Sealed vs Ported Subwoofers

There is no better..... but You can certainly prefer one over the other and there are implications of one being better over an extended period of time.
If a ported driver is ported correctly, it will be acoustically flat. If a sealed driver is in the correct encloser and you achieve a final QTS @ .707, you have an acoustically flat sealed driver. The big difference is that it is typically easier to find a driver that will achieve a very low frequency from a ported design and when the driver is at its minimum frequency a ported sub will then roll off @ 24 db per octave, so below its rolloff there is very little output. In a sealed design, once a driver hits its low frequency rolloff, it rolls @ 6db per octave, so you will still have very useable low end frequency below the point where it begins to roll. Because of this, the two do sound a little different from one to the other. Also, I had said that over time the implications are that one is better. That is because as a driver wears, its specs change, especially its qms... as the specs change a ported design has a tougher time maintaining its accuracy, where a sealed woofer will stay fairly true... Of course, that does take a fair amount of wear. As alluded to above by another... Any woofer in its perfect sealed box, will always need a larger encloser for its perfect ported box, But there are very few woofers (very few, not zero) that truly are versitile enough to use ported or sealed. I hope this helps, Tim

Bob, You are correct, sealed woofers do roll off @ 12db per octave. My fingers are faster than my head. Everything else is accurate. I have built several woofers in my time. The best we did back in my old SpeakerCraft/Marcof days was a woofer facing up in a encloser that had 4 ports also facing up, it had an identical section with a woofer firing down. The four ports on both sections were joined by PVC, so the top & bottom chambers were ported into each other. There was about a one inch gap between them. We made these to look like an end table, they had the benefits of a ported system, kinda like a passive radiator, yet still rolled @ 12db per octave. I haven't seen this done anywhere else. Ed Martin designed this and it was very good indeed.
If a driver has enough LINEAR excursion, I still prefer a sealed system, but I have zero issue sitting down to a good ported design anyday.

Bob, You are correct, sealed woofers do roll off @ 12db per octave. My fingers are faster than my head. Everything else is accurate. I have built several woofers in my time. The best we did back in my old SpeakerCraft/Marcof days was a woofer facing up in a encloser that had 4 ports also facing up, it had an identical section with a woofer firing down. The four ports on both sections were joined by PVC, so the top & bottom chambers were ported into each other. There was about a one inch gap between them. We made these to look like an end table, they had the benefits of a ported system, kinda like a passive radiator, yet still rolled @ 12db per octave. I haven't seen this done anywhere else. Ed Martin designed this and it was very good indeed.
If a driver has enough LINEAR excursion, I still prefer a sealed system, but I have zero issue sitting down to a good ported design anyday.

Duke, Nice accurate explanation. Still unless you have the ability to build your own subwoofer that you can factor your own in room response.... Normally if you built a Sealed sub with a finished Q of .5, most people would say that it had no low end output. It would be extremely tight and in the right room would be superb. Manufactures have no choice but to build subs as accurate as possible, then we are forced to deal with room interactions, which are all different from each other. Ideally a sub would come with some sort of built in rta, mic and eq circuit. We do see many subs with a low end boost, but as you alluded to, normally a filter network would be just as valuble if not more. Tim