In a nutshell, The 2312 / 2420 ( or H92 / LE85 ) will not fit into the venerable L200 cabinet so an access must be made on the rear panel to allow the driver to stick through. The 2420 / LE185 and the later 2425/26/27 are all 5.75" diameter
SINCE this an angled cabinet, the hole size, centering and angle precludes any simple "jigsaw" approach unless a significant amount of material is removed. The goal here was to make it "doable" with basic power tools and supplies available from the local home depot or next-door neighbor who is in general construction.
If carefully done, the gap around the driver is an even 1/8 inch on the inside AND outside... I did this in less than 30 minutes on the living room floor so no special "shop time" is needed.
Tools required:
1/2" chuck GOOD electric drill ( I used a Milwaukee hole shooter )
6" holesaw ( standard ceiling light fixture diameter )
6" or longer 1/4 diameter drill bit for the hole saw pilot.
In order to find that magical location for the pilot hole, I mounted a 2312 horn into the cabinet, installed an 18" long 1/4 diameter bit into the drill and used a plastic bottlecap to center it deep in the horn. Using a straight edge on the horn face between 2 mounting holes I drilled through the back panel.
This worked out well and the exact measurement for the pilot hole ( 11 7/8" ) is shown in one picture ( and is of course centered ).
NOTE that the hole goes into the cabinet at an UPWARD ANGLE that is the same as the cabinet sides when viewed from the back.
The Hole saw was then used ( note the angle that it cuts into the cabinet ) to make the hole. This is where the extra long pilot bit is REQUIRED!
After vacuuming out the debris and trimming the insulation, the horn was mounted and then the driver. Unfortunately the horn mounting flange is *just* a little larger than 6 inches otherwise the whole assembly could be mounted from the rear.
Now as you can see by the measurement, the top edge of the driver protrudes 1 3/8" so a cap needs to be placed over the whole driver OR a rubber / neoprene thin hose could be jammed into the 1/8 gap around the driver. Do not use silicone or the heritage members will hunt you down and noodle whip.
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