D-130 and Paragon?

[Harvey Gerst]

Some of the original Paragons were shipped with the 150-4C, but when the LE15 came out, we switched to that. The Metragon was not as critical as to components.

[Don McRitchie]

Harvey

Do you know if the LE15 was ever used in the Hartsfield? Hal Cox swears that it was, but I have never seen this mentioned in any of the JBL literature from this era. I never did understand why they put the LE15 in the Paragon since that driver never seemed to be meant for horn loading.

[Harvey Gerst]

Originally posted by Don McRitchie
Harvey

Do you know if the LE15 was ever used in the Hartsfield? Hal Cox swears that it was, but I have never seen this mentioned in any of the JBL literature from this era. I never did understand why they put the LE15 in the Paragon since that driver never seemed to be meant for horn loading.

First of all, the Paragon wasn't much of a horn, so the LE15 was an improvement. I remember vaguely that we did some experimenting with an LE15 after the Hartsfield was redesigned to make it easier to build and load. I don't remember if it was ever official.

[jcdahl]

I just bought a pair of JBL 1500 Subwoofers from Parts Express
http://www.partsexpress.com/pe/pshow...021904-299-750

I may try them in one of my Paragons. I May have to use Bi-amplification to get the proper balance.

[Maron Horonzakz]

JICDAHL......How would you mount them in the paragon? 1500 are front mounted woofers. A thick ring would need to be installed to keep rubber surround from interfearing. But its a great idea I hope you can do it.

[Rafael]

I tried the D 130´s, the 2226´s and finally the 2235´s. Depending on the room maybe you can get a little improvement- or should I say: it just sounded different. I prefer the 2235´s in a reflex design over the LE 15´s but for the paragon the LE 15´s are perhaps the best choice. I think it was no problem for JBL to install another woofer if they thought it was a better choice.

Rafael

[4313B]

" I think it was no problem for JBL to install another woofer if they thought it was a better choice."

Good point. JBL has been cranking these things out a very long time and the most recent driver I know of was the LE15H and I think that's after the 2235H had been out over ten years. Plenty of "swapportunity" time there

[rpstephen]

The technical data sheet on the paragon lists the 2235 as a replacement for the le15a " but only as a last resort". One of the reasons may be that the crossover is not optimized for the 2235.
I intend to try my 2234s in the paragon just for curiosity. I fully intend to replace the 075 diaphragms with the 077 at some point.

[4313B]

"One of the reasons may be that the crossover is not optimized for the 2235."

Well, that's a given. Completely different impedance curves.

[rpstephen]

The 2235 might be better than the LE-15a in the paragon with a custom crossover. JBL was probably unwilling to put the needed resources into such a low volume product. The LX-5 crossover was the same as in the S-7 & S-8 systems indicating no special customizing was done for the paragon originally.

[4313B]

Sure, you could run a curve on the two LE15's you have and then a curve on the two 223x's you have and adjust the crossover values accordingly.

[rpstephen]

would that involve measuring the impedence vs frequency in the enclosure, and then using a program to model the network with this data? Then we would probably have to do some frquency response measurements. This would be a nice assignment for someone with the expertise & tools.

[Rafael]

Due to different characteristics between these drivers, of course it is necessary to use different crossovers. When using passive x-overs this is a hard piece of work and when it works with a certain driver, you probably can´t remember the sound with the former driver. You can use an active x-over and many of these problems are gone. But as I said in an older reply, don´t modify the paragon too much. We tried all kinds of x-overs: active, passive, 6dB/oct, 18dB/oct, tried slightly changing and spreading the x-over points and shure, you can get a different sound character. When I tried a digital network/EQ the paragon sounded a bit like a modern high-end speaker and I went back to the original x-overs immediately.