Subwoofer


A couple of days ago I was talking to a dealer and he said that all speakers benefit from adding a subwoofer. What's are your thoughts? 
ricred1
I can be very particular and posses a keen sense of hearing. I was playing music by ear before I was introduced to my first music teacher. I do not require laser guided measuring devices or proper star alignment before partaking in sub woofer set up to integrate subs to a level of personal satisfaction. I can distinguish variances brought forth by things like cone material and surface areas. I can also appreciate multiples of 8" sub woofers as I find they often produce tighter cleaner bass. Not to say subs with larger cone surfaces are inferior in this respect I don’t believe that to be true all the time. I do believe not all subs are created equal even while being seemingly equal to some. Steps out.
"bo1972"..."In almost 18 years of time I learned that over 95% of all products in audio are not worth it’s money."

Using arbitrary percentages to make an across the board deduction like that is just plain silly. I would have to presume you have listened to every audio device ever made in the past 18 years ?

I also do not believe in running my main speakers through the sub's crossover just for purity's sake. I know there are certain advantages to doing so but I like to keep the mains as clean as possible. This way also allows you to just turn the sub off when not wanted or to compare with and without.
Ricred1, I hope you don’t mind me chiming in as I have enjoyed this thread and am considering adding a sub to my system.

I am driving a pair of Esoteric MG 10s in a room ~12.5 W x 15 D x 8.5 H. Though I am convinced that more than a single sub is best I would like to start with a single. I also think I would like to continue to use my 10s full range.  They drop off rapidly below ~50hz. I would be willing to buy a used sub to experiment with as I could resell it if desired. I believe a close box might be best, with variable phase. Any suggestions on a sub or my thinking?
I like Velodyne's DD series because of the room tuning and ability to play below 20hz.