late Friday ramblings... just talking out my ear here....
but RMS:
Root mean square - Wikipedia, the free encyclopedia
is basically an average. the speaker is rated at 500 watts RMS, it doesn't REQUIRE 500 watts RMS.
so... if you drive the speaker ALL day long at 500 watts RMS it will not burn up or degrade in performance.
Now.. you could go peaks of 50% higher without out damage, but prolonged extreme use, and the speaker will degrade.
Now.. you could go lot lower than RMS without damage -- because of HOW a speaker works:
Howstuffworks "How Speakers Work"
Howstuffworks "How Speakers Work"
now.. if you drive a 500 RMS speaker at 10 watts all day long will you damage it? no.
Distortion kills speakers -- not wattage; the key is good clean, reliable signal and power. Is your battery up to snuff, your alternator, do you have an inline capacitor -- all this and more effects signal quality.
Not to say good clean wattage CAN'T kill a speaker.. but you have to really try harder to go that route.
When the signal is distorted (IE you overdrive the amplifier by turning the gain all the way to 11, or the amp overheats, or under power the amp at 11V) the cone moves irradically and thus the voice coil rubs and "blows" the speaker. Yes you can blow a 500 watt RMS sub with a cheap 50 watt amplifier.
So... commenter's said .. "would that be enough power.." -- yes.
Alpine, Kenwood, Sony, Fosgate, JL, Soundstream, (name brand) amplifiers have a reasonable sound quality to drive a sub without damage. This is not to say that if you drive that alpine with the gains turned all the way up and give it 14 volts you wont damage this sub (or any other sub); but at 1/2 gain with the volume nob on the deck at 75% you are in the safe zone.
Will it be loud enough? That is a subjective question. Is 130db loud enough? Is 140db loud enough?
Separate amp? Not needed. He already said he wasn't going for competition level SQ or DB levels. He just wants a nice decent "upgrade" -- like the 3" OME.
Matching brand name? Nah not needed either. Companies would love you to believe the hype.. that is you buy our complete product line it will sound the BEST. Out right lie, if not a severe stretch of reasoning. Each car/truck/boat/atv is different. Each person's music preferences are different. You have to mix and match as you and your budget see fit.
Pioneer deck (heck even factory), JL sub, soundstream amp, cables from:
HDMI Cable, Home Theater Accessories, HDMI Products, Cables, Adapters, Video/Audio Switch, Networking, USB, Firewire, Printer Toner, and more!
or
Blue Jeans Cable -- Broadcast-Quality Cables at Reasonable Prices
However you mix and match the consumer products, you should be fine.
I would say in the given configuration, and comments made by the original poster -- that the configuration would be fine.