The way I look at it, Mike, if its something you'll worry about or might ruin your enjoyment ignore it. If you consider it as part of the fun with this hobby you have to do it.

The most cost effective way to improve quality of sound is not to buy more gear, its to analyse and adjust for room acoustics which is what Mojo is doing. On the other hand buying that second sub and placing it on the other mid-sidewall would also help tame those deep peaks and nulls.

John