Yes, the dogs in my neighbourhood will attest to that, i played your track at reasonable levels and it does appear to have significantly large amounts of sub 60hz activity. The quad 15" mids and Dual 18" Tannoys really sprang to life in my lounge room. I’m not sure that this is very productive however, i mean i am feeling slightly nauseous now and rather bothered. luckily the bowels held up ok. If the A4 can only do sine wave subs then it’s a shame as even at high levels, a 20hz sine wave is relatively unmusical to my ears. square waves however are another story. good show JGB