When did Kappas become 4 ohm again? A friend of my son installed a set last summer hooked up to a head unit, not an amp, and the 2 ohm suckers fried those (Alpine "high-power) chip amps in about a half hour.:thwack:
You do have to be careful about what HU you pair the Kappas with. I've had them in my Elise with an Alpine 9833 (now discontinued) for 3 years. The 9833 has an internal V-Drive amp that requires a direct connection to the car's battery due to the current it draws.
I haven't had any issues, but I'm certain that I would have fried a HU that didn't have this type of internal amp.
I bought those speakers for my old 81' mercedes 380slc. Sound warmer than the other sets that I've gone through in that old car. I installed an amp and built a custom thin sub box for the rear. They sound great and hold up to loud playing levels when plugged into an amp with cross-overs. As for an elise/exige application, I don't know. I really liked the way they sounded and its the brand and series that I would buy possibly for my elise.
I suggest an amp that can tweak the crossover frequencies for the speakers. It's a night and day difference in the quality of sound coming out. Engine noise will be hard to ever overcome.
BTW, I painted the covers in a matte black. Be careful to tape the grills well.
Speakers went in this morning and after 100 miles of driving I'd say there is a pretty big difference. Certainly a lot more clarity over the stock speakers and I can crank the volume up without distortion.
For others considering this I was told to go with either the Kappas or Focals. If you're considering the Kappa Perfects, get the Focals.
Also I kept the stock speaker grills as the Infinity ones were a bit too flashy(ugly) for my tastes.
I recently installed some Focals all around and kept the stock HU. Clear and clean sound. Great for when I'm just cruising. Bass is nominal; however, I am not looking for a complete supreme sound system for this car. I'm usually listening to the beautiful sound of the screaming engine, but the Focals are just right when I'm just cruising around town.
I didn't even need to take out the passenger seat when I installed the rears. The only issue was fitting the rear speaker, because of the bigger size. The connectors jutted into the foam seal.