You know one thing, im very tire of the ported box sound. It make noise but few music. All manufacturers never said themself if a close box is more musical than a vented ported box.
The added sensitivity of ported box is in reality added sound distortion. Anyway a close box can play louder and lower and better if you send the correct signal to the driver-box combinaison.
You just have to compensate the signal to the driver with added watts at low frequency, cut completely watts below f3 and tune the phasing with dsp of the driver-box combination because at those frequencies the large volume of air have counter reactance and also some added impact that add efficiency at left of max fs impedance and remove efficiency below fs. I want to build a double close box with one big woofer for low end bass and another one for high bass, these two woofer will be close box, so i think that it will be a new design that will be perfectly controlled and boosted by the new powerful digital amplifiers that have ton of watts. i think that old farted ported box designs are out of date because they were build because the amplifiers of the past were lacking power and control and bass correction dsp, so they just adopted ported box noise to give a sense of power at low frequencies but that bass is not musical and sluggish and the only thing people were saying is that it is boomy. No one ever talk to me than that bass were sweet.
