Underpowering subwoofer by half?
 

Before purchasing my car, I had some spare money so I though I'd spend it on a subwoofer. I bought a 1000W rms Pioneer TS-W3002SPL (Pioneer Link) which was advertised as a 2ohm subwoofer. As for the amplifier I then bought a Pioneer PRS-D3000SPL (Pioneer Link) which made 1000W @ 2 ohms. Since they're both 2ohms I though I'd made a good purchase.

Thing is it turns out since the sub is a dual 2ohm, it has to be wired as 4ohms, on which the amp only produces 500W.

Since the 1000W rms sub will be powered by 500W, will it make much of a difference in the sound quality, or will it only mean it won't play as loud as when powered by 1000W?

The sub will still sound pretty good with that amp, you really have nothing to worry about. If you had purchased this sub for purely an SPL aspect then you may have been a little disappointed with the overall performance, but not for what you plan to use this combo for.:smilie_da

In theory the difference would be 3db...not that big of a deal. (unless you want it for SPL)

keeping in mind that the box the sub goes into has a considerable effect on the sub's power rating, even with 500 wrms you could easily overpower the sub (well, mechanically at least). see if the manufacturer has power ratings for different enclosures and use that as a guide for your sub's true output capacity given the power at hand. nonetheless, 500 watts should prove plenty for that 12".

No problems there, sound deadening would make more of a difference than the extra 500W.

sometimes it's not quantity, but quality.
IMO if you reconnect the sub to a 2-Ohm load, you may find 2 things changed.
1- the sub is a bit louder
2- the bass is more boomy, less detail, lack of deep punch.