# Subwoofer Placement Question



## TheNivek (Nov 9, 2013)

Hi, new to this forum so hopefully I am posting in the right place. Common belief seems to be that placing a sub near a corner of a room is ideal to get good bass. I have also heard that placing the sub in the listening position, and then listening around the room for the strongest bass can determine a good location for the sub. I have set up three systems with a sub, but did not have any luck with these methods.

In the first and second setup, the best sounding bass was clearly when I put the sub directly between the two mains (with the listening position at one point of an equilateral triangle). For the third setup, that option was not available and I struggled to find the best sounding location for the sub. 

Measurements with REW seemed to explain why, and it had to do with phasing at the crossover with the mains. I could only EQ the sub to one of the mains, leaving a hole in the spectrum with the other main(horrible for imaging!). I could not get rid of the hole by moving the sub, equalizing the room, etc. – it just moved the hole around a little bit in frequency. I finally found a location which did not produce the most bass, so the sub had to be driven harder, but which had a smoother spectral response. The sound is now tight and sounds great.

So finally my question – my findings seem so drastically different than common belief - why? Have others experienced this?


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## mdanderson (Oct 3, 2009)

TheNivek said:


> Hi, new to this forum so hopefully I am posting in the right place. Common belief seems to be that placing a sub near a corner of a room is ideal to get good bass. I have also heard that placing the sub in the listening position, and then listening around the room for the strongest bass can determine a good location for the sub. I have set up three systems with a sub, but did not have any luck with these methods.
> 
> In the first and second setup, the best sounding bass was clearly when I put the sub directly between the two mains (with the listening position at one point of an equilateral triangle). For the third setup, that option was not available and I struggled to find the best sounding location for the sub.
> 
> ...


With every room and every speaker being different, trial and error with sub placement just seems to be the norm even when using room correction software. I got lucky with my dual PSA XV15s. The first place I tried for both of them was mid sidewall and that turned out to be very good for me. I used the sub crawl test with one of the subs and then decided to try mid sidewall and movies and music sound great.


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## Sonnie (Apr 11, 2006)

Corners are typically best to start with. You will usually get the most room gain, but you also will get some peaks, which can be easily cut. Peaks are okay to deal with, but the dips can be more challenging.

Do you have some REW graphs you can share with us... of just the sub by itself crossed over at 120Hz, since LFE goes to 120Hz.


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## TheNivek (Nov 9, 2013)

I have never heard it called a subwoofer crawl before - makes sense though. It is interesting that I also ended up with the sub midway down a sidewall. Thanks for your reply!


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## TheNivek (Nov 9, 2013)

I think the some of the problem areas are accentuated by the fact that I am fighting the acoustics of a small square room. Used absorber, but these areas are below their effectiveness. For example, there is a doublet mode at 47 Hz in which a 15 dB cut (at 50 Hz on my GEQ) can’t entirely remove.

- thanks for your posts!


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## ALMFamily (Oct 19, 2011)

TheNivek said:


> I have never heard it called a subwoofer crawl before - makes sense though. It is interesting that I also ended up with the sub midway down a sidewall. Thanks for your reply!


Interestingly enough, I also found the best location for my subs to be out of corners. As Sonnie said, you will get more oomph in a corner position (commonly referred to ask corner loading) but it does tend to excite room modes. I have 3 subs currently, and none of them are located in a corner.


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## tcarcio (Jun 27, 2007)

TheNivek said:


> I have never heard it called a subwoofer crawl before - makes sense though. It is interesting that I also ended up with the sub midway down a sidewall. Thanks for your reply!


Check out this video on the sub crawl...


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## sdurani (Oct 28, 2010)

TheNivek said:


> Common belief seems to be that placing a sub near a corner of a room is ideal to get good bass.


Ideal to get loudest bass, not the smoothest bass (since corner placement excites every room mode).


TheNivek said:


> So finally my question – my findings seem so drastically different than common belief - why?


It could be as simple as starting from the wrong premise. When people say corner placement is ideal to get "good bass", their idea of "good" might be loud while your idea of "good" might be smooth (fewest/smallest peaks & dips). 

Which means that conventional wisdom does work, but not for the results you're looking for. Starting from the premise that their idea of good is your idea of good might lead to you scratching your head at disappointing measurements (and posting on an AV forum to ask why).


TheNivek said:


> For example, there is a doublet mode at 47 Hz in which a 15 dB cut (at 50 Hz on my GEQ) can’t entirely remove.


Is one or more of your room dimensions roughly 12 feet? If so, moving your sub to the midpoint of that dimension should minimize that mode.


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## TheNivek (Nov 9, 2013)

Thanks Sanjay. Very good points - and actually both of my room dimensions happen to be 12 feet! ... and yes, I did find that placing the sub halfway down one wall gave the best (er ... smoothest I mean) response!!!


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## sdurani (Oct 28, 2010)

TheNivek said:


> Thanks Sanjay. Very good points - and actually both of my room dimensions happen to be 12 feet!


How about that math! You mentioning 47Hz gave it away.


TheNivek said:


> ... and yes, I did find that placing the sub halfway down one wall gave the best (er ... smoothest I mean) response!!!


Heh. You're going to be more careful in the future when you see terms like "good" or "best". 

If you ever get a second sub, then placing it at the midpoint of the opposite wall (directly opposite your current subwoofer) will minimize the 47Hz length AND width modes.


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## TheNivek (Nov 9, 2013)

Great advice everybody, and great video. Thanks for the replies!


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