Lloyd Borrett Posted June 19, 2020 Share Posted June 19, 2020 So I've managed to purchase a pair of Celestion CX 2012 Co-axial De Luxe Studio Series speakers made in England in the 1960s. 12 inch, 20W, 15 Ohms. I had hoped to be able to use these speakers to replace the Goodmans TwinAxiom 10 Twin concentric speakers in a custom made tuned enclosures. But the Celestion drivers are too big for the enclosure. Thus I need a design for a suitable enclose for the Celestion CX2012 speakers. Celestion published two designs for speaker enclosures in the 1960s, but I suspect there would be more appropriate enclosure design for the Celestion CX 2012 Co-axial speakers that could be used. Does anyone know of where to look, or who could help me out, coming up with such speaker enclosures. Link to comment Share on other sites More sharing options...
VanArn Posted June 19, 2020 Share Posted June 19, 2020 From past experience with these speakers an enclosure based on the T & S parameters would be better than relying on the manufacturer's designs. Be warned, it needs to be quite large. The crossover network is simply a capacitor and a pot for the shallow horn tweeter and it is worthwhile to use a more sophisticated design. 1 Link to comment Share on other sites More sharing options...
VanArn Posted June 20, 2020 Share Posted June 20, 2020 I found some old measurements for the CX2012. Fs 35 Hz B.l 19.79 T.m Vas 208.6 L dBspl 96.83 Re 12.88 ohm no 2.9031 % Qms 5.1359 Mms 40.872 g Qes 0.2955 Cms 1.49E-6 m65/N Qts 0.2794 L 1kHz 1.1866 mH From these parameters and allowing for normal losses and solid parts within the enclosure, a fourth order Butterworth enclosure of an effective internal volume of 197 litres would be a good match for the Celestion 12'' speaker. Link to comment Share on other sites More sharing options...
Lloyd Borrett Posted June 20, 2020 Author Share Posted June 20, 2020 2 hours ago, VanArn said: From these parameters and allowing for normal losses and solid parts within the enclosure, a fourth order Butterworth enclosure of an effective internal volume of 197 litres would be a good match for the Celestion 12'' speaker. Many thanks. Any idea as to where I could get such a design and someone to make it for me? Link to comment Share on other sites More sharing options...
Powerglide Posted June 20, 2020 Share Posted June 20, 2020 (edited) If you can find a build sheet I can build them for you. Just put a finishing coat on some Altec Lansing 846b Valencia's that I built for another member. I will update the thread once I reassemble them next week. Volume 240lts, close to what has been suggested for your Celestion's I also have some 12" Celestion's in the way of the Ditton 44's I'm about to build new enclosures for them, did a quick volume calc and they are 73lts bummer your in Rye Edited June 20, 2020 by Powerglide lt spec wrong Link to comment Share on other sites More sharing options...
cccrchairman Posted June 20, 2020 Share Posted June 20, 2020 +1 on powerglide. Very impressed with Alan's work to date on my Valencias. When you have speakers the size of washing machines sitting in your living room they gotta look right. Link to comment Share on other sites More sharing options...
Powerglide Posted June 21, 2020 Share Posted June 21, 2020 I'm no speaker tec, but can't see why this design would not be compatible with your drivers. https://www.stereo.net.au/forums/topic/298469-onken-jensen-ultraflex-with-altec-and-jbl-horns/?tab=comments#comment-4435273 One thing I do know is they work effortlessly and were a relatively easy built If interested I'm sure the OP,er would do the calcs and work out the sizes. 1 Link to comment Share on other sites More sharing options...
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