PE horns throat weirdness question.

[Andrew Eckhardt]

I'm a total horns novice, working on my first serious speaker project with some compression drivers. Of course it's extremely cost sensitive.

I'm wondering if anyone knows what's so hard about casting the most critical throat area of a horn properly. I know they don't make plastic gears out of ABS, but come on, a little precision shouldn't be all that hard. especially since it's obvious that the mold is turning out horns that are out of whack in a very consistant way.

Eminence helped monkeywrench the works on the new revision of the APT by making the throat outlet .050 oversize anyway, but the Dayton H07E throat measures .92" in some places. In fact someone (probably at the factory) obviously took a knife and carved it out by hand leaving, really, a total mess. It's some help but not much

I know you can buy 100 dollar and up horns that definitely aren't going to have such defects. But this is nonsese. I bought four different cheap horns from PE that are pretty much unuseable for production for needing major hand modification with a file and sandpaper to begin running right. Does anyone know why this must be? There is obviously some kind of "expensive" issue that affects the molding of parts shaped this way or it wouldn't be such a common problem.

[Andrew Eckhardt]

???

[speaker dave]

I'm guessing that is a parting line between mold sections. That means there will be a lot of flash to grind off. Rather than machine it nicely they use a hand grinder.

Not very pretty.

David

[Robh3606]

Well it's a trade off depending on how complex the shape and contour is through the throat. I have a couple where the begining of the throat is cast in two halves and assembled to the horn. The casting insures a very accurate contour but this raises another issue of matching it all up so you have a smooth transition. I agree though they look like crap. If I can I will post a picture of the 3 piece construction. The original 2344 was similar to this with a cast aluminum throat flange. On the latter version it was all one peice.

Rob