• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Home theater multi-sub front biasing of subwoofer upper frequencies


Mar 28, 2022
I run all KEF LS50 and SVS SB1000s in my multi-subwoofer home theater, which doubles as a 2 channel listening room about 50/50.

I chose and prefer the KEFs because I prefer the single-point source soundstage that is created by the concentric coaxial driver arrangement. It removes all side-lobe cancellations caused by stacked/sequential drivers and gives a wider (good seat) in my room.
The only downside with using KEF LS50 Metas is that the dynamic range suffers a bit unless you use a fairly high crossover, mine is at 110 Hz. So that fixes the dynamic range by allowing the KEFs to focus on what they do best, but starts to creep into the localizable frequency ranges (generally accepted as about 80 Hz or so).
So in comes the question of how to crossover that high with multi-subs while still keeping in the spirit of the Welti multi-sub method....but leaving the mains to have great imaging and blending with the subs. If let the back subs play frequencies over 80 Hz it negatively effects my overall soundfield in a way that I don't like and is very unnatural.

I tried multiple methods and have found one that was surprisingly effective.
I take four sweeps at each location a few inches apart, but put a low-pass filter on the rear subs at 80 Hz, limiting those subs to the deeper/LFE stuff. Then I load those sweeps into Multi-Sub Optimizer (MSO) and allow the unlimited front subs and limited rear subs to be balanced out by the software. MSO produces the PEQs, phases, delays and gains for the subs which are loaded in to the MiniDSP 2X4 HD.

What started this was that I wanted to be able to bypass the DSP in my AVR for 2 Channel music listening while maintaining the subwoofers as optimized. But the impact it has had on the overall performance of surround sound was unexpected. I realize what I am doing is a bit on the fringe but I can't seem to find any documentation to support the logic behind what I'm doing and would appreciate any links or thoughts.
Top Bottom