Koetsu compliance compatibility issues


hi guys,

am wondering, what arms are you guys using w/ the koetsu carts.
For example, a black has compliance of 5 only and weight is 9 grams.
If i use an arm of 14 grams, its resonance frequency is 15 hz which is the upper limit of being acceptable.
Nonetheless, would like to hear inputs on real world situations on what arms you guys are using with koetsu & despite of the high resonance frequency on most common arms, how the sound is ?
Thanks for the inputs.
nolitan
Geoch, You wrote, "So, don't bother. You simply can't trick the formula."
But in fact the formula itself is "tricky" and only gives you a ballpark estimate of the resonant frequency, even if your input data are accurate with respect to one's particular sample of a particular cartridge. So my approach would be to forget the formula but to try in a general way to match a low compliance cartridge with a medium to high mass tonearm, etc, etc.

I am one who does use ESLs and OTLs and who does very much like the Urushi that I own. I also have a Colibri and an Ortofon MC7500 and several tonearms and turntables. Many days, I prefer the Urushi over all. I don't think a 12" arm is necessary to enjoy the Urushi, but when I finally acquire one, I will try it.
Just to update, I'm enjoying greatly my Koetsu with my older phantom arm. Loving the musical combo!
I'm using a koetsu jade with a VPI JMW-10 on a TNT turntable.
On paper the JMW-10 is a poor match for the jade as it's a unipivot with effective mass is in the 10-11gm range. That being said it sounds awfully good to me. Would an arm with a higher effective mass sound better? Maybe and one day I plan on finding out but for now the combo sounds great regardless of the math formulas.
A few things to consider, the stone body koetsu by being heavier by around 4gms then their wood/urushi counterparts and thus increase the effective mass of the arm their used with.
The effective mass of an arm can be increased by adding a cartridge weight. I know that VPI sells a 3gm aluminum weight for this purpose and I've seen a 5gm brass head shell weighs available.
Additionally by using a LIGHTER counterweight further back on the arm as opposed to a heavier counterweight closer to the pivot point will also increase the effective mass.
Just my 2 cents.
Hi franks,

Additionally by using a LIGHTER counterweight further back on the arm as opposed to a heavier counterweight closer to the pivot point will also increase the effective mass.

This statement does not make sense.

The physics formula for levers is M=FxD (M = moment (effectice mass), F = force , and D is distance from the pivot).

From my understanding, the moment (i.e. effective mass) is the upward force by the lever, the downward force of the mass post fulcrum is dependent only on the mass of the counterweight (and a constant gravitational constant!) and its product with its distance from the fulcrum.
Cheers<

Bobby
Well, this not an area of expertice but the effective mass is the moment of inertia and the further from the pivot point wheather the cartridge or counter weight increases the moment of inertia and hence the effective mass.
In your formula the F would appear to be the VTF thus the larger the D for any given VTF the higher the effective mass/moment of inertia.
There's a nice discussion of the topic by AJ Conti on the Basis website in the Vector tonearm section were he discusses changes in effective mass with using one or two counter weights and their relative positions on the arm.
Most importantly, happy listening and enjoy the music.