Comparing two 2" HF Horns

[Kevin McDonough]

hey all

Compression driver horns is probably the area I'm least knowledgeable about, and while looking into a little project I came across these two horns.

Both are two inch horns that are roughly similar in size (5 or 10mm difference in some dimensions). Both claim pretty much the exact same spec, and low frequency cut off etc. Wont mention the brands or anything just yet, but just based on their design would be interested to see peoples thoughts on how different they would sound, both from the point of view of helping decide which one may be used and also just in general increasing my knowledge.

Pics are attached, one of each and then an overlay showing them both.

As you can see, while the main part of the horns is pretty parallel, there are differences at both ends. The first has a shorter initial throat area, the main part of the horn holds it's shape for much longer with a (comparatively) quite sharp/small radius round off at the mouth.

The second has a much longer initial throat section that ends up in a narrower diffraction slot, but then the main part of the horn is significantly shorter both because of this longer throat and also the fact that the rounding off at the end is much gentler and so starts earlier.


So how is this likely to affect things? Which one will be likely to sound better, all other things the same, and which will hold it's pattern control better or to a lower frequency?


k

 

[Art Welter]

Kevin,

The horns likely have polar response graphs that would answer most of your questions. Both horns should have similar LF pattern control. The horn with the more narrow throat pinch would have wider HF dispersion, but the sharper discontinuity will cause more diffraction. Diffraction results in a more "smeared" sound. That said, using a 2" throat horn generally implies using a 4" diaphragm HF driver, which are not known for clean sounding very high frequency response.

Art

 

[Bennett Prescott]

Hey Kevin,

The important things when talking about big throat horns for me:
1) How do they sound off-axis with the driver you intend to use? The throat of the horn and the throat of the driver need to play well together or your HF pattern will be effed.
2) How do they sound on axis at max SPL? You'll need to be able to get well away from them to really turn them up and see how the driver behaves. If you aren't planning on using them this loud, there's no reason to mess around with a large throat horn and driver. Something with a 1.4" throat or 1" throat will sound better.

 

[Ivan Beaver]

Hey Kevin,

The important things when talking about big throat horns for me:
1) How do they sound off-axis with the driver you intend to use? The throat of the horn and the throat of the driver need to play well together or your HF pattern will be effed.
.

This is something that many people miss.

If you take different drivers, and put them on the same horn, you will get different results.

Yes the freq response can be different, but the RESULTANT pattern of the horn can also change-sometimes quite a lot.

I have done some testing and found that some drivers will "fill out" a horn very nicely, and other drivers will be really beamy on the same horn.

Then you can put the same 2 drivers on a different horn and they both provide the same coverage.

As with most things that are a "2 part" system, you simply cannot expect 1 of the parts to do all of the work. They must work as a unit.