Ever since I got those old JBL 4320 Studio Monitors in Philly for $300 for my birthday last year, I’d added parts and collected bits and done a series of upgrades from the original 2 way design with horns, to a pair of DIY JBL 3-way studio monitors, and finally into DIY 4-way monitors. I’d found a schematic for a model 4333 (passive) crossover network, built that, and had gotten a nice improvement from all that.
I even got an electronic crossover, dual amps and biAmped them.
But, it was still a kind of hack.

So, after a lot of reading, I decided that a pair of factory-built JBL 4-way Studio monitors were the way to go. But – estimates are that less than 500 pairs of the 4345 4-ways were made (18 woofer) and the 4343, although more common, still bring a pretty price in any kind of good condition. But, there was a lesser-known early model of the big 4-ways – the 4341s. It was only made for 2 years before it evolved into the 4343s, it used the same drivers in a slightly smaller cabinet, and, with luck, you can still find a pair of them for under $2000, sometimes WELL under $2k. And so we did!

They weren’t perfect, they had the 2123 10inch mid-bass driver instead of the correct 2121 or later 2122 driver (I managed to do an even swap for one later on), and they had the incorrect 2234 15inch woofers (again, I managed to get a pair of the correct 2235 15″ woofers and swap them in later). The L-pads were noisy and I had to replace 2 pots, I will need to build new crossovers at some point to replace the aging caps and get the best sound out of them, and, worse of all, they have no grills! (Cats beware!!)
But the cabinets are clean and solid, and the walnut veneer looks quite nice after being oiled down a few times.
And the sound?? Magnificent!