Subwoofer

I never understand those who say it is difficult to incorporate a sub into a two channel system .Or that it is not a purist way . If your speakers do not have at least a ten inch driver why not add a sub . Have restraint when setting it up with volume and crossover and you will never know its there . Now if you have large speakers that go down to say 20 hz then why ? 

At what frequency do you crossover ? If at or above 27hz you have the subs plus your speakers doing low bass duties ? I tried a sub crossed around 30 hz with some Thiels cs7's which go down to 23hz  and it sounded like they were competing with each other , was not clean sounding but i did not use an external crossover . I am unclear on what frequencies your speakers are handling . I would like to know how that gets setup . Seems like it would be beneficial if less taxing on amp/speaker relationship . 

The beauty of a subwoofer is in it's ability to be placed in the best location for your room . Your mains are restricted in a fixed immovable location due to a triangle listening setup .