I'm not sure if this is exactly the same as the eponomous radio shack version, but it seems to be!
I used it to set up my home cinema accurately. The best thing is to use it to figure out your sub/sat crossover frequency correctly using this, and also to parametrically tune your sub so you get a flat smooth response all the way down. It will sound a lot lot better than any automatic system.
Oh and my one came with a new battery included despite it saying in the description above that it's not included. It was inside the unit (philips screwdriver needed to open). Just pointing out so it will save you a couple of pounds aaginst the already low price