I have had problems w/woofer pumping too. It could be a cartridge set up problem, cart/arm non-compliance issue or a issue with isolation of the TT.
It seems thre are a few ways to deal w/it. 1. Reloc TT 2. Get a filter to block really low frequency from interferring (try the KAB filter) 3. Try a different cart with your arm.
I had this issue when using a Sota Comet w/RB301 arm and Ortofon Blue. There should be no compatibility problems (per the manufacturer). There was not an isolation issue - yet the woofer still pumped.
Just so happens I changed the Sota for a OL TT with OL arm and Ortofon Blue. It sounds great and has no woofer pumping (except on a warped lp).
Hope this is useful.
It seems thre are a few ways to deal w/it. 1. Reloc TT 2. Get a filter to block really low frequency from interferring (try the KAB filter) 3. Try a different cart with your arm.
I had this issue when using a Sota Comet w/RB301 arm and Ortofon Blue. There should be no compatibility problems (per the manufacturer). There was not an isolation issue - yet the woofer still pumped.
Just so happens I changed the Sota for a OL TT with OL arm and Ortofon Blue. It sounds great and has no woofer pumping (except on a warped lp).
Hope this is useful.