Strange XO question

[MtnBob]

I'm refurbishing (or extreme tweaking) an old pair of speakers that I've had since '69 (Yeah, I know most of you weren't born then) It's a 10"/2" I want to do a new XO and I figure that I should probably use the same XO point. The original has a 2uF cap between input and a 3 position tweeter level switch, then a 8 uF cap between the switch and tweeter. To my electronically impaired eye, it looks like the caps are in series,but must not be, since that would give a XO point that's ridiculous for a 10" woofer. Adding them like they were parallel gives a 4000Hz XO point I think (4 ohm speakers) which still seems high. I don't need to keep the switch in the circuit, since I have always had it in the Increase position, bypassing the resistors. What would you advise?

For you other old timers, they're KLH model 20 speakers, electronics long since passed away, but they still sound pretty good - Kloss did some really nice work.

It's snowing like crazy - come ski Angel Fire!

[sreten]

It does sound a very strange crossover arrangement.

You need to be more specific about the switching arrangements,
resistors in parallell / series, as by your description the 8uF
capacitor is virtually redundant, and this is unlikely.

Its more likely the 2uF is wired across some resistor combination

Anyway, you should just replace old parts with better quality new
parts, its very unlikely you could improve the speakers with a new
crossover design without measuring equipment.

sreten.

[Volenti]

Many of those older speakers simply had a cap and L pad on the tweeter and nothing at all on the woofer, relying on the natural high frequency roll off of the woofer (which in some cases is quite effective)

You could simply design a network based on the drivers impedance and bypass the factory components.

[MtnBob]

Thanks for your replies, I finally got some parts in (I live in the middle of nowhere and everything is via the 'net) and I sorta tried both of your sugesstions. On one, I just replaced the old caps with new ones. On the other, I added an inductor and new caps and wired a series xo. No comparison - the series sounded much better.

[sreten]

Glad things worked out well.

Seems the series first order crossover is very forgiving
of misaligment and thus ideal for experimentation.

sreten.

[qwad]

yes, YOU ARE RIGHT in the past I have strung together a series x/over to no particular formula just having the parts to hand and after measuring with my mls enhanced imp I was surprised at it's overall integration that I could not get by any other means [ the woofer / tweeter responses were totally wrong for a normal x/over [ very cheap drivers with ragged responses] but with the series x-over i managed to get them to work together without much difficulty cheers tomcat