Placement of Single Subwoofer Affecting Sound of Main Speakers

Due to a recent furniture arrangement in the room, the subwoofer that was sitting dormant for several years had been reluctantly reinstated in the main system. I have been experimenting with the placement of the sub in the room. Due to limited placement options, the sub can only be placed in these 3 spots ;

1. In one corner of the room, very close to the side and rear wall (1 or 2 inches from the walls)

2. Just behind the left speaker, 5 inches from the rear wall

3. In between the speakers but very close to the left speaker, not at the centre of speakers.


To cut to the chase, I’ve briefly tried all options. The 1st option with the sub placed in the corner of the room gave the worst result. Now, the interesting part. Even though the sub was turned off, the sound quality of the system degraded. It appears that the physical presence of the box in the corner of the room made the sound worse.

I am currently settled with the 2nd option and this configuration sounds much better than the 1st option irrespective of the sub powered up or down.

The sub is currently on spikes as I’m still waiting for some Nobsound springs to arrive before I can plonk the sub on these.

I’ll be trying the 3rd option again although the WAF is the worst on this one.

Has anyone here experienced a worse sound quality from the system with the placement of the sub in the room? A sub that’s switched off and not working.

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I have done both number 2 and 3 while one of my subs was getting fixed. Number 3 worked pretty well. I was using a highpass crossover at the time. 

+1 jl35's crawl test suggestion.

Most any room has an optimum location for a single subwoofer that will result in efficient performance at the listening position. 

You'll need a pair of long interconnects and an extension power cord. Monoprice or Blue Jeans cable offer custom length interconnects at reasonable prices.

Playing a test CD or file with a low frequency cadence will aid in hearing the loudest area or mode in your room.

You don't necessarily need to crawl around your room but it can provide a more dramatic sound.  

Positioning the subwoofer at or near this area should provide a satisfactory location to begin the other adjustments. Good luck with the aesthetics.    

Ideally you want one sub front and center. Front and slightly off center is next best. Avoid the corners. Rear center is another decent option especially if you sit closer to the sub than the front mains.   You can get away with a lot with sub placement though when needed especially if sub is set to not do much above 60-80 hz or so. 

Hey, and yes, but I didn't know it could happen with a direct radiating subwoofer. :)

The effect you may be having is that the sub is acting like a tuned bass trap, OR you are finding it's reflecting a lot from the speakers.  The latter can be tested with a blanket.  If the blanket covering the sub fixes your problem it's purely an acoustic reflection issue.

If it sounds about the same it's probably because the sub is sucking an octave out of the room.