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audiomagnate
11-17-2016, 05:59 AM
I'm going to try making a half-doughnut-like (how's that for a new word?) horn extension for my 200b's (and adding a real tweeter) to get them sounding closer to my 300's (and adding a 2405 of course with a new crossover). Has anyone tried this before?

gibber
11-17-2016, 10:58 AM
I'm going to try making a half-doughnut-like (how's that for a new word?) horn extension for my 200b's (and adding a real tweeter) to get them sounding closer to my 300's (and adding a 2405 of course with a new crossover). Has anyone tried this before?

Wonder what JMLC would have thought about this, but great project and surely better than just putting the lens to the side as many seem to prefer. Haven't tried it myself but wonder if changing to a (behind-baffle) mounted HL87 wouldn't be a better option if you want to stay all-JBL and add a super-wide dispersion tweeter in the same modification step ?

Just a thought from this constant directivity fanboi
Related post here http://www.audioheritage.org/vbulletin/showthread.php?20973-Adding-2405H-to-my-custom-JBL-system&p=209907&viewfull=1#post209907

br, Ralph

ivica
11-18-2016, 11:11 AM
I'm going to try making a half-doughnut-like (how's that for a new word?) horn extension for my 200b's (and adding a real tweeter) to get them sounding closer to my 300's (and adding a 2405 of course with a new crossover). Has anyone tried this before?

Hi,

May be this would be useful:

http://www.audioheritage.org/vbulletin/showthread.php?3549-HELP!-2421B-Diaphrams-for-LE85&p=32394&viewfull=1#post32394

regards
ivica

toddalin
11-19-2016, 11:34 AM
I had actually though about doing this at one time. Certainly you could put a "half-round" circle on the face of the speaker to encompass the horn opening. But the long horn and short horn share the same mouth dimensions, so your flare would end up a bit wider than that of the long horn. And of course, if you had a half round sticking out on the baffle board, you have no way to securely attach the slant plate, if you still wanted to use one.

Rather than use a half round, you may want to look into buying a port flare and modifing that. The mouth of the horn is ~4", as is a speaker port. Just mill the "flare" away from the port section and use that. Or, get an existing horn flare and mill it to where it will mount to your horn mouth.

In fact, I modified some port flares just yesterday on my mill to adapt them to some existing JBL L200 cabinets to lengthen the ports by 2-1/2" to retune the cabinets for the 2235s. But, I recognize that not everyone has a mill in their garage.

Earl K
11-19-2016, 03:50 PM
I'd adopt the philosophy ( that once you put in a tweeter ) you should use a compression driver with a bigger diaphragm ( either 3" or 4" ).

These larger diaphragmed drivers will give better mid-range authority .

You can buy ( aftermarket ) 1.5" entrance to 2" exit adapters that would fit a 2311 throat quite nicely.

Personally ( now that JBL diaphragm prices have dropped to reasonable $$) I would use new D16R2451SL diaphragms in a pair of used 2451 ( 1.5" exit ) bodies.

Now having said all that, & since I much prefer radial style horns, I would likely remove ( & save the current baffle ) and then simply start again using the 2451(SL) coupled to the mentioned adapter, that feeds into a horn like the Emilar EH500 ( with that 077 residing above it ).

:)

hjames
11-20-2016, 10:12 AM
I'm going to try making a half-doughnut-like (how's that for a new word?) horn extension for my 200b's (and adding a real tweeter) to get them sounding closer to my 300's (and adding a 2405 of course with a new crossover). Has anyone tried this before?

You know, some time after I bumped my L200s to 3-ways with 2405 slot drivers and the Giskard crossover design, I tried a JBL smith horn and 2425 driver on top of my L200s - I disliked the look of the grey horn but liked the sound so much I had a walnut smith horn made and ran that with the 2425 drivers - but when I upped them to 2445 (larger) compression drivers, it was superb.
I just bypassed/ignored the internal L200 mid-horns.

Ask tinpan how it sounds ... he bought my L200s ...

tinpan
11-20-2016, 01:57 PM
Ha that's funny, I'm talking about the same thing on the next thread. Do what Heather did, extension and the smith horn, I have pics of it on my thread. You could also add the tweeter like Ward's Web did. I'll have to find a photo of it
disregard the other one.

74627
Here's Ward Webs

tinpan
11-20-2016, 02:02 PM
Here's the better one of Heather's
74628

tinpan
11-20-2016, 02:18 PM
Here's how they look now

7462974630

Too bad you don't live near DC. I'm thinking about selling these, we could have worked out a swap since these are already set up

BMWCCA
11-21-2016, 02:52 PM
Too bad you don't live near DC. I'm thinking about selling these, we could have worked out a swap since these are already set upThinking about it? ;)

Don't be shy: http://fredericksburg.craigslist.org/ele/5845264941.html

tinpan
11-22-2016, 06:07 AM
Thinking about it? ;)

Yeah, see the price, lol? I put these out there and a pair of 4333's and my Altec VOTTs to see if there was any interest.

I've got a Lowther corner horn I want to try and I want to build another 2 way system to use another pair of horns I have kicking around.

I think what'll end up happening is one or two of these will end up in the garage.