Jacob (owner of Sundown) designed the Skar and SA.... the Obsidian line is a joint venture between himself and Nick of Stereo Integrity. As such, there are a lot more differences than you may think. About the only thing shared between them is that they all have a 2.5" coil. Skar is designed as it is because it is what Kevin requested of Jacob. I am not missing the point... I am not suggesting for him to go out of his budget and go "super-high end." Skar is very budget for what you get. Not once did I mention, say, a Critical Mass UL12. In fact, I offered to assist him with an enclosure design for whatever sub/subs he chooses. I was simply pointing out erroneous statements made by yourself for the benefits of others. "Regular, low-budget, average subs" will perform based upon their proper implementation, and all of them are different. There is no rule of thumb about certain size subs for certain music. I am not attempting to offend you, but that whole concept is absolutely incorrect.