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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
mattmiller's avatar
mattmiller OP
1,497 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
6,158 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
700 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
1,497 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
11,841 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.
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