Combating bass nulls with off center speaker placement

[c1on]

I have a pair of KEF Q300 which produce more than enough bass for me to not require a subwoofer, this is primarily a nearfield setup. I've tried various placements and applied corrections where needed. What I've found though is that when I place the speakers centrally, there is a large -15db null around 80hz.

If I move the speakers closer to the corner, to where each speaker would have a different bass response, this evens out the nulls somewhat and I'm able to get a fairly flat response to 40hz after some correction, without too much boosting.

I've not found too much information on the subject of off center placement to even out bass nulls. Is this a suitable solution for a nearfield setup to (mostly) eliminate nulls?

 

[thewas]

Is this a suitable solution for a nearfield setup to (mostly) eliminate nulls?

Definitely, placement off centre is often recommended for subwoofers and whole setups, exemplary:

Source: https://www.harman.com/documents/LoudspeakersandRoomsPt1_0.pdf

"At low frequencies, it is crucial that the most fundamental room modes are equally excited. Using a single subwoofer, a placement along the front wall, slightly off-centre from the room's middle axis is recommended."

Source: https://www.genelec.com/monitor-placement

Welcome to ASR!

 

[sonitus mirus]

Assuming the room is smaller and there's only one listening position, speaker positioning emerges as the most straightforward and cost-effective strategy. Experimenting with the distance from walls, toe-in angle, and adjustments to the listening position can be beneficial. Adding one or more subwoofers can also significantly enhance the low-frequency response. If you're able to take measurements with multiple placements, you might discover a solution that effectively mitigates the null.

While room treatment could offer some improvement, it tends to be costly, especially for frequencies at 80Hz and below. Bass traps, diffusers, and absorbers are often large, cumbersome, and challenging to configure properly without significant time and energy investment. EQ and advanced room correction software might not be particularly effective on their own but could be beneficial when combined with any of the previously mentioned strategies.

Personally, I found that opening a large walk-in closet in the bedroom I use as my home office significantly reduced a 67Hz null I was contending with. Adding a single subwoofer and applying EQ further diminished the null's severity. This approach suited my setup, where my desk is positioned away from the back wall, just beyond the room's midpoint and slightly off-center. My ceiling slopes from 8 feet on one side to 12 feet on the other, and I've applied extensive wall foam to address higher frequencies and room echo.