Early last year or maybe late 23 I came across ad in CL offering a JBL SR4726 for $50 which is a exceedingly low price for such a speaker.
I contacted the seller and discovered why the price was so low, he had found it in his front yard after the hurricane driven seawater receded back into the Gulf, he couldn't test it as he couldn't figure how to connect to it, it had a Neutrik speakON connector which was something he had never seen before, so I got the address and stopped by.
When I arrived he let me know it had another problem, as he was moving it around seawater ran out of the "horn" the HF driver, which indicated to me it was shot, none the less if I still wanted it I could have it and back to the shop it went.
Once there having another job in progress on the main bench it was stored up in the loft.
Later in the year it was brought back down set on a roll around work table and I began tearing it down, to my surprise it wasn't as bad as I expected it to be, the HF driver was toast, but as best as I can tell between the weight of it's magnet and the horn it was mounted to it caused the cabinet to float upside down sparing the LF driver and the crossover from any damage, things where looking better.
This is what the HF driver looked like inside, yup it is pooched.
The way JBL designed the box the front panel could not be removed so once the drivers, crossover and most of the fiberglass padding had been removed I cut out the front panel using a Sawzall, internally the box being made of 3/4" hardwood plywood was till in very good condition.
So the next step was to begin taking a number of careful measurements, I had never built a wedge before so getting the angles for the cuts was critical to properly clone the box, I mean what good is one huge speaker when R&R played LOUDLY sounds best in stereo.
I decided to best clone the box I needed to use basically the same type of hardwood plywood, digging around the JBL Sr catalog I discovered they only used "void free" plywood commonly known as marine grade plywood, now that sort of plywood will not be found at the local LowesDepot, at one time they offered what they called marine grade but it was pressure treated plywood, which is not something one wants to use indoors.
So I stopped by a lumber shop over on Marina Mile in Broward that sold wood to the marine industry, I have purchased hardwood from them but never plywood and yes they had 3/4" marine grade plywood in stock, 3 sheets, I asked the price and was sort of setback as it was $175 per sheet, my mind said I needed two my wallet told me I could buy one for now, which would have been enough to build the box minus the front panel, if I didn't make a mistake when cutting the sheets and I didn't make a mistake not one at all, I made two.
I am not used to cutting angles and miscalculated the width including the angles, oh well back for another sheet next time I needed to go over to that Third World dump.
None the less without too many colorful words I managed to clone the JBL box.
The next post will be in a couple of days showing the completed work.
.