Horn in front of HF driver

What negative effect, if any, would placing a small horn in front of a 12" high mid driver make?

are you talking coaxil mounted hf....... i may no a few things hear, i done a fair bit of research and development in this area.........

bee wrote: are you talking coaxil mounted hf....... i may no a few things hear, i done a fair bit of research and development in this area.........

i guess. do u mean that the horn driver will be direct in line with the mid range speaker? if so yes. the mid range speaker will be in the cabinet and the horn driver will be approximately 8 inches in front of it.

Sometimes hard to imagine, but the horn in front of the speaker shouldn't affect anything, not unless the horn blocks the mouth up. It gets back to simple theory, and that is Diffraction. As long as the wave lengths are longer than the size of the object in front. the waves will simply pass around. If they are smaller than the object, they will be blocked and simply reflect back into the speaker. So this situation is affected by the high x/o point of your 12. For e.g. if you come out of you speaker at 2k into the horn, the shortest wave length will be 6.79 inches. This should put things into perspective a little.

Tony.A.S.S. wrote: Sometimes hard to imagine, but the horn in front of the speaker shouldn't affect anything, not unless the horn blocks the mouth up. It gets back to simple theory, and that is Diffraction. As long as the wave lengths are longer than the size of the object in front. the waves will simply pass around. If they are smaller than the object, they will be blocked and simply reflect back into the speaker. So this situation is affected by the high x/o point of your 12. For e.g. if you come out of you speaker at 2k into the horn, the shortest wave length will be 6.79 inches. This should put things into perspective a little.

x/o from mid to horn is around 5.6 k i tink.

Tony.A.S.S. wrote: Sometimes hard to imagine, but the horn in front of the speaker shouldn't affect anything, not unless the horn blocks the mouth up. It gets back to simple theory, and that is Diffraction. As long as the wave lengths are longer than the size of the object in front. the waves will simply pass around. If they are smaller than the object, they will be blocked and simply reflect back into the speaker. So this situation is affected by the high x/o point of your 12. For e.g. if you come out of you speaker at 2k into the horn, the shortest wave length will be 6.79 inches. This should put things into perspective a little.

x/o from mid to horn is around 5.6 k i tink.

that's indepth engineering for me! im trying to reduce cabinet amount by doubling the HF drivers and the horns. that is, one cab will have two 12" and two horns.

I don't think you will get that high with horn loaded 12's I would recheck. Why do you think it's 5.6k?

Hey Tony what if x-over to Comp driver is in the rangeof 1k to 1.2k. What would be the distance?

Wave length at 1200hz is approx. 11.31 inches. When thinking of diffraction you can think of this figure as a diameter trying to get round the object in front. If what you had in front was something resembling 8" (wait for the interpretation), the wave length would simply go around it.
As a matter of interest, in the mid section of the R2U system, there is a reasonable size horn and driver, But the x/o point is 700hz,and the wave length at this frequency is nearly 19 1/2 inches so you can see that it makes no difference to the propagation of the mid frequencies. Also at this frequency, because of the length of the mid horn, none of the frequencies coming from the mid break up, because all the waves at 700 and below are longer than the horn. All these things have to considered when designing mids.

Tony.A.S.S. wrote: I don't think you will get that high with horn loaded 12's I would recheck. Why do you think it's 5.6k?

This is sketch of the side view of what we want the cab to look like. two 12" at the back and two comp. horn to the front.