Do you use a Subwoofer when listening to stereo?

Atmasphere, phase is only half the issue time is the other one. I find it rather comical that people can say phase is not an issue. Wire one of your speakers 180 degrees out of phase and what happens to the bass. Any fundamental from impulsive bass sounds such as bass drums disappears. Most people would not notice this because their systems do not produce these fundamentals in the first place and I think this is what most of the mythology stems from.
Now it is true that the wavelengths are very long and physically getting a subwoofer 180 degrees out of phase would mean backing it up 15 feet and the degree of out of phaseness depends on the frequency. But, if you do that you have now created a 15 msec delay between arrival times making the situation even worse. Accurate bass transients at the listening position at least, requires the arrival times of the sound from each speaker to be exactly the same with the signal being in phase. In order to do this you need to be able to measure what is going on and then make the appropriate adjustments. In my case the computer makes the adjustments for me. I also have the ability to manually change delays and phase so I can demonstrate to you exactly what happens to bass transients. These are not something that you just hear by the way. They are something that you also feel. Now, I use four subwoofers but they are arranged in a specific way for a reason. They produce a single wave front without interference from the side walls floor or ceiling. There is essentially no back wall because of the way I designed the room. That wave front gets to my recliner at exactly the same time and in perfect phase at all frequencies as that of the satellites or main speakers. 
Swarm systems where you are placing the subwoofers at various random points in the room is a way of dealing with your typical room acoustics.
It is not necessarily the best way to integrate subwoofers with your main loudspeakers. Whether or not you can actually make it work satisfactorily? I have no idea. I have not measured a system set up that way. 

Nobil100, it is not just what you hear, it is what you feel. Eventually you will get a proper crossover and learn. Unfortunately, accurate bass below 40 Hz is a rarity is home systems. In order to use subwoofers at the state of the art you need digital bass management. Without it you are lost. If you think you can get it right just by listening...just keep listening. Listen to live performances in smaller venues like jazz clubs. See an artist like Dave Holland then buy one of his records. Are you even close?

 Adding subwoofers under the main speakers is just a cheap easy way to do it. The manufacturers would not be able to sell subwoofers otherwise. The Swarm system is a great way to deal with room acoustics which do cause a large share of the problems related to bass reproduction but not all of them.  

I find it rather comical that people can say phase is not an issue. Wire one of your speakers 180 degrees out of phase and what happens to the bass.

@mijostyn
Generally speaking, if you have a DBA setup, two of the subs will be in front and in phase with each other and the mains.  But the other two may not- take a look at Duke's instructions above. Below 80Hz time alignment simply isn't an issue.


Its great that you were able to build your room to prevent standing waves (which is hard for me to understand how that is possible). In such a situation a DBA does not make much sense. Most people do not have that luxury!! But that is such an exception to the norm that in a nutshell, your situation does not exist for most people. But having such a room, you must be aware that your comments, while correct for you, really won't apply to anyone else.

cakyol:"It is all a personal taste. Some do like it, some do not. I do."

Hello cakyol,

     Overall, I agree with your statement about supplementing the bass of the main speakers in a stereo system and room with subs. For readers of this thread who are considering adding one or more subs to their room or just want to learn more about how to do it well, however, I think it’d be beneficial to elaborate a bit.
     In my opinion, it’s very unfortunate and misleading when those opposed to the use of subs falsely portray the effects of subs as ’boom, boom, boom, one note bass’, ’subs are only good for ht’ and ’subs just draw attention to themselves and are too difficult to integrate well with the main speakers’.
     From my perspective and experience, these types of statements are just very obvious and reliable indicators that the commenter has failed to implement 1 or more subs in their own system, are simply describing the results of their personal unsuccessful sub integration attempts,, are unaware of how to do it well and, therefore, have never experienced the high quality bass performance and seamless integration when 1 or more subs are incorporated in a room and system skillfully.
     My experience is that good bass performance can be achieved, at a single designated listening position, in most rooms utilizing 1 or 2 subs provided the subs are optimally positioned in the room, and in relation to the LP, through the use of the sub crawl, automated room correction or in room electronic measurements. My definition of ’good bass performance’ is bass that is solid, powerful, detailed, tonally accurate and natural along with being well integrated with the main speakers.
     I believe in the axiom, however, that 2 subs perform about twice as well as 1 sub and 4 subs perform about twice as well as 2 subs. The main reason for my belief in this axiom is personal experience with its veracity in my own system and room. I find it amusing that some sub naysayers attempt to discredit this axiom by suggesting the use of 8 or 16 subs, wouldn’t that provide even better bass performance?
     Well, the answer is a definitive yes, in-room bass performance is improved in direct relation to the number of subs being utilized in a given room, according to scientific experiments and research conducted by acoustic experts Dr. Earl Geddes, Dr. Floyd Toole and Todd Welti of Harman International.
     Importantly, this independently verified sub research also discovered that in-room bass performance improved significantly with each sub added up to the threshold of 4 subs and that each sub added beyond 4 only improved bass performance to a smaller and more marginal extent. This research result, along with the fact that there’s a practical limit to the number of subs that individuals will accept in their rooms, are the rationale for the Audio Kinesis Swarm and Debra complete kit DBA systems, along with most custom DBA concept sub systems, typically utilizing 4 subs or less.
     Based on my experience, there are 3 main benefits of adding a 2nd sub to a single sub system: 1. The overall system bass power and bass dynamics capacities are increased, since bass is cumulative in a room and the number of subs has been doubled, which results in the bass being more capable of faithfully reproducing whatever the bass demands of the source material may be. 2. Bass distortion is reduced, since each sub is operating at a reduced level and well within its limits. 3. The other general benefits of utilizing multiple subs in a room also begin to take effect and become noticeable with the use of 2 subs. Qualities such as increased bass smoothness, speed, detail, sense of ease, improved stereo sound stage illusion and better integration with the main speakers.
     When I began using 4 subs in my room, I experienced further enhancements to all the 2 sub benefits mentioned earlier along with an immersive quality to the bass and an absolutely seamless integration of the improved bass with my main speakers.

Tim

I thought I wanted more bass in my stereo room so I grabbed the dolly and rolled my old mirage with 2 opposite side firing 12” woofers, set it between the two speakers and ran a sweep. Amazing, reasonably flat response to 20 hz. I didn’t care for the way the hvac ducts were rattling and tbh getting a stereo pair set for room gain, or when the bass is locked in 45 hz is great for 90 % of the music I play. Subs in my truck are another story.

@ Emergingsoul 

Hello It's a matter of preference I think it depends on the speakers your powering and the type of music your listening to also. I am using a set of large speakers that don't need a sub there set to full range and 2 channel is the way to go for me some others may not agree but it's what you prefer. I like to know that I can have concert level sound with just 2  good full range speakers and leave the bells and whistles off. Have a great day!