D-MAN Posted May 19, 2005 Share Posted May 19, 2005 JC, thanks for the vote of confidence, but I am not an expert on reflex drivers by any stretch... Here's my take. The back-chamber of the CS is 2x2ftx2 or 8 cubic feet in order to lower the resonant frequency of the driver and enable the reflex port. I believe that the CornScala internal volume is larger than the internal volume of the Cornwall (guessing here) by 1.5-2 cubic feet, but the difference can be made up by insulation upto 1/4 times the actual volume. If I remember correctly its called a 6th-order alignment? However, the point is, the CS can go a bit lower than the CW all things being equal. Also reflex drivers of low-QTS and with a VAS (volume) requirements that meet the range of 6-9 cu. ft should be somewhat more-optimal in the CW. Horn drivers such as the K33E have a higher QTS (above 5.0)than is recommended for reflex ported applications, or so I read on the Eminence web page. Unable to double-check right now. But I could be all wet. DM Quote Link to comment Share on other sites More sharing options...
BEC Posted May 19, 2005 Author Share Posted May 19, 2005 D-MAN You are using the external measurements for volume. The internal is 22.5 X 22.5 X 22.5 or about 6.59 cu ft. That is less by the volume of the woofer and shelf and bracing. Bob Quote Link to comment Share on other sites More sharing options...
D-MAN Posted May 19, 2005 Share Posted May 19, 2005 Bob, I stand corrected. {edit} I also previously mentioned QTS T/S values as related to horns, and should have been QMS. So I'm an idiot, so what?! DM Quote Link to comment Share on other sites More sharing options...
BEC Posted May 29, 2005 Author Share Posted May 29, 2005 bump Quote Link to comment Share on other sites More sharing options...
jwc Posted May 29, 2005 Share Posted May 29, 2005 Hey Bob, On that network, do you happen to have a schematic? If not, do you have one of the Type B. I can't seem to find it on past posts. So again, you basically changed out the cap on the sqwauker from 4 uF to 7 uF. Is that correct? The taps on the autoformer stayed the same...right? jc Quote Link to comment Share on other sites More sharing options...
jwc Posted May 29, 2005 Share Posted May 29, 2005 Heck, I found it. I think. Quote Link to comment Share on other sites More sharing options...
BEC Posted May 29, 2005 Author Share Posted May 29, 2005 JC That is right. On mine, I just made the 4 uF cap a 7 uF. I think that 6.8 might be closer to what it should be, but 7 is what I had around. Bob Quote Link to comment Share on other sites More sharing options...
jwc Posted May 29, 2005 Share Posted May 29, 2005 Bob, How about this. What if I just buy a used Type B network and change the 2 and 4 caps to a newer 2 and 7. For example, what if I used the ones below: http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=027-724 http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=027-734 or http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=027-534 http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=027-560 What kind do you use? Couldn't I just leave alone the wiring, T2a and the woofer 2.5 mH inductor? thanks jc Quote Link to comment Share on other sites More sharing options...
BEC Posted May 29, 2005 Author Share Posted May 29, 2005 JC, Yes you can use those. Or these. http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=027-414 http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=027-424 The Daytons seem to test a bit better than the Solens. At least more consistent in testing in the small sample I have tested. I could also provide you all the parts if you want to build completely new crossovers. Bob Quote Link to comment Share on other sites More sharing options...
jwc Posted May 29, 2005 Share Posted May 29, 2005 Again, I think I may take you up on this. Now that I think about it, the price is about the same for upgradin or starting from scratch. I have a good understanding of this now. Took me most of the day to figure it out. Now I just need to figure out how to biwire Thanks so much BOB Quote Link to comment Share on other sites More sharing options...
Deang Posted May 29, 2005 Share Posted May 29, 2005 I predict disappointment. Quote Link to comment Share on other sites More sharing options...
jwc Posted May 29, 2005 Share Posted May 29, 2005 This idea of converting a B network to something else then have the option to change it back could be useful. Especially when trying out different options for Cornwall-like speakers. My plan is to build another pair of these Cornscalas...maybe cheaper lookin for possible DJin'. I would also like to try out different woofers. Maybe even an 18 inch woofer. Sounds crazy. This would give me some flexibility. Plus, I have never built a crossover before. Could buy a cheap/old pair from Ebay and not get to upset if I screw them up. Quote Link to comment Share on other sites More sharing options...
BEC Posted May 29, 2005 Author Share Posted May 29, 2005 JC, You can also start out with a Type E crossover. They would have the T2A and the inductor and terminal strip. Just replacing the caps and a bit of wiring would get you where you want to be. Some others here on the board may have some T2As and 2.5 mH inductors left over from some project. I think Dean had some of those. Bob Quote Link to comment Share on other sites More sharing options...
jwc Posted May 29, 2005 Share Posted May 29, 2005 Thanks for the tip. I think there is an "E" on Ebay right now. Quote Link to comment Share on other sites More sharing options...
jwc Posted June 1, 2005 Share Posted June 1, 2005 Bob, I have a dumb question. When you changed your XO frequency to 400 hZ, how is it that you only changed the capacitor on the sqwauker and didn't do anything to the inductor on the woofer? Quote Link to comment Share on other sites More sharing options...
BEC Posted June 1, 2005 Author Share Posted June 1, 2005 JC All we can do is move the squawker down. I suppose we could tinker a bit with the woofer and roll it off with an added cap. Might be a good thing to try. I have been thinking about trying that. I would suggest about a 100 uF to try for that. Bob Quote Link to comment Share on other sites More sharing options...
jwc Posted June 1, 2005 Share Posted June 1, 2005 OK, I'm not tryin to be silly here. But is this what you have suggested so far? I know the woofer capacitor is just an option. Did you want that in series or parallel? Now Bob, I have a much more complicated question for you. I think this is the best place to ask this because you have the "driver test box". If you were to try other woofers in this cabinet of yours, what would be the specs of that woofer that would allow it to be integrated into this existing network design. I know, I know...you just intent to test and repair K-33's. Well humor me. Now below is the K-33 specs. I would assume the replacement woofer would need to be close to 4 ohms, inductance that is similar, and have a similar SPL. Exclude cabinet and port requirements for the sake of this discussion. Thanks man. PART # K-33 RE OHMS 3.39 FS HZ 34.46 LE MH .96 MMS GMS 78.59 QM 7.39 CMS mm/N .2714 QE .410 RMS NS/M 2.3037 QT .390 VAS LTRS 301.66 XMAX MM 8.20 SD SCM 889.59 BL TM 11.88 EBP 84.4 EFF % 2.91 SPL dB 96.6 Wattage 150rms The below image was changed since the original post Quote Link to comment Share on other sites More sharing options...
BEC Posted June 1, 2005 Author Share Posted June 1, 2005 JC, The cap would go in parallel. Bob Quote Link to comment Share on other sites More sharing options...
IB Slammin Posted June 1, 2005 Share Posted June 1, 2005 ---------------- On 6/1/2005 7:31:43 PM BEC wrote: JC All we can do is move the squawker down. I suppose we could tinker a bit with the woofer and roll it off with an added cap. Might be a good thing to try. I have been thinking about trying that. I would suggest about a 100 uF to try for that. Bob ---------------- Am trying to understand this stuff. When you speak of rolling off the woofer in this application; are we talking about a slope that would keep the cutoff point from "overlapping" as much? TC Quote Link to comment Share on other sites More sharing options...
BEC Posted June 1, 2005 Author Share Posted June 1, 2005 Terry, Yes, that is the idea, I think. Later Klipsch crossovers like the AK-3 use a 100 uF cap for this. That is why I would suggest trying that value. The AL-3 uses 128 uF for this cap. Bob Quote Link to comment Share on other sites More sharing options...
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