At what vol level do you get rumble / flutter?

07-06-12: Sbrownnw
@johnny, never had the factory cartridge on my Xpression. Had two mc-3 turbos on it and recently had the ortofon mc 25 fl with the heavier counterweight and it did the same thing (the 25 fl is about 10g). How do I add fluid? Is the tape u mention for my tone arm easily removeable if it does not work out?

Well, it looks like I shot my mouth off without paying closer attention. I realize now that the earlier post about adding damping fluid was contributed by someone else who has a tonearm that uses it. So never mind about that.

Second, one thing that makes this difficult is that what may be a normal amount of pumping for one person may be alarming or excessive to someone else. Third, pumping can come from record warps, how the bass groove was mastered, and tonearm/cart resonance. How bad the speakers pump is relative to the amplitude of the resonance.

If you tape your tonearm, it's reversible. There is no adhesive on the tape; it is very thin and stretchy. However, since you have a carbon fiber tonearm, the effect of an arm wrap is probably minimal. My tonearm is undamped hollow aluminum, so the arm wrap made a significant audible difference. With a more modern carbon fiber arm, probably not so much, but it's only a $1 experiment. We're talking about Teflon pipe thread tape, which should be a buck or two at Walgreen's or Home Depot.

After looking over the entire thread and getting a better feel for your rig, it looks like the KAB RF1 Rumble Filter addresses the various problem sources most directly.

You can use Blu Tack instead of tape as well.

I'm with Srwooten though - I'm very skeptical about claims that people's systems are completely free of rumble. I don't care how well your tonearm/cartridge are matched; if you have very low frequencies cut into the record itself during the cutting process, which is quite common and a fact, your speaker should flutter without a filter unless your system is incapable of reproducing these low frequencies. Certainly a mismatch will make it even worse, but scientifically, how would a full range system suppress subsonic frequencies cut into the groove?

07-07-12: Actusreus
....if you have very low frequencies cut into the record itself during the cutting process, which is quite common and a fact, your speaker should flutter without a filter unless your system is incapable of reproducing these low frequencies. Certainly a mismatch will make it even worse, but scientifically, how would a full range system suppress subsonic frequencies cut into the groove?

Are subsonic frequencies - below 20Hz - cut into records? AFAIK, there are good reasons cartridge resonance is generally positioned around 10Hz. Firstly to keep it above warp induced low frequencies, footfalls etc and secondly to keep it clear of recorded signals. It would cause serious tracking issues if recorded material coincided with cartridge resonance - witness what happens on a test record which has deliberately been cut with these low frequencies.

Cartridge resonance can't be avoided, it's how the cartridge/tonearm/table deals with this resonance (and other low frequency artifacts) which makes the difference IMO. I agree that having resonance in the ideal range doesn't mean you'll avoid issues. Some woofer movement due to low freq artifacts is perhaps to be expected in a vinyl system, but it needn't be excessive or problematic.

Are subsonic frequencies - below 20Hz - cut into records?

According to many high-end audio dealers and several engineers I queried about this issue, the answer is yes. Here is a quote from the KAB website:

One of the biggest let downs with phono playback is subsonic rumble. Actually part of the recording itself, even the best turntable will reproduce it. And with todays cross over video and music entertainment systems, response down to 10 Hz is common.
A good rumble filter will actually improve the bass response by removing those deep subsonic dynamic swings from the system altogether. The power amp breathes easier and the woofers can concentrate on the music at hand.

Getting into LP's and startled at the big speaker cone movements that you're seeing? Thinking a better turntable will help? It may not! This very low frequency energy is called rumble. Much of it is actually cut into the record groove when the master disc was made. Other sources are mis matched tonearms, poorly damped tonearms and acoustic feedback. Often, the only way to suppress rumble is with a really good rumble filter.
With rumble eliminated, the soundstage becomes more "still" and the bass actually tightens up because the woofers are no longer modulating and the power amp is no longer wasting current resources on sub audible noise.

I understand it's marketing as well on KAB's part, but I certainly noticed differences in the degree of woofer excursions between even two perfectly flat records where everything else was constant. How else to explain it other than the subsonic frequencies were part of the recording rather than generated by the playback system.

07-07-12: Actusreus
I understand it's marketing as well on KAB's part, but I certainly noticed differences in the degree of woofer excursions between even two perfectly flat records where everything else was constant. How else to explain it other than the subsonic frequencies were part of the recording rather than generated by the playback system.
Actusreus (Threads | Answers | This Thread)

I'm not disputing you have woofer movement, nor the fact that the KAB high pass filter removes these subsonic frequencies. The sub-sonic frequencies are generated by the playback process but probably not by music content. It would be asking for trouble to deliberately record music signals at around 10Hz and I doubt this would be done intentionally. Nonetheless I suppose there probably is unintentional low frequency signals recorded. However if most of your records have an *excessive* woofer pumping effect I'd say the problem lies with the arm/cartridge/turntable.

Whenever I have had this woofer pumping issue, the pumping was usually cyclic and continued regardless of music content on the record - more often than not linked directly to (even minor) irregularities in record flatness. I've also observed a contribution by 'bouncy' flooring - where I could see large pumping as I walked up to change the record. I don't get either of these issues with my 103R/Phantom/TNT in my current room.

Some cartridges I've tried in the past, the Shinon Red and Grado TLZ come to mind, have greatly exaggerated low frequency pumping to the point where they weren't practical to use in that particular vinyl system. Other cartridges, the Audio Technica Art 1 and Garrott P77 for example, were very well behaved on the same records/same system, with only minor pumping effects. It's worth noting that both the Shinon and the Grado were somewhat higher compliance than the AT, though theoretically both should have been ok in a medium mass arm (I was using either the Sumiko MDC800 or the SME V back then).

I've seen a huge variation in this effect over the years with different cartridges/tonearms. Some cartridges also behave wildly at resonance (observed with test record) while others have only mild movement. FWIW the lowly Denon 103R is one of the best behaving cartridges I've used in this respect. Whether this is because of its 'lossy' mechanical construction I don't know. I can tell you that even when this cartridge is made much heavier, 14.5 grams in the Al body I use, there is still no issue - even though the resonant frequency has dropped to around 7-8Hz in the Phantom (observed via test record).

By all means get the rumble filter if you must use a particular combo and you have issues you can't solve with damping etc - personally I'd rather avoid the issue (change combo), but that's just me. Either way I hope you can sort out your problem.