jl 300/4 power confusion

I have a new jl audio 300/4 v2 amp pushing a pair of 6.5 components with the front channels and pushing a sub with the two rear channels bridged. The speakers and sub are all 4-ohm. Once I got into reading the owners manual and tuning the amp (via DMM), I realized that, according to jl, I am running a "sub-optimum" configuration and the front speakers are only getting half of the amp's available power (38 instead of 75 RMS).

According to their chart, the optimum configuration for a stereo/bridged combo would be 4-ohm for the fronts and 8-ohm for the bridged rear outputs, which would give me 75X2 for the front speakers and 150X1 for the sub.

My questions are:

Should I switch out the sub for an 8-ohm version?

As an alternative, is there something I can install in-line between the amp and sub to make the amp think it's pushing 8-ohms?

Would I notice any difference anyway? (The front speakers are jl C5's and have a recommended power range from 25-75 watts RMS).

Thanks in advance.

It's a 4 ohm single voice coil.

Hi there DYohn: My manual (Appendix C on p. 9 of 13 of the PDF version) says the optimum configuration for a stereo/bridged combo would be 4 ohms for the stereo and 8 ohms for the bridged to get the full 75/150 watts at 17.3 volts and 34.6 volts respectively. (link for the manual is http://mobile.jlaudio.com/pdfs/13192.pdf)

For the setup I have the instructions say set the front channels to 12.3 volts and the bridged rear channel to 24.6, which gives me 38 watts X 2 and 150 watts X 1.

I talked to JLand they confirmed I was reading the charts correctly and they said 38 watts was plenty to drive the speakers and I wouldn't notice the difference. That may be true but for the $ I dropped on the amp I'd kind of like to be on the 'optimum' side! 

Bull.  Just set it to:

Stereo side: 75 watts @ 4-ohms (17.3 volts per channel) and Bridged side 150 watts @ 4-ohms (24.6 volts)

Yes Sir...and thanks!