Finally able to get info from both M. Kay and S. Linkwitz:
In
addition to removing the top, as Siegfried describes below the rosewood
trim panel on the back of the Beethoven must be removed to access the
screws in the Spine. This trim piece is also glued down with a soft
silicon glue. Use a 1/16” x 1” x 36” piece of aluminum and sharpen one
end and use a rubber mallet to tap it underneath the center of the spine
starting at the bottom to remove the trim cover, be careful not to
damage the small mesh grills over each hole in the rosewood trim. There
is a glue point between all the drivers and at the bottom so the full
length of the aluminum will be used. As you get near the last glue point
you will be able to lift the trim piece out of the channel. The grill
is affixed to the spine using 1/8” window screen spline available from
Lowes or Home Depot. You will need to remove the 1/16” x ½” wide
neoprene gasket that is covering the track for the spline holding the
grill cloth in place. Next remove the spline from the track and pull the
grill cloth to each side. This will reveal the screws holding the spine
in place, remove all the screws and unsolder the wires to both 8” and
10” drivers. The 8” and 10” drives are glued to the spine so once all
screws are removed gently lift the spine out of its mounted position and
all drivers will follow. Make sure you don’t damage the wiring to the
speak-on connector or simply unsolder those wires also. The drivers are
also attached with soft silicon glue, use a putty knife to slip between
the spine and the magnet working your way around to release the glue
holding the defective driver. Position the new driver in the cabinet and
put an ample spiral of silicon glue (a suitable version is available
from Lowes and Home DePot) on the new driver’s magnet. Next reposition
the spine and make sure each driver drops into the gasket arrangement on
the front of the speaker. Replace the screws in the spine and make sure
the glue does not spread beyond the magnet. (If you need to replace an
8” driver, there is a spacer that needs to remain in place). Re-attach
the grill cloth to the spine using a window screen tool and stretch the
cloth at the top and bottom of the speaker and press it into the glue
and replace the staples (HINT: Harbor Freight has an air operated
upholstery stapler for about $20.00 that works very well). The Neoprene
gasket must be replaced, I may have some here if you can’t find that
material. The spine will need to be glued in place and we held it down
using 25lb lead shot bags while the glue was curing (make sure you
remove most of the old glue). Follow the other steps in reverse to
complete the assembly.
IMPORTANT:
Remove the tweeter before laying the speaker on its face to work on it
and note the tweeter wiring polarity is inverse phase (red wire to the
minus terminal) on the tweeter.
Marshall Kay
