its the air blowing back out its comin in so fast, when that throttle closes, it goes back out. the woosh is....(...i t hink at least. i have the same sound)
i have jba headers and catback and afe2 cai. waiting on taking vids til i get my catted mids in.
once i do ill be posting a video too so stay tuned in the next week or 2
the jba system does drone a bit. when i first put it on (headers, stock mids, catback) it didnt drone at all, no matter how hard i tried. sounded stock on the freeway, but amazing at idle and wot.
now it does have some cabin resonance, but its from the exhaust system its self, now that the pipes are burned in. not from MDS. i can barely hear MDS kick in still, but its not really much of a change, in pitch as much as i expected.
if you are afraid of drone, this may not be the system for you. its not bad. but some people want their cars quiet as stock on the inside. then you gotta pay for corsa or zoomers ;/