The effect of phase adjustment (or delay if you will) is clearly measurable if you do frequency sweeps around the crossover point. Setting the correct phase is much more important with a single sub, and less important to not important at all as you add additional subs.
Critical subwoofer tip
I assume that everyone already knows the importance of phase matching a sub to the main speakers but it’s a little more complicated than simple 90 degrees or 180. The B&W sub that I have has four choices. In every case there has been a definite correct position that can be non standard. My current setup shined at 270 degrees vs the std positions. It’s completely obvious and the other choices would not have been satisfying.
From my lengthy experience I would want a subwoofer with several phase choices. I personally don’t see how one could seamlessly integrate the mains and the sub without this flexibility. No one asked but i thought this info might be useful to anyone purchasing a subwoofer. YMMV
From my lengthy experience I would want a subwoofer with several phase choices. I personally don’t see how one could seamlessly integrate the mains and the sub without this flexibility. No one asked but i thought this info might be useful to anyone purchasing a subwoofer. YMMV
- ...
- 83 posts total
Here’s some REW measurements I did today showing how changing the phase on the subwoofers effects frequency response. This isn’t about how good/bad the subs/mains/room are. No changes for volume or crossovers on the subs, phase only. Descriptions in the images should be self explanatory. The first image are the speakers, and basically my best attempt to get the frequency as flat as possible without using and EQ or DSP. The results are a combination of crossover/loudness settings and room position. I tried adding a third sub yesterday, and couldn’t improve on what I have with two subs. Mind you, it’s only an 8"/150 watt sub, compared to 15" and 900 watts. https://imgur.com/a/YJeNzUh |
Setting the correct phase is much more important with a single sub, and less important to not important at all as you add additional subs.Does it also become less important the lower you set your sub's roll-off point? For example, I have two subs set to roll off at a pretty low 40Hz because of the low frequency extension of my main speakers. |
@mitch2 If you're subs are hitting any frequency same as the mains, then it matters. It's either in-phase or out-of-phase, that is, the sub drivers are moving in the same direction as your mains. When they are out of phase, you run the risk of having frequencies cancel because the drivers are moving in opposite directions. There's lots of illustrations on the internet showing this. |
- 83 posts total