The biggest question was how it would perform with regular, 2-channel music. We started off with some mainstream music; the stuff you'd play to show off the capabilities of your system. The RFQ was a champ here. Vocals were always right out in front from either seat, while instrument placement and backup vocals were easy to place. Defeating the system raised the level too high to make easy on/off comparisons, but it immediately pulled everything to the doors and sounded awful. The biggest issue was that the rear speakers were as loud as the fronts.
So if the RFQ5000 is somewhat under-challenged on the above music, how would it do with the type of music people who buy Rockford Fosgate amps and woofers actually listen to? To find out, we moved to some Rage Against the Machine and Metallica, thinking that it was going to chunk because this music isn't about presentation, it's about energy and rhythm.
The results were good and bad, but the bad is really limited. In my experience, about the only time the RFQ5000 had trouble with rock music was when the recording was trying to create effects using standard 2-channel format. A recording engineer can suddenly put all the sound to one channel or do odd things with the phase or reverb.
The cool part is that the RFQ5000 did a fantastic job with rap, metal, hip-hop and rock music 98% of the time. Rage Against the Machine was particularly convincing, holding all the fanatic energy of de la Rocha's vocals. With the bass mostly just passing through, beats and rhythm pounded like you would expect from a Rockford system.
Overall the RFQ5000 worked exactly as advertised. Nearly all types of music were improved in the car audio environment (we didn't get to try it with movies) and it makes the passenger seat a much better place. Better plan on a little more than the $399 asking price, though, because you'll have to install a center channel and an amp to drive it in order to get the most from the system (you can do phantom center, but why?). We recommend the RFQ5000 for a nice change in your audio system.