do some cartridges have lower noise floor?

Everything has a noise floor, but for the most part, it should not be relevant when you are listening from a normal distance from your speakers, unless your phono pre-amp doesn't have enuf gain, or it also has a highish noise floor.

My medium output Benz Glider in my ARC SP10 displays a buzz and random noise that sets in at about the loudest I would ever listen to it, but without a stylus in a groove, it is audible. With a high output Grado MM cartridge it remains dead quiet intil the last click or two of the VC which is the noise floor of the phono stage. I haven't tried it, but I would guess that the Grado's noise floor would reveal itself in a phono stage with less gain than my ARC.

FWIW.

Assuming the cartridge is aligned properly and the record is cleaned, does the choice of cartridge make a difference for noise floor.

I'll suggest 'lower noise floor' means:
a) reduced distortion in replication of the original waveform as represented by the record, and
b) a reduction in 'information' not found on the original recording (record dirt, susceptibility to turntable noise, etc.)

With the cartridge/tonearm/turntable/wire/phono-stage all being part of a 'system', its difficult to isolate noise sources within individual components. I suspect much has to do with particular combination's and their interaction. For example the ability of the record-platter interface to reject or absorb the energy from dragging a rock across plastic or from the bearing on which the TT turns.

Noise generated at the stylus-record interface may partly be a product of radii and stylus shape and the suspended stylus' ability to track within its setup. I don't know which shapes tend toward lower noise, but I suspect they best promote stable tracking and better match the original cutter's shape. Noise generated by the engine of the cartridge can be a product of its physical design and how that design responds to any particular setup.

Cartridge designers may best speak to your question. With luck, Jonathan Carr may see this thread and respond.

A couple links:

Factors influencing cartridge design and performance as laid out by A.J. van den Hul

An interesting discussion in this thread: tt surface noise reduce or tolerate.
 
Tim

Tim,great post.....Boy,you've come a long way!!

Best