Battery biased crossovers

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I was wonder if anyone here has done this and if so what were the results?

I am thinking of trying with my 1981 Klipsch La Scalas, I am planning to make a type A that crosses midrange to tweeter at 4500hz and thought that would be an easy experiment to try. I know how to do it just wondering about you guys experiences with it.

I went to electronics school in the 70s and was an associate CET and state licensed, I understand circuits pretty well but sometime things that really shouldn't make much of a difference in theory really do in practice.

Thanks
 
I've used it, I find it to be equivalent to a significant upgrade in part quality- just overall somewhat cleaner with a better sense of space between notes. Whether it's worth it is an individual determination though. For the most part I used arrayed mylars- 10uF caps combined to make the desired value. This had the advantage of some improvements (less power per cap, the paralleled sections had lower inductive reactance and ESR because parallel. For 10uF (4 10uF caps series/parallel) you only get the upside on power handling, plus the bias away from 0V/winding tensioning from the voltage, but if you get to 20, you now have 1/2 the ESR/ESL in addition to the other advantages.

Again, is it worth doing? If you have a good quality crossover that's isolated from enclosure vibration, maybe not, but there is in my experience a meaningful but not huge benefit to be had.
 
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I've used it, I find it to be equivalent to a significant upgrade in part quality- just overall somewhat cleaner with a better sense of space between notes. Whether it's worth it is an individual determination though. For the most part I used arrayed mylars- 10uF caps combined to make the desired value. This had the advantage of some improvements (less power per cap, the paralleled sections had lower inductive reactance and ESR because parallel. For 10uF (4 10uF caps series/parallel) you only get the upside on power handling, plus the bias away from 0V/winding tensioning from the voltage, but if you get to 20, you now have 1/2 the ESR/ESL in addition to the other advantages.

Again, is it worth doing? If you have a good quality crossover that's isolated from enclosure vibration, maybe not, but there is in my experience a meaningful but not huge benefit to be had.

Thanks, I am going to give it a go and it is easily reversible.
 
I've tried it. Small difference. JBL have used it for years. I've more time for this than I have for a lot of ridiculously priced caps; even though it requires 4x the total capacitance value you can usually achieve it for a fairly modest sum.

Note that Greg Timbers later introduced diode rectification at JBL; you don't need the batteries, just run through the diode &, say, a 10kohm resistor. It's not a constant like the battery but that doesn't matter. Plus, no batteries to change.
 
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Probably hard to find, but Joe talks about this (or similar) in the Elsinore thread.

dave

Thanks for that, I found it and quite an interesting read it was.

I am definitely going to try it, I already have enough caps anyway. I have been wanting to use Bob Crites A/4500 design instead of the AA crossovers in my Klipsch La Scalas. When I build it I will the battery bias and see what happens.
 
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limited experience but positive results with MBGO and PEPT caps with Klipsschorns and with P-Audio coax in Karlson K15 - can't remember what it did with Obbligato motor run poly caps but didn't like those in the first place. I'd love to try it with decent electrolytics

here's a type A values Klipsch network of mine with MBGO (these had somewhat lower ESR than KBG caps)

(sorry for the picture sans battery - this one was taken during the build)

zpYH4Ml.jpg
 
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Nice! I was going to use MBGO caps also. Mine will be a little different as I am crossing to the tweeter at 4500Hz.

I see that you used one battery, I was wondering about that. What value resistors did you use, I was planning on 1M/1W.
 
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I think they were 1M - 500K might be good too - look for discussionws with Jon Risch and the late Dennis Kleitsch (DJK) at Audio Asymum.

Two 4uF and you're there with Type A. Are you using AA with Zener protection? - those are sweet caps and I first heard them in a Baltek brand speaker whcih sold on closeout 30 years back - its crossover was packed with them.
 
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