Originally Posted by
gibber
That two-port 28Hz tuning you like less is very similar to the 30Hz i have here. Instead of changes on the ports my cabs have, i just tried using a beefy transistor amp and gave it a 10ohm resistor in series to my (early version) K145's ca 9ohm coil dc resistance. New Qes' equals (Rg + Re) / Re * Qes, so Qes goes up to 0.52 or so and hence new Qts is around .49 (see Qms in tables earlier in this thread).
Result is a more "normal" bass sound, the mid is similar as before, and subjective speed is slightly less, imho not too much so to offset advantages in the deeper register. Mid output subjectively is down by 2dB (should be 3 dB but the higher Qts with series-R maybe reinstates some of the premature-but-gradual rolloff that a driver of Qts=0.23 w/o series-R has).