A bass presence issue

[Erik-Olson]

I have two leslie 122s and I've ran into a bit of a problem. One of the Leslies has a very nice bass presence(which I like because I play a lot of left hand bass at gigs). The other leslie has a very underwhelming bass presence. What do I do to fix this issue?

[geoelectro]

Try swapping the amps and see if the bass problem follows the amp or stays where it is.

Geo

[PGR]

HI Erik Olson
I'm not a tech guy but My guess is if you have them both hookup up at the same time (don't know if you do ) the one without the bass as described likely needs the crossover updated. If you run them separately the one with out the bass response would also need the crossover reworked. The only other possibility might be in the hook up of the first leslie vs the second leslie what I'm referring to here is the same wire going to what ever pin you select in both cables this of coarse assumes you have two hooked at the same time. if your using one cable you can assume it is OK You could always test this theory by exchanging amps to see if the under whelming bass moves with the amp or not. if it does then the crossovers are likely ok and you need to address the tubes and other parts of the amp in question. The substitution of one tube at a time will help to isolate the issue in the leslie. Some will suggest moving the balanced tube set at the same time - this is a good idea.

[David Anderson]

My guess is if you have them both hookup up at the same time (don't know if you do ) the one without the bass as described likely needs the crossover updated.

I would doubt this. Unless the capacitor in parallel with the woofer is actually shorted out, it won't make that big a difference in low bass. There are many other more likely causes of lack of bass. As Geo says, the amp is the first place to look.

[Tim_at_Jonas]

Are you comparing one at a time, or using one then adding the second to it and the bass falls off? If the latter, one of them has a polarity reversal of the woofer or the entire thing.