Transmission lines

[jj]

Hi everybody. This is the first time I have posted anything here. Years ago, I built a speaker system like the Fried H2, which consisted of two satellites like Ls35a and a sub woofer using B200 SP 1039's in a transmission line enclosure, somewhat like a coffin. The satellites are long gone, but I kept the B200's. I would like now to make a speaker with the B200's, 2 CSS WR125ST's in parallel, and a CSS Aurum Cantus ribbon RT-1. I would look at passive Xover in the MTM's at about 4000 Hz, and an active Xover like the B-1 or S-1 Reckhorn at about 100 to 150 Hz for the base. The cabinet would be 10.5" W, ~22" D and 45" H. , with the MTM's on top. This would bring the MTM's axis above a listener's ears while seated so I am considering to downward slant the MTM's so that at a certain listening distance, the axis of the MTM's would be at listener seated height like the Gershman.
I am have trouble designing a TL for the B200's, but I have come up with a closed end area of 145 cu in, open end area 32 cu in and a length of 90" and this tuned to 38 Hz. The line would be tapered and filled with Dacron. (By the way. Anybody know where I can get Dacron. None of the speaker suppliers seem to have it. Is Dacron the best stuffing for my line?)
I am having difficulty designing a suitable Xover for the MTM's. I am not that good at math, and frankly Mr. King's info for designing TL's makes my eyes cloud over.
It seems I need the 22" depth to put the TL inside the box.
I'm a beginner at this, so any help greatly appreciated. Thanks in advance.
Jim

 

[planet10]

I am have trouble designing a TL for the B200 SP 1039s

Are they really 1039? All the Hs i saw used 1022. The 1039 was from the KEF 104aB (specs are fairly similar)

As a starting point you should look at the line in the Fried H. Plans linked here: http://t-linespeakers.org/classics/friedH/fried_H.html

Then i'd run the numbers thru Martin King's tables: http://www.quarter-wave.com/TLs/TL_Theory.html

Factory driver specs (you'd be ahead if you actually measured your pair):

http://www.t-linespeakers.org/drivers/b200.html

(picture of 1054, looks pretty much the same as 1039/1022, but not suitable for TL)

dave

 

[jj]

On the frame of the driver it says SP1039. I bought the kit from a fellow in Detroit at the time. He gave me the info from Fried and I built the kit from it. Different from Fried was the stuffing. The kit I bought contained long fibre wool for the stuffing instead of the Dacron that came with the Fried Kit. The satellites came with the T27 and B110 KEF drivers. I think I will have to build a test unit right down to the stuffing etc. and test the unit and tweak it until I get what I want. Preciate the info and reply.

 

[planet10]

The ones we got & built/sold all came with foam damping.

dave