I new one XO designer that would tune each XO to the cabinet and drivers he was using. The left and right crossovers very seldom looked alike. When the drivers were pulled and matched top to bottom and left to right as close as his staff could get, they would load wire and seal the drivers.
The Passive XOs were point to point mounted to 3/4 pre formed MDF or HDF boards. He used two LPads and parallel quasi 2nd order for a 3/4 way.
Here is the real trick, he would put an untuned xo in, position the speakers in the same place every time and take tone burst readings.
He would add a small cap in the band pass to one side only, and normally unwind and remove a small amount on a hand wound inductor (made from a real dry 1/2" dowel and hand wound copper wire 20-18 ga) It had 16-20 raps. He would remove 3-5 wraps on a dowel, and retest the DB levels. That is how he balanced the DB level in the BP and lower or raise the pass side with a small cap of the same quality.
It’s not a bypass cap (super expensive), it’s a trim cap normally a long life poly or something.. It act differently, the same with the inductor.. It’s for trim ONLY doesn’t effect the SQ just the tonal balance..
THAT is how I learned to TUNE an XO. Making one it’s not rocket science but, you really need to be able to TUNE and know HOW to tune your work for a SOTA audiophile quality XO.. Production crap who cares..
The guy could build and tune 3 pairs of XO in a night, after spending all day selling, ordering and talking to customers..
The staff would ready the call in orders on the spot.. or paint the inside with sound coat or black hole or the different wire or wool vs fiberglass in the mids. 3 guys I think Brian C, was 1. RIP.
I stopped in after work 100 times, he would be there trimming OXs or making them or writing an article.. or getting ready for CES. the soldering iron he used, you could have soldered gutters it was so big.... no kidding.. ;-)
Regards
