Two subwoofers with a single, fixed listening position

[sigbergaudio]

I tried to simulate that. This is the best I could come up with in 4 x 5m and a reasonable listening position.
I assume this could be EQed to nearly flat, as there are no nulls below 160 Hz?
View attachment 349558

But this example also shows the limits of a single sub, if one switches on the results for positions around the point measurement from above.
Now there are differences of up to 12 dB from positions half a meter apart.
That puts things into perspective a bit (as I grew quite envious already ;-)

View attachment 349559

Yes, you are certainly likely to be limited to a single seat sweet spot with only one sub, and you are quite lucky if you can both position your sub in the optimal place and have the sweetspot in a good place too. But it isn't impossible.

 

[Weeb Labs]

In my experience, smaller rooms (<3x4M) can introduce unexpected complexities for subwoofers; especially if using just one or two. The modes can become so physically close together that the interaural response differs significantly, which is perceived as a rather unpleasant pressure difference between the ears. This is why there are four subwoofers in my office.

 

[HiMu]

I tried to simulate that. This is the best I could come up with in 4 x 5m and a reasonable listening position.

One thing that isn't included in simple simulations is modal support from adjacent rooms if the partition walls are flimsy enough. My small attic room shouldn't have ~18-22hz room modes, but look what comes up when I simulate the whole upstairs. Notice how the mode directions are perpendicular between the simulations, so instead of a single room acoustic puzzle, I now have to think 2 rooms at the same time!

Upper half: whole upstairs, lower half: room only. Room mode calculator view and room position in the upper simulation view added

GLM calibration only.

For a single listening position it's possible to get quite even bass from single subwoofer, but that takes a bit of perfectionist/madman approach.

That doesn't mean I'm not considering another sub.

 

[sonitus mirus]

Start with one sub and measure. Add another sub if problems can't be resolved through positioning and EQ. If satisfactory results cannot be achieved, consider adding and additional sub and repeat.

 

[ernestcarl]

One thing that isn't included in simple simulations is modal support from adjacent rooms if the partition walls are flimsy enough. My small attic room shouldn't have ~18-22hz room modes, but look what comes up when I simulate the whole upstairs. Notice how the mode directions are perpendicular between the simulations, so instead of a single room acoustic puzzle, I now have to think 2 rooms at the same time!

Upper half: whole upstairs, lower half: room only. Room mode calculator view and room position in the upper simulation view added
View attachment 349583
GLM calibration only.
View attachment 349623View attachment 349622
For a single listening position it's possible to get quite even bass from single subwoofer, but that takes a bit of perfectionist/madman approach.

That doesn't mean I'm not considering another sub.

My room is also larger than it really is if one reconsiders the flimsy drywall separating/dividing the floor areas. Though, I think I’ve been lucky enough to find a specific spot in the room where the bass from a single sub is quite even and smooth enough for my entire couch length which is positioned right against the wall. Position the couch a little bit more forward or back and the irregularities between seats increases.

 

[ozzy9832001]

If I’m in a desk set up, where listening will be at the apex of an equilateral triangle (3 x 60° angles), is there any use to having two/multiple subwoofers, or does this just help with multiple seating/listening locations?

The second sub can help cancel some reflections and modal issues. I use 2 and get better response than with just one. The key is to experiment with placement, because you probably don't want it in the same acoustic zone as the first.