Drivers like the PD 184 will work in a short folded horn because the cab
is not really a horn. For the driver to be properly loaded by a horn
means a horn length of over 5.5 feet, something none of the Turbo or
Funktion bins have. When the horn is less than 5.5 feet long we have
what I call a horn assisted design. Basically the horn just adds a bit
of gain from around 80 to 150 Hz, the cab will produce notes above and
below these frequencies, just at a lower volume. You want a driver with
a low resonance a powerful motor system and good damping, the PD 184 has
all of these. Most of my short horn designs will work down to 50 Hz
because I design them to be sealed boxes first that just have a bit of
extra gain and kick from the horn in the 80 to 150 Hz range. Below the
horn cutoff most of these short horns will still produce a useful output
down to the cutoff point of the sealed box. It's a hard thing to design,
do you go for a driver with high EBP that you know will work well in a
horn and have the output from 80 to 150 Hz controlled and fast, or do
you use a driver with a lower EBP and make use of the lower sealed box
cutoff point. Drivers like the PD 184 are ideal because they sit
somewhere in between the two. They are reasonably controlled and fairly
fast and also have good extension. The 1850 has a higher resonance and
more powerful motor system, so has a much higher EBP. This will always
make the 80 to 150 Hz range more prominent when it is used in a short
horn, hence the sound will have more grunt. If you change your 1850
drivers for 184 drivers you will get that smooth Hi Fi sound and a lower
cutoff point, but you will lose quite a lot of efficiency, will gain
more power compression and not have such a high power thermal limit. So
all in all you might lose up to 3 dB per cab of SPL. Whether or not you
can live with that only you know, but I guess not seeing as you said you
already don't have enough power to drive the cabs with and would like an
even higher SPL from them. If you have lots of these short horns, like
over 8 per stack then the effective horn length will appear to be longer,
so the use of a driver like the 1850 will pay of because the stack will
work as a true horn and so need drivers with a high EBP. You will find
that that most of the grunt to the sound will disappear if you can use
big enough stacks. If you used the 184 driver in very large stacks then
the sound may become very slow and heavy. So, it might pay to keep the
1850 drivers but just use more cabs per stack to achieve a bigger and
longer horn, because if you go with the 184 option then you will have to
use a lot more cabs anyway to get the desired SPL, so you might as well
use the 1850 if you have a bigger stack and have a lot higher SPL.
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