JBL 2344a modification for a 2 way - diyAudio
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Old 8th March 2008, 12:55 PM   #1
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Default JBL 2344a modification for a 2 way

In earlier posts, I was looking for advice on using the TAD 1201H driver as a mid bass, for a 4 way active design. We have just started building the cabinets, using 2 layers of Baltic Birch. I hope to post some pictures later of that progress.

While playing around with the JBL 2344a horns for this project, we have been thinking of an idea to build a modern version of the JBL 4430 or 4425, utilizing (2) JBL 2206 per side. One would be choked to cut off some mid bass information, but both 12" would share the bass duties.

This would use the JBL 2344a. We are wondering if anyone has looked into, or experimented with modifying the JBL 2344a horns to utilize a compression driver larger than 1". (Without using throat adapters) Also, has anyone considered how to remanufacture these? Would there be patent issues?

Thanks!
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Old 8th March 2008, 02:03 PM   #2
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Hello homebuilder

"JBL 2344a horns to utilize a compression driver larger than 1". (Without using throat adapters) Also, has anyone considered how to remanufacture these? Would there be patent issues?"


We have discussed it a few times over on Lansing Heritage. You can't simply modify them, you would have to redesign the horn. It is not a simple design. There are a couple of clones that have larger throats but the don't measure as well up top especially off axis which is the whole point of the design. When you open up the throat you open up the difraction slot. The spacing in the slot determines your upper limit for angle coverage in that horn. The wider opening lowers this frequency.

Why do you want to use a larger driver?? You could cross these over at about 1.2-1.5k to the 2206's. A 1" driver should be just fine crossed that high.

You are not going to get any extended bass response using 2206's. If you want to go with a 2 1/2 way using the 2344 you would be better off jusy cloning a 4435. If you want extended bass just add a sub and don't use the second 2206.

Rob
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Old 9th March 2008, 11:03 PM   #3
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Default JBL 2344a mod

Robh:

Thanks for your comments. I try to read the Lansing site too. It is full of great information.

I have read some of the tests of the clones, and they don't stack up very well. I kind of assumed someone had looked at the 2344a before. They have really started to go up in price (used) lately.

Our thought regarding the (2) 2206's is this: in our main projects, my friend and I are both building with 2242, 2344a, 2404. To round out the 4 way, his is a 2206 for the mid bass, and mine is the TAD 1201H. These end up being really large, really heavy boxes, and have to be built separately so you can move them. The thought (for a different project) was to get a bit more extension and output with the extra 2206, for a speaker that could be built in a much, much smaller cabinet. The 2206 only needs a bit over 1 cf. (The TAD 1201H is the same) Although I have a large room, I have moved numerous times for career reasons, and lugging around a speaker the size of the 4435 is tiresome. Or, several boxes that are large and heavy.

We hoped to keep the crossover a bit lower than you suggest, and wondered if a larger compression driver would help out on the top end too.

Comments?
Thanks!
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Old 15th October 2012, 01:50 AM   #4
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You built these 4 years ago BUT JBL distributed plans as part of their "UB" (U Build It) designs that were tuned for 2x2206H with a 2380A/2445J and a 2404H. The plans are intended to be a DIY version of the SR4735 and the UB series were intended for the European market because shipping actual SR4735's was not very economical.

The woofers were side by each, the 2380A was centered above, the 2404H was on either side of the horn and a circular port on the other... I don't remember if the plans showed the length of the tube, if there was one or what diameter it was.

That 2206 version of 4435's is 100% the match to those official JBL plans... Sorry for only registering today

I need plans and info about 4435 cabs... Anyone got that?
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Old 15th October 2012, 02:42 AM   #5
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www.pispeakers.com/AES_v31_n6_p408.pdf

Has some information.
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Old 15th October 2012, 04:06 AM   #6
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hmmm............

With the 2206, you can cross it around 1.2khz (you could push compression driver harder than crossing at the 2344a's standard 800hz crossover point).

Or you can get an adapter so you can put a larger compression driver on that horn.

The 2206 (ouch, that ain't cheap) can take bunches of power and it's clean (distortion rings, etc). BUT it needs serious power to overcome the stiff suspension, so at low to medium volumes it sounds constipated at less than 20 watts (I had the jbl an-2222). With the 2206's Fs=52hz and qts .312, your F3 ported would be around 70hz (yuck) requiring a subwoofer for all but the small rooms.

Norman
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Old 15th October 2012, 06:41 AM   #7
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I still have a single prototype enclosure using one 2206 togehter with a 2344 and they go well together IMO. I can have a lok at the HF dirver used (definitely not a TAD) When time allows I will build two of these in nice enclosures one fine day.

Waht I can say from, listening to it in mono is that it is very smooth sounding and the drivers go well together. At around 1200 Hz they have almost matching polar patterns.

I used a Vb larger than an optimal B4 tuning and the tuning was around 40 Hz. I.e. it needed some low-end EQ-ing.

I once posted a picture of it on this forum but I will have to search for it.

Regards

Charles
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Old 15th October 2012, 08:35 AM   #8
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Thanks Puppet for the link and Norman Bates for your knowledgeable assessment of any cab loaded with 2206's... The SR4732 and the official JBL DIY plans for another version were both intended to be used with subs and at high power; they were 1200 rms systems.

I can't remember off hand if JBL ever manufactured a professional 12" speaker in the 2000 or 2200 series that was foam surrounded... I have a feeling it would be a better reference speaker that way but it would still require a sub.

The SR4732 was intended to be used for sound enforcement and absolutely not for living room enjoyment with a pipe, Wall Street Journal and a leather wing back chair.

I have a feeling that the fellow who started this string ended up disappointed with his results unless he was intending to dj a block party with subs and a rack full of 1200 watt amps.

I still need plans for 4435's though if anyone has them.
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Old 15th October 2012, 09:02 AM   #9
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I could help with 4430 plans but not with its larger brother unfortunately.

Regards

Charles
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Old 15th October 2012, 09:23 AM   #10
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Thanks Phase_Accurate, I would appreciate having those plans stored away too because you never know.
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