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

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.

vtvmtodvm:

"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."

Hello vtvmtodvm,

Your statement is phrased as if it were factual or at least something agreed upon by a consensus of acoustical experts or experienced home audio enthusiasts. Based on my knowledge and experience, I believe your statement is merely your personal opinion, is mainly demonstrably false and should be completely disregarded by anyone trying to attain good bass response in their rooms.
It has been proven that using a single sub in any given room can provide good bass response at a given single position in the room if properly positioned but the bass response will also be very poor throughout most of the remainder of the room due to the large number of bass room modes generated by a single sub (heard variously as spots of bass exaggeration, attenuation and even bass absence).
Adding a second and third properly positioned subs to the room begins to gradually reduce the number of bass room modes which not only increases bass quality and impact at the assigned sweet spot but also begins to improve bass response throughout the remainder of the room. Doctors of acoustical engineering, Earl Geddes and Floyd O’Toole, have discovered and verified that having 4 subs properly positioned in a given room (in what they call a distributed bass array system) will eliminate the majority of bass room modes and provides excellent bass response throughout the entire room, making any position in the room a bass sweet spot.
I use the Audio Kinesis Debra 4 sub distributed bass array system in my 23 x 16 x 8 foot room and can verify this system definitely provides state of the art bass response throughout my entire room.
I wanted to point out that placing subs in the corners of your room should definitely be avoided since this will produce exaggerated bass and only multiply the number of bass modes existing in any given room. I’ve actually never heard of any benefit gained by toeing in subs in corners.
     As to bass traps, mics, room correction and parametric equalization, none of this is required with a properly positioned 4 sub distributed bass array system.
I don’t currently have the time to monitor the rest of your post for other misinformation, I never advanced past your first paragraph, but will try to do so soon.

Tim

Tim—With respect to the use of subwoofers to reduce room-related resonances, hey, the more, the better! Of course, most listeners have constraints that prevent adding more than two subwoofers to a modest-sized listening room. Certainly two is my limit, and I suspect that two subs is as much as most people would tolerate.

Regarding location: Assuming a front wall position (that's the normal personal preference), and given that such subs should be OUTSIDE the main speakers, a 16 ft. wide listening room (such as mine, also yours) would then dictate that the subs be in the corners—or virtually so. In that event, some toe-in would likely be helpful. In practice, decor-dictated personal concerns will probably determine where the two subs must go, and that's generally in the corners too, as they're likely be the only open area.

The "distributed array" concept is worthy with one notable exception: It generally (?) recommends leaving the main speakers UNfiltered. While that can be beneficial with respect to reducing low frequency room mode response, it ignores the primary benefit implicit when using an active electronic crossover to separate the ultra-low (<100Hz) bass passband (subwoofers) from the low-&-mid bass passband (main speakers). That separation assures that the main speakers (and their power amplifier) no longer have to process any heavy low bass energy. Those low bass frequencies now get shunted to the self-powered subs. That's an important advantage, and it's way too vital to bypass.