JBL L1 Crossover Mod Thoughts

[dangerdandanger]

Hi all,

Just a lurker, newb skill level diy audio. I have a pair of early 90s JBL L1 series of bookshelfs I really like. 2Way - Titanium tweeter and 6.5in woofer. Sound great, but they are a tiny bit too "breathy" for my taste.

Was hoping to make the tweeter a little more assertive, but they have a very smooth sound that I don't want to lose. I really like the JBL room presence these provide. Is there a way to keep that and bring some edge to the music. Was thinking of just lowering the 7.5ohm resistor on the tweeter to 5ohm, but I'm pretty sure that will change the xover frequency.

The crossover schematic is here:https://manuals.harman.com/JBL/HOM/Technical%20Sheet/L1%20ts.pdf

Thanks,
Dan!

 

[AllenB]

It will, but you might find that 6.8 or 5.6 makes a difference. You have options. You could put a small capacitor across the resistor to raise the higher frequencies more. Maybe you can get your hands on an amp with a treble control?

 

[dangerdandanger]

It will, but you might find that 6.8 or 5.6 makes a difference. You have options. You could put a small capacitor across the resistor to raise the higher frequencies more. Maybe you can get your hands on an amp with a treble control?

Thanks Allen. What do you mean by a small capacitor across the resistor? Like just adding a capacitor in the same spot. What would good values for this be?

Thanks!

 

[AllenB]

Yes, connect the capacitor around the resistor so it is in parallel.

The capacitor sets a frequency, around and above this gets boosted. Try 1uF for a lift at the top, and up to a few uF, but take it slowly.

Adding a resistor in series with this new capacitor, and putting this string in parallel with the existing resistor will set a limit to the amount of lift. Use above 7.5ohms for a smaller boost limit.