Cartridge Compliance

Hi, there's no simple method for converting 100Hz compliance (cu) to standard 10Hz cu. The conversion is a sliding scale. 100Hz cu of 6.5 = 15cu @ 10Hz. 10cu @ 100Hz = 18cu @ 10Hz. So 7cu @100Hz is around 16cu @ 10Hz. In general 15cu (10Hz) and below is low compliance. Up to 20cu is med, above that is high.

Matching compliance to arm mass isn't always straightforward. Sometimes a cart will perform better outside of predicted best range of eff mass. IMO it's prudent to ask about a particular match. For example, the Denon DL-S1 is 14cu @100Hz. That would indicate high compliance, yet the cart seems to do better in med mass arms. On the other hand, if you're looking at a MM like the AT7V (7cu @100Hz), that should be fine on a med mass arm.
Regards,

Thank you for your responses and i read the GC Audio piece but i still don't know how to convert the 7×10-6cm/dyne to a 16 µm/mN equivalent. what do cm and dyne represent in the formula and what are the equivalent numbers to insert. Let me reiterate i am a layman in this regard. Thanks

**Hi, there's no simple method for converting 100Hz compliance (cu) to standard 10Hz cu**

Compliance is a measure of springiness. Dyne is a unit of force. The 2 different expressions are identical, it's the test frequency that's different.
http://www.diyaudio.com/forums/analogue-source/143804-convert-cm-dyne-um-mn.html
Cu can be measured in both horizontal and vertical planes. Some think horiz is more telling than vert, which is normally specified. In reality, tracking is 3 dimensional. The GC explanation is a simplification that is somewhat misleading, but has the right idea. If you're looking for further explanation, I suggest google.
Regards,

Another poor innocent audiophile enters the netherworld of cartridge compliance....

Seeking in the fog for points of reference.... (all we need now are Scully and Mulder)

Yes those two measures are equivalent, and there are rules of thumb applicable to basic mass market rubber suspended cantilevers...

But they frequently are shown to be wrong when designers use different sophisticated suspension setups, and/or differing materials!

The other interesting yet awkward thing is that aiming for the ideal 10Hz resonant frequency (based on arm mass & compliance measured at 10Hz) - is only a partial story, there are plenty of examples where a setup sounds great running with res f of 8Hz or 14hz.

Damping plays a major factor, and a cartridge with a well damped cantilever has much wider latitude than one that is relatively undamped.

BUT - tests comparing identical setups varying only the level of cantilever damping (done by Ortofon in the early 80's) consistently showed that the lower the damping the better the sound!!
It's always a question of compromise with vinyl!

Grado's are some of the least damped designs - they have a strong following, and also a substantial reputation for being finicky about their setup. (not surprising given the undamped cantilever!)

If possible based your cart/arm matching on compliance at 10Hz... assuming the spec is published or you can find someone that has measured it!

Second best is to base things on the VTF - this is an indirect approach, but basically anything tracking at under 1.5g will be happiest in a low mass arm, and is likely to be over 18cu compliance... Tracking at 1.25g is usually 22cu to 26cu territory and tracking at 1g is 35cu+ territory.
Mid mass arms (most S-arms are mid mass) tend to be happiest with VTF's between 1.7g and 2.2g - compliances tend to be around 16cu to 12cu.

Looking at both compliance and VTF will give an idea of compliance AND damping.
A relatively high compliance with a higher than expected VTF, implies substantial damping....

Hope that helps

bye for now

David

More on compliance(might be helpful):(http://www.resfreq.com/resonancecalculator.html)

Perhaps this site will give you more data on yout cartridge: (http://www.vinylengine.com/cartridge_database.php?m=Dynavector&t=mc&mod=17D3&sort=1&Search=Search&sty=&ovlo=&ovhi=&can=&dclo=&dchi=&stid=&masslo=&masshi=¬es=&prlo=&prhi=)

Thank you everyone for the education especially David. One of the things I love about vinyl is there are no absolutes, it is a never ending learning curve and it sound like music that is unless you get your compliance, VTA, VTF, azimuth, speed stability, humidity.......wrong. I guess that is more than one thing.