Don't worry, you're right! Most sub crossovers are set too high and overlap with the mains, which is annoying to say the least.
Also, placement is quite variable. Corner placement reinforces the output the most, but also generates the most uneven standing-wave response. Best placement is highly room-dependent, so what works well in one room may be terrible in the next.
Also, placement is quite variable. Corner placement reinforces the output the most, but also generates the most uneven standing-wave response. Best placement is highly room-dependent, so what works well in one room may be terrible in the next.