Subwoofer Equalization

I came across this great podcast segment with Kevin Voecks from Revel about subwoofer equalization and placement. It’s absolutely amazing what subtle placement can do. I can attest to it first-hand.
I absolutely love my Revel B15 subwoofer, which offers equalization. Mind you, I did a lot of research on subwoofers before I made that plunge and I scoured the Internet seeing what I could get for close-out and used prices on things. I just missed close-out pricing on one of the finishes on the Revel B15a models. Oh well. I had to settle for an older B15, but got the best price I had been able to find in a year of searching! So, after much savings, Christmas and birthday money, I finally made the plunge.
Mind you, I haven’t paid retail price for any of my audio equipment. Closeout, used, and Tweeter going out of business (oh my the deals I got!) have all been great opportunities for a low-budget.
Like I said, I got the Revel sub used. I replaced my Martin Logan Dynamo (which I had purchased off Ebay) with the Revel and the bass difference was simply stunning. Let me say it again: stunning. It’s simply mind-blowing what a good sub does to the entire experience.
Mind you, the Martin Logan Dynamo I had was a fantastic sub for its size and price point. I would even say a spectacular sub for size/price. What I really noticed with the Revel was the attack, speed, clarity, depth, breadth and so much more that comes with a better sub. I finally understood and experienced all those terms once I got the Revel. Now, you then factor in equalization and placement and it’s stunning.
But back to the reason for the blog post: subwoofer placement. I can actually show you the difference.
Here are some screen shots to show you how much of a difference just placement makes. These are screen shots from Revel’s calibration software that shows what the curve of my B15 is. Each of these screen shots are showing different frequency responses just from minor placement differences of the sub. This is the same sub and the frequency response differences are coming from just moving the sub’s location–I mean, within a four-foot radius!
Notice here that I have basically no response at 40Hz! It’s like a dead zone acoustically at that frequency response. Even the calibration doesn’t help that. Now see below what a difference just moving the sub within two feet and orienting the firing in different directions made.

I was then able find placement that was good and then compensate for a single bump by using the notch filter on my Anthem! Below is how the Revel software will calculate a curve and tell you how to dial the EQ on the back and give you the expected response. Let me tell you, it’s not just cool but room EQ is absolutely fantastic.