Cabinet design for 2245H

[jerry_rig]

I have a pair of Bag End S18E-I cabinets and an ELF M2. (Now they call them INFRA units.) My understanding is that the Bag End ELF drivers have a very high resonant frequency. The cabinets are relatively small (around 3.8 cu ft) and sealed. The ELF "integrator" is a fancy EQ that boosts the bejesus out of the low end. I use a Krell KSA 300s to drive them and they go waaaaay deep.

I guess you could use a 2245 in such a setup, but there is no guarantee that it would work. However, you might wind up overdriving it below its resonant frequency and damage it.

[pos]

Here is an interesting design for a 2245H TL :
http://www.coolcat.dk/bjoern/JBL_2245_H_TL_Designs.pdf


EDIT: uploaded

[JBL 4645]

I'm planning cabinet design for a pair of 2245H and have a few differnet ideas:

- 2 x B460 clone
- 2 x Altec 8184 clone (simple box of 12ft3)
- 1 x Altec 8182 clone (one box of 24ft3 with both drivers in)
- 2 x sonotubes:

Now I’ve stumbled onto the Altec 8182 on a site called Boxoffice magazine that has an article about sub bass in cinemas on page 74.
http://issuu.com/boxoffice/docs/boxoffice_0384

Question what is the size of the enclosure and the port length diameter size?

Can you take a picture of yourself, standing beside it LOL I’m not sure but looks like its 5 feet!

From the looks of it you can fit x4 18” in that box!

[speakerdave]

What about an ELF system, any experince with 2245 in such a setup? . . . .

The 2245 native resonance is too low for that. Part of the idea of the ELF is to not play through the driver/system resonance; the woofer must be cut in below that. Use the 2242. It has a high-enough resonance and can take the massive power input and excursion required to be cut in at up to 60-65 Hz and play to subsonic region. Search that driver here and you will find Giskard's experiments with the 2242 in a <2 cu ft sealed cabinet. Also, I would not apply 12 dB/octave EQ; I would think less would be needed because of room gain. He felt it worked well even without EQ. There are digital subwoofer management systems like the Velodyne available that would be able to tailor the response to a specific situation.

[lgvenable]

I use a drive rack 260, and can provide my plans for this sub. Its port tuned to 25 hz, and uses two 6" ID ports 14.67"long.Volume was 12.06 ft3.
Let me know if you want the excel files.

Its a box in a box, 3/4" MDF inner box , lined with 3/4" walnut veneer plywood and 238lbs.

I drive it with a 600wpc AB Systems 821 bridged mono @ 8Ω.

[svollmer]

You might want to look at these designs I found on Google.

Both the 8 cubic foot and the 12 cubic foot designs are called "assisted" designs. That is, you need a special active equalizer to boos the bass where it rolls off to get good low end performance.

Lastly, the paper discuses a 4.5 cubic foot design for the 2235H.

I've built two of the 12 cubic foot cabs and love them. The certainly go "infrasonic." I use an Audio Control Richter Scale III crossover (at 40Hz) which can provide a boost similar to the BX63 in the article, but have never needed it. In fact, I have to antennuate the very low frequencies to keep it flat.

[lgvenable]

Certainly I agree infrasonic , I get shattering bass out of this sub. I'm in the process of turning a 4719 dual 18" sub to a single 18" 2245, to match the DIY 2245 I posted.

Absolutely stunning bass when driven 600 wpc. Passages like the moment Gort steps out of the sphere are just staggering, as the sub builds to a crescendo.

[eso]

Certainly I agree infrasonic , I get shattering bass out of this sub. I'm in the process of turning a 4719 dual 18" sub to a single 18" 2245, to match the DIY 2245 I posted.

Absolutely stunning bass when driven 600 wpc. Passages like the moment Gort steps out of the sphere are just staggering, as the sub builds to a crescendo.

I get "Shattering Bass" out of my 30Hz cement bass horns with K151 drivers and 125 PP el34 watts. A solid 106db 1w/1m @ 30hz, down about 5-6db @ 20Hz and still plenty of visceral output at 15Hz... The problem is that they weigh nearly a ton each and are built into the space.

Still, any of you who are patently insane, there is no ported box that will match a good bass horn for timbre, transient response, low distortion and overall sensitivity.

eso

[lgvenable]

the 12ft3 box is the size of small frig >> 47 x 31 x 23.5.

my wife would kill me if I wanted a bass horn like some of the extreme versions out there.

[robertbartsch]

I have a few (3) 18" 2245 sub bass systems and my earliest design has a downward firing woofer in a huge square not round cab.

With the rolling casters the 2245 frame is about 10 inches from the floor.

This has been operating for seveal years with no issues. It is a great performer with a 500 watt plate amp.

[baldrick]

Seems like I don't need custom cabinets for 2245h anymore, since I picked this one up today



In fact I was going to buy two B460 today, but one of the sellers screwed things up so I didn't get the second one today, but I will get it! It's not in the same condition as the one I got today, but B460 is very, very rare here so I will buy it anyway.

[hjames]

Seems like I don't need custom cabinets for 2245h anymore, since I picked this one up today



In fact I was going to buy two B460 today, but one of the sellers screwed things up so I didn't get the second one today, but I will get it! It's not in the same condition as the one I got today, but B460 is very, very rare here so I will buy it anyway.

Wow - Excellent success!

[baldrick]

Thanx I was quite shocked when I got it, the cabinet is near mint condition (The darker parts in the picture is just shadows in the picture) I bought it from the first owner and he has really taken good care of it since he bought it in 1989. Together with the B460 I also got the BX63

The other B460 I probably also will buy is not in the same conditon, it need to be restored and the 2245 needs recone, but these boxes are so rare here in Norway that I will probably buy it anyway.

[Valentin]

this is my pair

[baldrick]

And they looks as always awsome

I wish my second B460 was mirrored but unfortunately JBL didn't think of this even though the L250 was mirrored