500 hz horn to 400hz

[kg4guy]

I have a horn that has the same size mouth as the K-400 but only 10 " long is there away to make this from a 500hz to a 400hz with using a type A crossover?

[Guest " "]

you can't lower the frequency response of a horn that is designed to operate at 500hz with out modifiyng the horn and going to a larger format. Increasng the throat size contributes to lowering the frequency response of the horn. But you would need a 2" driver instead of the one your using now. Increasing the throat size requires cutting off the smaller 1" end at the point where it would be a 2" opening, and adding a faceplate to attach the driver to. Cost and time make this a kludge to do.

[WMcD]

SpeakerFritz beat me to a reply.

I agree that, basically, it can't be done, realistically.

The short length makes me think that your horn might have been made for a 2 inch driver. If so, maybe a kluged up an extension on the throat side with a more gentle flare rate and a one-inch driver. It might work but is not worth the effort or uncertainty. You'd have to be a master at metal work and/or work with composites.

Wm McD

[kg4guy]

SpeakerFritz beat me to a reply.

I agree that, basically, it can't be done, realistically.

The short length makes me think that your horn might have been made for a 2 inch driver.  If so, maybe a kluged up an extension on the throat side with a more gentle flare rate and a one-inch driver.  It might work but is not worth the effort or uncertainty. You'd have to be a master at metal work and/or work with composites. 

 Wm McD

 

You never know I may be anyway I like to explore all angles . Thanks for the info

[Erik Mandaville]

However, you can alter the values of two of the elements in the type A network for that frequency. In other words, compensate on the crossover end rather than altering and possibly damaging the horn.

[Erik Mandaville]

I guess I think, too, that if you can experiment with this while trying to preserve the original shape and dimensions of the horn, the possibility of learning through trying is sometimes worth the effort. If nothing else, it could help lead to other insights and possibilities. On the 500Hz crossover for the La Scala, I hope someone will correct me if I'm wrong, but I believe the La Scala low-end response, while very mildly down above 400Hz, is still reasonably strong quite a bit beyond that.

Erik

[djk]

The HF horn must be a minimum of 1/2W long at the crossover point.

This would imply about a 700hz minimum crossover point for a 10" deep horn (about what a Heresy uses).

If using an old style 2" throat driver like the JBL 2440, you can add about 4" (the length of the internal horn throat) to the effective length.This total 14" length will get you to 500hz, but not with a 6dB crossover (type A) unless using a phenolic driver.

[Guest " "]

"" If using an old style 2" throat driver like the JBL 2440, you can add
about 4" (the length of the internal horn throat) to the effective
length.This total 14" length will get you to 500hz, but not with a 6dB
crossover (type A) unless using a phenolic driver.""

would this work with a 1" throat horn....any cost penalty at the expected upper operating end of the horn by expanding a 1" horn to a 2" opening 4" inches down the road...then back to 1"....would this act as a band pass?

[djk]

You will lose some high end above 8Khz with the adaptors, it may cause some narrow dips lower than that.

[Erik Mandaville]

....or find/save-up-for a pair of K400 horns and use those.

[djk]

This horn is the right size for the top of a Klipschorn, and is often on eBay for a very reasonable price (usually $50~$75).

http://www.electrovoice.com/download_document.php?doc=1672

The 1/4W Fc, even with a modern pancake type shallow driver, is below 200hz, so it may be crossed at 400hz.

I have three pair of these with EV DH1A (which is what Klipsch originally used on their big stuff), and they sound very, very good.

[Guest " "]

You will lose some high end above 8Khz with the adaptors, it may cause some narrow dips lower than that.

That should be OK for a mid horn.

[Erik Mandaville]

I have two 2.5mH air cores that can be unwound and measured for the needed inductance (not a guess, I have a very accurate L-meter) at that frequency. Coils and labor: $0.00 payable however is convenient! I'm not using them for anything, and they make the parts bin drawer heavy to pull open!

Erik