JBL 2242H HT sub design questions

[robertbartsch]

OK, so this 18 inch driver will serve as my sub-woofer in my HT and I plan to design and have built a separate cabinet with a power amp mounted inside the cab.

Since the driver has a 99Db sensativity rating with 1 watt at 3 feet, I assume I don't need a large power amp for this home applicaiton.

Questions:
1. What amp specs: What SS amp would be a good candidate for this project; my budget for the amp is about $300-$400. Should only amps with very low THD, say .05%, be considered or is distortion less critical for a sub woofer application? I'm assuming a 150 watt amp will suffice; right?

2. Cabinet size: The JBL recomended cabinet size is 5 sq. feet; If I'm not planning to use it at high sound pressure levels, can I build the box smaller, say 3.5 square feet and not suffer adverse affects?

3. Cabinet design: My thouhts on the cabinet are to mount the driver facing down - similar in design to the current Klipsch's subs; is this OK?

Thanks...

[4313B]

That driver is really ~ 95 - 96 dB SPL when used as a subwoofer below ~ 80 Hz.

JBL uses it in the 8 cu ft 4645C.

You can use it in smaller boxes, just EQ it.

I think the suspension is stiff enough to allow for downward firing. I haven't looked at the numbers though since I don't care.

[Earl K]

Robert ,

Do an info search of this forum, using ;

- 2242H as the "keyword"
- 4313B as the "author"
- return these results, as posts or threads ( your choice ) / then read and absorb the info from the archives .


Once done, you'll see that your current direction is way off from what you need to do ( unless you're going to use massive amounts of LF boost EQ , along with massive quantities of watts to support that "boost" ) .

:)

[Mr. Widget]

I agree with 4313B and Earl. If you are planning on using a "plate" amp you may be disappointed.

You could probably use this woofer in an undersized box as Earl suggests if you give it a solid 500 watt amp and a Velodyne SMS-1.

http://www.velodyne.com/products/product.aspx?ID=15&sid=908r288e


Widget

[robertbartsch]

OK: I'm going with a 9 square foot cabinet and a 500 watt SS amp.

[mikebake]

Now yer talkin'!

[spkrman57]

http://audioheritage.org/vbulletin/showthread.php?t=4845&highlight=cubic

Regards, Ron

[Earl K]

Hi Robert,

Here's a thread to read, authored by JuniorJBL . (http://audioheritage.csdco.com/vbulletin/showthread.php?t=5882) It's mostly about the sub-box "build", that he did for his 2242H woofers .

<> :)