Interesting post as I had a similar post about a month ago regarding the compliance at 100 hz and I received no replies. Its a good question. A very good question. Someone at Lyra should respond to explain this as I am very interested in understanding this better. I noticed a similar thing, not that my woofers were pumping, but I heard what I believed to be a compliance issue. It is better now that the cartridge is broken in but sometimes I do ask myself this question as well. Maybe Lyras are made for lighter arms if the compliance is so high at 10Hz.
Why are my woofers pumping?
The other day, with sunlight direct from the side, I noticed that the
woofers in my speakers are pumping in and out, much more than I was aware of,
when the stylus is in the groove, even between tracks (no music). I can see it, even if I don’t hear it. Why
does it happen? The woofers behave normally (no pumping) with digital music, and
when the stylus it lifted from the groove, so it is not the speakers, amps,
preamp or phono stage.
I’ve read that the typical reason for woofer pumping is that the cartridge / arm resonance is too low. I tested, with my Hifi News test record, and yes, the lateral test puts the resonance at 7 hz or so – too low (but I’ve seen some doubts about the results from that test record). It is strange, since the combo I use – Lyra Atlas cartridge and SME V arm (on a Hanss T-30 player) is supposed to work well. I tried to strip my arm of extras, cleaned the damping trough, etc – but it did not help much.
Anyone has an idea, why it happens, or what to do about it?