Subsonic Rumble Solutions


I know many of you have tried to address this issue. Short of buying or building a subsonic filter (that will/may negatively affect your transparency) - what methods reduce subsonics (meaning the pumping of woofers and subs when a record is playing)?

My system:
I have a DIY VPI Aries clone with a 1" thick Corian plinth, a Moerch DP6 tonearm and Dynavector 20X-H cartridge. This sits on a maple shelf. The shelf sits on squash balls. The balls sit on another maple board floating in a 3" deep sand box. All this on a rack spiked to a cement floor. The phono stage is a Hagerman Trumpet (no built in subsonic filter and very wide bandwidth). I use the 1 piece Delrin clamp on the TT. Yes, I clean records thoroughly and there are no obvious warps, especially after being clamped.

So my isolation is very good - no thumps or thwacks on the rack coming through the speakers. But if I turn the sub on I get that extra low end pumping on some records that hurts my ears. Mostly I leave the sub off when playing vinyl, but I would like to use it if possible.

There was some brief discussion of this on Albert Porter's system thread. I'm hoping to get more answers here.

So ... what methods have you tried to reduce subsonics that you have found effective?

Thanks,
Bob
ptmconsulting
in 100% of the cases I've seen over the years where "rumbling" or "pumping" was a significant issue at play, the cause was a warped or poorly cut record.

Lets face it, even if our turntables and systems are darn near perfect, few if any records are. Some are real bad. You'll hear the effects of a poorly manufactured record way before the stylus starts skipping grooves, especially with most good turntables that track very well.

If you are playing a record and getting a lot of pumping or rumbling visible with your speakers, just be glad that your table is such a good tracker and accept the fact that this is par for the course. Either that, or go for the filter if it is something that cannot be lived with.
Hi Koegz, I was indeed suggesting that your system is not reproducing below 20hz and perhaps not even below 30hz.

Thats OK, no problem there, I am sure it sounds great!

Bob
I do suspect some cartridges with higher compliance (stiffer) styli might be more naturally immune to picking up low end noise due to record warping or irregularities in the way the record grooves were cut (off center, etc.).
Bob#2 - as much as I don't like to say it, because it might hurt some feelings and because we all know the size of our system reflects the size of our audio-manhood :-), I have to agree with you.

The subsonic problems I seem to have now were not there in the past. The resolution of my system has improved greatly with a better phono stage, better arm, teflon caps in my preamp, etc. Yes, the music got better, yes the sound is better, and yes I now seem to have a new problem caused by this increase in resolution.

Bob #1