As for the sound... It's pretty damn good, if I do say so myself. The bass is clear and very tight and the high end is much better than I was expecting from the co-axial tweeter.
I have now listened to this Jensen 210-based speaker in the basement/shop (a.k.a. the REAL man cave) for a couple of months. Initially, I found the sound acceptable, but the longer I listened the more its flaws began to bother me. There is no problem with the amp or tuner, because when I hook them up to a nice, store-bought speaker they sound fantastic. When hooked up to the Jensen-in-a-box, however, the highs are blunted and the mids and lows sound 'boxy'. By pressing on the cone, twiddling the tone controls, and putting my ear down into the heart of the speaker I determined that almost no sound was coming out of the coaxial tweeter. Maybe the tweeter was doing more in the beginning, when I first mounted it in the box, or maybe my opinion was biased by the fact that I was surprised to hear anything come out of that old driver.
At any rate, I finally decided to do a few tweaks and upgrades to this speaker. I removed the front baffle and exposed the crossover components by pulling the back cover off the driver. The cover was attached by metal tabs pushed into slots on the basket and then bent to prevent them from sliding out. I couldn't easily get to the tabs from the inside without removing the cone, so I used a screwdriver and CAREFULLY pried them out. The cover came off with minimal damage to the slots.
It was like opening an Egyptian tomb. Inside the cover was an ancient wax paper capacitor and two derelict resistors. The resistors were positioned in an attitude of prayer, as if paying homage to the great yellow capacitor god. One resistor was so corroded that the ceramic housing broke in two when touched (red arrow in photo below). The wires were green with verdigris and corrosion and they also disintegrated at a slight touch. I worried that maybe I had unleashed the Curse of the Forbidden Crossover.
The resistors and their leads were so decrepit it was impossible to measure a stable resistance, but the color coded hieroglyphs said they were 3.3 Ohm +/- 10%. The capacitor was nominally 2 µF but metered at 3.8 µF, and the solder joint between the two resistors had been pressed into the side of the capacitor so hard that the wax deformed and flowed around it.
I replaced the (3.3 + 3.3 =) 6.6 Ohm resistance with a single 7.5 Ohm power resistor and the 2 µF capacitor with a pair of 1 µF Dayton Audio caps left over from a previous recapping job. I soldered and heat-shrinked everything together and stuffed the components back into the original sarcophagus ... I mean mounting strap. I used a couple of dollops of hot glue to hold the parts together and stabilize the connections.
I then carefully fitted the cover tabs back into the slots and tapped them into place with a wooden mallet. The tapping helped bend the margins of the slots back toward their original shape, and the cover ended up fitting pretty tightly. The connection had no play and didn't feel like it would come apart spontaneously, but I add a couple more dollops of hot glue to make sure nothing worked loose.
Finally, I increased the amount of stuffing inside the cabinet. Initially, I just stapled some polyester batting to the walls but this time I packed the insides full (additional stuffing not shown in the photo below). Finally, I said a few verses from the Egyptian book of the dead, drew a few protective hieroglyphs, and remounted the front panel .
The sound out of the Jensen-in-a-box is now VASTLY improved. The lows have always been pretty sweet, but with the extra stuffing they no longer sound so boxy. More importantly: the tweeter is IN THE HOUSE. I sat down in the basement with a beer for about an hour, just listening to the local jazz radio station and marveling at how the brushed snare drums no longer sound like white noise and Miles Davis no longer sounds like he is trapped in a refrigerator box.
