Do you use a Subwoofer when listening to stereo?

wolf_garcia:" Using subs while running main speakers as they were designed at full range, at least the full range they're capable of, works fine. My 2 RELs simply enhance the sound of my mains and add the necessary low bass, and are easily dialed in without the unnecessary addition of an extra crossover...time for low bass is essentially irrelevant and correct phase is easily dealt with...note that if you're in a small club near the musicians (remember those?) with a band across a stage, you hear all the instruments with timing delays...drummer 10 feet away from the piano, guitar player on the side with plexiglass barriers...whatever...and the result of all that can be great sounding music. Don't be warned off by self appointed experts, except me of course."

+1 wolf_garcia  Well said and I agree with everything you stated.  Humans are not nearly as sensitive to the arrival time of bass frequency sound waves as we are to the time alignment of midrange and treble frequencies. 
     Bass sound waves are extremely long, spread out in all directions from the driver, whether the woofer is in a main speaker or a sub, and they continue to reflect off room boundaries (walls, ceiling and floor) until they're either absorbed or run out of energy. 
     In fact, we don't even hear or perceive any bass sound at all until the very long complete full cycle bass sound wave is detected by our ears/brain.  If we detect anything other than a complete full cycle sound wave, we hear or perceive any sound at all.   If the room is not very large, this means the very long full cycle bass sound wave must reflect off of 1 or more room boundaries before it is even recognized by our ears/brain as such and a perception of sound generated by our brain. 
     The truth is, much of the deep bass sound we hear in a room is perceived as a result of reflected sound waves.  Given these physical realities in most normal sized rooms, it's obviously not possible to time align  over the entire audible frequency range.
     It's virtually impossible to ensure  that the long and omnidirectional bass sound waves arrive at the designated listening position at the same time that the much shorter and highly directional midrange and treble sound waves arrive,  Fortunately,  it's not relevant since humans don't require time alignment for accurate sound perception.

Tim

Hello,
If you are using your subs for music please run your front or L/R speakers full range and set the limit on the subs crossover to meld with your speakers. You might be surprised going all the way up to 110hz on the subs crossover for music or melding with the front two speakers. When watching movies it is a different setup they tell you to do. I do what sounds best. Even my very small surround speakers play down to 60 hz and my center plays down to 45 hz. I set the fronts to large or full and the rest at 60hz. My ported sub comes in at 80 hz to blend in.  My main speakers play down to 25 hz and my subs are set to roll of at 50 hz. This is the frequency when I could tell when they disappeared. 

Nobil100, no it is not fine to run satellites full range while adding subs for three reasons. First is you miss the opportunity to lower distortion and increase head room significantly in the satellites. Second is you make integration much more difficult. You are down where the wavelengths are over 10 feet up to 30 feet. Unless you are using digital bass management matching phase and time are difficult, usually by trial and error  moving the speakers and perhaps by using a phase control on the sub. Without a two way crossover there will be more overlap making the problem worse.
Digital crossovers can use slopes as high as 10th order which is actually too steep! Third is you will get a hump where the speakers overlap. Unless you can EQ the subs, keeping the system from booming at the overlap will force the volume down below the overlap keeping you from getting the power you need below 40 Hz. 
The hallmark of a good subwoofer system is that at a modest volume there is no difference in sound on subwoofer bypass until a really low note comes along. Use an acoustic bass solo and switch back and forth.
At higher volumes the decrease in distortion in the satellites may tip you off. 

Thanx cleeds, you are right about the outputs.