2 x 12 loaded mid horn......

Hi guys a question for you all......... what is the advantages or dis-advantage of loading a mid horn with two drivers loaded in to one horn..... I have seen this done in the lab horn, but not in a mid horn. see pic below..... check out my drawing skills.....

Well, the usual issues of mid horn design will still apply if you use two drivers. They include

- need high EBP driver
- need (very) small front chamber
- need phase coherancy at the throat

Now, using 2 drivers can be a good way of getting more power handling without losing on EBP. However, it could be difficult to merge the output of 2 drivers without problems with front chamber being too big and/or poor phase coherancy.

Imagine (for example with 8 inch drivers) you need <200cc front chamber volume and your path length variation to a plane at the throat can't be more than 5cm. It's hard to do this with a single driver; with 2 it would be even harder. In your diagram, which I acknowledge is not to scale, you're getting several 1000s of ccs of front chamber and path lengths are varying by the driver cone's diameter. This would not get very far into the mid I'm afraid. Maybe up to a couple of hundred Hz.

Just for fun, I think I can see how to do it, maybe. Can any other forum users suggest anything?

you could load both drivers directly on to the horn sides and add a third in the traditional way, this would give a multiple entry type horn...... but this would be a very differant way of doing things from my original sketch.....

the other way would be to load exponential expansion rate near the throat for both drivers then joine both throats together followed by a conical expansion section.



(just a guess...........)

Hi all,
with this design you have a lot of resonance on high frequency, should be better divide the horn in 2 part.

the only reason im asking is alot of boxes use 2 mid horns ie. mt122 the xtro etc so could combining 2 speakers in to 1 horn reduce space and size of box........

This could be an interesting idea.
IMHO the main issues are:
-The driver angle, more degree less top end;
-Resonance in the horn because of 2 driver loading.
But this idea tickle me smiley2
What external dimension do you want? What about usable frequencies? what kind of driver?
We can start from here....more food for hornresp smiley20

cheers, bitzo

for me i do like the mt122 sound but size and needs mean i built an mt121.... could be a starting point.... what do other peeps need in a midhorn or low horn....

uhmmm could be impossible to get the same sound of an mt122, probably a good mid (i hope!) with same dispersion, crossover points, and mouth but not the same sound...
however...
Access panel or not?
Trapezoidal or not?
Flared or not?

lets hope it sounds better....... it would help to have access panel. the type comes down to build...... how easy you want and how hard you want the build to be........ i like a challenge..... i have made fibre glass horns in the past so coming up with a protype and making a mould from that is no problem. Im happy to make a few master moulds that we can share out amoungst fsp users to make final horns from...