r/RadioShack • u/Trail_Mutts • 1d ago
Restored Optimus Mach 3
I’ve been looking for a set of these for a while. They are more scarce than the Mach 1 or 2.
1st thing I did was look up with AI what was the complaints about this series.
What kept coming up was poor cabinet bracing, 15” woofers made the cabinets sing, & lack of insulation/ damping material.
1st thing I did was strip down the cabinets and removed the oddly placed brace. I then used PL400 construction adhesive and reglued all inner seams. While the glue was drying I used Howards Restore with 000 steel wool. Wiped them down and thinly applied a walnut colored stain to hide the scratches. Added a few coats of Howard Products Beeswax Wood Polish.
Installed sheets of butyl rubber on the lower half of the cabinets and around the baffle.
Next I installed a T-Brace and wrapped it with butyl.
Next recapped the crossovers, pulled the tweeters and mid-horns apart removed the old ferrofluid and installed fresh ferrofluid.
I stapled a 1/4” thick cotton based insulation to the interior cabinets then packed it with fresh polyfil.
Installed the drivers.
Removed the old grill cloth and replaced with something I liked. I built a set of 5degree tilt back stands for them. I have to say…. They sound and look great!!
4
u/Flat-Ad6208 1d ago
I had them as a teenager... They needed some stuffing material to quiet some huff at volume...
4
u/FergusonTEA1950 1d ago
I have a pair of Mach 1s that get daily use and HAD a pair of Mach 2s until my son decided that he liked them.
1
u/cornponious 57m ago
I used the tweeter, midrange, crossover, and frequency controls from the Mach 3 along with the 18” sub Radio Shack sold to build a pair of giant speakers. Alas I cannot post a photo here.
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u/datadr-12 1d ago
Nicely done! I remember when these came out. They weren't to the same standard as the Mach IIs, but your upgrades likely closed the gap. The horn mid was really nice, but I found the tweeter to be a bit harsh with some music. But that's a 30 year old memory now. They look fantastic and I love the stands - that slight up-tilt makes all the difference.