Making One SR4731x into Two cabs

[Minatogawaman]

Howdy folks. I just got a SR4731x with the dual 12" LF drivers and the magnificent HF driver 2447J. I am an amateur in audio box building but have carpentry experience and access to a full-bore cabinet shop.

My question is if I find another 2447j on ebay and used an electronic crossover to bi-amp, is it feasible to make two cabinets out of the one SR4731x, yielding boxes with one 12" LF driver and one 2447J each?

How would I figure out what the size of the cab should be?

Medium Density Fiberboard is probably the best material, right?

The primary purpose of these cabs will be to use as a PA for blues/rock noodling and jamming in my 30 ft by 20 ft home studio.

Any and all advice would be appreciated!

Minatogawaman
Takasaki City
Japan

[speakerdave]

Can you make some sketches of your intended subdivision of the cab?

David

[johnaec]

JBL's made a number of high-power 12" 2-way systems similar to what you're talking about, so the design is definitely feasible.

John

[Tom Loizeaux]

... but the 2 12s working together really sound great! You'll lose some punch and a little low end if you go with just one 12.

Tom

[Minatogawaman]

Thank you all for your input. I am still wondering what to do, but perhaps the best bet is to buy two more 12" LF drivers and put my extra HF driver in a custom cab with those...:)

...but that would require spousal clearance for a $600 purchase and take up even more space in our typical Japanese home (Ever heard the rabbit-hutch jokes?) :blink:

Minatogawaman

[speakerdave]

. . . . (Ever heard the rabbit-hutch jokes?) . . . .
No, but eagerly waiting.

David

[johnaec]

...my extra HF driverDo you have the second HF driver, (and horn)? I've got some leftover JBL cabinets that housed a 2206H and 2446/2380 combination I'l let go for free, (packing/shipping costs only). What is the size of the horn?

John

[Minatogawaman]

Wow, I do indeed have the second HF driver with the same 2381 horn as is on the SR4731x.

My address is a military FPO AP at US zip code 96328. I would really appreciate it. I can paypal you whatever it costs to ship them via US Postal Service Parcel Post, throwing in a little bit for the trouble.

The only snag is if the Cabs weigh more than 70lbs or have length + circumference that exceeds 130 inches...then I am SOL, but still appreciate your offer.l

[johnaec]

OK - these are the cabinets I have, (I actually have 3 of them). http://www.jblproservice.com/pdf/AS%20Series/AS2212-STD.pdf See if the dimensions fall within what you want for your cabinet size, and we'll go from there.

Your 2447 drivers are a little shallower than the 2446, but that should be OK. But can you measure the front dimension of your 2381 to be sure it's the same size as the 2380, (17.5" wide x 11" high).

Also, these cabinets don't have true crossovers - rather, they have some hi-pass caps for HF driver protection. They're exactly what's shown in that JBL doc.

John

[Minatogawaman]

The enclosures are just what I was hoping for! Lack of true crossovers is not a problem since I will likely use an electronic crossover to bi-amp them. The horn will fit so no worries there.

Please email me at [email protected] or send me a private message via the forum to let me know how I can best send the money for shipping and handling.

Since it looks like you are somewhere in the wonderful state of California from your profile on the forum, I punched in a zip code in L.A. and my own FPO AP 96328 along with the dimensions and maximum allowable weight of 70 lbs at http://postcalc.usps.gov/ (http://postcalc.usps.gov/) just to get a general idea...it was about $60 a piece, not bad for something so heavy going all the way to Japan!

Please let me know if you would be interested in something from Japan as a token of my appreciation. I will also add some extra money for your trouble and packing materials. The enclosures look pretty roadworthy so they should make it here just fine.

I cannot tell you how much this helps me out. I will try to pass on a good turn to someone else in need.

Thanks again for your generosity.

Happy holidays
Chris aka "Minatogawaman"

[johnaec]

Chris - do they have to go U.S. Post, or can they be FedEx'd to your FBO AP?

I may not get a real chance to get going on these until after the holidays - is that OK? If you're in a real hurry, I might be able to get them out between Christmas and New Years.

John

[Minatogawaman]

John

Thanks for the speedy reply. I am not in a hurry for the cabs so after the New Year would be fine.

Unfortunately, they must be shipped via US Postal Service to my FPO AP. FEDEX, UPS or DHL would probably cost at least $750 to ship the pair. As I mentioned before, I would be more than happy to send extra money for your gasoline, time and trouble.

In case you were wondering, FPO AP are U.S. post offices located in embassies and one military bases worldwide. The cost of shipping to an AP (Armed Forces Pacific) from anywhere in the USA is the same as shipping to San Francisco, the military takes it the rest of the way for free.

Can you accept paypal payments?

All the best
Chris

[johnaec]

Yeah, I can do PayPal. If you'd like them to arrive best, (they're in excellent shape), are you willing to spend about $30 for packing materials? Otherwise, I'll just wrap 'em in cardboard.

BTW - I'm just north of San Francisco. Can I drop them off, or do I still have to go through the P.O.?

John

[Minatogawaman]

Sure, how about $30 for packing and $30 for gas and the trouble of shipping them? That would make it somewhere around $180 for everything, but we should check to make sure it is enough for shipping from your zip.

[Minatogawaman]

John

If it is less of hassle for you, you could send them via FEDEX or UPS to my brother in Arizona (Shonto, AZ 86504) and then he could take them to the PO and mail them to me. I realize the Post Office is a lot of messing around and want to make it as effortless for you as possible.

Please let me know.

All the best
Chris

[johnaec]

I don't mind dealing with the post office. I just thought that it might be possible to completely bypass the P.O. since it sounds like I'd be sending them to San Francisco - I could almost as easily just drive them to S.F. and not deal with the P.O. at all, unless it's going to cost the same anyway...

John

[Minatogawaman]

John

OK, thanks for offering to send them via a US Post Office. As far as I know, I think there is no way to put them on a military freighter directly so the local PO is probably the best choice. Since you are near San Francisco, the postal fee should be very reasonable. About how much does each empty enclosure weigh?

I really appreciate it!
Chris

[johnaec]

OK - I emptied one box and come up with about 45 lbs. empty, but including the grille. So I'm guessing under 60 lbs. each packed. It also looks like the final size will be under the 130" limit, but it appears I'll have to file a form 2976-A. Shipping looks to be around $40 each.

I'll pick up packing materials next week, and try to get them ready to go right after new years.

'You sure you don't want 3 of them? :)

John

[johnaec]

Chris - I've done some close-up looking at pics of the 2381 horns in the 4731 cabinets and am virtually positive they're narrower than the 2380, or about 15" vs. the 2380's 17" or more. I imagine they'll fit in these cabinets, but you'll probably have to add some little "filler" pieces to each side of the horn openings to fill the gap.

John

[Minatogawaman]

John
Thanks! The shipping cost is even less than I expected. Yes, the form is a customs form. Please fill in the value of each as half of whatever the total cost ends up being.

I'll figure out something with the horns. A small filler piece of wood will be easy to install.

I wish I could take box #3 too, but my wife's a little anxious about our new Japanese-style house (i.e. "rabbit hutch") having more than one set of JBLs per room:D

Please let me know the total, including the $30 for packing materials and $30 for gas, and how you would like to receive payment, via paypal, personal check (I am in no hurry so I can wait till it clears for shipping), money order etc.

Happy holidays!
Chris

[littlemike]

Do you have the second HF driver, (and horn)? I've got some leftover JBL cabinets that housed a 2206H and 2446/2380 combination I'l let go for free, (packing/shipping costs only). What is the size of the horn?

John

John, do you still have 2 of these cabs?

cheers
mike

[johnaec]

John, do you still have 2 of these cabs?I've got 2 cabs going to Chris, and a third one left over. Free, for packing and shipping costs. Very good condition.

John

[johnaec]

I'll figure out something with the horns. A small filler piece of wood will be easy to install.Chris - PM sent.

John