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ngccglp
12-18-2005, 03:50 AM
Hi,

I am thinking of starting a project based around the LE14. Anybody has a cabinet plan that I could used? I tried to look up the plans in the libarary but couldn't find any. Thanks.

4313B
12-18-2005, 04:50 AM
1.8 to 4.0 cubic feet tuned to 28 Hz to 30 Hz.

ngccglp
12-18-2005, 06:51 AM
Hi Giskard,

Could you also kindly advise on the port size and length? Actually, is there a baffle design that only has an opening (sort of like the Altec A7) but w/o any duct? It would be much easier to fabricate.

Thanks.

Robh3606
12-18-2005, 07:08 AM
Hello ngccglp

You need the internal volume to calculate port size depending on the box tuning. You can get a free box program here WinIsd

http://www.linearteam.dk/default.aspx?pageid=winisd

Or use the clasic boxes JBL used from the plans section:

http://www.lansingheritage.org/html/jbl/plans/jbl-plans.htm


Rob:)

Hamilton
12-18-2005, 12:39 PM
I just built a pair on Zilch's recommendation using the L200t3 layout, but brought the internal specs down to 3.5 cu. ft, (2) 3" ports 8 " long for LE14As.

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L200t3%20ts.pdf

ngccglp
12-19-2005, 01:27 AM
Thanks. Will give the software a go asap.

Hamilton, nice cabs. :applaud:

ngccglp
12-23-2005, 02:58 AM
I think I have figured out the way to design and tune a bass cab to the required freq. However, I need advice on the optimal shape of the curve. I noticed a hump around the tuning freq as I increase the freq values, same thing happens when I increase the volume.

Is the objective to smoothen out the hump or is it OK to have a bit of the hump?

Thanks.

4313B
12-23-2005, 04:27 AM
These days the goal appears to be to get a nice banana curve that will self equalize when placed in a typical room.

I actually took a minute to run Hamilton's implementation mentioned above in BB6P and here's the result:

Usable response to ~ 25 Hz with a nice ~ 18 dB/octave rolloff as expected with a quasi-third order alignment.

4313B
12-23-2005, 05:56 AM
I just built a pair on Zilch's recommendation using the L200t3 layout, but brought the internal specs down to 3.5 cu. ft, (2) 3" ports 8 " long for LE14As.

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L200t3%20ts.pdfhttp://audioheritage.org/vbulletin/showpost.php?p=48365&postcount=295

http://audioheritage.org/vbulletin/showpost.php?p=48436&postcount=307

http://audioheritage.org/vbulletin/showpost.php?p=48448&postcount=308

gerard
12-23-2005, 08:18 AM
Hello


Question for Le14 ?.

What is the best : 1 bigger port or 2 small ones like the picture ?

Gerard

Titanium Dome
12-23-2005, 08:29 AM
The LE14H-3 is dual ported to the front in the PS1400 enclosure. It uses "Freeflow" flared tubes. The cab is approximatley 15x20x19.

Hamilton
12-23-2005, 08:52 AM
Giskard, the stock nL200t3 was WAY too hot in HF, we ended up installing a fixed L-pad, around -6 db I believe; Zilch drew up the schematic.

4313B
12-23-2005, 09:13 AM
Zilch drew up the schematic.Post it.
Giskard, the stock nL200t3 was WAY too hot in HF, we ended up installing a fixed L-pad, around -6 db I believe.There is absolutely no way the 14" LE14 is 6 dB less efficient than the 12" 120T3. What components are you using?

4313B
12-23-2005, 09:15 AM
Hello


Question for Le14 ?.

What is the best : 1 bigger port or 2 small ones like the picture ?

GerardA single larger port is always the best bet, but multiple ports can be used if compensated for. I usually go with dual ports myself.

Robh3606
12-23-2005, 12:06 PM
What's the DCR on L1 the coil across the driver?? Should be 7.5 ohms.

Rob:)

4313B
12-23-2005, 12:16 PM
I found this pic Rob:

Hamilton
12-23-2005, 12:53 PM
There is absolutely no way the 14" LE14 is 6 dB less efficient than the 12" 120T3. What components are you using?
Giskard, I'm guessing on the amount of attenuation, somehow that figure was stuck in my mind.

Those cabs have LE14A, nL200t3, 2426H & 2342. I have anything but a "golden ear" so I set one cab right next to a 4430 for a baseline, then adjusted the attenuation until they sounded near identical.

4313B
12-23-2005, 01:05 PM
Ok.

Did you post a picture of the completed systems somewhere? I'm sure everyone would like to see them. Nice job on the enclosures.

Hamilton
12-23-2005, 01:20 PM
Here is one, with a 4430 and B380 clone in the back. I'm waiting for a buddy to do all the staining/finish work but he seems to have fallen off the face of the earth.

The cabs came out ok, but there was a miscommunication with the cab shop. They were instructed only to cut the panels, but do no assembly. Well, they had them near fully assembled when I picked them up, http://audioheritage.org/vbulletin/images/smilies/biting.gif which made it extremely difficult to router out the holes. In fact, you can see on the front of the ports I wasn't able to leave any veneer to cover them since they was no way to work the router on the backside of the panel. http://audioheritage.org/vbulletin/images/smilies/biting.gif But those areas will be covered with JBL blue grill cloth.