OK, that falls in line with the 420's ~2x higher Qts than the 416s. Per this, Fs is quite a bit higher than the 414 and based on its 30 Hz low corner ~confirms the increased Qts: http://greatplainsaudio.com/wp-conte...-8B.420A.1.pdf


Ignoring the 9844's cab alignment and assuming Qts is 2x the 414's 0.21, Vas is ~the same and [Rs] is typical default 0.5 ohm..........


The basic default vented alignment formula I use is Margolis-Small's HP 67/97 & 41C calculator program: AES E-Library ? Personal Calculator Programs for Approximate Vented-Box and Closed-Box Loudspeaker System Design


Vb = 20*Vas*Qts'^3.3


Fb = 0.42*Fs*Qts'^-0.96


Qts' = Qts + any added series resistance [Rs]: HiFi Loudspeaker Design


414 = [20*230.22 L*.22^3.3] = ~31.13 L, Fb = 0.42*30.2*Qts'^-0.96 = ~54.27 Hz


412 = [20*230.22 L*.43^3.3] = ~284.2 L, Fb = 0.42*39*Qts'^-0.96 = ~36.83 Hz


A ~9.13x net Vb increase for just one driver, so now we know why Bi-flex speakers were sealed alignments.


Using basic 'acoustic suspension' math and max flat 0.707 Qtc': HiFi Loudspeaker Design


414 = 24.68 L / 97.05 Hz Fc


412 = 135.16 L / 64.12 Hz Fc


~5.47x larger, so even sealed it may be necessary to either use a lossy [~aperiodic] vent to bleed off excessive Qt or DSP its 'full range' frequency response.


GM