I thought is appropriate to start a new thread to illustrate and document the progress on building this monitor, or more correctly adapting my existing JBL boxes to the 4345 spec.
As the title of the thread suggests, Bo the damm Yankee from parts unknown is the catalyst for the idea, having published the dimensions in the 4345 plans thread elsewhere.
So where am I up to? Don't ask me, not exactly sure, but my back aches and I need an assistant.
O'kay here are some of the tasks: The 39 Steps
1. Sketch & sign off drawings for baffle cut-outs (done)
2. Purchase Jasper Jig and 1/4 in router bit (done)
3. Purchase 18mm Mdf materials (done)
4. Plan sequence of baffle fabrication and overall project
assembly (done)
Make jig frame for holding baffles (done)
Cut baffle circles (top layer then bottom layer - done)
Drill driver mounting holes (done)
Cut 18 mm MDF for Dog boxes (done)
Screw & glue dog boxes to 2nd MDF layer (done)
Laminate top and bottom MDF layer with PVA glue using a
dozen or house bricks for a press (done 1 baffle)
Clean, trim and sand & apply undercoat to finished baffles
5. Amend height of existing cabinet & volume by 6 inches (done)
6. Cut out existing baffles & make rear access opening
Drill screw holes for baffle mounting
Re paint cabinets with 2 pack Dulux effects paint finish (Arab
Sand effects paint)
7. Clean & vacum cabinets and fit new 3/4 inch fibre glass fill
8. Wire and fit crossover
Purchase 6 new x 100 watt faders (done)
Purchase Holvand capacitors for all horn filters (done ouch)
Assemble crossovers
Wire and calibrate faders with std JBL test jig
Fit crossovers in sealed sub enclosures
9. Fit new baffles, glue and scew
10. Fill screw holes, clean and paint baffles
11. Fit drivers
12. Check for air leaks & vibrations using low frequency sine
wave tones via Phase Linear 700.
13 Test, measure and evaluate new boxes (pray)
The list is my no means complete, with special jigs and processes being thought out as each step is taken.
Obviously this is not a weekend project, I'm down to task 5 or thereabouts, and there are plenty of new and sometimes daring challenges along the way. Photos are being taken as the project creeps forward.
So far touch wood, there have been no major issues, although cutting the top of the existing boxes was a painful, in more ways than one...Muhahahahahaha
The stouter boxes are more waf friendly I have to report and perfect elbow height for a beer tasting says I.
More news shortly...here is an early version of the baffle drawing:
Ian
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