Differences on ported and sealed subs

[KEW]

I believe that was josh Ricci.

Is there any way to verify that? It seems like a contradictory stance from what he said about the XS15se.
That was about three years before he did the review on the XS 15 SE, but it seems like if he changed his opinion on the topic there would have been another blog to reflect that.

 

[Steve81]

I agree with what you are saying that all room will be different in their specifics.
However, I still need to refer you to the fact that it is Josh Ricci and SVS that use the term "typical".
I don't believe they think there is a "one size fits all" solution; however, I do believe they are saying those responses are to some degree beneficial.

FWIW, here are a couple images from Bossobass w/ respect to measured room gain, and the curves he programs into his subs as a result of his observations:

 

[William Lemmerhirt]

Is there any way to verify that? It seems like a contradictory stance from what he said about the XS15se.
That was about three years before he did the review on the XS 15 SE, but it seems like if he changed his opinion on the topic there would have been another blog to reflect that.

Unfortunately, i can’t 100% verify that. I may have just made the assumption since it was on his site. I haven’t read the xs15 study, I will soon. My main point earlier was NOT that room gain isn’t necessarily a “thing” but that I feel like sometimes people think they can get the same performance as a ported sub, or even better performance by stuffing a sealed sub in a corner. Obviously anechoic measurments will be much different than in room, but IMO room to room variances won’t be suuuuuper big. Also, the 101db at 12hz(?) doesn’t seem that huge either.
Still on vacation so sorry if I’m not that clear. I just hate coming back to threads 2 weeks later. They lose their steam. Lol

 

[Ed Mullen]

We recently received a REW FR chart from a customer using quad SB16-Ultras in a smaller enclosed room. The amount of room gain he's experiencing is pretty shocking.

In theory a monopole subwoofer can experience a room gain transfer function of 12 dB/octave starting below the modal/pressure transition frequency. But usually it's more like 8-9 dB/octave due to lossy boundaries and room openings.

Given the quasi-anechoic FR of the SB16-Ultra, I wouldn't be surprised if he's seeing ~25 dB of room gain at 10 Hz.

At any rate, this is why we design the roll-off slope of our sealed subs to take maximum advantage of available room gain.

 

[KEW]

Also, the 101db at 12hz(?) doesn’t seem that huge either.

It is 10Hz, but I didn't mean to impress anyone with that in the general sense (and since then, ShadyJ highlighted that that is probably inaudible).
My intent was to point out that this relatively modest sealed subwoofer could do that, which leads to questions of what a more rigorous sealed sub like the SVS SB16 Ultra or Funk could do. Also, as I said, I'm not sure how desirable output at such low frequencies is.

 

[GrimSurfer]

Given that the human ear can't hear 10 or 12 Hz, and there there are no typical musical instruments whose fundamental frequencies are in the sub-audible range, I'd say that such performance is rather meaningless.

This reminds me of a review I once read. The author complained about the performance of the SVS sub he was auditioning because, in his view, anything that cannot put out meaningful bass below 20 Hz didn't deserve to be labelled a "sub".

I reminded him that the term "sub" didn't refer to sub-audible. It meant sub-bass (as in middle bass, sub bass), an audible region that lies between 20-60 Hz.

 

[Steve81]

Also, as I said, I'm not sure how desirable output at such low frequencies is.

Depends on who you ask. If you're on a suspended floor / riser and have enough output capability down low, it can add some extra tactile effects to the mix. Of course, other things may start vibrating as well, which tends to be less desirable.

 

[lovinthehd]

Given that the human ear can't hear 10 or 12 Hz, and there there are no typical musical instruments whose fundamental frequencies are in the sub-audible range, I'd say that such performance is rather meaningless.

This reminds me of a review I once read. The author complained about the performance of the SVS sub he was auditioning because, in his view, anything that cannot put out meaningful bass below 20 Hz didn't deserve to be labelled a "sub".

I reminded him that the term "sub" didn't refer to sub-audible. It meant sub-bass (as in middle bass, sub bass), an audible region that lies between 20-60 Hz.

The point of 10 or 12hz reproduction is not audibility, it's the tactile effect. Much music doesn't go even as deep as 20hz, traditional acoustic instruments particularly (except perhaps a massive pipe organ or drum). Chasing sub-20hz performance at significant levels isn't for everyone, especially outside of movie soundtracks. Some of us do it anyways

 

[shadyJ]

The point of 10 or 12hz reproduction is not audibility, it's the tactile effect. Much music doesn't go even as deep as 20hz, traditional acoustic instruments particularly (except perhaps a massive pipe organ or drum). Chasing sub-20hz performance at significant levels isn't for everyone, especially outside of movie soundtracks. Some of us do it anyways

I don't think that frequencies that low can have much of a tactile effect unless it is at extremely high SPLs, probably more than can be achieved by most home theater systems. If you are serious about have a tangible 10 Hz experience, you are going to need a whole lot of displacement capability. That will take a lot of space, electrical power, and money.

 

[Steelers252006]

I would gladly talk to you more about this but am on my way to the shop soon... I agree, it is overkill. I have two subs set at about 25% in my room because they two/too are overkill. Those Hsu's would be overkill, too.
Pwer isn't a bad thing, and it is better to have a little too much, rather than not enough! Consider the PB 3000. Or the 4000. Both will still be capable of numbing your ear-holes! Just like the Hsu subs that have been discussed.

Which sub would you compare most closely is specs to the HSU 15? Shoukd the fact it’s powered by 600 watts as opposed to the Monolith at 1,000 be a deterrent in any way, ie not gonna hit as hard? I’m re-reading a lot of these posts and am still not familiar with much of the terminology, so bear with me. I feel like I need to take a class or something. Lol

 

[William Lemmerhirt]

We recently received a REW FR chart from a customer using quad SB16-Ultras in a smaller enclosed room. The amount of room gain he's experiencing is pretty shocking.

In theory a monopole subwoofer can experience a room gain transfer function of 12 dB/octave starting below the modal/pressure transition frequency. But usually it's more like 8-9 dB/octave due to lossy boundaries and room openings.

Given the quasi-anechoic FR of the SB16-Ultra, I wouldn't be surprised if he's seeing ~25 dB of room gain at 10 Hz.

At any rate, this is why we design the roll-off slope of our sealed subs to take maximum advantage of available room gain.

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Hi Ed, I would agree that shocking is a good word. Question though. In that same room, what would you expect the SB2K to be able to do? I would say it would be nothing like the 16, as that is a very special subwoofer indeed. Also, is there any chance of user/equipment based anomalies? Like the accuracy of his mic for example.

 

[ryanosaur]

Which sub would you compare most closely is specs to the HSU 15? Shoukd the fact it’s powered by 600 watts as opposed to the Monolith at 1,000 be a deterrent in any way, ie not gonna hit as hard? I’m re-reading a lot of these posts and am still not familiar with much of the terminology, so bear with me. I feel like I need to take a class or something. Lol

At the end of the day, when I was doing my comparisons while shopping last year, the Outlaw X13, the Hsu VTF15H, the SVS PB 4000, the Monolith 15, as well as the Rythmik FV15 were all considered to be great options for using in a very large/extreme size room. I was planning for an 8000’3 space. The 16Ultra, too, but the price wasn’t worth it to me.
Frankly I was drawn to the Rythmik subs first, then the Outlaws and Hsus. A sale is what made my decision.
Subs are weird beasts. The amp isn’t the most important spec. So no, a 600w amp should not be what concerns you.
For subs, the more important aspects are the the CEA 2010 results: these tell you how loud the sub can play at specific frequencies and under what distortion threshold. ( @shadyJ can explain it much better than I.) Then what functionality it has for your needs. I.e: what tuning ability, what frequency response, do you want down or front firing, do you want piano black or cherry veneer...
The bassaholic room ratings are a big help! They basically tell you that most of those subs I mentioned earlier are capable of handling >5000’3 rooms! So will they get loud enough in your room to deaden your hearing? YES! (And this is why we started out suggesting smaller subs that will still be able to perform quite admirably in a smaller space.)
Most of us aren’t afraid to spend money where the value matters. But we mostly are looking to get the most bang for our buck! There is no knocking the 16Ultras, but at 2500 a pop, does that make sense? When you can get 2 amazing subs for less? (Why I kept saying every time you asked: only you can make that decision for yourself!)
So where does that leave us?
Your best performance and value is going to be the Hsu Vtf3, followed by the Vtf 15. Next on my list in your situation would be Pb 3000, or 4000 or PC4000(but those are getting up there). The monolith 15 has more output than my outlaws, but in a smaller rooms like ours, that doesn’t mean as much because you’re gonna have to turn it down just to be in the room with them for more than 5 minutes!

The end of the day man... it’s hard to go wrong with any of these! Is any one more golden than another? That, my friend, is really more in the eye of the beholder, I think. If anything, I would say shop for a sub 1 room size over your room, or bigger according to the bassaholic ratings. And if Shady wrote a review for it, that’s a good sign. Remember, too, he hasn’t reviewed the VTF15Hmk2, but he does own one! And it got him in trouble while testing it at one of the sites he used to use! (Strong praise from a guy that tests subwoofers for his job!)

 

[shadyJ]

Which sub would you compare most closely is specs to the HSU 15? Shoukd the fact it’s powered by 600 watts as opposed to the Monolith at 1,000 be a deterrent in any way, ie not gonna hit as hard? I’m re-reading a lot of these posts and am still not familiar with much of the terminology, so bear with me. I feel like I need to take a class or something. Lol

Enclosure size and driver sensitivity will normally have a lot more bearing on the sub's capability than amp wattage. The main performance difference between the Monolith 15 and VTF15h mk2 is the driver capability. The Monolith driver's moving mass is a bit heavier, so it is more efficient in deep bass, but not as efficient in mid bass as compared to the VTF15h mk2.

 

[shadyJ]

For subs, the more important aspects are the the CEC 2010 results: these tell you how loud the sub can play at specific frequencies and with what distortion. ( @shadyJ can explain it much better than I.)

The test is called the 'CEA-2010-A Standard Method of Measurement for Powered Subwoofers' but we just call it CEA-2010 for short. It doesn't really specify distortion quantities exactly, it's just a measure of burst output under certain distortion thresholds. A few reviewers, including myself, also state the distortion quantities in our reviews that were measured in testing, but that isn't mandated by the standard itself.

 

[GrimSurfer]

Many thanks for doing that. More test data for the reader to consider is a good thing.

 

[ryanosaur]

The test is called the 'CEA-2010-A Standard Method of Measurement for Powered Subwoofers' but we just call it CEA-2010 for short. It doesn't really specify distortion quantities exactly, it's just a measure of burst output under certain distortion thresholds. A few reviewers, including myself, also state the distortion quantities in our reviews that were measured in testing, but that isn't mandated by the standard itself.

Thanks! Appreciate the correction on my phone typo! And the elucidation for my better understanding.