Synergized HP640 horn?

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Thoughts on converting a fibreglass HP640 horn to a synergy type horn? I currently have a 2" compression driver crossed at 550hz 24db electrical and it sounds great. However my curiosity is getting the better of me and I'm considering drilling some holes. The throat is very narrow and it would be difficult to clean and smooth the holes but possible. And I could extend the mouth to to get lower directivity. Any thoughts on the advantages of this endeavour over my current setup? Thanks


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You cannot locate the cone drivers close enough to work properly, unless you would also bi-amp and use a delay line.

That's a great sounding horn, I wouldn't cut it up.

I add 2" of expanding foam on the back side of that horn for damping and rigidity.
Im hoping to get atleast another octave of loading, pattern control and point source behaviour. I realise I would need to extend the horn mouth to achieve this.

Is it worth it? Not sure.

If I stick with the current set up, what would you recommend for the 150 to 600hz range? Karlson probably wouldn't play that high?
I concur with Soldermizer.

Besides, with that horn's long throat, you might have problems getting the quarter wave notch high enough to be out of a midrange's way. It's one of the reasons most Synergys use conical profiles -- shortest distance on the throat from tweeter diaphram. Maybe if you had it cut in pretty low in freq....
Someone concurs with me? That is worrying :D

I've already blown enough money on my pseudo-Synergy rig for now, but among competing idiotic ideas in my brain ["cell"] :clown: here is one:

Some of the more expensive compression drivers (coaxial) can get well down into the 100's Hz -- the BMS 4952 is one I think, can go down to 300 Hz (???). Other than expense this would make choosing a midrange easier ( = longer port distance allowed.)

What the world needs is a compression subwoofer driver :)
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