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Refurbishing an old speaker

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Project by ferstler posted 05-17-2014 12:25 AM 823 views 2 times favorited 4 comments Add to Favorites Watch

Years ago, Boston Acoustics produced a lot of good speakers, and one of their nicer budget-level models was the A-60. It had an 8-inch woofer of good quality and a small cone tweeter (later versions opted for a dome tweeter), and a pretty basic first-order crossover network.

Anyway, I recently picked up a pair of 34-year-old units at an estate sale for ten bucks. The foam woofer surrounds were shot and it had the older tweeter. Still, I saw some potential.

I re-foamed the woofer surrounds (kits are available from various sources) and replaced the cone tweeter with a good domed version from Parts Express. It was on sale for about $17. The surround kit was about $28.

The original enclosure was in OK shape, but it was vinyl-clad chipboard, and so I re-cladded it with 3/4 inch thick poplar and gave it a mahogany stain and six coats of spray on semi-gloss lacquer. This stiffened things up considerably and since I could not similarly stiffen the front and rear panels, I installed a short front-to-back brace between them. I replaced the cheap press connectors in the back with five-way binding posts and built a new second-order crossover network, following basic industry guidelines. I even installed a two-position level switch, labeled “bright” (flat output from the tweeter in relation to the woofer) and “mellow” (rolled off about 3 dB above the 2.5 kHz crossover frequency).

The grills were in fine shape, and all I did with them was to replace the factory logo-plate with a new one with my initials on it.

I also built some 22-inch-high stands for the speakers (mdf top and bottom plates, with poplar verticals) that include a hollow vertical tube running top to bottom at the back that would hold the speaker wires and make for a better cosmetic appearance.

The result was a small (roughly 20×13 x 19) and solidly built pair of speakers and stand combination that can hold their own with most commercially made versions. I should know. I was an audio writer for many years and reviewed and reported on quite a few speaker systems for magazine articles.

I really have no need for the speakers and will look around for a friend to sell them to. I have about $200 invested, and to match their quality one might have to spend three or four times that amount on a factory built pair.

Howard Ferstler





4 comments so far

View aussiedave's profile

aussiedave

3014 posts in 578 days


#1 posted 05-17-2014 11:43 AM

Very nicely done beautiful wood and finish…thanks for sharing.

-- Dave.......Keep calm and make more sawdust....

View ChipByrd's profile

ChipByrd

85 posts in 681 days


#2 posted 05-17-2014 12:38 PM

That’s really great work. I actually got into woodworking from my interests in audio. I wanted to build a subwoofer and needed to develop my skills. I plan to build a pair of speakers this fall. Again, great job.

View dshute's profile

dshute

118 posts in 1440 days


#3 posted 05-18-2014 11:24 AM

Audio and wood just naturally go together.

-- dshute, Warsaw, New York

View ferstler's profile

ferstler

333 posts in 2274 days


#4 posted 05-18-2014 11:42 PM

After looking at the photos and also at the speakers themselves I decided that it just was not right to have the tweeters held in place by just three screws. I pulled them and drilled three new holes, symmetrically placed, in each (and in the cabinets) and now they look more solidly mounted. I have no idea why those Dayton models (probably made in China by Tang Band) use only three mounting screws. It probably is OK, but four (a more common way to do it) would be better and six are better yet. Remember, in a sealed acoustic-suspension cabinet like this there WILL be internal pressures pushing on the driver mounts, even if a subwoofer is handling the lowest bass notes.

Howard

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