Want to share your 2235 cabinet making plans?

[lovejbl]

My first post! Folks so new and I want to say hello to everyone. My first project is to make an effective enclosure for my jbl 2235s. Strictly for subwoofer purpose only so anyone out there kind enough to share there plans and measurements for the enclosure. Advance thanks to anyone wanted to help. regards lovejbl:)

[Don C]

Did you see this?
http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm

[lovejbl]

Did you see this?
http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm
first time I saw it; let me do some reading. Awesome help! thanks

[Robh3606]

I use a pair of the B380's with a BX-63A for my LFE and they work great in my room. Very easy to build and not that big.

Rob:)

[Lee in Montreal]

If you run a pair of 2235 as music subs, they'll work great as long as you don't push them too loud. If you intend to use them as home theater subs, you will realize very soon their limitations. 2235s are great hifi woofers. They just can't handle all that extra cone travel and power required for movies.

An 18" 2245 (the 2235's big brother) is perhaps better suited.

[lovejbl]

If you run a pair of 2235 as music subs, they'll work great as long as you don't push them too loud. If you intend to use them as home theater subs, you will realize very soon their limitations. 2235s are great hifi woofers. They just can't handle all that extra cone travel and power required for movies.

An 18" 2245 (the 2235's big brother) is perhaps better suited.

thanks for the tips, ill be using strickly for hifi.

[lovejbl]

I use a pair of the B380's with a BX-63A for my LFE and they work great in my room. Very easy to build and not that big.

Rob:)

thanks rob but where can i find a plan for b380's?

[4313B]

Here's some stuff I have. I can't remember where I saved the photos from. I built alot of black box versions of these back in the 80's. We would mount them flush with the walls in new house constructions.

[lovejbl]

This will help me a lot in reproducing a home for my 2235s. You made few of these back in the 80s; how low did it go(as far as hz is concern)?I like it! Thanks again.

[Lee in Montreal]

Done those two years ago. Complex construction but innert as a block of concrete. Heavy too... :D Tuned to around 27Hz if I remember.

53583
53584

[Robh3606]

This will help me a lot in reproducing a home for my 2235s. You made few of these back in the 80s; how low did it go(as far as hz is concern)?I like it! Thanks again.


Into the low 20's with the BX-63 which has a highpass to help protect the woofer from overexcursion and unloading of the woofer. If you DIY use the 4" Precission Ports. They work great and allow for very large air volume displacement with no audible port noise.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=268-352

If you use them in pairs it works out to about 96Db for 1 watt so a pair of them can easilly rock your world from about 25Hz and up to your crossover point. As with any ported box you have to watch out with any input with substantial energy below the tuning frequency in this case 26Hz. Other than that for music only they should work great.

Rob:)

[lovejbl]

Wow that is great! It will be nice if I can borrow your plans;hehehe. I have few horns made out of concrete and they have so low low resonance. Let me see if I can get the picture. Oh here is it....

53598

[lovejbl]

Into the low 20's with the BX-63 which has a highpass to help protect the woofer from overexcursion and unloading of the woofer. If you DIY use the 4" Precission Ports. They work great and allow for very large air volume displacement with no audible port noise.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=268-352

If you use them in pairs it works out to about 96Db for 1 watt so a pair of them can easilly rock your world from about 25Hz and up to your crossover point. As with any ported box you have to watch out with any input with substantial energy below the tuning frequency in this case 26Hz. Other than that for music only they should work great.

Rob:)

i have seen some pictures for 2235 cabinets that has 2 ports but im kind a scared to experiment it with this B380s.

[Robh3606]

i have seen some pictures for 2235 cabinets that has 2 ports but im kind a scared to experiment it with this B380s.

Well if you are going to be using the driver as a subwoofer where maximum air volume may at time be pushed through the ports you are better off going with the largest least turbulent design you can use.

You can always go with multiple ports but why if you don't need too?? Just adds cost and complexity.

Rob:)

[badman]

Well if you are going to be using the driver as a subwoofer where maximum air volume may at time be pushed through the ports you are better off going with the largest least turbulent design you can use.

You can always go with multiple ports but why if you don't need too?? Just adds cost and complexity.

Rob:)

Welll.....

Multiple smaller ports do have one big advantage- you can make a much larger chamfer/roundover at the port ends, relative to the port area. This reduces turbulence quite a bit.

[Robh3606]

Multiple smaller ports do have one big advantage- you can make a much larger chamfer/roundover at the port ends, relative to the port area. This reduces turbulence quite a bit.

Ok but I doubt it will be that different from the port that was reccomended. Here's a picture of it. I have used these in several systems and the difference is well worth the cost.

Rob:)

[Mr. Widget]

I have used these in several systems and the difference is well worth the cost.I've always used dual square cut 4" dia. PVC or ABS and I have never heard any port noise while playing music. The flared ports are cool looking, but worth it???


Widget

[Robh3606]

The flared ports are cool looking, but worth it???


Hello Widget

It is to me. I have had issues using straight single and dual 3" PVC. So I made the switch over to flared and no noise at all. I have never used dual 4" ports though. To each there own. For $13 cool factors fine too.

Rob:)

[Allanvh5150]

IMO a 3" port is a tad small for a 2235 box. Make the port big and make it square. Then you can design the port into the box without having the need of trying to flush in a circular port. Easy is good.

Allan.

[4313B]

Dual 3" ports or single 4" port, whichever fits. I've done both and they both do the job.
The flared ports are better looking and they are less turbulent under high power.
I personally use the 3" and 4" plumbing pipes these days.
I used to use 1/8-inch thick cardboard tubing. That worked fine too.

This will help me a lot in reproducing a home for my 2235s. You made few of these back in the 80s; how low did it go(as far as hz is concern)?I like it! Thanks again.These things are good to around 20 Hz if you use the BX63. Without the BX63 the mass ring and or the spider breaks away from the voice coil under high power. The Box and BX63 are tuned to ~ 26 Hz.

[Robh3606]

IMO a 3" port is a tad small for a 2235 box.

I agree I used dual 3" in my 4344 clones. The ports are on the back and from the back you can hear some port noise. Glad they are on the back. That's one of the reasons I moved up to flared 4" on my 1400 Arrays and my B380 clones.

Rob:)

[Allanvh5150]

Any ideas as to why people do not build a square port into the box? Either a square hole or have the port built into the side of the box with the exit on the edge of the box? I have always done it this way and is very easy from a construction point of view.

Allan.

[1audiohack]

From an air flow efficiency stand point, round is the most efficient shape if your not worried about spin, if you are the next is a D shape. The worst shape assuming your not trying to do something crazy like a star shape port is a high aspect ratio rectangle, like a very narrow slot.

For the record I regularly build slots in the bottoms and triangle ports in the corners of boxes, almost always out front for placement flexibility. Ports are boundary affected to a small degree.

[grumpy]

pipe-ish ports are easier to predict and adjust. Shelf/slots are easier once you have the
tuning pinned down... probably also lower-Q due to the likely increased flow resistance...
(as mentioned above)
may or may not be an audible issue depending on the driver and system design.