Compliant - definition

I cannot seem to locate in the search engine the definition of a compliant cartridge. Can one of you analogue experts please explain exactly what compliant / compliance means with respect to phono cartridge / tonearm. I only have a very vague idea. Thank you in advance. -EJC
I took your >>"Compliant-defination"<< post and googled it for kicks and it asked if I wanted "Compliance Cartridge ... not being a TT guy I said sure and this is what I found

Compliance Cartridge

I guess the word "Compliance" gets you what you want ... sorry I'm not a TT guy

"The difference between Knowledge and Wisdom is ... Knowledge is knowing the Tomato is a Fruit ... Wisdom is knowing not to put it in a Fruit salad"

HTH Dave
If you think of the cantilever as a spring, compliance gives you an idea of how "springy" it is. The cantilever must be able to move up and down, and left and right, to respond to the modulations of the record groove. A high-compliance cartridge cantilever will move a lot compared to a low-compliance cantilever cartridge. There are benefits and trade-offs to both designs. The type of cartridge that will work best will depend on the type of tonearm that you use. For instance, Unipivot tonearms don't really like low-compliance cartridges, because due to their relative rigidity, have the ability to move the entire tonearm. A low compliance cart is much better in a fixed-gimbal bearing style tonearm, whose angular position cannot be as easily influenced.

Hope this helps.

From a very basic perspective, 'compliance' is a measure of the 'softness' of the suspension of the cartridge (a cartridge/arm pairing is a 'mass on a spring' system). A 'high compliance' cartridge is effectively one which has a 'high level of softness', and vice versa for a 'low compliance' cartridge.

If you are carrying two huge steaming cups of coffee while riding down a potholed road in a pickup, you would hope that the springs on the pickup were of the appropriate springiness. Too soft is a problem - you'll bottom out in the potholes. Too hard is a problem - you'll bounce all over the place. If it's just right, you'll make it down the road without burning yourself. If too hard, the way to remedy that is to stick a half ton of bricks into the back end. Too soft? Remove the other half ton of bricks. No bricks to remove? Take the springs off and put them on a lighter car, or get harder springs for your pickup.
I think this is what Eric is looking for, if he hasn't already read this part. ;-)

* A tonearm whose effective mass is rated at 10 grams or below is considered low mass (e.g. early SME’s, Grace 747 etc.). A tonearm whose effective mass is rated between 11 and 25 grams is considered moderate mass (e.g. SME 309, IV, IV-Vi, V, Triplanar, Graham). Arms above 25 grams of mass are high mass in nature (Eminent Technology, Dynavector).

* A phono cartridge whose compliance is rated at 12 x l0ˉ6 or below, is considered low compliance. A cartridge whose compliance is rated between 13 x l0ˉ6 and 25 x l0ˉ6 is considered high to very high. Note: Another way of expressing compliance is um/mN. Here a rating of 5 to 10 is considered very low, 10 to 20 is moderate and above 35 is very high.

* Low mass arms mate well with both moderately high and very high compliance phono cartridges.

* Moderate mass tonearms are good companions for moderate to low compliance cartridges.
So then my question is basically the best matches are in the middle for example a Low to medium compliance cart of :

11 x 10-6  or 12 x 10-6 or 13 x 10-6 or 14 x 10-6

should match well to tone arms of anything between moderate weights of :

11 grams, 12 grams, 13 grams, 14 grams


Seems pretty easy this way to just remember anything 11 to 14 on both tonearm and cart. specs should match up pretty well. Anything outside of this you need to start being careful as a tone arm of 10 grams or 9 grams low weight would be now better suited with a higher compliance cart of 15 x 10-6 and up?

Don't forget to take into account the mass of the cart also. I always cheat and look it up in the cartridgedb. :-) But always remember that these numbers are a guide, YMMV.
Wow guys / gals! Very helpful info; much obliged and appreciated. I feel I can now make a more informed, knowledgeable decision. Many thanks!