Hi Frequency Tractrix Horn useful Low cutoff

[trekman]

What is the rule of thumb for low cutoff of midrange tractrix horns? I wish for a crossover point of 500Hz, so should I consider what people claim to be 250Hz horns or will 400Hz be sufficient? I have seen advice varying from Fc of one octave to a fraction of an octave. I figure one octave to be the frequency divided by 2.

Also, will the larger horns increase the beaminess of these horns to a noticable extent, given how beamy they are to begin with? Will they have any other non-desirable sonics compared to a smaller horn? thanks.

[spkrman57]

I have 350hz Edgar tractix horns that Bruce says can be crossed over @ 500hz. His 500hz tractix horns crossover @ 800hz.

Hope this helps...

Regards, Ron

[Mr. Widget]

Here's another approach. The JBL exponential horn many of us call the fog horn H91 or 2307 in pro nomenclature was originally used in JBL systems with a 500Hz crossover... a decade or so later JBL suggested that it should be used above 800Hz and then when they introduced the longer version of the horn they again changed their rating calling it a 1200Hz horn. The exact same horn...

I have found the single most effective way to reduce the honky horn sound that many dislike is to use a horn rather conservatively. I would go at least 1 octave above cutoff... higher if you can.


Widget

[Hoerninger]

I let build this Horn (http://www.audioheritage.org/vbulletin/showpost.php?p=121158&postcount=3) with a diamiter of about 50 cm (about 20 ") and used it above 500 Hz with a very clean sound. As far as I remember it was two octaves above "cut off frequency" but one extra argument we had , the width should fit the bass horn.
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Peter

[mar2mar]

i have a 400hz tractrix horn from speaker lab connected to an altec 288-16L. when i measured the frequency response it had a steep drop bellow 600 to 620hz. i personally feel that they sound better when i cross them over at 800hz.

[KCCT82]

I have Stereo Lab 400hz tractrix horns on TAD 4002 (w/o adaptors), don't cross them at 500hz... at least 800hz and with higher order slopes. I'm using the 400hz tractrix from 1.9k-12k right now, I don't notice the beaming probably because I point everything directly towards the listening position (1 seat).

Regards