ok.. great, your looking at the right area of subs. ill speak from experience, the BL is a great sub, even more so for someone who is stepping up to a real sub for the first time, it handles abuse like a champ, and will play hard and long,and it will get low enough for the average user, most people have no clue what lows really are any how. but when you speak of lows, the Q would be better for the lows, but not as oblivious to abuse as the BL, IMO, the Q is more so for the the experienced user, someone that can notice when and where a subs weaknesses are and play them in their strongest areas, people offten dont understand that all song are not the same, the notes are not the same, the recording quality is not the same, so very offten i see people playing a song and they tell me " this one bangs so hard in my car" but it sounds like shit to me, the recording is 3DB higher then the stereo is tuned for, and its basically clipping on a CD, but its louder so they think its better. i dont know your friend, so you would have to choose what user he is out of those two options. as far as the options