# Sealed vs Ported for my size room



## midasmagoo (Sep 24, 2011)

I'm looking to upgrade the sub in my sub/sat system. I have three M&K S150s for L/C/R, rated down to 77 Hz ±3db paired with a single MK105 sub. As happy as I've been all these years with that sub, there is so much more available now. I will be keeping the S150s.

My room is 20x18x10 (3600 cu ft), and sealed (double doors closed on back wall) when watching/listening. I definitely will be getting a PAIR of subs, connecting them both to my pre/pro that has outputs for 9.2 channels.

I wouldn't say price is no object, but I started this process by considering a pair of JL Audio f112s (though, admittedly, 2 of these would be a bit of a stretch for me). However, I am reading so many good things about several internet-direct manufacturers and I have no wish to overpay if I can get great performance elsewhere.

After reading through the threads on this forum, I am considering the following:

HSU Research ULS-15
SVS PB12-Plus
SVS SB13-Plus
Outlaw LFM-1 EX

If I understand correctly, the HSU and SVS SB13 are sealed, and the LFM-1 EX and SVS PB12 are ported. In reading opinions here, it seems that I can expect a more dynamic response from a sealed sub, but more volume and low end from a ported sub. I think my sealed room should help a sealed sub perform better. Using a pair helps as opposed to a single. But perhaps ported is still better for low end "punch" (I tend to watch more movies than music listening). I also need a sub that will perform well up to where the S150s take over.

Any thoughts and opinions on the above items given my setup would be most helpful. I think all of them offer a limited in-home trial where I can return them if unhappy (the only reason I'd consider ultimately purchasing without first hearing a speaker).

Thank you much!


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## GranteedEV (Aug 8, 2010)

midasmagoo said:


> In reading opinions here, it seems that I can expect a more dynamic response from a sealed sub,


Assuming all else is equal, any sealed sub with so-called "more dynamic response" is likely just underdamped, and causing reradiation of bass through the cone. That's not a good thing if the goal is accuracy. 



> but more volume and low end from a ported sub.


More _low end volume_, yes, but if a ported sub, all else equal, has more volume at the top of its passband, it likely has some serious tuning issues. The port should only really augment the bottom octave or so of a subwoofer's passband. I would never buy a ported sub if it doesn't get VERY close to 20hz or lower before it begins to roll off..



> I think my sealed room should help a sealed sub perform better. Using a pair helps as opposed to a single.


Assuming that the walls aren't significantly losing bass energy, room gain can do a good sealed sub (F3 around 35hz and F10 around 20hz) some big favors. The problem with commercial sealed subs however is that even with room gain they to me seem to lack headroom. Displacement is the name of the game, and I've managed to bottom out a sealed 18" driver with 40mm of xmech, listening below reference levels.

The key to sealed is 

1) Lots of surface area
2) A ton of excursion
3) Tons of power
4) More than one.

Doubling up on subs would give a theoretical 3db boost (or was it 6? I forget) but if you want to optimize sound quality you won't be colocating them - so it won't quite be "doubling up.

Then again, the sealed room can do the ported sub the exact same favor. Unequalized that might too much deep energy but once equalized it's an increase in head room down to the tuning point.



> But perhaps ported is still better for low end "punch" (I tend to watch more movies than music listening).


Dollar for dollar, yes. It'll likely require less watts, and it'll be more effortless in the bottom octave (though not if we're talking about the octave from 5hz to 10hz)

However size is a big deal. Placement/Multiple subs are the number one indicator of sound quality. If smaller subs can let you have superior placement, then go ahead with sealed.

What size is your room, and what are the walls made of?


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## tesseract (Aug 9, 2010)

Welcome to HTS, midasmagoo!

In a sealed room, I would go with sealed subs. You can use the room gain to your advantage, it may be possible to dig deep down into the 10 Hz region, something a ported sub will not be able to do.

Two SVS SB13 or two HSU Research ULS-15, that's a tough call. Both have plenty of power and shorting rings are nice to have. Can't go wrong with either, I would let price be the deciding factor.


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## SAC (Dec 3, 2009)

Horns.

Efficient and LOW distortion.

A pair of Danley DTS-10 kits (easy to assemble! for ~$1075USD) will cost you less than 1-JL112 and outperform them.

Add a Crown XLS Drivecore or XTi amplifier and have fun.


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## midasmagoo (Sep 24, 2011)

GranteedEV said:


> What size is your room, and what are the walls made of?


Room is 20'L x 18'W x 10'H. Walls are all covered in drywall. Front and Right walls are outside walls, Back and Left inside. Right wall is half drywall, half window covered floor to ceiling with heavy curtain. Floor is wall-to-wall carpet.

If I understand correctly, GranteedEV favors ported sub (if only slightly. I think I understand the caveats mentioned for going with sealed sub.) On the other hand, tesseract is saying sealed.

Let me center on the two SVS offerings for comparing ported and sealed. The SB-13 and PB-12 are similarly priced (the ported PB-12 even being slightly more expensive). I _think_ their website is speccing the PB-12 at a lower frequency response, but reading here seems to suggest that the SB-13 might actually reach lower frequencies? I haven't found any listening tests that have been able to compare the two.

In the sealed category, the HSU is less expensive, slightly larger amplifier and has a larger cone than the SB-13. I'm finding many rave reviews of the SB-13, though. I know there's more to a sub than size, but I'm reminded of the old adage about engines (there's no replacement for displacement).


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## GranteedEV (Aug 8, 2010)

midasmagoo said:


> Room is 20'L x 18'W x 10'H. Walls are all covered in drywall. Front and Right walls are outside walls, Back and Left inside. Right wall is half drywall, half window covered floor to ceiling with heavy curtain. Floor is wall-to-wall carpet.


I'm assuming by "outside walls" you mean they're concrete?? That's a really good sign for room gain. For reference I don't have a sealed room and I only have two concrete walls, and I get about 7db of gain at 20hz. I have a gut feeling it's just a low Q room mode though, because my so-called room gain appears to fall off the map below 15hz where it shouldn't.



> If I understand correctly, GranteedEV favors ported sub (if only slightly. I think I understand the caveats mentioned for going with sealed sub.) On the other hand, tesseract is saying sealed.


Cost-no-object, sealed drivers will pressurize a room whereas a vent will actually start to cancel out the driver output at some point (behaving as a quasi-dipole source). I think where cost becomes an object, vented subs tend to squeeze superior performance, and still have excellent sound quality. Where cost is an object you can't be worrying about what's going on below the vent's tuning.

If you're willing to spend the money on around three to six 18" sealed subs like the Funkywaves FW18.0 - I would tell you to take it and never look back.

But if you're on a budget and want the best performance for your dollar, sealed just seems irrational to me. The only reason I go sealed is because i'm dealing with 18" drivers here, i'm not comfortable with down firing, and the requisite large boxes for resonant alignements that wouldn't be downfiring, would weigh too much for anything but a forklift. So for me it was a matter of practicality. End of the day sealed is more practical with big drivers, and for me big drivers are the real source of true distortion-free bass.



> Let me center on the two SVS offerings for comparing ported and sealed. The SB-13 and PB-12 are similarly priced (the ported PB-12 even being slightly more expensive). I _think_ their website is speccing the PB-12 at a lower frequency response, but reading here seems to suggest that the SB-13 might actually reach lower frequencies? I haven't found any listening tests that have been able to compare the two.


Based on what I feel, to me a ported 12 will probably about match the extension (not output) of a sealed 18, but have a sharp rolloff below there where the 18 rolls off smoothly. For sealed subs, I wouldn't do anything smaller than a 15. If you wanna go sealed, the SB-16U is probably a better choice than the 13 - JMO - YMMV

There's really no replacement for displacement.



> n the sealed category, the HSU is less expensive, slightly larger amplifier and has a larger cone than the SB-13. I'm finding many rave reviews of the SB-13, though. I know there's more to a sub than size, but I'm reminded of the old adage about engines (there's no replacement for displacement).


....that's what I just said up there.

The SB-13 has one big edge over the HSU - DSP. It's impeccably engineered with digital signal processing to limit it - basically a foolproof sub.

Personally, I don't really care about DSP / engineering... i'd throw as much surface area, watts, and linear excursion at the problem as I can until it's solved - why drive one overengineered sub to its limits when you can run four "simplified" subs to half their limits and still have extra potential lying in wait.


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## chashint (Jan 12, 2011)

All of the subs on your list are well respected, but picking the right well respected sub is hard to do.

The Hsu ULS-15 has adjustable EQ so it can be flat to 20Hz anechoic or be adjusted to match room gain. 
The SB13-Plus looks like it is an animal too; the DSP could be very valuable matching room gain and with two PEQ filters it gives you some excellent built in bass management.
The PB12-Plus looks really good, lots of power and some DSP features.
This brings us to the Outlaw LFM1-EX, by comparison it is a really simple basic subwoofer and it is the only down firing design on the list. 
Nothing wrong with basic and simple at all, it works really well and sounds really good and I personally prefer the down firing design.

At one time I was absolutely convinced the ULS-15 or the Rythmik F15 would be my choice, but so many people buy two or even four of these that it scared me away. Same for the SB-13, too much feedback that +3000^ft needs more than one ‘small’ sealed sub.

While the new electronics are very interesting I decided to go with something basic and simple that had a flat response and 20Hz extension that did not depend on room gain.
That was the LFM1-EX; it is in an area similar to your room dimensions except my room is open to the rest of the house.

I am very pleased with the sub, but this is the only real sub I have experience with so it is my benchmark and that needs to be taken into consideration with anything I have to say.

Measured with a Radio Shack SPL meter the sub performs as advertised, I get a flat response down to 20Hz. 
I guess I am lucky that there are no significant nulls or peaks because I have no capability for bass management below 63Hz, which is where Pioneer ends equalization.
The sound stage is certainly improved with the sub; all the reports of people getting a real subwoofer and hearing sounds that were not previously there are true.
I would not say that my sub ‘pressurizes’ the space (open floor plan home) but there is a tactile presence to the sound that was not there before adding the sub.
This weight or presence is felt / perceived at all volume levels, not just when the system is cranked up for a movie.

After all that I guess the point of my post is, the least expensive most basic sub on your list is a really good (hate to use the word great when talking about a mid grade product) subwoofer. I don’t know if the others are better or not.

When it comes to pricing there is a significant difference between the Outlaw sub and the rest of your list. 
Anyone considering an Outlaw should also consider waiting it out for the sub to go on sale, which makes the EX come in (to the door) at less than 50% of some of the others.

For my money, when on sale the Outlaws are the best things since sliced bread.


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## tesseract (Aug 9, 2010)

midasmagoo said:


> I wouldn't say price is no object, but I started this process by considering a pair of JL Audio f112s (though, admittedly, 2 of these would be a bit of a stretch for me). However, I am reading so many good things about several internet-direct manufacturers and I have no wish to overpay if I can get great performance elsewhere.


Using a single JL Audio f112 sub as a metric of what your budget might be, I am not going to recommend a low cost solution. The Outlaw is a great sub for the money, probably the best choice in it's class. But it is clearly outclassed in the shadow of the others you have listed, so I would strike it from consideration. 



> After reading through the threads on this forum, I am considering the following:
> 
> HSU Research ULS-15
> SVS PB12-Plus
> ...


Based on this statement, my previous post left out other options.

Consider dual Elemental Designs A7S-450s or Chase Home Theater SS-18.T. Two sealed 18" subs in your room will absolutely slay, and either cost way less than dual SVS or Hsu.

I use dual 18s in my open floor plan room, am flat down to at least 16Hz (the lower limit of my measuring capability), and have plenty of throw left on the gain knob for even more clean SPL.

Also, is DIY or partial DIY (have somebody make the cabinets for you) an option?


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## midasmagoo (Sep 24, 2011)

tesseract said:


> Consider dual Elemental Designs A7S-450s or Chase Home Theater SS-18.T. Two sealed 18" subs in your room will absolutely slay, and either cost way less than dual SVS or Hsu.
> 
> I use dual 18s in my open floor plan room, am flat down to at least 16Hz (the lower limit of my measuring capability), and have plenty of throw left on the gain knob for even more clean SPL.


I'm not opposed to considering an 18" sub--thanks for the "heads up" on these two models. At the moment, Elemental Designs is backordering (though that could certainly change soon). I'm not sure about the Chase, as it is a down-firing model. I have a carpeted, plywood floor (over a full basement). My current sub has two cones, one front firing and one down firing. It used to reside on a concrete floor, and to my ear performed better there than in its current situation.



tesseract said:


> Is DIY or partial DIY (have somebody make the cabinets for you) an option?



My preference is a completed finished unit, one that if I'm not happy with I can return. I think I'd be uncomfortable with trying to figure out what I might have done wrong if I wind up being unhappy with a finished DIY project.

Chashint's positive experience with the Outlaw notwithstanding, I think I may drop it from consideration. I had missed that it was down firing. It sounds like a terrific sub for the money, but at that the same time most of these other subs seem to deliver performance that warrants their higher prices.


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## midasmagoo (Sep 24, 2011)

GranteedEV, thank you for the info contained in your PM. I will definitely consider your suggestions, but won't respond in detail here. I can't seem to find a link to reply in a PM. I gather the system thinks I am not "registered", although I did follow the email link sent to me when I first signed up---don't know what else to do to become registered.


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## tesseract (Aug 9, 2010)

midasmagoo said:


> I'm not opposed to considering an 18" sub--thanks for the "heads up" on these two models. At the moment, Elemental Designs is backordering (though that could certainly change soon). I'm not sure about the Chase, as it is a down-firing model. I have a carpeted, plywood floor (over a full basement). My current sub has two cones, one front firing and one down firing. It used to reside on a concrete floor, and to my ear performed better there than in its current situation.


Front firing subs have no performance advantage over down fire. And you can always lay the down firing sub on it's side, as I have done. Space is at a premium in my room, I fire them to the left and right. For me, this was the only way to get the drivers a little closer to the side walls for boundary reinforcement.


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## tesseract (Aug 9, 2010)

midasmagoo said:


> GranteedEV, thank you for the info contained in your PM. I will definitely consider your suggestions, but won't respond in detail here. I can't seem to find a link to reply in a PM. I gather the system thinks I am not "registered", although I did follow the email link sent to me when I first signed up---don't know what else to do to become registered.


You need 5 posts to send PM's.

http://www.hometheatershack.com/forums/testing/21659-post-padding-thread.html


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## GranteedEV (Aug 8, 2010)

> My preference is a completed finished unit, one that if I'm not happy with I can return. I think I'd be uncomfortable with trying to figure out what I might have done wrong if I wind up being unhappy with a finished DIY project.


We'll be glad to guide you through the process. DIY is surprisingly not as difficult as it seems, and the rewards are outstanding. For the cost of one of these 12" subwoofers, you could be looking at something like four 15" low distortion drivers, all driven off a mere single amplifier.

:innocent:


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## fusseli (May 1, 2007)

Your room sounds fairly big, but since it does close up I'd agree to consider a pair of sealed subs. IMHO, with the best possible response being the goal, big vented subs are best suited for larger and/or open rooms where room gain won't be significant. Putting a flat to 20Hz ported sub in a small room wouldn't yield a flat response, resulting in boomier sound.

Have you budgetted any $$ for room treatments?



GranteedEV said:


> Doubling up on subs would give a theoretical 3db boost (or was it 6? I forget) but if you want to optimize sound quality you won't be colocating them - so it won't quite be "doubling up.


it's +6dB to add a second sub and double the total input power. It'd only be +3dB to add a second sub and run either on half the power, I believe.


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## midasmagoo (Sep 24, 2011)

fusseli said:


> Have you budgetted any $$ for room treatments?


Any such thing as designer treatments? Don't suppose you have a web link or recommendation? WAF would be part of the story here. WAF cleared for two subs, but I won't be pushing for four. Though the room is sealed, it still doubles as a living room.


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## tesseract (Aug 9, 2010)

fusseli said:


> it's +6dB to add a second sub and double the total input power. It'd only be +3dB to add a second sub and run either on half the power, I believe.


Acoustic coupling from co location will yield a textbook gain of 6 dB, a 3 dB gain is realized otherwise.


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## GranteedEV (Aug 8, 2010)

midasmagoo said:


> Any such thing as designer treatments? Don't suppose you have a web link or recommendation? WAF would be part of the story here. WAF cleared for two subs, but I won't be pushing for four. Though the room is sealed, it still doubles as a living room.


GIK Acoustics has its art panels, although I suspect they're not thick enough to be effective over a wide enough bandwidth. 

I also believe that mated with well designed speakers, diffusion panels can not only sound great, but are rather attractive.. or at least as attractive as audio room treatments can get.


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## fusseli (May 1, 2007)

midasmagoo said:


> Any such thing as designer treatments? Don't suppose you have a web link or recommendation? WAF would be part of the story here. WAF cleared for two subs, but I won't be pushing for four. Though the room is sealed, it still doubles as a living room.


Ya, GIK is the only place I know of specifically though I'm sure thre are others. There's a link for GIK at the top of the forum window. 

Also considering good speaker placement is of at least minor relevance, sub placement follows similar principals. http://www.cardas.com/content.php?area=insights&content_id=26&pagestring Sorry that's the only link I have laying around at the moment. Having a pair of subs will help a lot in a room, you'll be better off than a single sub although it's too bad you can't do four.


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## Gorilla83 (Sep 21, 2011)

That's a fairly large room. Are you open to running a pair of subs?


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## midasmagoo (Sep 24, 2011)

Gorilla83 said:


> That's a fairly large room. Are you open to running a pair of subs?


Oh, absolutely. I am getting a pair. Just trying to decide WHICH pair. I found myself leaning toward the Hsu ULS-15 from the list I initially indicated. I'm now wondering about the VTF-15H (also from Hsu). Even though it is ported, any review I can read about it indicates that the foam included to seal one or both ports leads to the best of both worlds and the opportunity to make an after-purchase choice (between ported and sealed) based on what sounds best in my room. The VTF-15H is a bigger box, and lacks the wireless option...but I have enough room and intend to use cables.


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