Mt121 with hf horn inside

i would say boxes start to become particularly directional after about 200-300hz IMO

the mt121 is tight (the 40h degrees i found was about right) - a tight 2" horn is needed to go with it...

IMHO

once ran b&c me45 horn above a 60h horn loaded mid (instead of usual beyma td245 horn) and the result was not so good

saul if you are running two mt121's a side then i would agree, but if you are running one aside then the me45 horn sounds good.... but i think it depends on the listener smiley2 ......

sorry it wasn't an mt121 :oops: i can see why it wouldnt be so much of an issue with 1 per side.

when i had mt121s - my top horn was a beyma with 90h degrees. i remember how uneven it sounded when walking around it with the 40h mid horn below (played in pairs).

for many people i don't think it's really much of an issue, but i do understand why some PA guys get very particular about dispersion and summing. sometimes it can effect the perceived sound quality which is when it's not nice. smiley29

saul wrote: i would say boxes start to become particularly directional after about 200-300hz IMO

the mt121 is tight (the 40h degrees i found was about right) - a tight 2" horn is needed to go with it...

IMHO

once ran b&c me45 horn above a 60h horn loaded mid (instead of usual beyma td245 horn) and the result was not so good

if you put that in an another horn...this would affect the mouth size and the expansion rate of the larger horn. But this should be noticeable ?

Still think reflex 2 x 10 with uber sensitive 10's is an option.

BEYMA 10MI100

Cost of an extra driver v cost of a simple box/complicated mt

bitzo, sorry i had completely gone off topic - ive never tried the CD inside the midhorn.

i wonder if you could get away with it with a smallish horn. thing is, you need a half decent sized horn to go down low enough to reach the 12"

im sure it can be done, alot of the big players all make this kind of horn loaded cab, ass, DnB, etc

that's exactly point. it's like having a phase plug. Now an idea blame in my mind. What if we consider the cd horn and the cd like a plug? I mean model the mid horn starting from the plug formed by these elements? The mid horn must the same lenght of the cd horn, and the cd is inside the cone volume like a phase bungs.
Ops...mykey already done something similar.

With these big coax comps, you need to take the specs with a pinch of salt. Consider crossing over at about 800-1KHz instead of 500-600 as you mentioned.

On the other hand I would not run the MT121 12" above about 1K if concerned about quality. For many years, to avoid comp distortion, people have crossed from mid to high at too high a frequency, leaving a gap between the mid system's real rolloff and the crossover frequency. Remember, even with phase plugs there are still rolloff mechanisms like front chamber, phase cancellation, driver mass and inductance.

I think people have got used to a gap around 1-2K, and sometimes kid themselves that they are hearing "sharper" or "more articulate" HF, when in fact the HF is being accentuated by being near a gap.

I think an MT121 with a 2" coax crossed at 1K could sound good.

Cheers, John