Fig. G: The side view of the terminal board. Fig. H: The
finished terminal board, as seen from the outside.
Fig. I: The plastic edge on the New Large Advent must
be trimmed slightly to clear the waveguide.
Fig. J: Finished speaker. Fig. K: Finished speaker with
new grille. Fig. L: An alternate version, with back-mounted woofer and a fancy finish, including a new
veneered baffle board with brass trim.
trimming, but the other speaker models require
some more work. With the Original Large Advent,
sand 5" (or less) from both sides of the waveguide
to make it fit. The New Large Advent has a bit less
space, so you can trim ¼" off each edge of the
waveguide, or get tricky with a router and undercut
the walnut rim to make room to slide the waveguide
edge underneath. I’ve seen both done, and I’d just
cut away the plastic waveguide edge myself, rather
than attempting fancy router work.
To reinstall the plastic trim, shave it down where
necessary to clear the waveguide rim on each side
(Figure I). Nail in the top, bottom, and one side piece
using ¼" brads, and screw in the other side so it can
be removed for service.
Solder the woofer wires to their terminals, observing polarity. Screw the woofer down and replace the
grille (Figures J and K). That’s it!
Ross Hershberger posts on Audiokarma ( audiokarma.org)
as Bauhausler. He’s been interfering with electronic stuff of
all kinds for 40 years.
To mount the woofers more securely, drill out their »
screw holes to y" and press in eight 8-32 T-nuts.
Make new grilles using the Large Corner Grill »
Frame Kit and an extra set of corners (Parts
Express #260-344 and #260-345). Choose thin,
stretchy fabric, like polyester jersey fabric (1yd).
Attach the grille with velcro tape, and the fabric
with foam tape.
Here are some additional restoration options, mostly
cosmetic, that won’t affect the speakers’ sound:
For a homogenous appearance, paint the cabinet »
back, woofer frame, baffle, and screws all black.
You’ll need ½ pint of interior latex trim paint.
150 Make: Volume 20
Cross-Grain Sanding You should always sand with the grain, right? Well, not necessarily. Take spruce or cedar, for example. These woods have such soft grain between the hard winter growth rings that particles of abrasive from the sandpaper that break off just roll around in the soft grain, scarring it. If you sand across the grain, you’ll cut the hard and soft grain equally. And, as you get to the finer grits, the sanding scratches become so small that they don’t show under even the most transparent finishes. —Frank Ford, frets.com/homeshoptech Find more tools-n-tips at makezine.com/tnt.