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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
rodman99999
6,206 posts
 
From your description of the woofer motion(four large excursions/stops/four large excursions/stops/etc); neither acoustic feedback or tonearm/cartridge resonance are your problem. As Mr J stated; you'll find it's mechanical(belt/bearing/platter). If it's under warranty, take it back.
sbrownnw
710 posts
 
I had woofer pulsing with my pro-ject xpression III. Went to a regs rp6 and no more woofer problems.
mattmiller's avatar
mattmiller OP
1,502 posts
 
So, I received a large piece of granite from a good friend. I placed that under the TT and it really helped calm things down. I still get some woofer action, not always. I think it is in the records we play and the only way to really stop it is to buy a subsonic filter. I took the Pro-ject apart (to fix the cable connection) and put it back together again being super careful with the belt and everything. I was able to listen to music and it was awesome! I really want to thank all of you who have tried to help me trouble shoot this problem.

Matt
atmasphere's avatar
atmasphere
11,979 posts
 
My phono section has bandwidth to 2 Hz but I don't experience excess woofer motion. A lot has to do with the match of the arm and cartridge.

But making sure the turntable (especially if it has no suspension) is properly isolated and also does not have a malfunction (in this case a main bearing that needs lubrication is the most likely problem) is paramount- you start there first.
lewm
13,359 posts
 
Matt, Take a second look at your own logic in your post of 08/02. If the woofer pumping in your system were due to "the records we play", then a slab of granite placed under the tt could not have much effect on the problem, because the source of the energy that pumps the woofer is or would be endogenous. If the granite helps, then it is more probable that the speakers are positioned such that they are interacting with your tt by introducing mechanical energy that is vibrating your tt shelf via the floor, etc. So, the granite experiment might further move you to re-position the tt or the speakers in your listening room.
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