Internet gent and multi-instrumentalist Rob Scallon recently posted a video called "The Down-Tuning Experiment."
In it, he tests the theory that down-tuning makes your guitar, and your riffs, sound "heavier."
To do so, he plays the same riff on the same guitar, but he keeps changing the strings and tuning lower and lower, from E to drop-D to drop-C# to "drop-Q."
The cool thing is that, even when he's in what he calls drop-Q (Note: There is no drop-Q in real life; he's kidding), he's actually still playing the riff on these fat-ass bass strings that don't even fit into the guitar's nut.
Please use Scallon's findings for good, not evil. Enjoy!