Rockford vs. JL amplifiers

Running at higher ohms has it's pros and cons as with everything....

Just remember that ohms is the resistance of current flowing through your electrical circuit. The lower the ohms, the less resistance and more current is then allowed through. The higher the ohms the more resistance and less current is run through.

This to what it actually means as far as affecting the sound of your system:

The lower the ohms you run, the louder the speaker will sound since it is obviously running more current through to the speaker. Of course, the downside is that your speaker will be seeing more of a distorted signal from the amplifier. The higher the ohms, the less current is running to the speaker, so the speaker won't sound as loud, but it will be getting a much "cleaner" signal.

SPL is usually run with lower ohms, and SQ primarily uses higher ohms. Anywhere from 4 to 8 ohms is sufficient for your application. (assuming SQ is your goal) Since you already have a 4 ohm setup then you should just leave it alone and enjoy the music.