I'm building a "speaker" (its really two separate horns/cabinets), a 3" compression driven horn housed in plywood and a 10" cone driven horn. I'll be crossing over actively so time alignment is not an issue. I'm crossing over at 1400hz. The 10" will be high passed around 180-200.
I'm wondering if I should just make the horn mouths as close as possible to eliminate phase issues, or if there is another consideration I'm not aware of. Reading about MTM spacing (which is not what I'm building of course) put it in my head that there might be something else to consider there.
I'm wondering if I should just make the horn mouths as close as possible to eliminate phase issues, or if there is another consideration I'm not aware of. Reading about MTM spacing (which is not what I'm building of course) put it in my head that there might be something else to consider there.
Hi,
Is your compression driver with 3" voice coil or the compression driver horn is 3" in diameter?
Not knowing your plans more accurately just some quick thoughts:
Its about impossible to get them close enough so you might go whats visually nice. There is trade-off with some diffraction if you want to get them closer together as bigger roundover on the devices would get their own responses nice but again perhaps little further apart. What the far apart c-c makes is very narrow main lobe which you need to be cautious about to get the main lobe at ear height at intended listening position. The closer you listen to speakers the narrower the beam in centimeters.
I haven't played with multiple horn speakers in simulator but similar things would apply as with direct radiators that:
make the horns about similar in size to get similar directivity for both at some bandwidth to make smooth crossover. The 10" will beam some at 1400Hz so you need quite a big devices to make similar beaming for the tweeter as well or make phase plug for the 10" horn to keep response wider higher up. Or just live with some mismatch. 1.4kHz is only 24cm long so its impossible to get c-c less than 1wl bigger than 24cm waveguides even if you squeezed the devices very close together without any roundovers. >1.5wl c-c could be realistic (with quick imagination) and produce somewhat manageable main lobe, especially if listening distance is multiple meters. If you can't do devices so small the only option is to lower the crossover to accommodate the sizes. You could go with 1.4" throat driver and / or smaller woofer. Some 1" driver can go < 1kHz nicely for home listening SPL levels.
Is your compression driver with 3" voice coil or the compression driver horn is 3" in diameter?
Not knowing your plans more accurately just some quick thoughts:
Its about impossible to get them close enough so you might go whats visually nice. There is trade-off with some diffraction if you want to get them closer together as bigger roundover on the devices would get their own responses nice but again perhaps little further apart. What the far apart c-c makes is very narrow main lobe which you need to be cautious about to get the main lobe at ear height at intended listening position. The closer you listen to speakers the narrower the beam in centimeters.
I haven't played with multiple horn speakers in simulator but similar things would apply as with direct radiators that:
make the horns about similar in size to get similar directivity for both at some bandwidth to make smooth crossover. The 10" will beam some at 1400Hz so you need quite a big devices to make similar beaming for the tweeter as well or make phase plug for the 10" horn to keep response wider higher up. Or just live with some mismatch. 1.4kHz is only 24cm long so its impossible to get c-c less than 1wl bigger than 24cm waveguides even if you squeezed the devices very close together without any roundovers. >1.5wl c-c could be realistic (with quick imagination) and produce somewhat manageable main lobe, especially if listening distance is multiple meters. If you can't do devices so small the only option is to lower the crossover to accommodate the sizes. You could go with 1.4" throat driver and / or smaller woofer. Some 1" driver can go < 1kHz nicely for home listening SPL levels.