View Full Version : Improving The Bass Response of JBL Lancer 77

06-09-2016, 05:21 PM
Greetings All!

I have a small collection of JBL speakers and recently acquired a pair of Lancer 77's that have been professionally re-foamed. To my ears, they sound very good. I know the LE20-1 isn't the last word in hf drivers, but it suits me just fine. The mid-range of the L77's are, in my opinion, very lively. My only complaint is the lack of bass. I have been pretty happy with the bass from my L88's, although the mids are somewhat weak. No surprise since they rely on the tweeter and woofer for this purpose, neither of which seem to be up to the task.

I have an extra set of L77 drivers and crossovers that I plan to build custom enclosures for. The LE10's and passive radiators need to be re-foamed which I will have done professionally. I may look into the crossovers and recap them if needed.

So I'm wondering if the bass response of the L77's can be improved upon with larger enclosures. Or can the bass be improved upon by eliminating the passive radiators and building reflex (or horn loaded) enclosures. Any thoughts?

Ed Kreamer
06-13-2016, 08:57 AM
Hello from the Left Coast!

You can alter the response of your L77. If you remove the passive radiator, you'll see that it has a cardboard disc installed where the voice coil is normally attached to the cone. It should have a t-nut in its center with a bolt sticking out of it.
More mass can be added to the PR10 by adding the cardboard controlling discs or metal washers to the back of the cone. This comes at a price as it will change the curve of the system so make certain that you can remove any mass you add.
It's a cut and try process so a lot of listening and testing will be involved.

I've done this to Altec 890 and the JBL LE10a/PR10, so it can be done. However your best option will be to add a VLF speaker or " sub woofer" ( I've never liked that term) to your system.

Have fun


06-18-2016, 10:23 PM
Thanks Ed, I almost forgot about adjusting the passives, I'll try that on my stock L77's. My goal though, is to build custom cabinets for the extra set of L77 components I have.