JBL 4343 Renovation

[georgebrooke]

Hi,
Years ago I promised a description of a 4343 renovation. It has taken me nearly 5 years to get anywhere with this... due to work pressure and the number of steps in my house. Neighbours who volunteered to help move the speakers from the garage to the house have aged but luckily some passing builders were talked into getting the speakers into the house.. but only after Rich (of Richluvsound) had performed some minor miracles.

The speakers were purchased (via eBay) from an ex-roadie of Pink Floyd. The initial problems were poor cabinet finish (in spite of the claim of a "piano finish") and rotted surrounds. Apart from putting them on wheels (since removed). They sat in the garage while I pondered active crossover, passive crossover, charge-coupled. Meanwhile I went ahead with building the electronics (Pass B5 buffer, F5 power amp, Crown K2 (purchase) bass amp).
Eventually I decided that I needed to get them into the house and that would not happen with them in their poor condition.

Having met Rich a few times I asked him if he would help on the woodwork. In this case, "help" turned into doing it all. He did an outstanding job as the attached before and after photos show. He has made his own thread on the work he did at http://www.audioheritage.org/vbullet...test-project-! One of my attached photos shows a close-up or the veneering and mitred corners. He has done a really superb job.

The situation now is that they are more than acceptable in a living room. Moreover, they sound ... even in their present un-tuned state so much better than my old L300s that I am sure that I am on the right track with these.

So, things to do.

1. Refoam the bass speakers. They had nestled in the house, not the garage, but that had not saved them from the ageing process. I have ordered kits from Rick Cobb. I have used his products in the past with good results.. and his method avoids the use of shims and dust cap removal.
2. Set up the balance of the speakers.. on 4-way systems not as easy as it should be
3. Listen to the speakers... on all kinds of music and take notes
4. Decide on upgrade priorities. From related threads I am awash with suggestions and ideas. My current thinking is to wait for a DIY version of the B4 crossover from our friend Nelson Pass and combine that with a rebuild of the remaining parts of the crossover. Given the similarity, it may even be possible to adapt the L300 crossover, recently redesigned by Nelson, for use in the 4343.
5. Preserve the original form and components of the 4343

If any one has comments or thoughts on what I am planning to do I am more than keen to hear them

I find it very satisfying to bring back top quality equipment to as near to its original state as possible. With this sort of equipment I am not so much the owner as the keeper, for now. Remember the Patek Philippe advert. "You never actually own a Patek Philippe. You merely look after it for the next generation". Well, if the next generation have big enough living rooms this might just be true!