My JBL L100 Grille Refurbishment Project;
When I first bought my JBL L100 speakers circa 1975, I selected the Ultra
Blue grilles. They looked like this:
Here’s the hang tag referring to the grille material:
In retrospect, I sometimes wished I had opted for Burnt Orange instead of
Regardless of color, the original material started deteriorating after a
decade or so. I eventually contacted JBL. They informed me that the
Sculptured Air grilles were no longer available. They sold me serviceable
but utterly blasé brown cloth grilles:
The speakers have continued to sound fabulous throughout their long &
storied career with me, but their visual impact had been greatly diminished.
Then in 2020 I ran across a L100 posting on the James B Lansing Audio
Society group on Facebook. When I commented that I needed to find some
Quadrex grilles, Robert Melchers contacted me to tell me he had them
Since I live in Texas & Robert is located in The Netherlands, we arranged
our deal through PayPal. Robert packed & shipped them promptly upon
receiving my payment. After winding their way through customs in several
countries, they found their way to my home in Texas:
It had not previously occurred to me to disassemble the cloth grilles, but
it was now time to figure out how they were put together.
As it turns out, the cloth is stretched across a hardwood frame which fits
snugly within the outer wooden grille. I pried the cloth frame out easily
with my fingertips.
As Robert points out in the instructions provided, the Quadrex foam is cut
a bit larger to accommodate the size variations between different L100
generations. I found mine to be 1/8” (3.175 mm) too wide on each side:
Regarding height, I found them to only be 1/16” (1.59 mm) too long at each
Per the instructions provided with the Quadrex foam, I used a straight edge
& hobby knife (X-acto or equivalent). Clamping was precise when only
Then it came time to glue the Quadrex foam into the wooden grilles. I chose
a Liquid Nails multi-surface adhesive:
Here’s a side-by-side comparison of the two grilles (makes the cloth look
Then it was time to transfer the JBL logos, which were held onto the cloth
grilles by a spring nut which had to be pried off.
A wee bit of glue on the back of the logo.
And the finished product:
Coupled with my Onkyo A-9050 integrated amp (70 watts/channel @ 8 ohms),
this is an awesome computer sound system. Coupled with a Denon DP-47F
turntable, a Denon DCM-520 & a Nakamichi DR-3 cassette deck, it is also a
very fine stereo.
Many Thanks to Robert Melchers for providing the Quadrex foam & for sharing
his expertise & advice for a successful outcome.