Hello guys, I want to finally get a SUB…but now I am again in front of a Dilema….so HERTZ I would best buy (as you ordered), but which is exactly better…es250d or it300….I calculated here and I got this at the end:ES250D box volume in liters: 75.4 marginal frequency f3 (-3dB) in Hz: 25 marginal frequency f8 (-8dB) in Hz: 21 efficiency in dB (1W/1m): 86 length of the bass reflex tubes in cm: 37.7 diameter of the bass reflex tubes in Hz: 21 efficiency in dB (1W/1m) cm: 10 Number of bass reflex tubes: 1 Total surface area of the bass reflex tubes in cm2: 79 Ql: 7 ES300 Box volume in liters: 71.3 Limit frequency f3 (-3dB) in Hz: 31 Limit frequency f8 (-8dB) in Hz: 25 Efficiency in dB (1W/1m): 89 Length of the bass reflex tubes in cm: 30 Diameter of the bass reflex tubes in cm: 10 Number of bass reflex tubes: 1 Total surface area of the bass reflex tubes in cm2: 79 Ql: 7 …what does “Ql” mean? So it’s about a Polo 6n, trunk reserver admulde, amp must CARPOWER HPB-1502 2 be…or something like that… So you already have an idea? Thanks again in advance! MfG Nik