Cabinet design for 2245H

[baldrick]

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

- 2 x B460 clone (http://i24.photobucket.com/albums/c7/ValentinR/DSC_0055.jpg)
- 2 x Altec 8184 clone (http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=37822&stc=1&d=1236413628)(simple box of 12ft3)
- 1 x Altec 8182 clone (http://avforum.no/forum/attachments/hoyttalere/47686d1237027710-nar-svs-blir-litt-smatt-p1000718-800x600-.jpg) (one box of 24ft3 with both drivers in)
- 2 x sonotubes:

http://avforum.no/gallery/files/1/9/2/2/9/DSC00633.JPG

http://avforum.no/gallery/files/1/9/2/2/9/2_778379.JPG

I would love a pair B460 clones but I'm not sure if I have the skills needed, and they are expensive if I should get them builit.

Is 2 woofers in one big box a bad solution compared to two smaller ones?

Any experince with 2245 or similiar in sonotubes? They are very popular in DIY woofers with i.e. SVS, SoundSplinter & TC Sound, but haven't seen many of them been used with "our woofers". Big advantages with these cabinets are that they are very easy to build and the weight of them

[LE15-Thumper]

You need to do some searches, all of your questions have been answered here at some point in time.

[baldrick]

If I found the answer via search, maybe I hadn't asked the question :bouncy:

[robertbartsch]

The design looks like a water heater.

[baldrick]

I totally agree about the look of it, when I think of cabinet design I was thinking about the sound, not the look :)

[grumpy]

worth a read:

http://www.passdiy.com/pdf/el-pipe-o.pdf

[spkrman57]

You will experience that the cone sag will eventually have the voice coil out of its required location in the gap!

Somewhere on this forum it has been discussed using drivers facing down using heavy cones. Do a search and read what has been written about it already!

Regards, Ron

[Doc Mark]

Hey, Friends,

Many years ago, when lived up in Minneapolis, MN, and I worked at Schaak Electronics, one of my co-workers was a German fellow, named Heinz. He invited me to his place, to hear his home-cobble speakers, and it turned out he had made them out of very large terra cotta pipes, similar to what has been shown in this tread. From what I can remember, I thought their bass range was very limited, almost like blowing across the open top of a bottle. He got Peerless components, from DLK, which was a Schaak House Brand, at the time, and so I knew that they "should" sound good. But, to me ear, it didn't. The bass seemed like it as a "one note Johnny", and was quite limited. Now, maybe Heinz didn't know beans about putting such a speaker together. I don't know.... But, that's the only such system I've ever heard, and I was not too impressed with it, to be honest. Take care, and God Bless!

Every Good Wish,
Doc

[16hz lover]

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

- 2 x B460 clone (http://i24.photobucket.com/albums/c7/ValentinR/DSC_0055.jpg)
- 2 x Altec 8184 clone (http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=37822&stc=1&d=1236413628)(simple box of 12ft3)
- 1 x Altec 8182 clone (http://avforum.no/forum/attachments/hoyttalere/47686d1237027710-nar-svs-blir-litt-smatt-p1000718-800x600-.jpg) (one box of 24ft3 with both drivers in)
- 2 x sonotubes:



Is 2 woofers in one big box a bad solution compared to two smaller ones?

Any experince with 2245 or similiar in sonotubes? They are very popular in DIY woofers with i.e. SVS, SoundSplinter & TC Sound, but haven't seen many of them been used with "our woofers". Big advantages with these cabinets are that they are very easy to build and the weight of them

The JBL 4642 is a fine example of (2) 18" 2241 drivers in a single box.

[baldrick]

What about an ELF system, any experince with 2245 in such a setup? Would 3ft3 be enough for each woofer or do they need more? (I do not have much experince with ELF and don't know how to calculate box for it)

The idea that came up is to run each 2245 in a 3-4ft3 sealed box, powered by a 2x1kw Crown amp and a BagEnd ELF-M box :)

[Loren42]

What about an ELF system, any experince with 2245 in such a setup? Would 3ft3 be enough for each woofer or do they need more? (I do not have much experince with ELF and don't know how to calculate box for it)

The idea that came up is to run each 2245 in a 3-4ft3 sealed box, powered by a 2x1kw Crown amp and a BagEnd ELF-M box :)

I did not model a 3 cuFt cabinet because it is way too small. I tried a sealed cabinet of 4 cuft and heavily packed with fill. The F3 for such a design is 63 Hz!

The curve rooloff is such that at 20 Hz you are 17 dB down from where it is at 100 Hz.

A vented cabinet of 12 to 14 cuft gives you something better (F3 of 40 Hz).

[baldrick]

I know a sealed box of that size normally is too little, but that's where the ELF do its thing :) But maybe I have to calculate an ELF box the same way as an sealed, and therefor need a bigger box even with ELF :dont-know

[Loren42]

I know a sealed box of that size normally is too little, but that's where the ELF do its thing :) But maybe I have to calculate an ELF box the same way as an sealed, and therefor need a bigger box even with ELF :dont-know

Does ELF = Extremely Low Frequency?

http://www.mdbq.net/2245.jpg

The violet curve is the 2245 in 4 cubic foot sealed cabinet.

The cyan colored curve is the 2245 in a vented enclosure of 14 cubic feet.

The basic rule of thumb (someone correct me if I am wrong) is to get deep bass you need a lot of volume behind the driver.

The - 3 dB point for the 14 cubic foot vented enclosure is 40 Hz.

The -3 dB point for the small sealed enclosure is about 65 Hz.

If I pump up the volume of the vented enclosure to 18 cubic feet, then I can get the -3 dB point down as low as 27 Hz.

[Loren42]

I know a sealed box of that size normally is too little, but that's where the ELF do its thing :) But maybe I have to calculate an ELF box the same way as an sealed, and therefor need a bigger box even with ELF :dont-know

You might want to look at these (http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm) 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.

[Joe Alesi]

You might want to look at these (http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm) 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.

Hello Loren and Baldrick,

I would have to agree with Loren's recommendation for these designs. I built a 2235 sub to the design in this paper with an active filter- Great sound (well done the boyz at JBL for publishing this). Nowdays the eq is easily achieved with many of the digital eq products around. I have a couple of 2245s that will eventually get the same treatment.

To this day I still remember the incredible slam of this sub, in part of the opening scene of Jurassic Park I, when they were using a shot gun cartridge to create a shock for measurement/underground scan for dinosaur bones. Check out that scene with a good sub- Many that I've tried since don't cut it as well.

Good luck with your project

Best
JA

[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 (http://i24.photobucket.com/albums/c7/ValentinR/DSC_0055.jpg)
- 2 x Altec 8184 clone (http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=37822&stc=1&d=1236413628)(simple box of 12ft3)
- 1 x Altec 8182 clone (http://avforum.no/forum/attachments/hoyttalere/47686d1237027710-nar-svs-blir-litt-smatt-p1000718-800x600-.jpg) (one box of 24ft3 with both drivers in)
- 2 x sonotubes:


http://avforum.no/forum/attachments/hoyttalere/47686d1237027710-nar-svs-blir-litt-smatt-p1000718-800x600-.jpg


:applaud:

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!:D

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

[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 (http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm) 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 :D , 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 :D , 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 :D

48448

In fact I was going to buy two B460 today, but one of the sellers screwed things up :banghead: 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 :D

48448

In fact I was going to buy two B460 today, but one of the sellers screwed things up :banghead: 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 :bouncy: 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 :applaud:

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