Honest Experience on Effects of Subwoofer Please

@phusis 1+. Live concerts are in much larger venues than a residential room. Bass is much less of a problem in larger venues. Then you have to deal with echoes which can be profound. We really do not have echoes in our homes or rather very little. The distances are too short which makes the delay shorter. We have difficulty with reflections which can be perceived as part of the music then as a distortion of the original signal. 

There are very few systems that could not benefit from subwoofers. My goal is to save people, who want to get into them, time and maybe some aggravation. I have always used a two way crossover, always, right from the beginning. I had a single sub for 6 months when I discovered that one was not going to do it. This lasted for 22 years and as I said before it was a love/hate relationship and at times very frustrating. 22 years later TacT entered the market and I jumped right one, their 1st preamp and I upgraded to another one down the line. The results floored me. Then I realized that I needed 4 subwoofers, next is 8. The TacTs time has come to an end as there is now better tech out there. I thought I was going to get a Trinnov unit but I am waiting to see what the next high end DEQX unit is going to like. It is supposed to be released next quarter. The company has not yet released an owners manual so I can get a handle on it's capability. But, from the outside it looks great.

The point of all this is that if you start out with two subs and a digital crossover like the MiniDSP you will saving yourself a lot of time, frustration and expense. Don't do it cheap. Do it right. On the other hand if you have to learn the hard way like I did fire away. You will learn a lot in the end.

@b_limo , that is an interesting way to do it. What are you doing to delay the sub so the arrival time and phase are the same as the main speaker's Your version is surely visceral when you are seated but everywhere else not so hot. The realistic way to do it is multiple subs out front and a lot of power. 

@scm , I also cross over at 100 Hz. You need subs that sound good that high and they have to be in a stereo array. The rational for it is to take the load off the main amp and speakers to lower distortion and increase head room. In my case IMHO it is critical. I use full range ESLs. One diaphragm handles everything. Taking out the bass literally cleans up everything and they play louder than anyone could stand for 30 seconds. 

@mijostyn

So you aren`t running the mains full range then right ? Are you using a high/low pass filter on one of the subs ? By stereo array are you running L&R to each sub ?High level ?

I have 3 musical subs...

2 - HSU ULS-15 MKII`s and a Revel Ultima 15 all sealed. 

As a last comment, I previously mentioned 8 subs. What I plan on doing is 8 drivers in 4 enclosures.  I'm doing this because in comparison to live performance I feel my bass which is wonderful for a home system, needs just a little more authority. Doubling the drivers only gives you another 3 dB but I think the array will pressurize the room better for lack of better terminology. It may not work. The problem might be with the dynamic range of the source material. It will definitely lower distortion in the bass so it should be worthwhile in the end.   

I think the issue with subs is its far more complex than it appears:

1) SOURCE MATERIAL has varying bass levels. The deep bass in source material is all over the place, and its not your fault.  It's not consistent at all and we find a large variance in quality.  Many records, especially old english records have no bass (Genesis, Selling England by the Pound, Kate Bush, etc).  Many streaming services strip bass out to prevent clipping within their processors.  If you adjusted your sub to sound good on one thing, the next thing will likely be very different.  This makes one think its the sub not working correctly when its no such thing.   

Conversely, if you set up your sub to sound good on Eminem, very little has that much bass in it.  Technically, this is where recording quality has improved dramatically over the years but old recordings or some broadcast mediums roll the bass off tremendously.  

So the music you play may determine if you say "my subs don't do anything".. 

2) SUB LOCATION in the room is also greatly varied compared to someone else.  Since most of us are horrible about setting up subs in room, or we love to use just one-in the dead center between two speakers (the single WORST place) - we get vastly varying results of a given model of sub in the room.  Quite often this center position is the null point in the room and the owner never tries a different place because he or she has been told or mistakenly believes "they belong there".    

3) Use of HIGH PASS FILTERS in line with mains is very audible, introduces a major phase shift due to the larger physical distance between mains and sub, and almost never sounds good.   Using mains full range and subs low passed and then blending to taste is my preferred way, getting the subs as close as possible to the mains, maybe even on the same stand (if you are using sound anchors).  I've heard and set up many systems where this technique makes the subs almost 100% undetectable.  Not always, but certainly better than HP inline with an expensive speaker I bought for "resolution". 

4)   The idea of one big sub is not the best way.  The best plan is the opposite, multiple small subs set up on multiple different walls at different distances from corners.  This is far more likely to yield a smooth response in the room.  That's why I like Duke Swarm idea, it works. We use multiple subs in pro studios all the time, it always works better to excite more room modes rather than fewer room modes.  Then, one mode doesn't dominate.

5) Use subs somewhere from 125 Hz to 95hz on down works better than trying to get subs to work up higher.  It might work in Live sound, but not for home.   

6) Make sure you have inverted phase on the sub to see if its better.

7) do not depend on measurement with a low cost or built in system.  Those little mics that comes with receivers or lower end preamps are absolutely terrible- they have no bass, they are not accurate below 200Hz 99% of the time. 

8) People expect there to be bass in small room.  Bass wavelengths are long, and if the frequency's wave is longer than your room dimension guess what, you won't be able to hear it.  (32Hz = 38 feet long wave.  Anything room dimension shorter than this means you cannot propagate (reproduce) 32Hz in there.  20Hz wave = 54 feet.  10 feet means 60Hz is about the best you can do.

Brad