![]() ![]() |
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
174.131.166.128
In Reply to: RE: Hornresp 1st pass - comments/critiques welcome. 40hz "L" horn posted by Rod M on January 03, 2024 at 13:00:02
Your right about length, that defines the lowest F it can have any gain over a direct radiator.
You posted a drawing of an old friend, the A-7. I wasn't sure i had the measurements but i found them.
In 2003 i rebuilt a pair of them for a good cause and he didn't care what i did.
If i have seen anything in my life, it is that driver properties and the ability to model things have actually made a pretty big and for me giant difference at work and worth considering drivers when building.
So here i have posted that Altec A-7 with the normal drivers and ones i picked.
For hf it's a bms 4550 an excellent driver and keeping it at least partly Lansing a JBL2226 which i had on hand and looked good at the time.
Notice the difference, on the low end and top end a very noticeable diffidence in raw bandwidth (there is no crossover involved here, these were measurements for figuring that out).
When done, this was a considerably wider bandwidth and flatter speaker than it started and sounded good.
Follow Ups:
I have several of the 2226 woofers, which, represent the best of the mud magnet woofers of the last millenium. California made by American Labor also means an almost $600 price for that driver new.
Most of the Chinese made units now sell for 1/3 to 1/4 that price with similar performance.
I fact, SKAR car Subwoofer drivers, at about $300 vs. about $900 for American ones with similar TSP's, make great Tapped Horns!
Of course, I don't mean to preach to the choir here. LOL.
Did you re-use the 800 or 500 Hz. horn with the new driver?
![]()
Hi
Yes i did, it was the 511. I did change a couple things other than to the 4550 and 2226 drivers.
There was a spot on the back side of the vertical flare in front of the flat flange that had "sensitive" spot i put some damping material on.
There was a spot mid point on the woofer flare that had a resonance where i glued a brace to the outer cabinet wall. The baffle at the bottom (bare plywood in the picture elsewhere) for the woofer port was added after measuring the box sealed (i didn't want to try and calculate the volume when i can measure it's effect).
When trying to work out a crossover, i found if i moved the horn back an inch and a half, could get a Synergy style crossover with very little or no XO phase shift.
This was a long time ago, i don't have a measurement file in the folder for it but i know i did once haha. Red scale is phase, + - 180 degrees scale. Crossover is about the center left to right
![]()
2226 vs stock raw response
![]()
hf raw response bms 4550 vs stock
Thanks for the curves, Tom. They pretty much tell the story!
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: