Horn mouth termination

[Panomaniac]

Interesting stuff. Does look like it would be hard to work with. But might be very good, sonically.

You want a large area and smooth rollover from the lip, so just keep that in mind while building.

[Earl K]

Hi,

- Here's the FR for my 288K/Emilar horn combo . ( Oh, btw, this horn has the 2.25" pipe-foam bell-extenders attached to the upper & lower lips ).
- This is a raw curve ( unsmoothed ) captured using HOLMimpulse ( a new freeware ) acoustic test program that I'm test driving .
- It's available for download here .




( FWIW , it's a .png file / ( Windows "Paint" file ) / if it doesn't work for the Mac heads out there )

>< cheers

[Panomaniac]

Thanks Earl. I'm using the same sofware now. It's nice.

A little smoothing would make the curve easier to read, tho it will obscur some detail.
Did you manange to get a plot without the foam lips?

[Earl K]

Thanks Earl. I'm using the same sofware now. It's nice.

A little smoothing would make the curve easier to read, tho it will obscur some detail.
Did you manange to get a plot without the foam lips?

You're welcome !

- I still have the HOLMimpulse ( H.I. ?? ) files. I'll repost something with smoothing that's easier to read ( as you can tell , I'm not embarassed by the raw data ) .


- I got the software up & running after my last Emilar radial was foamed ( so , unfortunately no ).


- ARTA did my comparisons of "NO-FOAM vs the FOAM BELL EXTENSIONS. These are saved as PowerPoint Slides right now . I'll see if I can find something meaningful to post .

- All in all, I like the foam ROUND-OVERS a whole lot for a bunch of reasons . The biggest being that I tend to use overly small horns with large drivers and the foam helps mitigate the negative consequences of this choice .

>< cheers

[Earl K]

Alrighty now, here's a slightly easier pic to look at, allowing one to follow the trend-lines .



- ( btw, that low-end rise is intentional on my part / originally it was caused by only the electrical effects of a 2-pole passive "bump-filter" / but then the additon of "FOAM-X" gave a little extra LF boost before the final HP rolloff .

( "FOAM-X" will now be my shorthand for bfishs' ; half-roll, foamed-edge, bell-extension )


>< cheers

[bfish]

Any thoughts on how this stuff will work? The fiberglass is rigid so it would be tough to bend but I think it could be segmented to fit a curve. I’m thinking here of stripping the paper from the fiberglass and using it raw or perhaps fogged with some flat black paint.

Fiberglass insulation, copper tubing insulation, fiberglass pipe insulation

That stuff is extremely rigid, you'd be lucky to get a 5 degree bend in a full stick. It cuts smoothly, so segmenting might work, but it's so dense you'd have to cut almost all the way through, and in very close intervals. Acoustically, it's the equivalent of duct board, so a fairly wide atten. BW. The jacket's just a vapor barrier, removing it improves damping, but is no help for flexing. If you had to buy either, go with foam. If the 'glass is free, sharpen the knife and get ready to itch...

[martyh45]

What do you all think, would it be worth trying something like this with a 32B horn?

[Steve Mac]

What do you all think, would it be worth trying something like this with a 32B horn?

I would make sure that the natural flare of the horn is not made unnatural by the fiberglass....which it appears to slightly constrict at the start from the mouth. But I do not see why it wouldn't work other than that.

[Steve Mac]

I picked up some armaflex and redid the legs of the mid range horns.
Then I decided...well...this stuff has sticky stuff on the inside so
I did a test and here's what it looks like:

[Steve Mac]

Now I almost have a perfect plan...what d'ya think?
See photo for instructions....just need to determine
the technique and material to easily build the lip up.