Question About Sub Placement and Controls

Hi All,

I just moved my sub to in between my speakers, and I’m noticing drastic differences to my rig’s bass response between sitting back and sitting upright on my couch.

In short, sitting back on the couch makes my bass much more deep and punchy, but when I sit up on my couch, it becomes noticeably thinner!

A couple of questions;:

  1. is this normal? If not, should I be looking to get an even response between the two seating positions?

  2. is this a subwoofer phase control issue? Or is it some other control on my JL Audio F112v2?

Thanks in advance!

What you hear is the normal room response to low frequency. It builds up on the walls (the pressure is the highest near boundaries). That‘s why it’s advised to not place a listening position near walls.

Is there any way you can sit away from the wall?

Thanks, it’s actually a window behind me, but I guess it doesn’t make much difference with sound pressure.

I live in HK where apartments are really small, so I don’t have the flexibility of moving my listening position around.

I’ve been tweaking my sub for days now, but it’s been frustrating since the sweet spot is really small and the bass response changes so much when I move my head a few inches!

Photo of the opposite side of my rig below…

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Sorry, my comment is out of thread but I had the impulse to write my thoughts.


I suggest that you reposition the subwoofer and consider some room treatment. I have a similar problem with bass in my home office but moving my subwoofer to the other side of the audio rack made a significant audible difference. The room is not symmetrical with a barn door on one side. I have limited room treatment but have ordered bass traps and waiting for the delivery.

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You might also try to put the sub at the right hand end of the couch in the last photo.
Closing the drapes might or might not help. Moving away from the window a couple of feet while listening should help a lot.

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Another option would be to add a second subwoofer and place it on the sidewall if possible. Multiple subwoofers when properly placed would help to smooth out room modes.

Adjusting the phase will move the peak/null forwards or backward in the room. If all you care about is your seating position, then you could try to tune it so that the bass sounds good whether you are sitting back or leaning forward. The easiest way to do this is to sit in the listening position with a bass test track while a friend or significant other rotates the phase knob. If it is a phase switch with only certain phase shift settings, then you will need to experiment with the speaker position and the phase switch.

Multiple subs is always a better option if you can do it though.

Good luck. Here are some videos you might want to review on the subject.

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I agree with mycrowave. Multiple subs seems to be the best way to deal with peaks and nulls in the low bass frequencies. I believe the theory was developed by Earl Geddes where you would place multiple subs throughout your listening room in an asymmetrical pattern. Not all of the subs need to be placed on the floor. I know of at least one guy that placed one sub on the floor and mounted thee others at various heights on shelves mounted at various locations in his room. I believe Earl thought that three subs was the optimum amount but two should be an improvement over one if you can do it.

My setup is in a medium-sized room, and the only way I could place my sub, that didn’t sound like caca, was to put it behind and to the left side of my electronics, facing side-to-side( not forward), with the woofer output facing center, and the port facing opposite the woofer. It’s a 12" servo sub. Playing music this way, the sub seems to disappear, and it sounds like my main speakers have more bass. My electronics cabinet sits out about 18" from the wall. You might try this. It did seem to tame my room.