In his paper on resonances in turntables,Paoul Ladegaard of the air bearing tonearm fame,theorises that cartridge/tonearm resonance is by far the most important issue to be addressed here.Therefore matching your cartridge to the effective mass of your arm,so that you have a cartridge resonance of 11-12HZ is the most optimal adjustment you can make,coupled of course with good isolation.Ladegaard was sure rumble does not exist and you corrected this parameter.
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
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