I am planning my first 4-way build and am struggling with the choice for the mid-bass to mid crossover frequency. The crossover is active, so I have a wide choice of parameters like baffle step, time delay, parametric EQ as well as the usual gain, frequency, phase etc. The drivers are 2x8" woofers, 6.5" mid-bass, 4" mid, 1" ring-radiator.
I am comfortable with 100 Hz low bass to mid-bass and 3.5 kHz mid to ring-radiator but I am in new territory with the mid-bass to mid transition. I have provisionally chosen 350 Hz for no other reason than the woofers and mid-woofer have good behaviour around this frequency. The relevant drivers are from the SB Acoustics range, SB17NRX35-8, SB12NRX25-8. The closest commercial speaker to what I have planned are the NHT 2.9 (no longer in production) but with slightly different bass alignment (sealed dual-forced opposed 8" in place of sealed 10" boundary re-inforced). If anyone has suggestions for the mid-bass to mid transition, based on actual experience and acoustic principles, I would be glad to hear them.
I am comfortable with 100 Hz low bass to mid-bass and 3.5 kHz mid to ring-radiator but I am in new territory with the mid-bass to mid transition. I have provisionally chosen 350 Hz for no other reason than the woofers and mid-woofer have good behaviour around this frequency. The relevant drivers are from the SB Acoustics range, SB17NRX35-8, SB12NRX25-8. The closest commercial speaker to what I have planned are the NHT 2.9 (no longer in production) but with slightly different bass alignment (sealed dual-forced opposed 8" in place of sealed 10" boundary re-inforced). If anyone has suggestions for the mid-bass to mid transition, based on actual experience and acoustic principles, I would be glad to hear them.
You would be better off with a 2" dome mid than a 4" cone in such a 4 way setup and cross it higher plus a 3/4" tweeter.
I am still tweaking my 4way with HiVi planar tweeter, 2x 2"Dayton domes, 2x 6" Dayton mid bass, and one (for now) 15" woofer. I have selected 150, 800 and 4k.
With only minor modifications its already singing beautifully.
With only minor modifications its already singing beautifully.
There is, for good power response one would want the unit to not lose spl off-axis in larger quantity to keep the even response in that respect as well.
Floor bounce may be another factor. Where are your bass and mid-bass drivers positioned on the baffle?