Ported is louder, sealed sounds better. choose accordingly. By "better," I mean that the bass will be more accurate, have better transient response, and have a flatter frequency response. Ported systems have a tendency to turn into the "one note" subs we've all heard at traffic lights.
Not necessarily, most ported systems are simply poorly done. The transient response won't be as good as sealed, but the distortion will be lower at any point above tuning. In a car, sealed poses a better frequency response, but in an open room, ported is flatter down to the tuning frequency.
most distortion heard in car stereos is caused by amplifier clipping, not the speakers themsleves distorting, and for the record, I have no problem with properly designed ported systems, especially in open rooms.
I wasn't jumping on you or anything, sorry if my post led you to think that . I will admit that I don't agree 100% with the amplifier clipping comment, in many cases that is true, and I do agree that there are many users that unknowingly drive their amplifiers into clipping, but speakers (especially subwoofers) distort far more than any amplifier does. Your run of the mill car subwoofer can have 10% or more distortion at high volumes even when the amplifier is still within it's limits. Ported can aid that, but only to an extent. Even JL Audio boasted the fact that the W7 has 10% distortion at it's limits, less than most subwoofers do at that point.
When you push an amplifier to it's limit, the transistors will begin to clip (overload). The reason that it is called clipping is because the waveform produced is square at the top instead of rounded like a normal sine wave, it looks like the top was clipped off.
"Even JL Audio boasted the fact that the W7 has 10% distortion at it's limits, less than most subwoofers do at that point."
You definately have a point there. No matter what driver's bl curve you look at, you'll see a pretty high derivative slope at the limits of its excursion. Just seems like all I've been hearing lately is clipping. Maybe just because I'm listening for it...
It's definately a problem that occurs, especially in a car since you're combatting a lot of road noise. Takes a lot of headroom to get clean power. While JL was straightforward with that statement, the W7 still suffers the problems of a short gap/long coil design, which is high inductance, high moving mass, and only really surpasses other motor designs in BL once you reach very high excursions, past what most users listen at. It has around a 6:1 coil to gap ratio. An XBL^2 or underhung unit will surpass it in BL strength until you begin approaching around 70% of a drivers peak linear excursion.