Sealed vs Ported Subwoofers: Which Is Right For You?

[Steve81]

Sealed vs ported subwoofers: it's one of the great debates within the A/V enthusiast community. Unfortunately, stereotypes plague the discussion; we've all heard the comments, "ported subs are slow and boomy", "sealed subs lack low end power", etc. Unfortunately, the stereotypes fail to tell the whole story. Interested in learning the real deal about how sealed and ported alignments compare?

Read about Sealed vs Ported Subwoofers.

Now the million dollar question is, what do you guys (and gals) think? What is your favorite type of subwoofer?

 

[Adam]

I have both a ported and sealed SVS Ultra, and I like them both. They sound pretty much the same to me. There's currently no poll option for "both" or "either," though.

 

[shadyJ]

Nice article Steve, a lucid and succinct treatment. One thing I think is worth mentioning is that sealed enclosures are really begging for a high excursion driver, but low excursion drivers can work fine in a ported enclosure, as long as they are limited from over excursion below the tuning point. High excursion drivers will work fine in ported enclosures too, of course, but you need a gigantic enclosure to get the most out of them.

 

[3db]

Ported with servo control

 

[fuzz092888]

I like a setup I had seen on AVS. While definitely not typical and somewhat insane, the guy had huge ported subs handling from the crossover frequency down to 20ish hz at which point they passed off to quite a few sealed subs for the teens and single digits.

 

[Steve81]

I have both a ported and sealed SVS Ultra, and I like them both. They sound pretty much the same to me. There's currently no poll option for "both" or "either," though.

I can't say I've noticed a huge gap in sound quality when both alignments are tuned to the room. However, if I hit the lotto tomorrow, I'd get a couple more sealed Funks, or possibly commission some ungodly IB system.

 

[jinjuku]

I like a setup I had seen on AVS. While definitely not typical and somewhat insane, the guy had huge ported subs handling from the crossover frequency down to 20ish hz at which point they passed off to quite a few sealed subs for the teens and single digits.

I did something like this for a friend:

Ported Kappa Perfect from 30 Hz down. Dual Opposed Infinity Reference from 31-80Hz. It was bliss. Used a Crown XTI2 4002 with it's built in DSP and Dayton Omni-mic to dial it all in.

 

[afterlife2]

All I've had is ported, so I voted ported, like Adam said I'm sure that I would not hear any difference between the two. Would the SB1000 be the cheapest good non ported sub out there?

 

[fuzz092888]

I can't say I've noticed a huge gap in sound quality when both alignments are tuned to the room. However, if I hit the lotto tomorrow, I'd get a couple more sealed Funks, or possibly commission some ungodly IB system.

No no no. If you hit the lotto I insist you get a rotory sub

 

[GO-NAD!]

2500ft^3 is considered a small room? I know it wouldn't make a good ballroom, but really? Maybe in the McMansion world...

When deciding on the most suitable type of subwoofer for a room, should we not also take any openings from said room into account, i.e. hallways, stairwells, etc? My own HT room is barely 2400ft^3, but I don't consider myself "over-subwoofered". But then, I have a stairwell leading upstairs, with no door at either end, so effective volume would be appreciably more, I would think.

Any thoughts?

 

[fuzz092888]

I did something like this for a friend:

Ported Kappa Perfect from 30 Hz down. Dual Opposed Infinity Reference from 31-80Hz. It was bliss. Used a Crown XTI2 4002 with it's built in DSP and Dayton Omni-mic to dial it all in.

Sounds awesome. I know I'd like to do something like that someday. I'd really like to get my hands on two more LMS Ultras so I can build two of these and then use the UXL's in a sealed alignment.

 

[Steve81]

2500ft^3 is considered a small room? I know it wouldn't make a good ballroom, but really? Maybe in the McMansion world...

You won't mistake it for a broom closet, but compared to a 10000 cubic foot great room, it's on the smaller side of the spectrum.

so effective volume would be appreciably more, I would think.

Correct; you have to look at the total space.

 

[jinjuku]

There can certainly be differences as they are different subs with different designs with different goals.

Using a LLT (large low tuned) vs sealed as example:

Using two LLT's, watching Tron: Legacy. You feel the couches get kicked, but don't hear, when the light bikes land on the arena floor. Totally awesome to feel that thump.

You can get this with very expensive sealed systems that have plenty of driver throw, high power handling, and EQ'd bottom. That is the one thing about a high quality sealed system: you can EQ it to look almost like any other alignment of sub.

Most sealed systems though you aren't going to get this at all.

 

[Swerd]

Nice article Steve. It gets straight to the point. As long as system Q is kept in the "damped enough" range, it shouldn't matter whether a subwoofer is sealed or ported. The figures go a long way to explain this.

At the risk of getting too complicated, you might have included a short discussion (with more graphs) of how critically damped or overdamped subwoofers generate a single pulse of sound when given a single impulse signal, and how an underdamped, high Q, subwoofer tends to ring on and on with a single impulse. A graph of SPL vs. time for several different system Qs can illustrate the ringing and helps to explain how it can make for muddy sounding bass.

 

[GO-NAD!]

You won't mistake it for a broom closet, but compared to a 10000 cubic foot great room, it's on the smaller side of the spectrum.

That's McMansion territory, for sure! That could 50' x 20', with 10' ceilings! I can't remember the last time I was in a private home with a room that large - if ever. I can't believe that it would be a typical room volume for a HT. If I take into account the upstairs space open to my HT, then the 10,000ft^3 figure becomes relevant.

 

[Steve81]

At the risk of getting too complicated, you might have included a short discussion (with more graphs) of how critically damped or overdamped subwoofers generate a single pulse of sound when given a single impulse signal, and how an underdamped, high Q, subwoofer tends to ring on and on with a single impulse. A graph of SPL vs. time for several different system Qs can illustrate the ringing and helps to explain how it can make for muddy sounding bass.

Here's an image which shows the simulated step response for a few different Q configurations for curious parties.

 

[Steve81]

That's McMansion territory, for sure! That could 50' x 20', with 10' ceilings! I can't remember the last time I was in a private home with a room that large - if ever. I can't believe that it would be a typical room volume for a HT.

It might be more common than you'd think, and not necessarily limited to McMansions. Great rooms that combine the living room, dining room, and kitchen into one big space get pretty big; I've seen a few on the order of 40x20 or more; toss in some vaulted ceilings, and you can crack the 10K cubic foot mark pretty easily.

 

[GO-NAD!]

It might be more common than you'd think, and not necessarily limited to McMansions. Great rooms that combine the living room, dining room, and kitchen into one big space get pretty big; I've seen a few on the order of 40x20 or more; toss in some vaulted ceilings, and you can crack the 10K cubic foot mark pretty easily.

Yeahhhh, I suppose you're right.

 

[its phillip]

If I had the money, it'd be many sealed units for me

 

[shadyJ]

Sounds awesome. I know I'd like to do something like that someday. I'd really like to get my hands on two more LMS Ultras so I can build two of these and then use the UXL's in a sealed alignment.

If you were going to combine the UXLs with the ported LMSs, you would want to put a pretty tight limiter to UXL low end to prevent that distortion from creeping in the sound. But the thing is, there are better mid and upper bass woofers than the UXLs. The UXLs aren't bad for that, of course, but a lighter and higher sensitive driver would make more sense in that role, like a pro audio live sound type driver. It would get just as loud and wouldn't need as much wattage.