A while back I found these Sansui SP1500 (SP-1500) speakers and I’m trying to finish some more projects as summer comes out. There are several radios on my bench right now being worked on, but during a natural break in the progress, I was able to swap out a few parts in these old crossovers to bring them back to life.
These were manufactured in the mid-late ’70s and are solid walnut 4-way speakers with beautiful wood lattice grills. The grills are really even more impressive than the photos show as there’s scalloping on the inside of each bar. I like these earlier to middle Sansui speakers, they have a nice warm sound and frequently interesting driver designs. They’re also pretty efficient, I think these are rated at 98 dB at 1W*1m, accepting 60W RMS.
Inside, the wiring is pretty clean. The crossover caps are pretty straightforward. This one uses a 2.2F, 6.8uF, 22uF and 47uF capacitor in each speaker which are all the original construction and have started to fail. When speaker crossovers start to fail you might get distortion, intermittent or failed output of one or more drivers, changed response curves, or in the worst case the drivers may even blow. I have stock parts on hand which match or exceed the original factory specs for those crossover capacitors.
A couple of simple snips and solders later and we’re good to go! The speakers sound great refurbished, very warm and rich!
With new, up-rated components these speakers should be good for another 40 years.
If you’d like to buy the parts to complete this repair on your own set of Sansui SP-1500 speakers, visit Easy-Kits!