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In the Forum: Horn-Loaded Speakers
In the Thread: Deep End DIY - Australian take one Macondo.
Post Subject: More about angling the hornsPosted by Romy the Cat on: 7/2/2017
As some of your know
Anthony live in AU and they have for themselves a site where Anthony regularly
post the progress of his project. I do not post in there, I was banned from
there, I am not sure why but usually it is because I refuse to suck the moderator’s
disk and because the moderators have no other place to stick it then into the feeble
brains of unfortunate audio people. Anyhow, it id not about the AU site but
about the subject that was touched at the forum.
http://www.stereo.net.au/forums/topic/75784-deep-end-diy-my-first-speaker-project/?page=66
Q: Are you
able to angle the top horns down at all?
A: There has
actually been a big discussion about angling of horns (or making them
non-parallel) on Romys site and the quite firm opinion is that it does not work
as we think it would. The opinion was firm enough that I did not consider
it in my design.
I never understood the
desire the people to angling horns. Horns are not guns, the do not shoot bullets
from the middle axis. Yes, the maximum HF you get from the center line horns have VERY predictable
and very constant attention of HF off the middle axis. If you need a slightly
more HF then probably the main axis is a good place to be but in Macondo topology the upper horn is rolled
at 1000Hz and the difference between to be at axis and to be way off is absolutely
negligible. In fact the more HF will be removed from that top horn then better
it would be, this is why I use third order in there is I am not mistake…
So, there is no benefits for angling horn but let to consider the problems.
Time align the speaker of Macondo topology and then angle down the top horn. Not even angle down the top horn
but angle any horn’s axis in any direction. Your time align will collapse.
So it is normal that with attention we have time delay that throw the whole angling out of balance. Now, anybody who did experiment
with time angling and listening benefits know that a time angling in a single
point it is good but is very much not sufficient. The objective is to align the
playback and to make the playback to go away from the alignment in proper axis of
line in the room. In most of the cases the alignment escape line need to be parallel
to floor but in some of the cases it might be very slightly angled to the floor.
It is not only for the purpose of multiple listeners or have wide sweat spot
but also to improve the imaging in the very sweet spot. So, with angled horns
you NEVER will be able to get a long and smooth alignment escape line but you
will be getting 5” sweet spot and then the alignment will be very abruptly
ended.
There are many arguable points to the subject. At what frequency
to measure the alignment in reference to the angled horn? What cut off got reverberation to set when you
measure the time alignment? They are all valid point but as we go lower than
1000Hz then there is no good answers. One might hear it during subjective experiment
other not. My question is: if the rules of alignment and angling works at 10Kz
then why they should not work at 500Hz. Particularly if there is no benefits to
angle the horns….
I have been opponent of the horn angling for many years. I remember
even 16 year back I gave giving a difficult time to an idiom who angle the horn
just to make good picture and to write a review…
https://db.audioasylum.com/mhtml/m.html?forum=hug&n=6349&
Rgs, The CatRerurn to Romy the Cat's Site