S'pose there was a $125 200-Hz JBL Horn

[Zilch]

A PT waveguide, actually:

[subwoof]

I snagged 2 of those off ebay and I also have the drivers and 8's BUT I don't have the nice aluminum condoms for the 8's...

Any unique engineering inside them that precludes DIY??

sub

[Zilch]

All the parts are relatively inexpensive, including the phase plugs, a surprise. It's the drivers that are expensive.

DIYers will have to check whether the cones of alternative drivers line up with the phase plug. The compliance on 2250s is VERY stiff, and it's a tiny half-roll cloth surround. 2118s come to mind. I can check those.

The other issue is getting an adequate seal to the driver at the rear of the back can. JBL doesn't list a gasket for that for 2250, even, so, assuming it's supposed to be tightly sealed, I used foam gasket tape. The front of the can seals to the driver with the traditional "Noodle."

Another option is not to use them in compression mode, rather, merely as waveguides. The throat is 4" diameter, and 104H(-x) is a perfect fit, for example. I don't know how low various LE5 derivatives will play on waveguides. Edgar use them on Tractrix. This might work, too.... :dont-know

The HF can be 243x, 1.5" 245x, or, as I have shown, with JBL throat adapter, thread-on 1".

If I was one of those bass horn enthusiasts, I'd sure be lookin' real hard at these.

These are two-ways with LF augmentation, right Sub?

[They'll play 132 dB continuous.... :p ]

[subwoof]

Back in 1980 I started making 4530 clones for the band market and made hundreds of them. A few times I made custom 2-3 ways with extended tops for theaters, clubs and other semi-permanent venues that wanted high output plug-n-play.

Of course designing the wood flares and making comp chambers was fun along with the complete lack of flat front horns. We had to get pretty creative.

Here is a quickie cabinet profile sketch of that waveguide if it sat on top of a jbl scoop clone. Using a foam woofer wouldn't help the LF so sticking with the higher output, tight suspension cones will actually work better. I *think* the Nd 15 is too deep? I know the auto ones would be but unsure about the SRX model(s)

With a sharp rolloff at 30hz, this would re-arrange caulking and dryclean your drapes. Size would be 24 X 24 X appox 60

sub

[Robh3606]

Another option is not to use them in compression mode, rather, merely as waveguides. The throat is 4" diameter, and 104H(-x) is a perfect fit, for example. I don't know how low various LE5 derivatives will play on waveguides. Edgar use them on Tractrix. This might work, too.... :dont-know

Hello Zilch

He used Le5-2's. The rising response is what you want when you horn load them. If I remember right he had them play into a throat with a rectangular cut out and a backchamber. It was a rectangular tractrix horn. Unfortunately you can't just drop them on the waveguide. You would have to come up with a throat assembly to load the waveguide and a backchamber. There are a couple of his DIY articles about. There is one for that horn somewhere. I think it was in Speaker Builder?? I have it at home.

2118?? I would think more towards am M 209-8. That's hornloaded in the 4315??? The one's Mike Baker had at the MAF. Similar set-up this seems to be the next generation.

Rob:)

[jackgiff]

A PT waveguide, actually:

I would want some, yessir!!!

And some LE14H-3's to put under them.

[Zilch]

If they're made like the 18s, 15" Nds could poke through, looks like. The pressures aren't huge, so a resiliant seal of slits would probably do well enough. Pipe the vent out the back, if necessary:

[Zilch]

Edgar Tractrix. They sold for $261, more than a pair of these PTs. Compression, but no phase plug. Bolting a 2118 with a sealed back chamber on the PT appears analogous. That I can try. I haven't measured anything for a baseline yet....

[toddalin]

Edgar Tractrix. They sold for $261, more than a pair of these PTs. Compression, but no phase plug. Bolting a 2118 with a sealed back chamber on the PT appears analogous. That I can try. I haven't measured anything for a baseline yet....

So you got hold of them! Cool!

[Zilch]

So you got hold of them! Cool!Nope, somebody else bought 'em.

Rob says there's an article in Speaker Builder, which maybe details how to make them.... :dont-know

[Zilch]

2118 seems to be a "Go" with the phase plug, mechanically. Add the larger diameter (~3.5") 2250 dome, remove the tire and make a 1/4" plywood adapter ring to seal the rear to the stock back can with foam gasket tape.

[Gonna get yelled at, I jus' KNOW it.... :p ]

What these have is best characterized as "SMACK!"

[toddalin]

If they're made like the 18s, 15" Nds could poke through, looks like. The pressures aren't huge, so a resiliant seal of slits would probably do well enough. Pipe the vent out the back, if necessary:

Not to hijack the thread, but this just looks so wrong..., like someone forgot to put a magnet on it..., sure it's not a passive radiator? ;)

Also, looking at the pic it occured to me that maybe some of the difference between the Alnico "sound" and the ferrite "sound" is that the Alnico magnets are on the inside of the V/C (away from the windings) whereas the ferrite magnets are on the outside (toward the windings), and that's just account for something. I'm assuming that the Nd magnets are also inside the coil like the Alnico magnets?

http://audioheritage.org/vbulletin/attachment.php?attachmentid=30534&stc=1&d=1200689874

[Zilch]

It's quite amazing, Todd.

I can literally pick that 18" driver up with one finger.

For those who haven't read it, here's the Tech Note on the CMCD (Cone Midrange Compression Driver) technology I've shown above:

http://www.jblpro.com/ae/pdf/CMCD%20TechNote.pdf

[pos]

Is it the PT-K95MH ?
It sure looks appealing! Do you think it could be suitable for a studio monitor?

[Zilch]

Yes.

And from what I'm hearing, yes.

I don't have measurements yet.

[18" square.... ;) ]

[JoMoCo]

A PT waveguide, actually:

Zilch, Could there possibly be a "3wave" in the future?...:blink:

I noticed the PT double looks (wider HF guide) than the picture in the waveguide (TN V1 N31)

Which products did your double PT's come from originally?

Cheers:cheers:

[Eaulive]

It's quite amazing, Todd.

I can literally pick that 18" driver up with one finger.

For those who haven't read it, here's the Tech Note on the CMCD (Cone Midrange Compression Driver) technology I've shown above:

http://www.jblpro.com/ae/pdf/CMCD%20TechNote.pdf

HELP! The link does not work and I'm interested, anybody have the new link or a backup of the technote?

[Eaulive]

A PT waveguide, actually:

This waveguide looks an awful lot like the SRX738. :D

---------------------------------edit--------------------

Or better, like the 90x50 waveguide of the AE series. http://www.jblpro.com/catalog/general/Product.aspx?PId=150&MId=2

[JoMoCo]

HELP! The link does not work and I'm interested, anybody have the new link or a backup of the technote?

On the JBL site that the old link takes you to, just do a "search" for CMCD tech note...

[Eaulive]

On the JBL site that the old link takes you to, just do a "search" for CMCD tech note...

Did already, 0 results.

[Eaulive]

Apparently the system has changed... new URL: http://www.jblpro.com/catalog/support/getfile.aspx?docid=201&doctype=3

[JoMoCo]

Did already, 0 results.

"CMCD Technology" in the search engine worked...but several other tags did not:banghead:

Don'cha just love some search engines:barf:

If at first you don't succeed...try...try again:bouncy:

http://www.jblpro.com/catalog/support/getfile.aspx?docid=201&doctype=3

[Eaulive]

If they're made like the 18s, 15" Nds could poke through, looks like. The pressures aren't huge, so a resiliant seal of slits would probably do well enough. Pipe the vent out the back, if necessary:

I don't have one on hand so I can't measure, but I'm looking for the depth of the 15" version, the 2265, like the one used in the SRX series and the newest AE.
I'm wondering about the mounting depth, that is from the inside of the flange to the back of the frame (I was tempted to say "backplate" :))

I know they're deeper than the standard drivers, and they're also ugly, but nobody will see ;)

[badman]

Seems to me that the thing would be unlikely to actually control directivity at 200Hz. Cool toy tho. Are they $125 each or the pair?

[JoMoCo]

Seems to me that the thing would be unlikely to actually control directivity at 200Hz. Cool toy tho. Are they $125 each or the pair?

I don't know if the crossover actually would use them that low... :blink:

I just noticed some of the 2250h neo mid drivers assemblies :uhmmmm:on ebay for approx $150ea...

[JoMoCo]

Seems to me that the thing would be unlikely to actually control directivity at 200Hz. Cool toy tho. Are they $125 each or the pair?

According to the 10/1/09 Horn Parts Listing the PT-K95MH looks to be part # 350412-001 ref AM6200/95 which is the 1.5" HF with the 8" CMCD mid driver @ $158. ea I would imagine...:blink:

The spec sheet may be of interest...:hmm:

http://www.jblpro.com/catalog/support/getfile.aspx?docid=653&doctype=3

[Zilch]

350 Hz:

http://www.jblproservice.com/pdf/AE%20Series/AM4200,95-WH.pdf

Two-piece, 480 Hz:

http://www.jblproservice.com/pdf/PRX%20Series/PRX535.pdf

That's a closed-back Eminence 6.5" midwoofer there, OEM'd by JBL, and a very familiar waveguide for the VHF.... ;)

[JoMoCo]

Zilch, how did the two wave you started this thread with sound? Any measuring on it by chance?
That "Throat Adapter" 339308-001 is curious. It does not show up in the Horn Parts Listing that is all I have. It looks to be a 1" screw-on driver to 1.5 bolt on horn transition....:dancin::banana::dancin::banana:

I wonder if it works and what it cost...:hmm:

same $158. 1.5" waveguide just with the "Throat Adapter".

[Zilch]

No measurements worthy of posting, alas.

Yeah, a mighty nice throat adapter keyed for use with any of the 1.5" PT waveguides, with contouring inside, what Geddes would call a "Diffraction Device." ;)

Ten or 20 bucks, as I recall.

Verify part number on the Tech Sheet and inquire.... :yes:

[badman]

http://www.jblproservice.com/pdf/PRX%20Series/PRX535.pdf

Any idea of cost on the mid horn? Looks like it's about 8"x14" ?

[rlsound]

Am I reading that paper correct? You can load an 8" CMCD driver onto a 2393 horn?

[Zilch]

http://www.jblproservice.com/pdf/PRX%20Series/PRX535.pdf

Any idea of cost on the mid horn? Looks like it's about 8"x14" ?Call Pro Parts and ask; $15, as I recall. The Eminence mid driver is cheap, too.

The combo's only good for one octave or a little more, but that's all that's needed in many apps.... :yes:

[badman]

Call Pro Parts and ask; $15, as I recall. The Eminence mid driver is cheap, too.

The combo's only good for one octave or a little more, but that's all that's needed in many apps.... :yes:

W00

Okay. I have some 98dB mids that might just match up nice :}

[JoMoCo]

Edgar Tractrix. They sold for $261, more than a pair of these PTs. Compression, but no phase plug. Bolting a 2118 with a sealed back chamber on the PT appears analogous. That I can try. I haven't measured anything for a baseline yet....

Zilch, did these turn out to be promising or worth considering?....:hmm:

[Zilch]

The Edgars I did not purchase; they were just an illustration of the principle here.

The others I have tried only on a preliminary basis....

[JoMoCo]

I have not yet found this part on the horn list... maybe there is a separate CMCD or other part list?. or Maybe they will be updating the Horn Parts List in the future.....:hmm:

I also can't tell if this is a closed back can assembly from the pdf or if it is open to the back of the 6.5" driver....:blink:



http://www.jblproservice.com/pdf/PRX%20Series/PRX535.pdf

Any idea of cost on the mid horn? Looks like it's about 8"x14" ?

[Zilch]

You call them up and order by part number.

The driver is a closed-back Eminence.

[cosmos]

2118 seems to be a "Go" with the phase plug, mechanically. Add the larger diameter (~3.5") 2250 dome, remove the tire and make a 1/4" plywood adapter ring to seal the rear to the stock back can with foam gasket tape.

[Gonna get yelled at, I jus' KNOW it.... :p ]

What these have is best characterized as "SMACK!"

Would something like a Radian 8" 508/2B Coaxial driver be appropriate in a 200Hz CMCD waveguide? I have never heard these, but I have read great things about them. They aren't exactly cheap, but they'd cover everything from 150 to 20K Hz.

[JoMoCo]

You call them up and order by part number.

The driver is a closed-back Eminence.

So after searching you are thinking that the Eminence "closed back" is sourced for this mid wave? No additional gaskets shown or needed...:blink:

I will give JBL a ring next week, but I do have a pair of 2118 collecting dust also and I do appreciate that IPA hoppiness ....:hmm:...:cheers:

[JoMoCo]

Would something like a Radian 8" 508/2B Coaxial driver be appropriate in a 200Hz CMCD waveguide? I have never heard these, but I have read great things about them. They aren't exactly cheap, but they'd cover everything from 150 to 20K Hz.

You may want to ask that over at the modern coaxial drivers thread...:hmm: http://www.audiokarma.org/forums/showthread.php?t=276365

Speaking of a large (er) waveguide...(of particular note check out the phasing plug on the tech sheet)...here is a pic of the JBL 12" unit....:blink:

http://www.jblproservice.com/pdf/PD_52000_Series/PD5212,95-Wh.pdf

[rlsound]

That 12" Waveguide is big bucks, something like $970. I looked into it last year.

[spkrman57]

Since Northridge shut down manufacturing I was wondering if the waveguide/horns can still be had!

Regards, Ron

[pos]

HELP! The link does not work and I'm interested, anybody have the new link or a backup of the technote?
here it is:

[cosmos]

Any update on this CMCD waveguide? Has anyone seriously tried and listened to them yet?

[JoMoCo]

I heard of someone over on one of the HT forums using the QSL combo high/mid unit, which is very reasonably priced comparitively to JBL ....:blink:

From the anuls of history...I noticed that the Jensen TR-10 Tri-ette used a closed back mid driver between a horn HF and a 12" Flexair surround alnico (on the earlier units) LF woofer....