I’m going to attempt a combo build. Not sure if I’ll be able to attend both events, but this way I’ll be ready for both, just in case.
Current driver retail prices:
• SB13PFCR25-4 woofers: 37x2=74
• SB19ST-C000-4 3/4" tweeter: 24.5x2=49
• PC83-8 3" full range mid: 16x2=32
• Total: $155
Target xovers: 700Hz and 3kHz, 4th order; totally passive for Indy; active for Iron Driver. Think I’ll do the active xover first, even though the event will be later. This way I can dial in the sound before ordering parts.
Woofer alignment: 0.5 to 0.55 cu.ft. box tuned to 45Hz. 2"ID x6.8"L port.
Handi-panel: A single thickness 3/4" handi-panel would create a box with an approximate internal volume of about 0.93 cu.ft. Internal volume will therefore need to be cut in half by doubling up the wall thickness as necessary until the entire handi-panel is used up. This will make for a very heavy, dead cabinet with an approximate wall thickness of 1.5" on most panels.
Sides: 15 x 15 x 0.75" (2)
Top/bot: 6.5 x 15 x 0.75" (2)
Baffle/back: 8 x 15 x 0.75" (2)
The total internal volume will be 6.5*13.5*13.5 = 1184 cubic inches or 0.68 cu.ft. This is intentionally oversized to compensate for the required scrap usage. By my calculations, the above 6 panels will use 77% of one handipanel. 23% will be therefore be offcut scrap material, which equates to a volume of 198 cubic inches.
So, if I glue all the scrap material inside the cabinet, the net volume will be 1184-198 = 986 cubic inches. 986/1728 = 0.57 cu. ft. The driver magnets will reduce the internal volume a little bit more and I will also need to glue the driver cutouts inside the box, so the net volume should come out to roughly 0.50 cu. ft when all is said and done. More to come.
Alignment with 0.5 ohms series resistance:
