In Reply to: RE: What happens if... posted by Rafaro on April 25, 2017 at 07:59:45:
It's more than just circumference in controlling polars.
Take the K-400 midrange horn--a so called "collapsing polar" design. It allows frequencies below ~1700 Hz to spill on the ceiling and floor of your listening room due to the short vertical dimension of the mouth, but not in the horizontal direction until you get to ~400 Hz-thus ending its horn loading/gain: the so-called "cut-off frequency" for an exponential horn expansion profile. It was designed that way to avoid having to EQ like a controlled directivity horn requires. It works extremely well doing just that - requiring no EQ from 400 Hz to ~2 kHz or higher (depending on how flat you think flat must be) using the ubiquitous K-55 driver.
You can determine the polar control loss frequency of a horn by measuring the mouth dimension in each direction and comparing to the 1/4 wavelength that corresponds to that horizontal or vertical mouth size.
"As far as the ear can tell, consistently clean and spacious bass can be reproduced only by a driver unit coupled to a horn-type acoustic transformer..."; Jack Dinsdale, May 1974This post is made possible by the generous support of people like you and our sponsors:
Topic - What happens if... - KanedaK 07:02:59 04/25/17 (9)
- It'll certainly sound different - Inmate51 08:43:18 04/26/17 (0)
- Does it effectively lower the cutoff frequency? - Bill Fitzmaurice 08:20:17 04/25/17 (1)
- RE: Does it effectively lower the cutoff frequency? - Cask05 09:04:41 04/25/17 (0)
- RE: What happens if... - Cask05 07:48:45 04/25/17 (5)Follow Ups
- RE: What happens if... - Cask05 08:21:47 04/25/17 (0)