4688 TCB Monster Subwoofer

[Zilch]

Triple Chamber Bandpass sub uses dual 18" drivers in "Push-push" configuration. Motors in center chamber.

Drawing shows center (red) and outer (blue) chamber details separately. Bracing comprising center chamber "port tubes" only shown.

[Oodles more bracing therein. ]

Tech note here: http://audioheritage.org/vbulletin/s...ead.php?t=6289

JBL Lit here: http://www.jblpro.com/pub/obsolete/4688.pdf

[JBLnsince1959]

at what power does this achieve "escape velocity" and orbit the earth

[Zilch]

Never thought of that.

More down to earth, we're construction contractors.

It's on the capital equpment list here under "Demolition."

[richard c.]

Zilch,

I noticed this awhile back in your photo, and it got me thinking. "I bet I could build one of these IF I had some pictures and the plans for one. And here they are.

I wish I lived closer to you, so I could take a bunch of pictures, and take all measurements. I would love to build one of these monsters. I think it would be perfect for realistic pipe organ "power".

I could build this and install a couple of $29.95 "Super Woofers" that I could find in a surplus catalog somewhere, and I would be in heaven.

AND, than I could tell everybody that it was "genuine" JBL.

No, really I would like one to lay down and use it for a platform under a big screen TV. Talk about LF effects!

Richard C.

[JBLnsince1959]

Zilch,


No, really I would like one to lay down and use it for a platform under a big screen TV. Talk about LF effects!

Richard C.

or better yet, make one and put cushions on it and sit on it while watching the movies... girls I think would REALLY like that......

[Eaulive]

or better yet, make one and put cushions on it and sit on it while watching the movies... girls I think would REALLY like that......

When we just got married, my wife used my two Cerwin-Vega 18" bass bins as a couch, she made some cushions for them and it looked OK for her, I didn't want to get rid of my system so she worked around it

I was going to post a picture but I realize the only one I have is when she's laying on them, kind of indecently.
I won't post it because you probably won't pay attention to the cabinets anyways

[mikebake]

Oh, go on and post the photo and we'll work around it.

[Eaulive]

Oh, go on and post the photo and we'll work around it.

I don't want to get banninated from the site

[richard c.]

Zilch,

Do you think this would require a medical release form to be signed by everyone in a normal sized room with this? Might reveal some underlying heart problems.

Richard C.

[Zilch]

Yes.

"Informed Consent" forms are a necessity....

We need info on the 15" and 12" versions, now, models 4685 and 4682, respectively.

Who's got 'em?

http://www.jblpro.com/pub/obsolete/4685.pdf

http://www.jblpro.com/pub/obsolete/4682.pdf

Consider all of the homeless drivers out there....

[pelly3s]

Why does someone need that? Oh I know because its really cool

[Zilch]

Why does someone need that?

Surely you KNOW this ain't about "need."

[We're doin' RESEARCH here.... ]

[loach71]

Triple Chamber Bandpass sub uses dual 18" drivers in "Push-push" configuration. Motors in center chamber.

Drawing shows center (red) and outer (blue) chamber details separately. Bracing comprising center chamber "port tubes" only shown.

[Oodles more bracing therein. ]

Tech note here: http://audioheritage.org/vbulletin/s...ead.php?t=6289

JBL Lit here: http://www.jblpro.com/pub/obsolete/4688.pdf

This looks to be quite the subwoofer. Do you have any more dimensional information on the center chamber? I am interested in building four of these beasts -- I just acquired qty. 8 JBL 2245H drivers from a government auction. Do you think these drivers would work OK in this particular enclosure?

Thanks!

[Zilch]

Do you think these drivers would work OK in this particular enclosure?

My initial thought was "No way," but first looks in BB6P say 2245H will work fine.

Subwoof knows where there's a couple available for sale. Paying the freight and acquiring an original to build from would be my suggestion. That way, you can try it out first to be sure, too.

If you do that, prepare detailed construction drawings for the benefit of the forum.

I'm still looking for a 4685 and a 4682. Those smaller ones would also be fun to build. I have a preliminary design for 4685 in BB6P that I may build while the search continues....

[loach71]

My initial thought was "No way," but first looks in BB6P say 2245H will work fine.

Subwoof knows where there's a couple available for sale. Paying the freight and acquiring an original to build from would be my suggestion. That way, you can try it out first to be sure, too.

If you do that, prepare detailed construction drawings for the benefit of the forum.

I'm still looking for a 4685 and a 4682. Those smaller ones would also be fun to build. I have a preliminary design for 4685 in BB6P that I may build while the search continues....

I'm modeling this thing with BB6 Pro - but I only get gibberish on the center chamber and its vents. I've tuned the two outer chambers to 24 Hz ... and your 4" x 14" vent fits the model. I've tuned the center chamber to 68 Hz -- but BB6 Pro says NO WAY for the 4" x 14" vent. I must be doing something wrong..


The 4688s for sale on E-Pay are in upstate N.Y. and the seller wants $400 each for the cabs with no drivers. Shipped to rural Montana, the costs would be huge. So that is why I am doing the math... Sweat and sawdust equity for the impecunious..

Here are my initial results: (don't laugh too much!)

Internal dimensions quoted.

Outside chambers - 25.5" x 25.5" x 19.5" - single vent 5.991" I.D. x 14" long

Inside chamber - 25.5" x 25.5" x 22.6" - vent data comes out totally silly!

After I get this worked out I'll publish the complete data set and cut sheet info.

Any insights would be welcome.... thanks in advance for your kind help offered to this n00b...