PDA

View Full Version : Foam wrap on midrange horn



Bluegrassmaven
07-28-2015, 02:25 PM
Seems I saw a reference somewhere to wrapping horns with sound deadening foam. Is that a valid tweak or the emperor's new clothes?

more10
07-29-2015, 05:24 AM
Dr. Geddes has a patent. Here is some info from a guy who has done it: http://www.enjoythemusic.com/diy/1110/oblate_spheroid_waveguides.htm

grumpy
07-29-2015, 07:02 AM
Wrapping, stuffing, or edging ... they're all addressing slightly different issues,
although the last two are similar.

What example of "wrapping" might illuminate your question further?
Mass loaded paint or putty or tar can move a resonant point and/or
reduce it's "Q", as can simply mounting the horn to a baffle.

Flaesh
07-29-2015, 07:04 AM
not foam but wrapping: http://i029.radikal.ru/0909/69/9022fa551072.jpg :crying:

pos
07-29-2015, 07:08 AM
not foam but wrapping:
66197 :crying:

:eek:

Here is the 4-way version :
66196

Wagner
07-29-2015, 07:17 AM
Klipsch tweekers have done it for years using various and sundry types of rope caulk

As many variables are involved, I would think the degree of improvement would be commensurate with the amount of "ringing" or other unwanted behavior one was experiencing with the given horn related to spurious resonances as well as the overall size of the horn, it's construction material and the job it was being asked to do

In other words, a try it and see what happens type of thing

If you experiment with it, just do it in a fashion that is easily reversible

Clearly, there is some legitimate application for this (and reasons), witness the "tar filled" horns of ALTEC and many others during the "Golden Age"

I have tried it myself with the Klipsch "squawker" horns in several boxes back in the early 2000s; the results were negligible to my ears after being tempted with promises of great changes for the better

For smallish mid and high frequency applications I am skeptical (co-axials being the exception as the little horn sits right in the middle of an ocean of low frequency energy)

Still think it's degree of efficacy would be best determined on a case by case basis

more10
07-29-2015, 07:18 AM
+20 dBWaf. Make shure it is synthetic :D

Wagner
07-29-2015, 07:26 AM
Wrapping, stuffing, or edging ... they're all addressing slightly different issues,
although the last two are similar.

What example of "wrapping" might illuminate your question further?
Mass loaded paint or putty or tar can move a resonant point and/or
reduce it's "Q", as can simply mounting the horn to a baffle.
I agree and was about to say and cite the horn to baffle "interface" could have as much of an impact if not more
The use of a gasket there for example, as well as the rear support (if any) of the entire driver/horn assembly can and does impact tuning and resonance

Flaesh
07-29-2015, 08:22 AM
.. Make shure it is synthetic :D
Do you support\advise usage of genuine natural foam :) for horn wrapping?..

Bear genuine fur can be more patriotic :D or longer rose hair can be more glamour..
I'm not personally acquainted with the author of this system and can not manipulate the wrapping..

Flaesh
07-29-2015, 08:48 AM
Here is the 4-way version :
Cats are usable for damping at the bottom of backload horns in lower Cessaro models in Hong Kong..
p.s.: Link to pics is dead :( :( . Cats where installed :D in Cessaro Alphas.

Bluegrassmaven
07-29-2015, 09:17 AM
Wrapping, stuffing, or edging ... they're all addressing slightly different issues,
although the last two are similar.

What example of "wrapping" might illuminate your question further?
Mass loaded paint or putty or tar can move a resonant point and/or
reduce it's "Q", as can simply mounting the horn to a baffle.

Specifically would it be of value to wrap an Le85?

Wagner
07-29-2015, 09:53 AM
Specifically would it be of value to wrap an Le85?

I know you directed this to grumpy, but I say "no"

Don't think you'll encounter too many resonance problems with horns built like the H91!

What lens you choose (or build) now that's another matter


Is that a valid tweak or the emperor's new clothes?

Yes it is "valid" if it cures a problem

Do you have a problem or are you just looking for one?

grumpy
07-29-2015, 11:09 AM
yeah... seems unlikely. Properly mount the horn to a baffle
and support the driver.

I know of at least one person who used a rubber-like spray on one
and it did indeed ring -much- less when whacked in free air, but I
don't recall if the owner thought it made much of an audible difference
once installed...