Horn recommendation for GPA 390 Drivers

[Sootshe]

Looking to upgrade the mid range of my modded Klipsch La Scala's with some Great Plains 390 drivers.
They currently use the standard Klipsch K55's, but mounted to a 1" timber tractrix horn. Wondering what the best altenative horn would be.

So far I have a short list of Altec 1003's & Altec 311-60/90's. Liked the look of the Audio Engineering Leagues mod....here....http://home.comcast.net/~wooferboy/Page_5.html

I'll throw a red herring in here to see what you think of a 1.4" timber tractrix or alternatively an adaptor from 1.4" to 1" & fit to my current horn - ALK (Martinelli) 1" throat timber tractrix.

Crossover point will be standard Klipsch 400Hz with 6db slope on the bass, 12 db slope on the mid & 18db on the top end. (ALK universal).

Thanks,
John

[Tom Brennan]

If you run a 1.4" driver into 1" horn you'll cause dips and peaks and bugger things up. The EV PA Bible (which is available on the EV site) explains.

[Sootshe]

If you run a 1.4" driver into 1" horn you'll cause dips and peaks and bugger things up. The EV PA Bible (which is available on the EV site) explains.

Thanks Tom,
I pretty much figured that....just needed someone to confirm.

The other forum has come up with a good option. That is to run 2 x 511's with the 902 drivers & this will allow them to run down to 350 Hz. Tech. explanation was given, but way over my heard. Would be worth trying though.
Cheers,
John

[Altec Best]

Tech. explanation was given, but way over my head.

You wouldn't be talking about GM's post would'ya, He's the man !! It helps to have someone help interpret his explanations sometimes.I once told him GM could you please try to explain as simple as possible.Because I said I get lost real quick in some of your explanations.He told me don't feel bad I get lost in some of my explanations too.:rootn_tootn::rotfl:But he gives fantastic advice and has been helping me out quite abit behind the scenes. :bouncy:

BTW You don't want to run a 1.4" driver into a 1" horn as you will put undue stress on the diaphram from back pressure back into the diaphram.You will be blowing diaphrams much more frequently.

[Sootshe]

You wouldn't be talking about GM's post would'ya, He's the man !! It helps to have someone help interpret his explanations sometimes.I once told him GM could you please try to explain as simple as possible.Because I said I get lost real quick in some of your explanations.He told me don't feel bad I get lost in some of my explanations too.:rootn_tootn::rotfl:But he gives fantastic advice and has been helping me out quite abit behind the scenes. :bouncy:

BTW You don't want to run a 1.4" driver into a 1" horn as you will put undue stress on the diaphram from back pressure back into the diaphram.You will be blowing diaphrams much more frequently.

Yes, GM sure is the man......some of his explanations are completely beyond me....sure is great to have that fountain of knowledge available & shared so freely.

Been following your build on HB & things seem to be coming along nicely....you're getting pretty close to actually hearing something...can't wait!

[Altec Best]

Been following your build on HB & things seem to be coming along nicely....you're getting pretty close to actually hearing something...can't wait!

Me Too !!!!!!!!!!!! ;)