Stewart Pinkerton wrote:
Freehand a manifold, i. e. a conical horn (x), as the adapter between
the unit and the slit. Conical horns are wonderfully simple: the faster
they expand the higher their range. They also have the advantage of low
distortion due to the fast initial expansion.
This doesn't make sense to me, as there is no horn expansion if the
slit is the same area as the driver Sd, as you suggest below.
Expansion prevents too many parallel walls. If you go for the suggested
model with 3" as the smallest dimension of manifold and slit then you
have to make some kind of a transition from the 13" membrane. This is
not about midrange, so doing it the crude way comes to mind, i. e.
starting the manifold with a - tja da dum - 3 by 13 inches or 3 by 10
inches initial area. Even to simply enter the room with the membrane
area will then require expansion.
I'm still looking at a manifold exit area of 0.3-0.5 the Sd of the two
drivers (for improved WAF....) , expanding into the 1/8 space of the
room corner. As you say, there may need to be a back box to equalise
cone loading.
Ah, going to the room corner is a mitigating factor because it allows
you to use the corner as an extension of the conical horn in the
manifold. And with an "L" shaped slit in the ceiling in the corner it
ought to be possible to make it a lot more compact than I had first
thougth.
OTOH, since I'm staying well below Xmax for normal operation, perhaps
this is all a little paranoid! OTGH, design time costs me nothing, so
why not do it right first time..................
Minimizing distortion and getting an optimum coupling to the room are
worthwhile aims and probably pre-requites for a system that is supposed
to be able to play well in trippel forte as well as in the way more
difficult trippel piano.
Try searching for hornresp ... it may be possible to express this as a
conical horn it can understand, in which case it could be helpful to try
modelling in it.
Stewart Pinkerton | Music is Art - Audio is Engineering
Kind regards
Peter Larsen
--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at:
http://www.muyiovatki.dk /////// *
************************************************** *******