ZplyonZ Posted October 22, 2004 Share Posted October 22, 2004 Here's a testimonial for anyone questioning whether it's a good idea to do something about the vintage crossovers in a Heritage system. I installed my freshly-rebuilt (by BEC) AA crossovers back into my 1977 La Scalas a couple of days ago... and it makes just an astonishing difference. From really great before the upgrade to now just about the best thing I've ever heard. Bob let me know that in one of the crossovers the value of the 2 uf cap came to 1.708 ohms and on the other crossover, 1.727 ohms. This is in contrast to the desired .04 ohm value. Bob estimated I was losing around 20% of the energy going to my tweeters... the other values were off too. I have also taken advantage of Bob's design of his upgrade, which offers the ability to easily switch the board to the "A" configuration, bringing a little more juice still to the tweeter. Now everything sounds balanced and nuanced in ways I find hard to describe... Especially the female voice, which has become completely riveting. So how to explain how these things sound... Here's a try: Imagine a sheet of perfectly clear glass, totally transparent, without a flaw... now imagine that glass made out of smoothest, finest-spun silk... now imagine that wrapped around the otherwise undraped Angelina Jolie... And that's what these speakers sound like! Chris L Austin, Texas Quote Link to comment Share on other sites More sharing options...
D-MAN Posted October 22, 2004 Share Posted October 22, 2004 Holy cow! if they did the dishes, you'd have it made! DM Quote Link to comment Share on other sites More sharing options...
BEC Posted October 22, 2004 Share Posted October 22, 2004 Chris, Thanks for the comments. I like to say that if you are listening to original crossovers that are over twenty years old, you are likely listening to bad caps. That is just a good amount of time for them to last. You will likely need to do the rebuild again around 20 years from now. Just put that on your preventatiive maintenance schedule. Bob Crites Quote Link to comment Share on other sites More sharing options...
psg Posted October 22, 2004 Share Posted October 22, 2004 Well, that's some more incentive for me to get my 31 year-old LS crossovers in BEC's hand... Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted October 25, 2004 Share Posted October 25, 2004 Hey, Chris! I live just next door in Houston! I'm very interested in learning more about Bob's crossovers myself. I had a pair of stock AAs in my Klipschorns, and have also used the ALK as well as an A network I built from the old AAs. I found the original AAs with stock caps rather dull and uninvolving. Would you say that your own experience with them is similar? It seems that the difference between the stock networks and Bob's updated version is pretty striking. Thanks for any more thoughts you might share on this! Regards, Erik Quote Link to comment Share on other sites More sharing options...
Deang Posted October 26, 2004 Share Posted October 26, 2004 The caps in your original AAs were/are probably shot, so it doesn't surprise me they sounded "dull and univolving". Quote Link to comment Share on other sites More sharing options...
J.4knee Posted October 26, 2004 Share Posted October 26, 2004 I know virtually the exact thrill you experienced hearing you La Scala's delivering sound you have not heard in years. I recently replaced my AL's with ALK kits and the improvement was incredible. There is no doubt if you are using decades old crossovers in your speakers you are listening to a duller, diluted sound. Upgrading or replacing your old and likely worn out crossovers makes an amazing improvement. Quote Link to comment Share on other sites More sharing options...
ZplyonZ Posted November 2, 2004 Author Share Posted November 2, 2004 Erik, "Dull and uninviting" is a not-bad description, but doesn't take into account the wonky overall balance with the dud components. The mids and mid-bass were also VERY improved by BEC's update of my crossovers. It's hard to convey the difference, but music, all music took on a very different shape when I installed the rebuilds. I have been listening to a mix of classical (Living Stereo re-releases on SACD), rock (early Rod Stewart, "VU" by the Velvet Underground vinyl), and some funk (Blue Note Revisited vinyl) among lots of other stuff ...all were enormously better after the upgrade. I have now bounced back and forth between the A and AA configurations. For some records/cds the A is a little bright, but I love the crispness and clarity, so the A is my default config. One thing I've forgotten to mention is that the size of BEC's components and their placement on the board made reinstalling the crossovers in the original place impossible. I ended up removing a screw on the board and shifting some of BEC's capacitors over and it worked fine... If you have any additional questions, fire away. Chris L Austin Texas Quote Link to comment Share on other sites More sharing options...
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