Placing the second sub

[jsteinhauer]

I finally picked up my second subwoofer yesterday and hope to get around to installing this weekend. From Big Daddy's subwoofer guide posts, it seems the best way to position two subs is front corners, front-back, side-side. Front-back is not possible. Side-side would be very impractical. My issue with corners (actually just medial from the corners) is that while taking measurements with one sub, it did not matter which front corner I placed it in. I had about a 15dB hole in the listening position in the 50-60Hz range. Can placing subs in both corners alleviate this, or will it only emphasize it?

Is there a problem with placing one in the front and one on a side? Or does it just depend on the measurments?

Also, if adding a second sub via a RCA splitter from a single sub out, do I need to bump up the gain on the sub at all?