Trials and Measurements
The best location for a subwoofer can be determined by trial and measurements using the appropriate acoustical measuring tools. When measuring a subwoofer system you are looking for a smooth extension of the frequency response from the main monitor low frequency cut-off (85 Hz when using the internal subwoofer bass management crossover) down to the subwoofer low frequency cut-off point.
Placing the subwoofer slightly offset from the centre of the front wall
The subwoofer is typically placed slightly offset from the centre of the front wall. This gives the following benefits:
- Increased acoustical loading from the front wall and floor improves the sound output in the subwoofer
- No acoustic cancellations because of the front wall and the floor
- Typically a relatively flat low frequency response in the subwoofer
If the sound is still not completely right...
If the sound is still not quite right, then try the following:
- Move the subwoofer slightly further away from the room’s centre line. This modifies the way the subwoofer interacts with the room.
- Add a second subwoofer, located at some distance from the first subwoofer.
- If there are two subwoofers, try moving them to the front corners or to the side walls, as this sometimes helps with problematic rear wall reflections.
Some additional things to consider
- Subwoofers can be flush-mounted; the cabinet takes up less space in the room. No changes in the low frequency radiation load will occur.
- Subwoofer driver can face the wall. A subwoofer can be placed with its side along the wall. Make sure there is enough space at the reflex port opening (at least 50 mm). Subwoofers are not directional.
- Do not place the subwoofer front baffle (driver) more than 0.60 meters from the nearest wall. This avoids acoustic cancellations in the subwoofer output.
- Place the subwoofer first at the listening position. Move the measuring microphone to different possible subwoofer positions (typically along the walls) to see which position gives the flattest response. Then, move the subwoofer to this position. This is called using the reciprocity principle of acoustics. It is easier to move a small microphone around than a heavy subwoofer.
You can find more useful information from the following links:
Choosing correct monitors: https://www.genelec.com/correct-monitors
Monitor placement: https://www.genelec.com/monitor-placement
Calibration and acoustics: https://www.genelec.com/calibration-acoustics