Where do classical vinyl records get their rumble from?

RB, Your wrote: 

"I have used a test disc from Tacet (L210) which has tracks to detect pick-up arm resonance. Basically, simultaneous tones of 1000-Hz and 1125-Hz are superimposed by a low frequency tone in steps of 1-Hz from 5-Hz to 15-Hz.  The Holbo / DS Audio clearly resonates at 6-Hz.  I thought it might move up the scale as the cartridge breaks in, and it is very early days.

I have no way of knowing whether this is lateral or vertical resonance.

Using the Tacet test record, I can detect no resonance from my Garrard 301 / SME 3009 / AT VM540ML combination."

Good point about the source of the resonance.  Since very low frequencies are said to be encoded by lateral movement of the stylus tip, you would think this is mostly lateral but I don't know either.

Your notion that the resonant frequency of your Holbo/cartridge may go up as the cartridge breaks in is not in keeping with the formula for resonant frequency which states that Fr is inversely proportional to both effective mass and compliance.  So, as compliance goes up during break in (I think this is what you were assuming), that would cause Fr to go down, not up.  But the change would be so tiny as to be irrelevant, because the inverse proportionality is to the square root of M*C. Likewise, if you want to raise Fr, try a lighter headshell (to decrease effective mass), not weights on your present headshell.

Finally, if your Tacet test LP cannot make the SME/AT combo resonate at all, then I would question its usefulness, unless Fr for that combo is either below 5Hz (unlikely) or above 15Hz (possible). But every tonearm/cartridge will resonate at some frequency or other.

You don't have to try my idea.  You can think yourself out of it.  Or you can try it and see if it makes a difference.  What I am suggesting would raise effective mass.  Your tonearm has a very low effective mass and your cartridge has a fairly fairly low compliance.  For no money, try my idea.  With all due respect, I have set up a few TTs in my time.  BTW, what you are hearing on the Garrard is a combination of too low lateral compliance and the ubiquitous rumble of idler drive.  Although we could work out the resonance problem, the rumble is inherent.

Bill, what I say is that raising M by adding weight to the headshell will lower resonant frequency. Perhaps I need to read more carefully the posts that are farther up the thread, but it seemed to me the subject is RB’s reading of  6Hz for the Fr. of his Holbo/cartridge, using the Tacet test LP, and he would like to raise it into the generally accepted range of 8 to 12Hz.  Having understood it that way, that is my response; you need to decrease M or C in order to raise Fr. But more important, I am not sure RB was hearing any "rumbly" noise with the Holbo to begin with.  So, the Tacet test LP is telling him Fr is 6Hz, and he is concerned with the numerical value of Fr, not with any particular actual noise with the Holbo. Confronted with that situation, I personally would leave it alone unless I hear an actual problem when playing music.

But Bill, I now see what might be your point.  If the Tacet test LP is giving a wrong answer as to the actual value of Fr, and if Fr is in fact higher than 6Hz, more toward the upper end of the accepted range or above it, then your advice is valid. 

@billstevenson @lewm 

All good suggestions.

Some of the extraneous noise I hear is like a distant murmur - say a Miele dishwasher swishing water around - with a rhythm corresponding to one record revolution.  It could be recording venue air-conditioning, but why the rhythm?

The Tacet record is trying to detect actual audible resonance (mis-tracking) and as such includes every possible resonance source including floor, shelving, sub-plinth, plinth and so on.  I suspect the Garrard is just tracking too well to get over excited!

My main table is the Holbo with the Garrard as a backup.  I cannot use a lighter head shell because it has not got one, but I can add mass as Bill suggests.  I'll let you know.

Both platters are topped with Funk Firm's acrylic Achromats, for what it is worth.

The quieter records have tended to be 180-grams, which could just indicate that their manufacturers have tried harder.  Or used better vinyl?

Lew, as you suggest I expect compliance to numerically increase as the cartridge breaks in.  So much to try, and so little time to try it in.

Thanks to you both

@billstevenson

You don't have to try my idea.  You can think yourself out of it

Unfortunately, I cannot always respond immediately . I am about 15 hours ahead of you timewise, so probably asleep when you post and not awake for many hours afterwards. 

I did as you suggested, but only for the Holbo.

I have taped a 5-gram weight to the cartridge. and am now tracking at the geometric limit of the balance weight - a bit over 3-grams instead of 2.1.

Vertical effective mass has gone from 15.1 grams to about 20.1 grams, while horizonal mass is up from about 39 to 44.

On the Tacet test record, there is still audible mistracking at 6-Hz and a few signs of discomfort on the 5-Hz and 7-Hz bands.  Clean from 8-Hz to 15-Hz.

The Telarc record has been mine for decades, was digitally recorded, with flat frequency response from 0-Hz to 50,000 samples per second.  There are no scratches, or significant tocks or pops.

It subjectively seemed a bit clearer with the extra tracking weight, which is not something I expected, and a little bit more crud appeared on the stylus than I expected.  I think the stylus is getting a bit further into the groove and digging a little bit more dirt out.  but I would not testify this in court!

For the record  the Holbo puck weighs about 630-grams

Can you make anything from this?