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woofer pumping

Today I tried to play some vinyl through my new setup (Dynaudio C1 speakers and VTL MB-450 amps/VTL 5.5 pre) and I noticed a large amount of woofer pumping (Whenever I listen through the CD player or Squeezebox the woofers barely move at decent listening volumes).

My turntable is a Technics SL1200, cartridge is AudioTechnica 440 MLa and the phono pre is a Cambridge Audio 640P. Nothing fancy but the woofer pumping is worrying me and I'd like to reduce it. It's currently sitting on an Ikea Expedit so it's not the best for isolating vibration since just tapping it immediately makes the woofer travel more.

I was thinking of getting a 4" maple platform from Mapleshade with the Isoblock footers. Any other suggestions?
jibbonacci
apachef1
164 posts
 
I would invest in a decent audio rack to start. Any subsonic filter switch on your phono pre? I'm gonna say you're getting feedback from the speakers being on the Ikea furniture. Being a direct drive TT will also add to the situation. Isolation is gonna be key.

How big is your listening room?
olimpico
33 posts
 
A KAB rumble filter will solve the problem.I use one and very happy with the results.
jibbonacci OP
31 posts
 
There's a subsonic filter on the 640p but it doesn't do all that much... there's a bit of a difference, but slight.

Listening room is about 12x16 with the speakers setup on the shorter side (turntable is about 4ft to the side of one on the speakers). I'm moving from my current place soon which is why I haven't invested into a serious audio rack yet, but that's something that I'm looking into getting in the future.

In the meantime, would the maple platform and isoblock footers help the situation? (also not sure if the 4" would provide any advantage over a 2" in this case).
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