"Bridge the amp's channels together and send thoose JLs 160 wRMS, set the frequency at around 160hz, and they should eat it all up. The reason they say to only put 75 wRMS is cause if you give them 100 wRMS and play them at around 50hz or so they will blow, but setting the frequency up higher, you can slap on the power no problem, they might even take more."
What exactly do you mean here? Are you suggesting that I should bridge the front and rear right channels and the front and rear left channels of the amp and use it to power the front speakers and then buy another amp for the sub?
If this is the case, each of the JLs will be getting 320wRMS, not 160, since 80x4 = 320. Obviously, way too much power.
Or do you mean that I should bridge the two front channels and power the front JL speakers off that and let the two bridged rear channels power the sub? This comes with it's own set of problems. The most obvious is that I will not be getting stereo out of the front speakers since bridging two channels results in a mono signal. Secondly, each of those JL components are 4ohms. This means I can wire them in parallel and get a 2ohm load or wire them in series and get an 8ohm load. Now, let's look at what happens when I bridge the channels in each of these situations. First, the amp is not stable at 2ohms bridged so that rules that out. Second, if I bridge the channels and send the power into an 8ohm load, I will only be getting 160wRMS total since doubling the impedence cuts power output in half. That means each speaker will get 80wRMS, the same as it would if I just ran the channels to each speaker individually. So there's no point in doing that. Plus it would be a mono signal.
Please correct me if I am wrong here.