SP10 Mk II vs Mk III

Hello everybody!

I am new of this forum. I am writing from Tuscany, Italy, where i live. I happened here looking for info on how to build a plinth for the SP10 MKII. I went quickly to the posts and there's already so much information that I must first of all say thank you to everybody.

My SP10 is flying here from Australia just now, i got it on ebay (from a respectable seller) a few days ago. I hope it will arrive safely...

I think that building a plinth is great fun! Also nice that all SP10 will look very differntly!

I've seen Albert Porter's plinth on soundfoutain and ordered there the template. So now I am working on the plinth project. I really liked Albert's ones (except a few minor hestetical choices), and I will probably work on the same ideas. Specifically i would like to ask you all if some of you has experience with graphite (carbon block) as a mean to add mass and dampen resonances. I can acces a cheap source for this material as well as a CNC machine to work it, so i wondered if it could be of any use.

Meanwhile, thank you again.

Silverprint, As far as I know, graphite has some excellent qualities for audio use, but I don't think it's very dense. In other words, the weight per unit of volume is not great. Therefore graphite might not be so good for mass loading. This is not to say that it could not be useful in building a plinth, but probably in conjunction with other more dense materials, like hardwoods or slate.

I think one of the advantages of carbon graphite would be constrained layer damping effects achieved by varying material thickness and directionality of carbon fibers. This is how it's done in bicycle frames to obtain strength where necessary as well as lightness. The resonant signature of the material could be varied throughout the construction-- which might have interesting if unpredictable effects unless computer modeled.

Dear Dgarretson and Lewm,

Thank you for your promt reply! But i think i shall avoid a probable misunderstanding. I am talking about graphite block, not carbon fiber. The density of the material is about 2.2 g/cm3 ie. 0.08 lbs/inch3. So not very heavy, nor light tough. It is made of heavily pressed carbon powder, its structure is amorphous. It is available in different densities and hardnesses.

As soon as possible I'll try to post a sketch, so it will be easier to understand each other.

Again many thanks

Well it’s denser then wood but not as dense as slate. ART made a footer type thing with it that had a brass insert, I still have a couple floating around. I would say make it thick enough that the overall weight of the plinth is significant or do what ART did and add brass to it. My concern would be that IIRC the graphite is somewhat brittle and may be chipped easily.

I just got my SP10 today and will be putting it in a slate plinth at some point in the near future..:-)