Best substitute for 150-4c in horn loaded enclosure?

[Harkness]

Specifically the C40 Harkness exponential horn with 500 hz crossover.

Guessing maybe the 2220B might be it, but very grateful for anyone’s experience in this type of situation.

Cheers!

[Robh3606]

I think either a K or E145 would be the closest function wise.

Rob:)

[Harkness]

I think either a K or E145 would be the closest function wise.

Rob:)
Thanks very much for the suggestion. I am having some trouble finding specs on the E145, do you know what it is rated for in efficiency? I am not biamping so I have to try and have similar output as my N400 is already at the minimum setting for the horn. Also did some reading and it looks like the pro version might be a good fit, with perhaps flatter midrange response from 100-600. Can't find specs on that driver either, but still looking..

Looking into it more, it seems the 2220 is most similar to the D130, which probably means the low bass would be lacking even with the horn loading.. I am pretty happy with the low bass I get with the 150s so I don't want to sacrifice that range.

[edgewound]

Thanks very much for the suggestion. I am having some trouble finding specs on the E145, do you know what it is rated for in efficiency? I am not biamping so I have to try and have similar output as my N400 is already at the minimum setting for the horn. Also did some reading and it looks like the pro version might be a good fit, with perhaps flatter midrange response from 100-600. Can't find specs on that driver either, but still looking..

Looking into it more, it seems the 2220 is most similar to the D130, which probably means the low bass would be lacking even with the horn loading.. I am pretty happy with the low bass I get with the 150s so I don't want to sacrifice that range.

The E145 is the direct, most modern descendant of the
150-4.

[Riley Casey]

A 500 hz crossover would make life awfully hard on that 1" compression driver even if the potato masher horn loaded the driver at that low a crossover.

[Robh3606]

The E-145's are 98Db 1 meter. I use them in my HT mains.

http://www.audioheritage.org/vbulletin/showthread.php?10655-E145-8-150-4H



http://www.lansingheritage.org/images/jbl/catalogs/1980-pro/page15.jpg


Rob:)

[Harkness]

A 500 hz crossover would make life awfully hard on that 1" compression driver even if the potato masher horn loaded the driver at that low a crossover.

You'd be correct, except I have possibly the only C40 system that was factory ordered with Hartsfield drivers and crossover. They came to me as a mirror stereo pair with the 150s, N400 and 375s with H5041 bent horns sitting in the scoop.

I have been running the 375s with 2397s for 20 years and although the 2397 spec calls for a 800 hz crossover they do say they can go down to 500 "with some loss of pattern control". They still sound great to me and sine wave sweeps show they don't lack coverage. The power levels I run in my living room don't present any danger to the 375s, that's for sure :)

I am interested in trying a different LF driver in place of the 150s or at least having a substitute that can work similarly if I take them out. The tough part of the equation seems to be matching the effeciency as the 150 is so efficient.

I am interested in possibly getting the magnets regaussed. Before they came to me they were sometimes subjected to high power and I think it's possible they do not match magnetically anymore. Fortunately the cones are fine.

[Harkness]

The E-145's are 98Db 1 meter. I use them in my HT mains.

http://www.audioheritage.org/vbulletin/showthread.php?10655-E145-8-150-4H



http://www.lansingheritage.org/images/jbl/catalogs/1980-pro/page15.jpg


Rob:)

Thanks! That's most helpful :)