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FS - BMS 4552nd Compression Drivers - Brand New (Australia)

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Pair of BMS 4552nd 1" compression drivers. 16ohm.

A$500 including postage Australia wide.
Will ship overseas at additional cost.

Drivers are brand new. Will happily e-mail photos on request. These were for a project which never eventuated. I am selling as I am building a new home.
These are not available in Australia. I had to have these shipped to Australia from a supplier in America.

Taking into acount what I paid for them, International EMS To Australia and then the $US - $AU conversion I am not even recouping what I paid for them.
Oh, thanks. I would like to understand internal layout of the ring diaphragm, rear chamber, compression chamber and the first horn section that goes from the diaphragm to the exit of the motor. It seems that the new BMS ring radiators don't use the same layout as the classic inverted dome compression drivers.
The patent shows the structure quite nicely.


I´ll take some pictures tomorrow to support the patent.


(Found a recone kit)

Here´s a blurry re-cone-kit for 4554 1,4" driver.


  • 4554r-cone-990.jpg
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Thank you very much. I think that patent drawings solved my doubts, I was not sure about wehter the cavity had a 180 degree fold in the beginning or not. The dual diaphragm version got me quite impressed too.

They solved the old problem of lack of repatability in compression chamber size, usually resulting in different response in the top octave and bad stereo imaging by including the chamber in the diaphragm assembly.

Hey Rialb, are you alive?
Hi Eva

Sorry I have had another party here in Australia interested and I'm just qualifying them as a serious buyer before I look at shipping overseas.

I have looked at shipping and It's going to cost approx A$100 plus insurance to send via Airmail to Spain....

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