Placement of subwoofer in comparison to left main. (1 Viewer)

[John Fishburn]

Will there be any acoustical problems with my subwoofer about 6 inches behind my left main? I have it set this way with the subwoofer in the corner and was just wondering if this is somthing i shouldn't do.

 

[Kevin C Brown]

What's more important, is once you have a spot that you think is OK for your sub, is to properly adjust the phase of your sub with respect to your 2 front speakers.

You can do this with Avia, or with a discrete tone test CD and an SPL meter.

Because of the crossover in your receiver/pre-pro, and even the crossovers in your mains, there no way you just place a sub and not worry about the phase.

*Any* kind of filter, whether it be a crossover, low pass or high pass filter, or even an external EQ, can subtle change the phase between your mains and sub.

 

[Rick Radford]

even an external EQ, can subtle change the phase between your mains and sub.

That's interesting, Kevin. I need to run some tests with inverting the phase on my sub. My receiver has no variable xover (fixed at 80 hz) and my sub does not have a phase adjust (Samson 700 to 20-39cs). So my only option is a 180 phase shift by reversing the inputs.

I just put in a BFD1124p parametric eq and feel the need to tweak a bit more.

 

[John Fishburn]

My sub only has 0 and 180 phase also. But I have ran a test with the sound and vision dvd and it sounds in phase to me.

THanks

 

[Kevin C Brown]

John- Be careful:
When I tried to adjust the phase by "listening", (I used Avia), I was completely off.
I got it right only by using a discrete tone test disc, and measuring the response below, through, and above the crossover point with an SPL meter. (Sub+mains output must be higher than that of the sub by itself, and the mains by themselves.)
(Basically, by ear, with the correct phase, I felt the bass was too "boomy." So I adjusted to an "off-phase" value. I didn't get the "boominess" taken care of until I got an eq to tame the low freq/room induced peaks I had.)
Rick- Yuppers! That's what motiovated me...