cbc said:
Seems kinda strange that those Polks wouldn't sound ok with just the OEM HU. They are rated at 90db , which is pretty efficient, so unless you are seeking Metallica-esque sound levels inside your car, I'd bet they would sound fine. Mos def an improvement over the stock ones. And protecting your hearing for the future ain't such a bad idea either.
What? I can't hear you.
Anyway, they DO work, there's just a night and day difference between HU power and amp power. I was using deck power (and aftermarket HU power at that) while I was working on my amp rack and they sounded dull and lifeless. Now driving them with 100w rms x 2 and the sound is MUCH better, although >=50W w rms will work perfectly fine. Besides, why pay $100 or more for really nice speakers when driving them with crap HU power (OEM or Aftermarket)? Pioneers or equivalent are fine for that. I suppose you could get them anyway if you know for sure you are going to amp them later on.
I don't really trust sensitivity numbers. That value may be the sensitivity at a certain frequency or across the full audio range, or some other trickery. Most entry level speakers are designed to reproduce most of the frequency spectrum at decent levels with lower (deck) power. Higher-end speakers tend to use higher quality materials tp produce a better and flatter range of frequencies; maybe a heavier surround, or thicker cone to prevent cone flex, or a tighter spider to increase clarity, etc. These things make a speaker less sensitive due to added mass or "stiffness", but sound better overall. Unfortunately, more power is needed to make up for the reduced sensitivity.
Really it would be best to take a ride to a local shop that has the models you are looking at hooked up and take a listen test. Make sure they use the power source you plan to use (HU power vs amped). Maybe do it with your eyes closed and have the sales guy switch between the two to prevent "brand bias" (where you know brandX
should sound better, so you
think it does). Also, any speaker set will most likely sound different in a car vs an open room, but at least you'll get an idea of the
relative sound quality difference between the various models. No matter what the numbers say or don't say, it only matters what sounds good to your ear and your wallet.
By the way, about 25w rms (50w "peak") x 4 is about as much as you can get from a 14.4v DC electrical system without the use of a switching power supply (which is what amps use to turn 14.4v into much higher amp power supply rails). OEM decks don't usually use the "higher-end" amp IC's or adequate cooling that will allow this. I would say from some experience you can expect from 10-15w rms tops from a run-of-the-mill OEM deck. This equates to the useless "peak" rating of 20-30w, which is the number you are most likely going to find listed, if anything.