When sub is further away from listening position

[alaios]

Hi all,
I am posting this here since I think the question relates to room acoustics (how room shapes the sound at the listening position).
I know that subwoofers, that play lower frequencies (i.e. below 100Hz) send omnidirectional signals question is if they can be put further away from listening position (related to the main spakers)

The below attachment explains the problem:

We have two speakers at 1.80 meters apart and the ideal listening distance is at 1.80 meters. With Latin capital letters, we have potential sub-positions where cables can be hidden. Even though these might not be the ideal positions it does not harm to test those as well.

Positions C and D, top right in the figure are places that are further away from the listening position. MThe mainspeakers are 1.80 meters from lthe istening position and the C,D are around 2.5 meters from the listening position. Also, the subwoofer will be sending sound from the back of the listener's position.

1. Will that be a problem? Main speakers will have much longer cables compared to the subwoofer (subwoofer at position C and D is placed close to the main equipment). Then the sound itself travels a smaller distance from main speakers to listening position and of course, we have the room acoustics in the equation
2. What about going with a second sub in the future? For example position A(close to the main speaker) and then C or D on the other side and diagonally to the A.

What does the theory of room acoustics say about this type of setup? Do subs need to be somehow close to the listening position and close to main speakers?

Thanks a lot
Regards,
Alex (

 

[-Matt-]

Position B looks likely to be the best to me.

1) It is in a corner (for a bit of bass boost).

2) It is towards the front of the room.

Depending on how high you have to crossover the sub to the mains it can become slightly localisable. In that situation it feels more natural to have the bass coming from the front.

Position A would be my next choice.

If you will be crossing the sub at 80Hz or lower then it would probably also be fine at C or D.

The longer distance to the listener should be corrected for by delaying the sound to the mains. Any AVR will do this. What devices you are using for amplification and processing?

 

[alaios]

Yes I was thinking to cross it below 80Hz. If I read you correct you are (slightly) suggesting to try to avoid C and D positions.
The plan would be to drive those subs with the lyngdorf. (Stereo guy here)
I also get that if I put everything on the wall of the main speakers I would avoid having to delay things.

 

[HarmonicTHD]

Yes I was thinking to cross it below 80Hz. If I read you correct you are (slightly) suggesting to try to avoid C and D positions.
The plan would be to drive those subs with the lyngdorf. (Stereo guy here)
I also get that if I put everything on the wall of the main speakers I would avoid having to delay things.

Yes. B than A or alternatively right around the corner from B (left of the curtain). Avoid C, D. Cross-over and delay (phase) is best to be adjusted by automatic Room EQ (e.g. Dirac, Audyssey) or manually using REW. (BTW. delay in subs does not only relate to distance but also to the room modes - in simple words).

 

[-Matt-]

Yes I was thinking to cross it below 80Hz. If I read you correct you are (slightly) suggesting to try to avoid C and D positions.
The plan would be to drive those subs with the lyngdorf. (Stereo guy here)
I also get that if I put everything on the wall of the main speakers I would avoid having to delay things.

Yes, that's right. I'm not saying that C or D couldn't be made to work, I just foresee more potential problems if you try with those positions.

So what controls does the Lyngdorf offer for delays and EQ? (I'm not familiar with them). Time to consult the manual!

Note: Ideally I'd probably want to adjust the delay even with the sub at position B.

 

[alaios]

Yes, that's right. I'm not saying that C or D couldn't be made to work, I just foresee more potential problems if you try with those positions.

So what controls does the Lyngdorf offer for delays and EQ? (I'm not familiar with them). Time to consult the manual!

Note: Ideally I'd probably want to adjust the delay even with the sub at position B.

Time to check manual. I hope lyngdorf adjusts delay automatically.