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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

Showing 4 responses by yogiboy

yogiboy's avatar
yogiboy
5,464 posts
 
A cartridge arm mismatch will cause that problem. The rule of thumb is low compliance cartridge, high mass arm and high compliance cartridge, low mass arm. You should get a test record like the Shure test record TTR 115 that can be gotten on Ebay for about $15.00. The ideal resonant should be from 8 to 12 HZ. Years ago I was blowing woofers until I corrected the problem and replaced my heavy arm with a lighter one.
yogiboy's avatar
yogiboy
5,464 posts
 
The tonearm mass is a low 8.5 grams ,the cartridge has a compliance of 15 (on the low side). That combination looks like a mismatch to me. You can try a headshell weight to add some mass to the arm and see if that improves the problem.
yogiboy's avatar
yogiboy
5,464 posts
 
Mattmiller,I standby that the cartridge arm combo is not a
good combination,and will wreak havoc. The sound is good
because the problem is in the subsonic region that you will
not hear. If you don't address this you will have the problem till
the cows come home. You should get the filter if you think
that will work and return it if it does not fix the problem. BTW,if
the NeedleDoctor tells you there is not a problem then he
should go back to med school ! You should get a test record
with the resonant frequency test. I use the Shure TTR 115
ERA lV,you can find them on Ebay for about $20 bucks. The
other fix is to get a higher compliance cartridge or an arm with
more mass.
yogiboy's avatar
yogiboy
5,464 posts
 
Schubert, Ortofon,Grado,and some Soundsmiths all have medium compliance and will work with a tonearm that is from light to medium. I don't think they make super high compliance cartridges and super low mass arms that was the fashion many moons ago. I was kind of surprised that the arm the OP has was only a low 8.5 grams mated with a cartridge with a low compliance
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