BTW Grumpy's mention of the JBL Synthesis is interesting too. It will require some processing, but nothing out of the extraordinary (6 to 8db bass boost). The cabinet's internal volume is 7.4cft (with the ducting. The three round ducts can be replaced by a square vent that could be part of the cabinet's bracing as long as it respects the length and area.
http://www.jblsynthesis.com/tl_files...ec%20sheet.pdf
if you are limited to 18" depth (outside measurement), that cabinet could be horizontal (or vertical if you prefer). Around 36" wide x 24" tall x 18" deep external measurements = 7,4cft internal volume including ducts.
Square vents can be per Onken style where vents act as bracing too.
Onken cabinets are pretty awesome. The rectangular vents allow retuning by stuffing closed cell upholstery foam into them to seal them off, which is, obviously, reversable. Makes it nice to be able to tailor the bass response to your driver/room for more or less impact.
And...with void free baltic birch plywood, they're built like a tank.
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
[QUOTE=edgewound;406235]Onken cabinets are pretty awesome. The rectangular vents allow retuning by stuffing closed cell upholstery foam into them to seal them off, which is, obviously, reversable. Makes it nice to be able to tailor the bass response to your driver/room for more or less impact.
And...with void free baltic birch plywood, they're built like a tank.[/QUOTE
Lee, edgewound & grumpy, this information is nothing short of incredible!! Incidentally, are we speaking 2242 HPL or 2245H for these boxes? Although, it looks as though it is for a smaller woofer. How I wish I actually KNEW something about this!!! Thank you, thank you, thank you!!
[QUOTE=Valveglow;406282]You can use it with both drivers. And you can fine tune accordingly by blocking vents as Edgewound suggested. The 2245 in a 8cft cabinet (per exemple) may not reach as low as in a 12cft box, but you will get more "real life bass" with more kick. Many will even tell you that under 25-28Hz, there's usually not much content... You could tune the cab to 25Hz, and lower that frequency by blocking some vents if needed.
Basically, build one set, and test both 2242 and 2245 drivers. And yes, this photo shows a cab for a 15" driver. Just make the hole bigger for your 18" unit.
These cabs are pretty easy to draw up and fabricate. Simply add a single vertical brace that ties the top and bottom with the front and rear panel with a notch for the woofer. Very easy to do.
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