Finishing up this project and thought some of the information on the crossovers might be useful to others.
Refresh included the crossover upgrades outlined in the article by Jim Forte, “A New Crossover for Cambridge Soundworks Model Six” in AudioXpress 2001-10 Page 50-55 (and discussed in other parts of the AK forum).
Also included were new woofer foam surrounds, cabinet repair/re-veneering and new grill cloths.
First the crossovers. I followed the instructions in Jim Forte’s design with one slight component value change to an available value. R2 in the design was specified as 5.0 ohm, I substituted 5.1 ohm.
After a couple component layout attempts on paper, the crossovers mounting boards ended up being 5” wide by 7” high. I do not have a lot of experience in optimizing component layout but I did spend a bit of time on getting the crossover layout as simple as possible (least number of jumper leads), woofer terminations at bottom & tweeter termination at top; and followed Jim Forte’s advice to position L1 & L2 fields minimizing interference with each other. As in the article, mounting to the cabinet was through the tweeter and woofer openings.
Reused the driver connection wires from the originals and original rear speaker terminals.
Thought someone might benefit in the future from reviewing the layout, dimensions, etc.
Woofer Surrounds
Woofer surrounds replacement was pretty standard however I found the voice coil was a tight fit, used 250Hz signal for centering during glue-up. Also, replaced acoustic suspension seal tape on back sides of all four speaker baskets.
Cabinet Repair/Re-veneering
As found, cabinets were in fair shape, only box damage was one corner had swollen and the miter joint opened, apparently due to moisture exposure at some time. Vinyl veneer was also damaged in this corner and other spots. Vinyl veneer was stripped from cabinets with hot iron.
Damaged paperboard corner was stabilized with J-B Weld Wood Restore Liquid Hardener; three (3) coats saturated the paperboard corner and filled the gap. Sanded between coats. This worked very well.
Had some walnut wood veneer on-hand and applied to cabinets with wood glue and iron. Walnut veneer was finished with a 1st coat of Danish Oil (natural), five (5) thin coats of Zinsser wax-free shellac & a final coat of paste wax applied with “0000” steel wool.
Grill Covers
Original gray colored grill cloth was replaced with cloth as close as possible to the originals.
Re-assembly
Boxes were “re-stuffed” with the original polyester fiberfill acoustic damping material; drivers reinstalled & grill covers installed.
Fun project, fairly straightforward and I’m pleased with the resulting performance of these bookshelf speakers.
I had a couple other bookshelf sets on hand, Advent 2W & JBL 2500.
I don’t know if these are considered “fair comparisons” but A/B’ed these and the refreshed Model 6’s were easily on top; very pleased.
As background, this pair was manufactured 1996 (date stamp on woofer magnets) in Newton MA; prior to manufacturing transfer to China with Creative Labs acquisition in 1997.
Refresh included the crossover upgrades outlined in the article by Jim Forte, “A New Crossover for Cambridge Soundworks Model Six” in AudioXpress 2001-10 Page 50-55 (and discussed in other parts of the AK forum).
Also included were new woofer foam surrounds, cabinet repair/re-veneering and new grill cloths.
First the crossovers. I followed the instructions in Jim Forte’s design with one slight component value change to an available value. R2 in the design was specified as 5.0 ohm, I substituted 5.1 ohm.
After a couple component layout attempts on paper, the crossovers mounting boards ended up being 5” wide by 7” high. I do not have a lot of experience in optimizing component layout but I did spend a bit of time on getting the crossover layout as simple as possible (least number of jumper leads), woofer terminations at bottom & tweeter termination at top; and followed Jim Forte’s advice to position L1 & L2 fields minimizing interference with each other. As in the article, mounting to the cabinet was through the tweeter and woofer openings.
Reused the driver connection wires from the originals and original rear speaker terminals.
Thought someone might benefit in the future from reviewing the layout, dimensions, etc.
Woofer Surrounds
Woofer surrounds replacement was pretty standard however I found the voice coil was a tight fit, used 250Hz signal for centering during glue-up. Also, replaced acoustic suspension seal tape on back sides of all four speaker baskets.
Cabinet Repair/Re-veneering
As found, cabinets were in fair shape, only box damage was one corner had swollen and the miter joint opened, apparently due to moisture exposure at some time. Vinyl veneer was also damaged in this corner and other spots. Vinyl veneer was stripped from cabinets with hot iron.
Damaged paperboard corner was stabilized with J-B Weld Wood Restore Liquid Hardener; three (3) coats saturated the paperboard corner and filled the gap. Sanded between coats. This worked very well.
Had some walnut wood veneer on-hand and applied to cabinets with wood glue and iron. Walnut veneer was finished with a 1st coat of Danish Oil (natural), five (5) thin coats of Zinsser wax-free shellac & a final coat of paste wax applied with “0000” steel wool.
Grill Covers
Original gray colored grill cloth was replaced with cloth as close as possible to the originals.
Re-assembly
Boxes were “re-stuffed” with the original polyester fiberfill acoustic damping material; drivers reinstalled & grill covers installed.
Fun project, fairly straightforward and I’m pleased with the resulting performance of these bookshelf speakers.
I had a couple other bookshelf sets on hand, Advent 2W & JBL 2500.
I don’t know if these are considered “fair comparisons” but A/B’ed these and the refreshed Model 6’s were easily on top; very pleased.
As background, this pair was manufactured 1996 (date stamp on woofer magnets) in Newton MA; prior to manufacturing transfer to China with Creative Labs acquisition in 1997.
