12" JBL speaker $29 on black friday at Bestbuy - Page 82 - AVS Forum | Home Theater Discussions And Reviews
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post #2431 of 2441 Old 08-14-2019, 02:55 PM
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Quote:
Originally Posted by lknhomeaudio View Post
Interesting because it's the specs on the website for the 4 hole box, and they give something different with what you guys come up with. Internal dimensions, minus the 3 braces/separations, gives about 6 ft exactly.

Does anyone know the internal volume of the sub? Maybe 0.1 cubic feet?

Based on those specs, for the current box, it's very close to 1.5, and not 1.2.

But, like you say, the website is probably wrong.
I need to measure it tonight. I'll update this post when I do so.
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post #2432 of 2441 Old 08-14-2019, 03:05 PM
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I'll measure mine again too. I wouldn't be surprised if they sub'd out the work and whoever does it has, uh, generous tolerances.
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post #2433 of 2441 Old 08-14-2019, 05:33 PM
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16.75" deep, 13.75" tall, 52.125" wide. There are 3 internal braces/dividers, so let's simply take 2.25" off the width to account for them.

External volume: (16.75 * 13.75 * (52.125-2.25))/1728 = 6.647 cuft, or ~1.66 cuft per sub, external.

Internal: (15.25 * 12.25 * 48.375)/1728 = 5.23 cuft. Divide that by 4 to get: ~1.307 cuft per sub, before you subtract the volume of the sub. So ~1.2 cuft per sub.

Not the 1.6 cuft per sub that was advertised.


Chris


P.S. I was generous with my measurements. You could whittle a little more volume out with a more critical eye.
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post #2434 of 2441 Old 08-14-2019, 05:56 PM
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Fantastic! Really goes to show how ridiculous some cheap drivers can get in small boxes. What a value!
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post #2435 of 2441 Old 08-14-2019, 06:56 PM
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Great. Now he's going to buy MORE.

Michael
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Did you really need to quote that entire post in your reply?
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Don't guess, measure: https://www.avsforum.com/forum/91-au...l#post22789786
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post #2436 of 2441 Old 08-14-2019, 07:05 PM
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Originally Posted by LastButNotLeast View Post
Great. Now he's going to buy MORE.

Michael
My wife just realized that I have 50 drivers in the house. The look I got was... fantastic. Bemused admiration with disapproval. I did a victory dance and told her "that's right!!!!" She laughed.

Totally married the right woman.
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post #2437 of 2441 Old 08-14-2019, 08:14 PM
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Quote:
Originally Posted by Chris Popovich View Post
16.75" deep, 13.75" tall, 52.125" wide. There are 3 internal braces/dividers, so let's simply take 2.25" off the width to account for them.

External volume: (16.75 * 13.75 * (52.125-2.25))/1728 = 6.647 cuft, or ~1.66 cuft per sub, external.

Internal: (15.25 * 12.25 * 48.375)/1728 = 5.23 cuft. Divide that by 4 to get: ~1.307 cuft per sub, before you subtract the volume of the sub. So ~1.2 cuft per sub.

Not the 1.6 cuft per sub that was advertised.


Chris


P.S. I was generous with my measurements. You could whittle a little more volume out with a more critical eye.
This is essentially what I found too. The measurements from the website are external specs, and my measurements of the actual boxes are very close.

Using the published external dimensions: Height: 14", Width: 52.25", Depth: 17". To calculate internal dimensions, (a) I subtracted 1.5" from the height to account for the top and bottom panels that are each 3/4", (b) I subtracted 3.75" from the width to account for the two end panels plus three internal dividing panels which are each 3/4", and (c) I subtracted 1.75" from the depth for the 1" front panel and 3/4" back panel. The resulting internal dimensions of 12.5" by 48.5" by 15.25" yields 5.35 cubic feet, which divided by 4 is 1.34 cubic feet per box. I'm not sure how much to knock off for the driver itself. But we’re obviously well short of the advertised “airspace” of 1.6 cubic feet.

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post #2438 of 2441 Old 08-14-2019, 10:06 PM
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Quote:
Originally Posted by Chris Popovich View Post
Don't get me started on TS parameters. Those spec'd by JBL are not what I tested.

Matt provided tested specs from a driver that was broken in at the beginning of this thread.


Quote:
Originally Posted by mtg90 View Post
I grabbed a pair of these just to check out, I thought I would share the T/S specs I measured on one after some break in:

* This data was exported from DATS the Dayton Audio Test System
*
* Manufacturer: JBL
* Model: CS1214 #1
* Piston Diameter = 260.4 mm
* f(s)= 25.57 Hz
* R(e)= 3.439 Ohms
* Z(max)= 40.8 Ohms
* Q(ms)= 6.488
* Q(es)= 0.5972
* Q(ts)= 0.5468
* V(as)= 104.6 liters (3.694 cubic feet)
* L(e)= 3.16 mH
* n(0)= 0.2792 %
* SPL= 86.56 1W/1m (90.72dB 2.83v/1m)
* M(ms)= 147.4 grams
* C(ms)= 0.263 mm/N
* BL= 11.68

A few other thoughts, I would not use these past about 15mm as the spider really locks up beyond that point and audible distortion ramps up quite a bit when trying to push them further. But they are nice and quiet up to rated xmax. The 1260w/1262w followed a similar pattern. Likely designed with durability in mind to prevent over excursion and bottoming.
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post #2439 of 2441 Old 08-15-2019, 12:10 AM
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Quote:
Originally Posted by Chris Popovich View Post
Fantastic! Really goes to show how ridiculous some cheap drivers can get in small boxes. What a value!
Indeed !

I am on the lookout for deals as i might need some more


Dual Atmos Receivers - Atmos 13.1.8/DTS X 9.1.8/Auro 3D 13.1 - Denon AVCX8500H+AVRX7200WA - Klipsch+KEF - 6xSI18" - 8xJBL 12" BOSS - 4xJBL 12" w/SLAPS M12" VNF - 3x2 stacked Crowson MA - 4xBK-LFE - 6xNU6K(fan&trig mod) - Minidsp 10x10HD - Oppo UDP203 - XBox OneX - Apple TV4K - JVC RS600 Dreamscreen V2 120"- Philips 65OLED873.
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post #2440 of 2441 Old 08-15-2019, 07:42 AM
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Quote:
Originally Posted by Chris Popovich View Post
16.75" deep, 13.75" tall, 52.125" wide. There are 3 internal braces/dividers, so let's simply take 2.25" off the width to account for them.

External volume: (16.75 * 13.75 * (52.125-2.25))/1728 = 6.647 cuft, or ~1.66 cuft per sub, external.

Internal: (15.25 * 12.25 * 48.375)/1728 = 5.23 cuft. Divide that by 4 to get: ~1.307 cuft per sub, before you subtract the volume of the sub. So ~1.2 cuft per sub.

Not the 1.6 cuft per sub that was advertised.


Chris


P.S. I was generous with my measurements. You could whittle a little more volume out with a more critical eye.
Quote:
Originally Posted by Blue View Post
This is essentially what I found too. The measurements from the website are external specs, and my measurements of the actual boxes are very close.

Using the published external dimensions: Height: 14", Width: 52.25", Depth: 17". To calculate internal dimensions, (a) I subtracted 1.5" from the height to account for the top and bottom panels that are each 3/4", (b) I subtracted 3.75" from the width to account for the two end panels plus three internal dividing panels which are each 3/4", and (c) I subtracted 1.75" from the depth for the 1" front panel and 3/4" back panel. The resulting internal dimensions of 12.5" by 48.5" by 15.25" yields 5.35 cubic feet, which divided by 4 is 1.34 cubic feet per box. I'm not sure how much to knock off for the driver itself. But we’re obviously well short of the advertised “airspace” of 1.6 cubic feet.

Thanks, guys, for the actual dimensions. You probably talked me out of buying one of them lol

@Blue 0.1 cubic foot is about right for a small 12 inch driver like these.
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post #2441 of 2441 Old 08-15-2019, 08:04 AM
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Actually, I think I'll go ahead and buy one anyway. WinISD says about 1.5-2dB less in the lower regions. Basically undetectable.

Red = 1.5ft each
Yellow = 1.2ft each

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