Question!!!

[retro soulman]

Question! i got these crossovers 8ohm 58651 .... and i want to use a JBL 2445j 16ohm on each crossover ... how can i modified the output of the crossover to get 8 ohm from the driver or to see 8 ohm from the driver? i cant modified anything internal cause all the capacitors are inside a black material like glue or silicon.... !

[fpitas]

You can parallel an appropriate resistor (maybe 20 ohms) across the driver to bring the impedance down, although you'll lose significant power in the resistor. Does that crossover attenuate appropriately for a horn driver? Usually you need substantial attenuation to the horn because of its greater sensitivity relative to the woofer. You may want a resistor divider attenuator after the crossover, which would give you an opportunity to adjust the impedance.

[retro soulman]

Does that crossover attenuate appropriately for a horn driver? Usually you need substantial attenuation to the horn because of its greater sensitivity relative to the woofer. You may want a resistor divider attenuator after the crossover, which would give you an opportunity to adjust the impedance.

i have no idea... i know almost nothing about this crossover. It got 3 way output. for low , mid , and highs and its is 8 ohms as it says in the front plate

[fpitas]

i have no idea... i know almost nothing about this crossover. It got 3 way output. for low , mid , and highs and its is 8 ohms as it says in the front plate

That makes it rather hard to help you, except in a very broad way. Some measurements might be in order if you can't find a datasheet.

[Mike F]

Why not just build a dedicated crossover? God only knows what is in that box you have, I`d bet it wasn't made with a 2445 in mind.

[fpitas]

Mike has a point. Unless you are willing to characterize that crossover, it's a crapshoot at best.

[retro soulman]

i was wondering if i use the 2445 as is with this crossover what it would happen?... ill use a dynaco st 70 tube power amp for the system in low to medium volumes.

[just4kinks]

i was wondering if i use the 2445 as is with this crossover what it would happen?...

An 8-ohm L-pad has a special taper so that it always loads the network / amp at 8 ohms, so long as the driver is also 8 ohms. With a 16 ohm driver, the load on the network can vary depending on the level setting. The cutoff frequency could shift a little.

[Alien_Shore]

Mike has a point. Unless you are willing to characterize that crossover, it's a crapshoot at best.

+1

QFT.
The wrong crossover can make good speakers sound bad. The converse, however, not so much. :)