Cascade

[Mr. Widget]

Rob just posted a library link for the JBL Prima... I had not seen it in the library before so I did some snooping and saw that Don and others have been busy at it again... thanks!!!


So among other treasures I saw this brochure for the JBL Cascade.

http://www.lansingheritage.org/html/...88-cascade.htm

What the hell was that? JBL trying to be Infinity or something? I've never been much of a fan of dome line arrays, but who knows about these? I was pretty much over JBL by 1988, no longer needed the glass top speakers you know , so I missed a few models during those years.

Widget

[Don McRitchie]

The Cascade never made it into production. A prototype was built and it was displayed at the 1988 CES, where this brochure came from. According to GT, they never did get satisfactory performance out of it and it was scrapped.

Another speaker from that era that had a similar fate was the XPL250. This was a 250Ti using the 093 midrange dome. Performance of this system was thought to be exemplary, but changing markets resulted in cancellation of the project. GT has one of the prototypes to this day and considers it an excellent system.

[Tomas M]

More about PRIMA.......

[wsilva]

Is any information available about the XPL250 prototypes?
Such as the crossover modifications to accommodate the 093 mids.
Would be interesting to try out on the 250ti's.

"Another speaker from that era that had a similar fate was the XPL250. This was a 250Ti using the 093 midrange dome. Performance of this system was thought to be exemplary, but changing markets resulted in cancellation of the project. GT has one of the prototypes to this day and considers it an excellent system."

[4313B]

Originally posted by wsilva
Is any information available about the XPL250 prototypes?

They were totally custom and were meant to be biamped from the start so there is no LF network. The 093Ti (and 046Ti) pretty much demand a stepped baffle such as found in the XPL series. The angle of the sloped baffle of the L250/250Ti was sufficient to place the 093Ti on that baffle plane. A 3-inch VC 8-inch transducer (112H/2108H) was used in place of the 2-inch VC 108H (2118H with aquaplas) used in the L250 and 250Ti. A special UHF network was also used. Additional information might be forthcoming providing the documents can be found.

I'm currently working on a hybrid design like this using the LE14H-1, 112H, 093Ti and 046Ti along with the stepped baffle instead of the sloped baffle. I've decided to make the system modular so I can swap out the LE14H-1 subs with 1500SUB subs, etc., as desired.

[4313B]

Originally posted by wsilva
Is any information available about the XPL250 prototypes?

Here is a photo of the prototype courtesy of JBL.
I'll try to post the network schematic tonight.

[Robh3606]

Nice!!!

So that's the mystery speaker! Is that an 046ti up top??? Network would be great!

Rob

[Don C]

The tweeter looks like an 035Tia to me.

[4313B]

Network

[Robh3606]

Thanks!!! Now if I try to build these?? My wife will get the comminment papers for sure

Rob

[Don C]

Where would you get an 036Ti tweeter? Or an LE-109 woofer?

[Robh3606]

"Where would you get an 036Ti tweeter? Or an LE-109 woofer?"

Don't know! If I waited to get all the right drivers to build my XPL 200's I would have packed it in for sure. Take the closest drivers and give it a whirl. Figure an 035ti or 046ti and a 112H. The 109 designation could be because it has a black frame. Am I serious about building it?? Probably not. But if the right things fall into place like I can get a pair of LE-14H's and 112'S on the cheap off E-Bay Yeah I would try. Why not?? If it doesn't work what's the worst that can happen??? With that driver set how bad could it be???? Half the fun is building it anyway so no loss.


Rob

[wsilva]

Giskard
Excellent job on digging up the picture and crossover info. !!!!!
I really might consider trying this out, always thought it would be neat to run the 093 mid in my L250's.
Thanks again for the info.

[pasadena]

Giskard,

If one would buy a pair of 250Ti's and modified them to become like the XPL250 prototypes, could they be hooked up with the DX-1's? If so, what modifications to the LF and HF cards would be required? Would the DX-1's be useful in this scenario? I would be talking about using a pair of DX-1's in this case.

The thought of converting a pair of 250TI's into XPL250's seems a rather interesting project, especially if DX-1's can be used.

Cheers
Pasadena

[4313B]

"could they be hooked up with the DX-1's?"

Definitely.

"If so, what modifications to the LF and HF cards would be required?"

Changing out some resistors and capacitors.