What cart. for the Reed 3P?

@rauliruegas do you use online resonance calculator or you’re talking from personal experience?
I was quite sceptical about optimal performance of Stanton 980 LZS on my 18g Reed 3P Cocobolo "12 untill i received my cartridge and mounted it.

From my experience all those online calculatora are incorrect and i don’t trust them. I only use Hi-Fi Test LP to measure actual resonance frequency of cartridge/tonearm combo.

Don’t forget about this special brush on Stanton 980 LZS - this is really works well with 2 - 2,5g tracking force. So my samle of Stanton in actual lateral/vertical resonance test (with Hi-Fi News LP) stay between 10-7Hz!
Again: Tonearm effective mass is 18g

Maybe suspension is a bit stiff as the cartridge looks unplayed NOS, we will see after some hrs with Cardas Burn-In record. 

Dear CH: I think that this audio subject is not about to trust on something or not. It is just mathematics and you can use any calculator over the net and will gives you the same resonance frequency ( 6 hz. ). 

What we can't trust is in a test record that comes with " natural " errors " from the recording process and during playback. This is what I don't trust, mathematics are just mathematics and here it's not a " rocket science ".

Regards and enjoy the music,
R.

Hmm, that's interesting, never heard about errors on Hi-Fi Test Record before. How can we measure resonanse freq. in real life with other record? Any other records (proper one) available to make sure the Hi-Fi Test record is not a good tool for it? Anyone?? 

Raul, (1) I have removed the brush entirely from my 980LZS. This probably reduces its weight by 2-3 gm. (It would be interesting to know the exact weight of the brush assembly.) And (2) with age, it is quite likely that the actual compliance of the 980LZS is lower than factory spec.

Both of these factors would tend to increase the resonant frequency somewhat, perhaps into a more acceptable zone.  As you said, it does work well, regardless.

I wrote elsewhere that I mounted an Acutex LPM320 (Compliance = 42) on my FR64S with Dynavector headshell, and amazingly there is NO problem with resonant frequency.  If the FR64S + headshell + Acutex has a collective effective mass of 30g, then the predicted RF is ~5 Hz.  My guess is that the Acutex has lost compliance.  (On the other hand, it tracks piano as well as or better than any other cartridge I own.) I do take you seriously as regards your reservations about the FR tonearms, but this combo sounds superb, much to my surprise.