Where do classical vinyl records get their rumble from?

@richardbrand 

REW can display the arm/cartridge resonance quite easily. Use the RTA function. Expand the graph's low frequency cutoff to 2Hz. Play any record or test record as long as there's no information below 15Hz or so. You will see the arm/cartridge resonance as a peak (it can be broad) somewhere between 4 and 15Hz. In my setup, the peak is broad and a bit variable. It is about 50dB below normal listening level.

The arm/cartridge resonance is mainly determined by two physical parameters. These are the stylus/cantilever construction (stiffness mostly) and the effective mass of the assembly. If you make drastic changes to either of those parameters you should see the REW RTA spectrum shift frequency in response to that change. If it doesn't then the source is not the LP, but is coming from somewhere else..

The LP surface generates a noise spectrum. It is highest in the tens of Hz, dying down into the noise floor at 20-30Hz. Any arm/cartridge will have a resonance in this region, so it will be excited.

Rumble is caused by the table vibrational noise coupling into the arm/cartridge assembly and can be somewhat ameliorated using rubber or sorbethane on the platter. I think there's little more one can do. The table motor and its construction can't really be changed without a lot of bother. This effect will add to the excitation of the arm/cartridge resonance.

Isolation from the environment is also a contributor, but can be addressed and reduced.

That once around whooosh you hear has been pressed into the LP. I've received (and returned for a full refund) several LPs that had this problem. I bought them from the Sade website. Some other LPs have this whoosh also but to a lower, tolerable amount.

Every mechanical component or assembly in your system has a resonant frequency and overtones. These cause no problems until one excites them. There will always be always multiple sources with individual spectra. 

One must go through the list of possible sources until a response is discovered (measured). Since the source has been discovered, one can then employ a variety of approaches. Noting which ones reduce resonance will lead to a solution.

@richardbrand 

Use double sided tape.That way you can remove the mat whenever you want. Just throw the old out and cut some new.tape.

Works fine for me.

@kevemaher 

Use double sided tape.That way you can remove the mat whenever you want. Just throw the old out and cut some new.tape

Thanks.  I used the double-sided tabs provided with my 3-mm Achromat.  The film is incredibly thin, I presume to firmly couple the mat to the platter across the entire surface. 

Note that in this application, the primary function of the Achromat is to absorb those vibrations generated by the stylus and propagating through the vinyl of the record.  You can hear airborne vibrations generated by the stylus if your ear is close enough.

@kevemaher 

That once around whooosh you hear has been pressed into the LP. I’ve received (and returned for a full refund) several LPs that had this problem. I bought them from the Sade website. Some other LPs have this whoosh also but to a lower, tolerable amount

Thank goodness, somebody else can hear the whooshing! 

When a record has obvious whooshing, the severity seems localised.  Any idea what sorts of pressing defects can cause this?

It seems to be a function of vinyl composition rather than the stamper, because replacement records can be much better.

Presto Classical has been very good at refunds / re-supply but I am too embarrassed to go back more than once for the same recording

@richardbrand 

If I could go back to the sticky tape for the Achromat mat for a second.

I use golfer's double sided grip tape. Comes in a long roll. It is exceedingly thin because golfers don't want a thick squishy feeling when hitting the golf ball. Using this tape frees you from the hassle and cost of obtaining tape from the manufacturer.

There are no audible differences between the two tapes.

Back to the Whoosh....I don't have any engineering knowledge of the mastering or stamping processes. It could have occurred at any step in the creation of the LP.

It seems that this is a more recent phenomenon. I have over a thousand LPs. None of them have anything near the once around whoosh heard on those Sade LPs I returned. When I initially asked for an RMA, I was told that these things are from a poor table, not their LPs. I quickly replied with a detailed description of my expertise, equipment and experience. They quickly provided an RMA and fully refunded the funds I used to purchase these LPs. I won't be using their services ever again.