I've been lurking for years but I signed up just to post this. RTR 1530s are great for budget setups. I currently have two sets in my living room driven by a Kenwood M2A @ 4 ohms. OH. MY. GOD!!!! I got the two sets on craigslist/facebook.
The M2A has ALWAYS made speakers sound their best, but having four 15" woofers makes the bass almost indescribably good, so precise yet powerful. I started with one set and decided the M2A could run another so why not?
They need decent power to sound really good, don't slap them on a 60w per channel and expect magic.....it'll still sound good though