl it goes 4 very quick beats then nothing then 4 very quick beats and so on... it even speeds up when I play 45's
Good observations, which lead one to suspect an irregularity in the new TT's drive or bearing system."

I have never had an issue like this, but amplifying on Doug's suggestion I would put a piece of painter's tape on the side of the platter and see if the pumping correlates with the tape location.

If that happens, and your Rega does not have this issue, you should call your retailer and have a more detailed discussion. It could be that you have a defective turntable and they should work diligently to help you resolve this issue, regardless of whether it is system based or a defective turntable.
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