jinjuku said:
When you take into consideration (and use it as much as you can) the driver and cabinet acoustical roll-off and add an electronic crossover how is it summed? Simply additive?
For an individual driver, it is simply additive. However it also depends on the pole and Q for the electronic crossover, which may differ from the fs and Q of the driver. Depending on the desired frequency response, you may have to stagger your slopes - IE use different, cascading 6db electronic filters.
The driver's acoustical rolloff at the bottom end is not different from the cabinet's acoustical rolloff. The cabinet is simply altering the driver's rolloff.
The driver's acoustical rolloff in its upper ranges is affected by
- the baffle step which imparts a rise in frequency response of around 4-5db, but this ends rather than continuing on on up in frequency. Often the way to deal with this is to include the compensation into the low pass of the woofer and use multiple poles.
- inductance and mass will accelerate rolloff, but you probably won't have to worry about this with the dayton drivers.
- cone and surround resonances with give uneven rolloff and decay. You want to push these well down (IE 30 to 40db down, and response should follow the intended rolloff)
For multiple drivers, the degree of summation however depends on the phase difference.
Swerd said:
Skip a test baffle and use a cabinet of suitable volume for the RS180S (one or two?) and wide enough for the wave guide.
+1 on this
Measure the drivers all in the same box, and then aim for a specific driver interaction in the simulations. Are you using
Active Crossover Designer?