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In the Forum: Horn-Loaded Speakers
In the Thread: Problems with horns: upper bass
Post Subject: Bass Horns and Tractrix vs. other Curves Posted by Kerry Brown on: 3/25/2005
Romy,
More to come soon but a couple comments regarding bass horns ( and one on Tractrix horns ) :
The Edgar Seismic subwoofer ( 18" JBL E155-4 hyperbolic-exponential folded horn, 40 Hz Fc ) works very well in my room - much better than the 1954 Klipschorns it replaced.
Yesterday a friend of mine brought over a CLIO analyzer and we graphed the impedance vs. frequency. I was surprised that the subhorn measures like a ported box tuned to 50 Hz !
Doesn't sound like typical ported bass though... as you know. I am very happy with low bass right now ( strong - though uneven - audible response to 15 Hz on the impedance test tones ).
We also measured the impedance response of my 100 Hz straight horns. Even though they are too short and the throat is too big, they DO measure like horns. No double hump. Throat reactance nulled, apparently, by the ( unfilled ) back chamber ( though I'm sure it could be ' fine tuned ' with bricks or whatnot.
I will forward the graphs if you like ( after my friend emails them to me ).
Regarding the Tractrix curve for HF horns ? I don't have your experience, but compared to other ( mostly PA style ) horns I have listened to they are much better. No other horn has imaged like my Tractrix horns ( in my room etc., etc. ). Not even close. And they all had audible distortion - all of them sounded raspy compared to my Tractrix horns - regardless of type.
Some of that may be better damping in my ( massive MDF ) horns, but it's mostly the geometry ( imho ). The old talk through the horn thing y'know.
Best Regards,
Kerry Brown
AKA KerrB
AKA Vintage Audio Trader Rerurn to Romy the Cat's Site