What Does a Cartridge Compliance/Tonearm Mass Mismatch Sound Like?

It does not have one possible sound. You can have a cartridge too stiff for a very low mass tonearm. It will cause some resonance in the interaction between the stylus and the arm mass. And, you can have a cartridge too compliant for a tone arm with more mass than required, That will also distort the sound because the stylus will not be stable as it tracks the groove. All tonearms affect and will color the sound of every cartridge. As long as it sounds good/great to your ears? That’s what counts. I used to be a repairman for a vintage TT company, and sold audio after wards. No tonearm cartridge combination will be 100% neutral in the truest sense. What matters is what sounds good to your ears. If you want to know what is as close to neutral as it gets? Get your hands on some master tapes, and play on a state of the art reel to reel. Otherwise... shoot for what will sound good to your ears.  There is no perfect match between a tonearm and cartridge, as far as neutrality.  Only a match that sounds perfect to you, is a good match. High compliance needs a low mass arm.  Low compliance may need a higher mass arm to prevent the stylus vibration effecting the arm vibration...  But,  there are even exceptions to that,  as with a Decca London.  Again.. if it sounds good?  Be content.  

Thanks, gents. Is it correct to say that there are different DEGREES of mismatch which might manifest differently? What I am hearing is low frequency rumble/distortion that is inaudible unless the volume is cranked up. Interestingly, the rumble/distortion exists during quiet/silent passages so this does not appear to be external vibrations from high SPLs disturbing the table, which is well isolated. I checked and the cartridge setup appears correct (overhang, VTF, etc) so it does not appear related to this either. Could there be a slight mismatch that is only audible when the volume control is aggressively amplifying the tonearm resonance? This is a buddies set up (Systemdeck II with a Rega arm and Goldring Eroica) which SHOULD be an OK match. Unfortunately, he lives quite a ways from me so I'm not able to do a lot of listening and intervention but thought I would get some opinions in an effort to help him out.

stringreen, maybe you should have responded to Dodge using Viper in your example instead of Porsche.

Oh wait, doesn't that already have a truck engine? ;^)

Dear @moonglum : """  can appear to split into 2 separate voices one in each channel! """

Could you tell us with what cartridge/tonearm combination and LPs experienced that specific situation?

Regards and enjoy the music,
R. 

Dear @lewm : Resonance frequency is an important parameter to take in count in the cartridge/tonearm combinations however and at other priority levels is the self cartridge tracking habilities, the kind of design and materials used in its suspension and how well the cartridge designer damped it overall.

The Acutex is a champ on that critical cartridge design target: very high tracking abilities and this characteristic makes a difference on the thread's subject.
Btw, that Acutex cartridge sounds good no matters wich tonearm we are using but if it's matched with better tonearm its quality performance level can goes higher.

Regards and enjoy the music,
R.

Tom, I think the reason why you find Stringreen's metaphor a bit confusing is because, with all due respect to String, it IS a bit confused. I think possibly he is referring to an analogy between a high compliance cartridge and a lightweight, agile sports car, on one hand, and a low compliance cartridge and a truck, on the other.  Think of the cantilevers on these two groups of cartridges as the spring suspension in the respective vehicles. The compliant sports car suspension will sag down to its bump stops with a heavy load, like that of a high effective mass tonearm, and vice-versa for a truck with a very light load, analogous to a low effective mass tonearm; it will start to fly around on turns and bumpy roads.

What I don't understand myself is why my high compliance Acutex cartridge (cu = 42 according to Acutex specs) and my high mass Fidelity Research FR64S tonearm, albeit with a light weight headshell, sound so good together, with none of the typical symptoms of a compliance/mass mismatch. I keep waiting for something bad about this match to make itself evident, but not so far.

My experience with this is that everything just sounds wrong and or lost.

Tom...even though the weight of that truck engine can be carried with my Porsche example....can you imagine how awful the suspension is able to respond to the bumps and curves in the road....

OK  I will bite how does the weight /torque / horse power car example have to do with compliance of a cart and the weight of tonearm?

The stylus may leap out of the groove, and visible pumping of the woofers is also common.

Dear @dodgealum: I imagine you are just curious because looking at your tonearm/cartridge combination you have not problems coming from a mismatch in between regarding compliance/tonearm effective mass.

When exist a true/real mismatch normally it can be reflected ( mainly ) at the low frequency range but because the generated harmonics in reality affect all the frequency range. Sometimes we can hear a mismatch when in a very well know LP tracks the bass is not tight and comes with bluring or to much overhang or in excess of fatty sounds there. This kind of sound can be generated even that you are not aware of a mistraking on high velocity recorded grooves.
Of course that as @stringreen posted many times you can " see " the mistraking but not always is evident at our eyes.

That kind of sound I’m pointing out here could comes from other kind of problems down there diferent to that mismatch you are asking even several times exist an evident mismatch at the cartridge/tonearm resonance frequency value and we like what we are listening and can’t detect it. This happens all the time and for we can detect it we need to be trained. I think there are no strict rules on this elusive audio subject.

Regards and enjoy the music,
R.

mistraking...even bouncing out of the groove.  It's like putting a huge semi-truck diesel engine in a Porsche sports car.