Help with tone arm geometry and bass


After installing a new cartridge, I checked that my SME 309 tonearm was level. The sound of voices especially male voices was a bit bass heavy. so I added a ringmat turntable mat which raised the level at the head shell by 2mm. The bass heaviness disappeared. This is the opposite of what I was led to expect. I always thought head shell up meant tail down and more bass. have I got it wrong?

I would like to dispense with the ring mat so I can use a record clamp on the spindle. But this would mean tone arm level again. Which way do I adjust the tone arm to remove the bass heavyness without the mat?

 

 

 

rrm

What @macg19 said.

JR analyzed two of mine (MSL Signature Gold and Hana Umami Red) and set up my table. (Luckily we’re both in the Bay Area.) 

One of the best & nicest guys in the biz. Give him a call & he’ll set you straight.

If you want to get it perfect with zero guessing, call JR at Wally Tools and get the cart analyzed and use the tool set to align to objective measurements.

I’ve just done this with a MSL Signature Platinum on a Clearaudio Universal arm.

Results are astonishing. One and done.

see my recent post on this if interested 

The mat itself can alter tonal response, but whether that can outweigh the change in VTA is the question. I'd take the mat off and adjust the height of the 309, especially as that is easy to do.

Cleeds is correct. But I don’t think a change in overhang would enhance bass. The OP is also correct in thinking that “tail down” usually enhances bass, contrary to his direct experience. I suggest maybe the change in mats is the cause. I agree with Pindac, let the cartridge break in before fiddling. Also “level” is the best start point for VTA with every cartridge I own.

Using the mat shouldn't affect the overhang. 

If the mat thickness alters VTA, then it also changes overhang.

New Cartridge ?? How Long in use ??

In my experiences had with assessing New Cart's across 50-100 hours of usage.    Bass is the most obvious frequency effected from the period it takes the Damper > Tension Wire assembly to settle in.

Enjoy the Break In Period, it is good for training ones ears to detecting changes to t an end sound.

Toying with Geometry may be a little early as an investigation.

SRA (Stylus Rake Angle) is always a guess. Different LP's are often cut with different  rake angles. There is no industry standard. Your cartridge as presently setup may sound heavier for bass on certain LP's and lighter on others. That's why it is good to have a tonearm with easily adjustable height at the pivot, like a Jelco.

Good point. I usedthe SME supplied gauge on the naked platter without the mat

I will try again with the mat in place to see if it makes a difference.

Changing the turntable mat did more than change the VTA/SRA, it also changed the overhang. What tools are you suing to align the phono cartridge?