Subwoofer Question

Thanks for all the responses. Took a while for moderator to post this, for some reason. I've been moving this sub and playing with crossover freq and gain. I finally found a good position, which is behind my left speaker. Crossover is set to ~80Hz and gain is set to 2 o’clock. So far I am very pleased with the sound. This really is a very good sub, no question about it. Still thinking about adding a second one. \\ Thanks again.

Do understand your comments, at least I think so. However, my experience is that the waves including lowest audibles can be felt and /or heard coming from a direction. Asking the question after the event, where did the event (sound) come from and one's answer must be their best estimate and I don't know being disallowed as an answer.

The first subs I auditoned were way back in time and in Seattle at a Magnolia audio store. I went back five or so times as I am a hard sell by most standards. The designs were downfiring as many were, and some still are. Nearly impossible to detect, immediately, the direction from which these low HZ originated. The sub fregencies just were in the room. The richness of sound was very much UP a notch or two. The side-firing designs, which are the two I have (Genesis Servo's), do emit sound to my ears from a direction either directly from the drivers and reflectively off objects, as I roam continuously about the listening room. With only one sub operating, what I am hearing is originating from a general area, and only one area. The walls and floor are very significant in this room and any room, we all agree? When both subs are connected and placed one on the right and one on the left (I prefer maximum separation and have settled at fourteen feet between), the low HZ are coming from a larger area. And the room is filled with more low HZ sound. And the direction that the sound originates from becomes very difficult to ascertain. Move away from SPOT and the point of origin becomes more ascertainable, including pinpointing some reflective sound and surfaces.

I decided on side-firing for one reason. I simply wanted as much of the music (sub sound) to arrive at my ears before bouncing off of other objects, that being the floor. It would seem logical that the shorted distance and most unobstructive path to the ears, when at the SPOT, produces the least delay and a positive result. Two side-firing, and set up to face the SPOT, are the best I have ever listened to, to this day.

Moganes, here is a suggestion I got from Mapleshade Audio that did work for me. I was having just a little too much highs from a front firing sub causing the "balance" to be off a bit. I ended up turning the sub sideways, as suggested in the catalog. It worked pretty good by eliminating most of the highs from the sub. Give that a shot, seeing it would cost you nothing about placement.

The reason that a subwoofer is non-directional below a certain frequency is because eventually the actual sound wave is so long that the ear cannot differentiate it. The reason is, usually, for high frequency sound, the ears will compare the sound they recieve with respect to one another do localize the sound. With very low frequencies, the wave is actually longer than your head is wide, so the ears cannot compare one side to another because to them, the look the same. This is why you get non-localized sound.

Chelan313,
For what it's worth, in my opinion that was an excellent and very informative post. I'm considering going to a double sub set-up myself. Thank you for providing some very helpful information for making that decision down the line.
-Bill

Another contribution. I lived with a single sub (powered Genesis Servo 12) and do, or did, hear some lop-sidedness. I use Outlaw ICBM Base Management (an active x-over unit) to filter the lowest HZ to the sub, and away from the low-mid drivers of the main speaker pair.

A second sub (powered REL Q 200e) was brought in by another audio friend and connected at the stereo subwoofer outlet of the ICBM. Mode switch set to stereo, and the blend (combine) to off, and spl level of each sub set as equally as possible.

As I roamed the room, the bass was coming from the left arena and bass was coming from the right arena, so far good. Sitting in the "sweet spot" or SPOT about center and each sub pointing to about the SPOT and spaced fourteen feet, I quickly realized that the bass was centered and not lop-sided. Very noticeable, very blended, very balanced, very different from only one sub. In a nutshell, it is bigger-bolder-better. Important to this is the sound levels of each sub is adjustable. Also, I do not have access to and use of corners like some of you have. My sound room is also owned and used for sitting by my wonderful wife.

I bought a second sub (used Genesis) after one week of listening, yet would have after the first thirty minutes. Never any regrets, extremely happy. Difference to me was between 5% and 8% improvement.

Sound level of entire system with two subs is simply controlled by me at the preamp (First Sound Reference, a dual mono design). ...Lower frequencies may be less directional, yet in a larger room size, you have to fully fill a room with sound. One sub just doesn't quite cut it, as the room size enlarges. My space is 18 x 22 x 16 (lwh).
Thanks all for reading....

Totally agree with both of the above posts. In one of the threads (Velodyne Digital Drive in Stereo, or something like that), one versus two subwoofers is hotly debated. I came away with this: Below 60 hertz or so, subwoofers are non-directional to the human ear. Don't know if that's true but it makes intuitive sense. My sub has the crossover set at 27 hertz and blends seamlessly with the mains, both in terms of sonics and in terms of seeming to be non-directional. It sits in a corner but the deep bass sounds like it's coming from between the speakers, or sometimes just to the left of center (towards that same corner, but still only a foot or so off center).

Agree. A 2nd sub is best but you need to make sure the sub blends with the output of your main speakers. Don't be tempted by the urge to make the sub heard. Try to blend the sub so that it's only adding an octave or 2 to the bottom end when the music plays it. The key is being judicious with the added bottom end extension.

You may have the crossover set to high...try a lower setting or move the sub between the speakers. Another sub will of course fix the problem also, and may be the best way to go if you can not do the other fixes.

Dave