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(Named in honor of my favorite English ale - George Gale's Prize Old Ale)
When I first heard about the SB Acoustics 5 ¼ inch mid-woofer for $19 I knew I had to try it. Good specs, very good frequency response, papyrus cone (!!) and of course that SB name.
http://www.sbacoustics.com/index.php/products/oem-only/sb13pfc25-08
I’ve heard that Meniscus is planning to stock this driver long term, but they are currently out of stock (June 2, 2013)
After I listened to a single driver running full range in a ½ cube box, I figured they deserved a MTM design, with an eye to replacing my Maurbacs mains. Originally I had thought to use a nice Tangband soft dome, or one of the large face Vifa domes but I wanted to try a MTM with the drivers as close as possible, and I had 2 tweeters in a failed 3 way, so once again the venerable Vifa BC25SC06-04 was brought back.
http://www.parts-express.com/pe/show...umber=264-1028
I’d read some articles on Dual-Chamber-Reflex (DCR) alignments, and I wanted to try that also. Once I got the theory of design right (thanks guys!) – I modeled 2 woofers in Unibox (and WinISD) – 27 liters net, 2 ports, 2 inch inside diameter (SCH 40 PVC) that were each 6 inches long should give me an F3 of 42.5 Hz.
Box internal dimensions 22H x 7 ¼W x 14D
Local Home Depot had some “cabinet grade” ¾ ply that looked good, so I bought a few sheets. It did not disappoint! Faces were A/A to A/B, internal plys nice and even, and I never found a void.
DCR theory says model for 2 ports, then use another port of the same length to join 2 chambers, one 2/3 of the volume, and the other 1/3 of the volume. I figured and planned, and still got it a bit wrong. I lined the insides with DOW 703 – really, really nice stuff.
You can see a "brace: on the right one from front to back. Found out that it basically did nothing! I added some cross braces from side to side that helped a lot.
When I first heard about the SB Acoustics 5 ¼ inch mid-woofer for $19 I knew I had to try it. Good specs, very good frequency response, papyrus cone (!!) and of course that SB name.
http://www.sbacoustics.com/index.php/products/oem-only/sb13pfc25-08
I’ve heard that Meniscus is planning to stock this driver long term, but they are currently out of stock (June 2, 2013)
After I listened to a single driver running full range in a ½ cube box, I figured they deserved a MTM design, with an eye to replacing my Maurbacs mains. Originally I had thought to use a nice Tangband soft dome, or one of the large face Vifa domes but I wanted to try a MTM with the drivers as close as possible, and I had 2 tweeters in a failed 3 way, so once again the venerable Vifa BC25SC06-04 was brought back.
http://www.parts-express.com/pe/show...umber=264-1028
I’d read some articles on Dual-Chamber-Reflex (DCR) alignments, and I wanted to try that also. Once I got the theory of design right (thanks guys!) – I modeled 2 woofers in Unibox (and WinISD) – 27 liters net, 2 ports, 2 inch inside diameter (SCH 40 PVC) that were each 6 inches long should give me an F3 of 42.5 Hz.
Box internal dimensions 22H x 7 ¼W x 14D
Local Home Depot had some “cabinet grade” ¾ ply that looked good, so I bought a few sheets. It did not disappoint! Faces were A/A to A/B, internal plys nice and even, and I never found a void.
DCR theory says model for 2 ports, then use another port of the same length to join 2 chambers, one 2/3 of the volume, and the other 1/3 of the volume. I figured and planned, and still got it a bit wrong. I lined the insides with DOW 703 – really, really nice stuff.
You can see a "brace: on the right one from front to back. Found out that it basically did nothing! I added some cross braces from side to side that helped a lot.
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