Resonant Frequency

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.

I see that there is some difference as to what an acceptable figure is.A reply on Vinyl Asylum gave the example of the Goldring cartridge that comes with the MMF 5 having a rf of around 8hz,but said to be o.k.Some on Vinyl Engine believe 10 hz is too low,deriving from the original paper of the '70's,and have said you want a bit of give,to around 12hz and can go to 14hz.So far I have seen a range 8-15hz.In fact a lot of people seem to retreat from the original 10 hz and are justifying combos of 7,8hz because thats where their tables are.Interestingly a Blue Point Special on a Rega RB 250 comes to almost exactly 10hz.Does it sound fantastic or do I notice a slight "grey"tonal colouring?(ha ha)

Quoting from "The Audioperfectionist Journal," (No. 9, 2003)I have this to offer as food for thought. It is also a view I agree with and have experienced, and this as a person who has been spinning vinyl for 30 years or so, and the last 10 with a strong dedication to the format:

"Expert opinions differ on the optimum frequency for cartridge/tonearm resonance. The range usually recommended is 6-15Hz but I will state without equivocation that the magic number is 8Hz. Go higher than that and you'll get fatter bass with less definition. Go much lower and the stylus will jump out of the groove if it encounters the slightest warp."

The higher resonances are a function of reality, and for most of us this is not a problem as most records are not going to have a lot of information in this area. However, having said that, there are of course those frequencies that are a function of the fundamental or base frequency; double it and this begins to make sense.

For ex., if your RF is 14Hz, then 28Hz, 56Hz etc are effected. If only 8Hz, well second and third order RF is at or below what most systems will reproduce. Otherwise, we could have a primary RF below, say, 32Hz or so.

Very few pipe organs produce a true 16 foot, BTW. Those that do, well you feel this in your bones in the church...

FWIW

Have you seen the paper in the Vinyl Engine's archives? "Audible Effects of Mechanical Resonances in Turntables" This was the original paper that started the ball rolling.It was given to AES Covention In New York in 1977 by Poul Ladegaard of Bruel and Kjaer.He is talking about optimum's in the 13-18hz range and elucidates the reasoning for this.Although it is old,it is an oldy but a goody and has sparked a lively discussion.Stefanl