Will a subwoofer add depth and clarity to my system, or just bass?

"Q"

John de Lancie! https://www.imdb.com/name/nm0209496/

Your turn.

Sub will add depth, weight and fullness but not clarity. 

I continue to be amazed by the knowledge of this group.

i wonder why the group does not talk about master setting speakers.  One of our local dealers demonstrated the art of master set.  He demonstrated this in one of his listening room.  When he moved the right speaker 2 feet, we suddenly had to raise our voices to hear each other.  I also noticed how I suddenly began to hear right and right speakers.  The sound also was not relaxing.

This dealer is one of the largest REL dealers in the country.  During his demo he donstrated adding a REL S3 to a pair of   Vienna Acoustic Mozart’s and I had a difficult time hearing a difference when adding the sub.  I wonder if this was because the Mozart can get down to 24 Hz.  Have really good ears and wonder why I couldn’t hear the difference.  I was expecting to really hear the bass beat.  I do think I heard greater in the mid range.  I purchased a pair of Paradigm Prestige 85F’s and now feel they sound harsh in the mid voicing.  The dealer came to my home and told me they needed to be master set. He also suggested adding a pair of REL T/9i’s.  He told me this would clear up the mid’s And make them sound less harsh.  Based on this discussion this must make sense.  However, before buying the REL’s I wish I could hear the difference in sound.  The dealer told me REL’s are not designed to pound out the bass and if they were they would eventually drive me out of the room.  So far, I am saving up to buy the REL’s.

I listened to a pair of SALK Song3 Encore’s at the RMAF and had I listened to them before buying my Paradigm’s would have never purchased my Paradigm’s.  I certainly would not need to add a sub other than for home theater.

A couple of clarifications…

One of the major benefits to be derived from the addition of self-powered subs (use at least two, generally spaced wide, and towed-in from the front wall corners) is that they'll help you defeat room mode peaks/nulls. They're the next best thing to 4 inch thick broadband bass traps.

Another important benefit is that they'll allow you to take the heavy lifting off your main woofers/power amplifier. To do so, you'll need to install via an external active 4th order electronic crossover controller. Marchand's XM66 is a good solution.

Yes, proper integration is vital. You need to accurately phase-match the subs with your mains at the crossover frequency, and you need to assure that you've properly set the subs' input gain (at xover frequency) so that it's +3dB more than mains output. I have very recently posted a paper about how to do this (with instruments) on the Classical Candor website.

In quickly surveying this site it's evident that some commenters confuse phase-coherency with timing. Yes, it's vital that you synchronize the phase of your mains and subs (at xover frequency); however, that does NOT mean that wavefront time-of-arrival will be matched. An inherent time-of-arrival disparity will still remain because the related low-pass filtering entails group delay on the order of some 12-16 msec. in the crossover region, so subwoofer output will lag the main speaker by about one full wavelength (equiv. 13.5-18 ft.). Regardless, after the two signals are accurately phase-matched at the listener site little evidence of this timing offset will be apparent. A good self-powered subwoofer that offers a continuously variable phase angle control over the span of 0 to 280 degrees will provide sufficient additional delay to allow you to accurately phase-match with your main speakers' output. A 0-180 degree control is NOT adequate.