Resonant Frequency

Hi, I am the guy who started this whole discussion. Whhhhooooh...! Did I frighten you?
11Hz would be splendid, but higher values are better. At Vinyl Engine you can find this other thread, where you will find out that a Rega RB 250 is 11 to 13 g effective. Depending on the type of the Ortofon, the compliance will be 20 cu or above.

In the thread called "MC cartridge recommedation needed" you will find a comforatble resonace reference table. The total mass will be: 6cart + 2bolts + 13arm =21g. So when the compliance is 20, the product of these is 20 x 21= 420. This points at a bit below 8 Hz. This will not give optimum tracking stability.

Note that I take a compliance of 20 for the Ortofon, because you did not mention the model designation.

The best check is Track 2 of Side 2 of Turntable & Record Review Magazine Test Disc.

A Rega is not a light arm, as anyone would think. So be carefull with cartridge choice. And not all Ortofons have the same compliance. If you have questions about this: Just ask them to me in this or another forum.

Thanks for the reply.I have just received an e-mail from Origin Live who state that the effective mass of the Rega RB 250 is unaffected by the mod so it is at 11g as quoted on their website.The Ortofon is an X-5 MC so it has compliance of 13um/mN.Weight is 4.1g.So 11+4.1+1=16.1 and I arrive at 11 hz by calculation? I think that this is o.k.On Vinyl Asylum there is stuff in the archives and some say 12hz is optimal maybe 14hz.There is a page on the site for modding Thorens tables called cartridge/arm matching.Their formula is rf=159/sq root((eff.mass+cart weight+fastener weight)*(compliance))they say 10hz is optimal.I would like to know the current concensus on optimal resonance.stefanl

There is no "perfect" resonance frequency, just an acceptable range. Organ notes go as low as 16 Hz so you need to be safely below that. Go too low and you'll interact with footfalls, earthquakes and the guy driving by with a 500W sub in his trunk.

11 Hz is fine. So are 12 and 10, and probably 13 and 9. IOW, don't fret about it.