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jessie.dazzle wrote:

The AK150 and 152 are not new creations dreamed up by Mike; they were made back in the day by Vitavox but nobody ever talks about them and I have never seen either. See the Unofficial Vitavox web site; AK150 = Catalog N° CN143; AK152 = Catalog N° CN327. http://website.lineone.net/~empson/CN.html My understanding is that all these drivers use the same chassis and motor assembly and that it is only the addition of a cone/voice coil that finally determines what they end up; if that is so, then presumably the original AK driver was designed with consideration for the lower Fs. I would hope the lower Fs were achieved via an additional pleat in the suspension. This would of course require additional tooling, so it is possible that the lower Fs were achieved via simple mass-loading of the membrane (i.e. making the cone thicker) which comes at a price.

But adding mass to membrane change the dynamics of everything, it also increases the exertion as it will add moment of inertia of the cove movement. Anyhow, I did not realized that they existed in past, I never seen them. Most likely they were used as direct radiators and have burned out long time ago….

jessie.dazzle wrote:

As with the S2, my understanding is that every attempt was made to be as faithful as possible to the older production units which would suggest simply continuing production of the parts unchanged. This in theory is possible, as I read a while ago that, along with the rights to produce the drivers, the original tooling was purchased and is presumably still being used (though it did require refurbishing). If so, the question then becomes one of availability of the materials and of course the know-how. In response to both of these issues, given the fact that this is all taking place in England (wonderfully resistant to change as it is!), there's a fair chance both are possible.

Hm…. I do not think that mike would “as faithfully as possible” reproduce the original S2 diaphragms. I do not like the original S2 diaphragms, at least they need to be used very differently from how I would like to use my S2 drivers.  The Mike’s production from 2000, with white plastic suspension was much better then the original diaphragms, even they had that ugly response. I hope he will use the white plastic suspension in his new production…. The bass driver is a different story. There is no materials that were available 60 year back and nothing you can do with it. It for sure will be new production with new sound. It might be even better but it will not be the same as 50-60 years back. No one company ever was able to make a comeback with the same sound…..

Anyhow, my main concern is that Mike in his documentation stated the S2’s poser handling of 100W. This is very interesting. There are two option why I think it happens. He might consider that original 10W of power handling would scare the Morons who accustom to drive horns with 1000W digital amplifiers.  So, he wrote 100W to be more conventional among the competitors. Alternatively Mike could use the thinker wire for his voice coil and to make the S2 driver to be able to handle 100W. This would mean that the new production has thinker VC and consequently heavier diaphragm then before. Heavier diaphragm = lower Fs = different dynamic of back and front loading = pretty much different sound. Mike could find new ways to wind the VC that would add thermal-resistance of VC with preservation of mass, I do not know what he did but generally I would prefer to use a driver with lover power handling, not higher….

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