That's a myth. A false one, at that. I could get my 15" TDX to sound just as "tight" as its 10" version. It's all in the setup. I could make a 10" sound boomy and I could make a 12" sound tight. Build the enclosure properly and limit the more capable low-end extension of the larger sub with the use of some crossovers and you'd have a hard time arguing that the 10" is tighter. This is a comparison between a 15" and a 10". You'd have to have a dog's sense of hearing to think there'd be much of a difference between a 10" and a 12", if any at all.