another crossover question - welborne labs (BD-Design)
by fu_man 
, Thursday, May 24, 2007, 05:27 (6191 days ago)
I know the prevalent recommendation around here is passive crossovers, but I was wondering what's the opinion on the active Welborne Labs crossover. (which was developed for the Oris)
Please though, keep the answers non techie.... I don't understand those circuit diagrams... so an out of the box solution seems attractive (although I read a quote the other night that it takes a lifetime to tune a horn system... so maybe i hoping for too much) 
another crossover question - welborne labs
by Bert , Thursday, May 24, 2007, 08:25 (6191 days ago) @ fu_man
Hi fu_man,
I was wondering what's the opinion on the active Welborne Labs crossover.
(which was developed for the Oris)
Never played with the active Welborne filters because:
Active filters in general need their own power supply adding things and therefore not optimal. If only used for the bass then this is less of a problem but still, the integration is harder (if not impossible) to get on spot.
It is an advantage in systems where the main amp has a hum problem or provides lousy bass to begin with, there you can improve the quality of the bass by using an active filter.
It is also not a real advantage if you have proper amplifiers to play with as any filter (passive, passive line-filter, active, etc.) needs to be tuned (slope, phase, frequency and gain). Just flipping the phase with 180 degrees does not help much if we need 90 degrees..
Basically you'll need to mirror the response and minimise the overlap in the crossover range for optimal results.
Bert
--
BD-Design - Only the Best!
another crossover question - welborne labs
by fu_man , Thursday, May 24, 2007, 11:40 (6191 days ago) @ Bert
edited by unknown, Thursday, May 24, 2007, 12:37
hhhmmmm...
Nice answer. Thank you.
somewhere along the road i made some choices and decisions which didn't really get me to the place I was trying to get to. that is into a system where someone else(who knows what they are doing) has done all the work. But now I find I have made my bed and must sleep in it.:eek:
So to tune a system I would need to:
Learn how to read inductor and capacitor diagrams(& understand their units);
Learn how to solder, and;
Learn how to measure in-room frequency responses
Then copy and modifiy typical designs. I suppose you can find suitable values using cheap parts and when you find the right values substitute with good parts?
Am I on the right track? (yes, I know I sound like a thicko!)
How do you measure phase?
and balancing gain, by measurement or by ear?
another crossover question - welborne labs
by Bert , Thursday, May 24, 2007, 16:26 (6191 days ago) @ fu_man
So to tune a system I would need to:
Learn how to read inductor and capacitor diagrams(& understand their
units);
Learn how to solder, and;
Learn how to measure in-room frequency responsesThen copy and modifiy typical designs. I suppose you can find suitable
values using cheap parts and when you find the right values
substitute with good parts?
Sound all okay to me and it would be a good start. Learning while experimenting... 
How do you measure phase?
No need, if things are most out of phase then you'll see a big dip (close to 180 degrees out of phase) in the frequency response at the crossover frequency.
and balancing gain, by measurement or by ear?
Both, measuring is only helping you to get on the rigth track...
Bert
--
BD-Design - Only the Best!