[pbc]

Tried a few readings today on my PB13 (put it in sealed mode to try it out). The first graph is with the sub placed on the right side of the room (in a corner), the second is the sub moved to the left (one side to the open doorway). No EQ applied by the sub's amp or the receiver. Crossover on mains set to 80hz, the below is sub only. Curious as to why I have such a huge drop off around 40hz, settling some 8db down at 55hz, then dipping again at 95?


Sub on right

Sub on left

 

[glaufman]

On the left, most likely a peak due to modes at 40, no so much a drop. Same with the drop higher up. On the right, we see the same peak, so you're likely sitting in the peak, why the level looks so low between 60-80 could be a combo of issues, modes and SBIR overlapping...

 

[pbc]

SBIR overlapping?

 

[glaufman]

There are a few different phenomena that can cause peaks and dips in your response... these will happen at different frequencies, based on your room and your placement choices... when 2 of these are close enough in frequency, the effects can overlap, and make it seem like something it's not.

 

[pbc]

Sorry, meant what does SBIR stand for?

 

[glaufman]

 http://www.gikacoustics.com/education_sbir.html