avguytx Posted January 5, 2018 Share Posted January 5, 2018 I'm going to build another pair of networks just to tinker with passive bi-amping and either buy the parts to build one from scratch or maybe try to come across an AB-2, AL-3, or AK-3. If anyone has a pair of any of these just laying around "gathering dust and taking up space", send me a message. Thanks! Quote Link to comment Share on other sites More sharing options...
avguytx Posted January 8, 2018 Author Share Posted January 8, 2018 Still looking. Primarily for T4A autoformers, unless T2A would work, for building the AB-2 network. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 8, 2018 Share Posted January 8, 2018 I don't trust the old autoformers any more. I had a pair give the exact same weird response on Bob's spectrum analyzer. Quote Link to comment Share on other sites More sharing options...
jimjimbo Posted January 8, 2018 Share Posted January 8, 2018 10 minutes ago, CECAA850 said: I don't trust the old autoformers any more. I had a pair give the exact same weird response on Bob's spectrum analyzer. No offense Carl, but I'd like to see a bit more data on that, rather than on just a couple of units. What was that weird response, how severe was it, and how would it affect the crossover performance and sound quality? Wonder if Bob could shed some light? I would bet he's got a bunch of cast off autoformers. @BEC Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 8, 2018 Share Posted January 8, 2018 40 minutes ago, jimjimbo said: No offense Carl, but I'd like to see a bit more data on that, rather than on just a couple of units. What was that weird response, how severe was it, and how would it affect the crossover performance and sound quality? Wonder if Bob could shed some light? I would bet he's got a bunch of cast off autoformers. @BEC The graphs were posted in my rebuild thread, I'll see if I can find them for you. It would certainly have been audible. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 8, 2018 Share Posted January 8, 2018 I bumped the thread in the Tech/mod area to make the thread easier to find. This should be a link to the graphs. https://community.klipsch.com/index.php?/topic/167936-al-crossovers/&do=findComment&comment=2111868 Look at the blue squawker frequency line. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 8, 2018 Share Posted January 8, 2018 1 hour ago, jimjimbo said: I would bet he's got a bunch of cast off autoformers Bob builds new units with new parts so I doubt he has a bunch of old parts but that's just a guess on my end. It was a fluke that we actually found this. This was my first attempt at building a set of crossovers and I was doing it for a pair of Lascalas that my brother owned. As it was my first go-round with this I asked Bob to test them for me. He found the odd frequency response and it had both of us scratching our heads as the caps tested good and they were wired correctly. Bob swapped out an autoformer as that was the only thing left and it fixed the response. The fact that both autoformers had identical issues makes me wary of the old units. Quote Link to comment Share on other sites More sharing options...
avguytx Posted January 8, 2018 Author Share Posted January 8, 2018 I don't really mind buying a new pair of autoformers; in the grand scheme, it's not a lot of money to build a new set from scratch. I may just go that route. New speakers/parts....new crossovers/parts. It looks like Bob's 3636 autoformer that has -1db steps would work in place of the T4A with no problem. That would be more control than the -3db steps of the others. Quote Link to comment Share on other sites More sharing options...
jimjimbo Posted January 8, 2018 Share Posted January 8, 2018 14 minutes ago, CECAA850 said: Bob builds new units with new parts so I doubt he has a bunch of old parts but that's just a guess on my end. It was a fluke that we actually found this. This was my first attempt at building a set of crossovers and I was doing it for a pair of Lascalas that my brother owned. As it was my first go-round with this I asked Bob to test them for me. He found the odd frequency response and it had both of us scratching our heads as the caps tested good and they were wired correctly. Bob swapped out an autoformer as that was the only thing left and it fixed the response. The fact that both autoformers had identical issues makes me wary of the old units. OK, so reading the posts and looking at the graphs, the T3A is what was tested. Wondering if anything similar has been done with the T2A which is fairly common throughout the Heritage line.... @BEC Quote Link to comment Share on other sites More sharing options...
avguytx Posted January 9, 2018 Author Share Posted January 9, 2018 Doesn't seem to be a lot of love for the AB-2, huh? Quote Link to comment Share on other sites More sharing options...
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