In Reply to: RE: Electro Voice 12TRX's need a new cabinet posted by Paul Eizik on June 17, 2012 at 08:27:20:
...It looks like Terry's website has been down for awhile, and as I recall there were T.S. specs for the 12TRX there. For reverse engineering in the meantime, EV listed the same size recommended box for the SP12C as the 12TRXC, and there are T.S. specs for the SP12C:
Fs= 45 Hz; Vas= 0.1671; Qes=0.75; Qts= 0.6654. There are various websites which have explanations of the significance of the Theile Small perameters. Beware mixing metric and inch/feet specs, which can result in nonsensical results, as well as using the wrong conversion formula to convert one to the other.
If you're not into a faith based initiative, then you can measure the drivers in question yourself. Room EQ Wizard (REW) can be downloaded from the Home Theater Shack website (both mac and pc versions are available) and it features a T.S. measuring procedure (with which you need to construct a simple test box to use) and the headphone output from a good laptop (macbook at least) should be fine to drive it. I have'nt tried it yet myself though.
I've never heard a Karlson, so I'm outa the loop there. For an open baffle design, do a search here for the "baffle step" formula, which you can use to predict the 3 dB down point of a baffle.
Paul
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Follow Ups
- RE: Ping Kapt. Freddyi and Terry Gesualdo.... - Paul Eizik 19:45:33 06/18/12 (2)
- RE: Ping Kapt. Freddyi and Terry Gesualdo.... - GM 21:53:29 06/18/12 (1)
- RE: Thanks GM.... - Paul Eizik 19:54:53 06/19/12 (0)