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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
 
Good followup suggestion from Jperry. I would try his simple diagnostic and my suggestions before schlepping a hunk of granite, which seems unlikely to alter the behavior last described.

Do whatever you like of course.
mattmiller's avatar
mattmiller OP
1,479 posts
 
I don't have much faith in the "higher mass shelf theory" but Its easy for me to test that one. I really think the new Project Xtension 10 is not the problem. All the table has done is push a lot more music through the system than before. Also, made it a lot more sensitive to play vinyl. I have 2 cheap phono preamps and I think one is even going bad. So, there is a lot going on that's not good right now. This is very interesting to me also though. I am sure there is a resolution coming soon.
rodman99999
5,981 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
686 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
1,479 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
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