atkinsonrr Posted August 15, 2002 Share Posted August 15, 2002 Am wondering if anyone knows the diagram and values for the original Cornwall xover with the big oil caps? I would like to take my Cornwalls back to that genre crossover. Thanks! Quote Link to comment Share on other sites More sharing options...
mace Posted August 16, 2002 Share Posted August 16, 2002 Were type B crossovers the originals for the Cornwalls?? Mace Quote Link to comment Share on other sites More sharing options...
atkinsonrr Posted August 16, 2002 Author Share Posted August 16, 2002 Yes, I think so. My Cornwalls are from 1975 and they originally had the B crossover, but they had been modified. I believe the B just had the autoformer, the choke and two caps. I did a search and have seen schematics here for the B2 but not for the B. Quote Link to comment Share on other sites More sharing options...
Good2BHome Posted August 16, 2002 Share Posted August 16, 2002 Are you sure they have been modified? I'm reasonable sure that in the 1975 - 1976 time frame that the "B" was constructed without the oil caps. Mike ------------------ 4 Cornwalls & McIntosh SS This message has been edited by Good2BHome on 08-16-2002 at 06:35 PM Quote Link to comment Share on other sites More sharing options...
Dflip Posted August 16, 2002 Share Posted August 16, 2002 Am wondering if anyone knows the diagram and values for the original Cornwall xover with the big oil caps? I would like to take my Cornwalls back to that genre crossover. Thanks! In the B network in the Cornwalls: The original caps are Aerovox, 100 VAC, 60 Hz. The high end one is 2uF and the bottom one is 4 uF. They are no longer made by this company. Old ones (NOS) are just that, old. Capacitors have a shelf life. You don't want to be buying a "dead" parrot that is just pining for the fijords of Norway from John Cleese. You would be much wiser putting good quality capacitors in their place, especially th 2uF cap. The inductor (part 2133) can be replaced with a 2.4 mHy inductor. Solid wire is fine, although you can go to litz wire if money is no object. The wire should be 12 awg., although 14 gauge is fine. The inductor makes a tremedous change in the sound and bass response. What you end up with is better parts, but the same crossover configuration. Good luck, Don Quote Link to comment Share on other sites More sharing options...
mace Posted August 16, 2002 Share Posted August 16, 2002 Here is a collection of pictures which I got off this board at some point or another. I can say that my 77 cornwalls have the B type. Hope this helps in determining what you have. Mace Quote Link to comment Share on other sites More sharing options...
atkinsonrr Posted August 17, 2002 Author Share Posted August 17, 2002 Thanks for all the input. Yes, I think mine are the type B's but without the oil caps. I quess I will try replacing the inductor and the two caps with high quality stuff and see what happens. Quote Link to comment Share on other sites More sharing options...
Klipschguy Posted August 17, 2002 Share Posted August 17, 2002 There is a B network schematic somewhere in the archives (not sure where). In the "Great Inductor face off" thread, I know there is a schematic of the Heresy E network which is just like the B network, except for the following: 1. The B uses a 4uF and a 2uF cap. The 4uF is the furthest from the tweeter. 2. The T2A autotransformer taps for the B networks are "4" and "3" in lieu of "3" and "2". The little number are visible on the T2A if you look closely. 3. Polarity all IN PHASE for B network. 4. Both the B and E use a 2.5mH inductor. If you draw out the Heresy E network from the named thread and follow the above steps, it will make a lot of sense. BTW, I do like the sound of the B network and think it is a worthwhile venture to build a pair. Warmest regards, Andy This message has been edited by Klipschguy on 08-21-2002 at 03:22 PM Quote Link to comment Share on other sites More sharing options...
Weiming Posted August 18, 2002 Share Posted August 18, 2002 Don't know if this helps, but here is the Cornwall B2 crossover. ------------------ Solstice Quote Link to comment Share on other sites More sharing options...
Klipschguy Posted August 18, 2002 Share Posted August 18, 2002 Thanks Weiming! If you also want a 'B Network' schematic, just remove the 245uH inductor, the 20mF cap, and replace the 3uF cap with a 4uF cap. Polarities all IN PHASE with the B Network (unlike the B2 network). Andy This message has been edited by Klipschguy on 08-21-2002 at 03:24 PM Quote Link to comment Share on other sites More sharing options...
Weiming Posted August 18, 2002 Share Posted August 18, 2002 OK, for those interested in constructing a Type B crossover, here is the schematic ------------------ Solstice Quote Link to comment Share on other sites More sharing options...
ChuckElliot Posted August 19, 2002 Share Posted August 19, 2002 The schematic of the B Type does not show the polarity of the speaker connections. I believe that the B is non-inverted on all three drivers, while the B2 had the horns inverted? 1971 Cornwalls with rebuilt B Crossovers Quote Link to comment Share on other sites More sharing options...
Klipschguy Posted August 19, 2002 Share Posted August 19, 2002 Polarity of B Network. From woofer to tweeter on schematic: +/-, +/-, +/-. This message has been edited by Klipschguy on 08-21-2002 at 03:26 PM Quote Link to comment Share on other sites More sharing options...
Weiming Posted August 19, 2002 Share Posted August 19, 2002 Anybody knows the reason why the squawker and tweeter's positive leads are connected to the negative input lead? What's the significance and purpose for this? Thanks! ------------------ Solstice Quote Link to comment Share on other sites More sharing options...
Klipschguy Posted August 20, 2002 Share Posted August 20, 2002 Weiming, Basically, crossover component cause phase shifts in the drivers. The phase shifts cause holes in the frequency response due to destructive interference in the region of the crossover points. To compensate for the phase shifts, one or more drivers may be wired in or out of phase with each other (usually done on the crossover). In the B2 network, the squawker and tweeter are wired out of phase relative to the woofer. In the B Network, all drivers are wired in phase. Andy This message has been edited by Klipschguy on 08-21-2002 at 03:28 PM Quote Link to comment Share on other sites More sharing options...
Weiming Posted August 20, 2002 Share Posted August 20, 2002 Hi Klipschguy, Thanks for the explanation. Much appreciated ------------------ Solstice Quote Link to comment Share on other sites More sharing options...
ChuckElliot Posted August 20, 2002 Share Posted August 20, 2002 Schematic sent to me by Klipsch (Today) of the Type B Cornwall Network! Quote Link to comment Share on other sites More sharing options...
Weiming Posted August 20, 2002 Share Posted August 20, 2002 Okaaaay...now I am really confused. Are the tweeter and squawker connected out-of-phase or in-phase? Perhaps someone from Klipsch can verify once and for all the polarity for the B2 and B crossovers? Puzzled. ------------------ Solstice Quote Link to comment Share on other sites More sharing options...
Klipschguy Posted August 20, 2002 Share Posted August 20, 2002 Alright, I drew the schematic for my B Networks a couple of years ago when I had the backs off (first time ever removed). It's possible I'm wrong about the polarity. I'll pull one of the backs off and check it out again. Andy Quote Link to comment Share on other sites More sharing options...
Klipschguy Posted August 21, 2002 Share Posted August 21, 2002 Okay, I pulled the backs off - I was wrong (sorry). The drivers are ALL IN PHASE like the B Network shown in ChuckElliot's post. I will go back and correct my previous posts to make sure the info is correct. Best I can figure, is when I drew my wiring diagram a while back, I must have assumed the driver polarity was the same as my Heresey E networks (very similar crossovers to the Cornwall B networks) which do have reverse phasing for the squawker and tweeter. Warmest regards, Andy P.S. I'm reminded of a Deep Thought by Jack Handy: "It takes a big man to say he's sorry, but it takes an even bigger man to make that man say he's sorry." Quote Link to comment Share on other sites More sharing options...
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