Monacor Speakers Project 3-way


2007-11-30 5:47 am
hello to all

i want to make 3-way speakers with monacor drivers, partly because of price, partly because of availability.
i'm not decided yet over the bass speaker, but midrange and tweeter i want to use the sph-135kep and dt-109.
one ideea for bass is sph-200ke, 8", or sph-255/sph-265, 10".
another idea is to use beyma 8br40, but this one has a pretty low Bl
basically speaking, i would prefer an 8" driver since i don't have too much space in my room. anyway, maxim possible witdh for front baffle is around 32-33 cm. room is arround 18 square meters.
speakers will be used let's say "music dedicated", meaning i want a full-range system as much as possible, but not a "boomy" one (more flat/linear amplitude).

crossover frecquency 300-250 hz and 3000-3500 hz, from midrange and tweeter point of view i guess this is ok.
crossover type linkwitz-riley or maybe butterworth "adjusted" for flat amplidude, 0.7692*F(low) and 1.3*F(high). still to investigate the better option.
sph-200ke is very good regarding bass extension (low fs, low f3, moderate box volume), but seems it didn't have 90db spl as mentioned in monacor specs, more around 86db (or at least in enclosure, not free-air) difference between bass and midrange/tweeter will be 3db...not too optimistic.
another problem about sph-200ke is group-delay, because around 30hz it raise, doesn't matter if alignment is sbb4 or qb3. i only take bass-reflex because none of these monacor drivers seems to be good for sealed type. i'll see today how beyma simulates in sealed enclosure.

baffle step compensation and time alignment is to be checked, once drivers combination will be finally.

further simulations will follow.
any comments/sugestions are welcome.