[ctviggen]

Last night, I changed the position of my sub (an SV sub -- older model PC+) and setup my two channel system to use the sub.  I did a minor amount of level matching but no phase control.  I previously have not used the sub because I can locate it and also because I didn't like the sound in a house with wood floors.  With my current house (on concrete floor), I don't mind the sub, at least for as much as I've listened to it.  However, I can easily tell where it is.  (Current cross-over is 80 Hz.)  Can people really not tell where their subs are?  

Luckily, I'm going to (attempting to -- the seller has disappeared) buy another sub to have stereo subs.  

So, do you have a single sub you can't locate, or can you locate the sub but just ignore this fact?

[Marbles]

Bob,

What's happening is that the sub is still playing higher frequencies than 80 hz, and that is what you are hearing.

If you crank the LP down to about 50hz, then hopefully the sub will not play above 80 hz and you shouldn't be able to hear it.

I'm gussing your Low Pass (LP) crossover filter is not a steep brickwall type, but a more gradule one, most likely 12-24db per octave.

[audioengr]

Room acoustics have a lot to do with this as well.  I have had good luck sometimes positioning the sub at the listener position (invert the phase).  Also, you can try aiming it into a hard structure, such as a masonry fireplace.  Dont be afraid to aim it into a wall etc...  Positioning is critical.

[R_burke]

Can't speak to the why and how, but a good sub that is truly integrated into your system cannot be located, but it can be heard.  Emphasis on GOOD sub and INTEGRATED into your system.

[Daniel]

I still have a Phase tech PC60/PC80 sub/satellite set of speakers.  They served me adequately for years and now are on loan to a friend.  I could always hear the sub no matter what I did, using the built-in passive cross-over in the sub.

[Rob Babcock]

You do have to X a sub over fairly low to prevent localization.  Then you need a fairly steep slope to keep higher tones out of the sub.  Lastly your sub must be able to play cleanly without a lot of harmonics that give away its location.

[_scotty_]

One of the major problems with most subs is the non-linear phase nature of the sub-woofers cross-over. The phase-shift produced by the cross-over causes most of the localization problems. The sub and satellites are out of phase at the cross-over frequency which makes integration of the separate speakers into coherent system difficult or impossible. Scotty