Question about XS30 vs Vtf-15h - Page 3

Because that was the OP's question when they posted.


Personally, as a consumer of goods and services, I don't see a valid reason why sealed, ported, duals or radiated subs can't be directly compared. In the end they're going be used for a single purpose, sound reproduction and the consumer of the purchased goods or services is the final arbiter, not a reviewer, you, me or some over intellectualizing lamp post.

If one manufacture wants to make and sell a dual driver subwoofer and another manufacture wants to build and sell single driver subwoofers to consumers, I'm all for them doing so and if a consumer wants to compare a pair of single driver subs to a quad setup of dual driver subs, or purchase and integrate one of each into their listening room's acoustics, I'm all for them doing so. It's their money, their questions; their mental health funeral.

When it comes to consumerism, there are no rules, there's only getting the best bang for available bucks. Consumers get to freely choose their AVR, accompanying appliances, TV, speakers, subwoofers and room to put it all in and bless those willing to put forth the effort to try and make it all happen.

Maybe Marantz should be allowed to only sell AVR's with XT32 installed. Maybe subwoofer manufactures should only be allowed to manufacture to the highest consumer standards. Maybe it should be, only upon completion of accredited appropriate room analyzing course work at local level community colleges, a degree/license needs to be issued before one is personally allowed to buy and install ID purchased subwoofers. And like an online pharmacy, if the individual doesn't have the required license in hand, they can only buy from outlets like BB and they must purchase "Geek Squad" installation services before turning their AVR on.

Just saying.

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Edited by BeeMan458 - 2/6/13 at 4:13am

Stuff and nonsense. Oh, and try using a spell checker.

Just because you don't understand it doesn't make wrong.

Who's not understanding what? You intentionally took my comments out of context by removing the second quote. My follow on comment was obvious editorializing. What's with the need to intentionally change the context of my post?

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Edited by BeeMan458 - 2/6/13 at 5:35am

There is nothing wrong with comparing subwoofer designs. I think that's needed actually. The problem though is the misinformation some people seem to have about how some of these designs work.

Just because you have two 15" X drivers doesn't mean it will play louder/deeper than one 15" Y driver. Total cone surface area of a subwoofer is not the only spec that matters. It's an important spec of course, but not on it's own. It's important because it typically means that the other more important specs for a driver will be present.

Now, will a dual opposed sub really play like a single sub? I don't think so, but I do think the differences would be minimal. Perhaps a slightly better response on whatever side of the room you place it, but it wouldn't be anywhere near as effective as having two seperate subwoofers(equivalent in output).

The OP asked about and I responded to their question which was a comparison between the XS30 and the VTF-15H and yes, the two 15" drivers in the XS30 will play louder and deeper than the one 15" driver in the VTF-15H. This is an unequivocal fact.

I like how folks keep trying to drag my comments off topic. If someone wants to step outsides the bounds of the OP, they're welcome to but please, at least have the honesty to acknowledge that's what is being done because when this admission is made, one is discussing a whole different horse race. And please, have the honesty to acknowledge that I've been discussing both the VTF-15H and the XS30 in pairs, not as singles or a pair vs a single. If you want to engage my comments, please maintain the context of my comments. If the context of my comments is not being maintained, then we're not having a dialogue. You're welcome to expand on the context of my comments as you will but please, acknowledge that's what you're doing and if you want to go off topic, that's on you, not on me.

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Edited by BeeMan458 - 2/6/13 at 6:39am

Oh well they were very rude to me.

It's possible. No one is saying you couldn't have had a bad experience with HSU's customer service, just that you shouldn't suggest against buying a company's product because of it. Most likely you talked with someone who had a bad day. I'm sure if you called back now (and were respectful yourself) you would most likely have a better experience.

Great if this is a fact please post the CEA 2010 Ground Plane Measurements from an independent third party that show this. As was already pointed out to you above the Epik Empire which, on paper, has much more in common with the XS30 than the VTF-15H cannot play as loud at the tuning frequency. The fact that the XS30 is not even as loud (per PSA) as the XV15 at 20-31hz hz seems to be completely lost on you. Again ported and sealed subs have advantages and disadvantages. There are no free lunches no matter how many drivers you stuff in a box. I suspect the XS30 will play louder above 40hz, but lower from 20-31hz and will have slightly more useable extension below 18-20hz. To say the XS30 will play louder and deeeper is an unequivocal fact is just not an accurate statement.

But you seem hellbent on ignoring these points and you seem to do that to a lot of people on this forum whenever information is presented to you.

I have probably spoken to Hsu a half dozen times in the past 5 years and have always had a positive experience and immediate feedback. Dr. Hsu is always helpful here at AVS and goes out of his way quite often to offer his assistance.

PSA customer service seeems top notch as well, I suspect this is pretty much a wash. Hsu has obviously been around for much longer so that may count for something.

And the OP asked about the XS30 and the VTF-15H and that's the sole context of my response. You're welcome to take the OP in any direction of your choice but that's on you, not me.

+1 After following you in your diy build and the plotting and comparison of ported vs. sealed you have a pretty solid understanding, unlike some.

This is for others since you "get it".

The OP isn't getting duals at this time that I have seen so that can be put to rest. Yes two point sources are better than one and four is better than two. Colocated subwoofers and dual opposed are not two point sources.
A dual opposed will be less prone to changes in frequency response in regards to boundary interaction if rotated.

http://www.data-bass.com/data?page=content&id=77

Did we get room dimensions and whether it is sealed or open and the connecting spaces? This is important for the decision between ported or sealed as flat frequency response is desired and transfer function to the seat is room dictated. Here is an article on room gain with a bit on modal smoothing from adding additional subwoofers also.

http://www.data-bass.com/data?page=content&id=80

HSU had Don Keele who created CEA 2010 come out and verify their measurements. Of course to go from 1 meter peak to 2 meter rms you need to subtract 9 db. Neither PSA's or HSU's customer service is lacking.
Edited by Luke Kamp - 2/6/13 at 7:46am

So what's on you? Have you heard either sub? Have you heard any subs from either company? What are the differences in ported and sealed including output and frequency response?

And maintaining the context of my comment, my comment regarding rotating a sub was in reference to a single driver unit, not a dual driver unit.

This would be funny if you weren't serious. Feel free to back up your claims. (i assume you can?)

Nope, haven't heard either of these subs and the main difference between ported and sealed is going be in group delay which for the most part, at lower frequencies, isn't detectable to unaided hearing. Reads like you're wanting to drag this thread off topic. That's on you, not me as the OP asked about the XS30 and the VTF-15H. If the OP wants to expand their question, that's a different story.

If you want to "argue" the nuance differences between ported, sealed and subwoofers with radiators, I suggest that's a different thread.

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I posted a link to a calculator. Feel free to find out what the Xmax of each driver is and enter the asked for information and yes, the comment is accurate. Reads like you're trying to drag the thread off topic as yes, the XS30 is going be able to dig deeper and with more authority then the VTF-15H as you have more driver surface area moving more air with more amplification and you know it. And with the colocation factor of the dual drivers in the XS30, you also know there's a 6dB bump in reinforcement that the VTF-15H doesn't have benefit of.

It's obvious you're trying to be disruptive. I'm going stop responding to you now.

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You stated " Personally, as a consumer of goods and services, I don't see a valid reason why sealed, ported, duals or radiated subs can't be directly compared". did you not? Each design has a goal and not all can be directly compared. Ported rolls off sharply below tune where as sealed does not, and that's not taking room size etc into consideration.

Man, you must be the most misunderstood person here as you're always claiming it..

Quick clarification here that I've seen being confused. For practical purposes with the box dimensions involved in this discussion, a dual opposed subwoofer has an effective source location centered between the two woofers in the middle of the box. This does make for a modest difference from a front firing design. This also makes for a lesser difference than is seen when you rotate a front firing enclosure 180 deg where you effectively move the driver the depth of the box, vs. the dual opposed configuration being maybe 1/2 that difference. Similarly, since the virtual source is in the center of the box, you will see much less change when rotating a dual opposed box as effective changes really only occur at higher frequencies.

Not at all I said,"My opinion between the 15H and xs30 is you can't really go wrong and will enjoy either one. Others here have pointed out the differences and both are solid choices:)"

If it's a larger more lossy room, I would recommend a ported sub such as 15H or xv30 at his budget. If smaller or sealed the xs30 would be great. It was more along the line of sputter1, "This would be funny if you weren't serious. Feel free to back up your claims. (i assume you can?)" I was talking about the obvious like frequency response, output, sensitivity at port tune... not group delay.

You stated that the XS30 will have more output and extension than a VTF-15H because it had 2 15" drivers vs one, and had a larger amp. I simply challenged you on that and used the Epik Empire to prove my point since we do have measurements to compare.

If you want to play connect the dots we can. The XV15, per PSA, has more output at certain frequency ranges than the XS30. The XV15 has a single 15" driver with a lower rated amp than the XS30 and is a ported sub. Do you agree with PSA on this? The XV15 has been reviewed and measured at Audioholics and even using the conservative VTF-15H measurements there the VTF-15H has more output between 20-31hz than the XV-15. So saying the XS 30 has more output than the VTF-15 is an inaccurate statement. At some frequencies it does, but not all.

Once again, I believe Tom from PSA has said below 20hz the XS30 will have more output then the XV15. Its only in that 20-31hz range where the XV15 has about a 1db advantage.

If you note my quoted comment, you'll see that I refer to "driver" as opposed to "drivers." I'm doing my best to articulate differences between single driver units and dual driver units when comparing these two dissimilar subwoofers. Also, in the discussion, comments regarding differences between ported, radiator and sealed subwoofers, the conversation goes on as if a perfect world and don't include how readings are jumbled up when subs are moved from 2m, open plane readings to indoor, real world readings where now, one has to deal with the real world inconsistencies of individual room acoustics.

The differences are so stark that I'm inclined to think of "The Picture of Dorian Gray."

2m ground plane reading:



Real world reading in someones home:



In my opinion, a bit of maintained perspective in conversations of this type is always helpful so as to help the OP better understand the realities of their comparison question.

And when one moves their sub indoors, these differences get swallowed up by the inconsistencies of their rooms acoustics and placement issues. The point, yes, I was aware of your point of your question and the accurate answer was, once moved indoors, "Group delay."

I am sure this is true. Ported subs will quickly drop below the tuning frequency. Ported vs sealed, there are trade-offs and I hope I am not sounding like a ported sub fanboy here since I replaced my ported sub with sealed subs, but this was mostly due to box size. Had I gone ported vs sealed, I would have seen a significant bump in output around and above the tuning frequency.

Here is an example of four 5 cu ft ported sub (grey line) tuned at 20hz vs four 3.5 cu ft sealed enclosure (yellow line) using the same 15" driver and about 500 watts each:



You can see the advantage of the ported sub at and above the tuning frequency, and then you can see how fast the ported sub drops vs the sealed sub below the 20hz tune and how the sealed subs have more useable extension.

Tradeoffs I myself needed the smaller footprint of the sealed subs, and since I built four of them for my large room, knew I had enough output in the 20-50hz range. Had I only been able to build one or even two subs, I would have gone ported with the biggest box I could get with the lowest tune. But room is a huge factor here. In a smaller sealed room, ported vs sealed is a different argument vs a large open room like mine.

I think we have a member of the superfamily Apoidea that is a little confused.

If the OP wants to expand their OP to include the Epik, Empire, then you'll have a valid position. How easy is it to purchase an Empire subwoofer these days? My understanding, currently Epik isn't shipping any subwoofers and if that's correct, even if the OP did expand their choices to include an Epik, Empire, due to lack of availability, doing so isn't a valid consideration.

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Edited by BeeMan458 - 2/6/13 at 9:43am

I would advise the OP to stay as far away from Epik as he can. Maybe even run in the other direction, 10mins of reading the latest on that thread will pretty much confirm that.

LOL, I would not advise on Epik either, but I think my point went right over your head which seems to be a common issue with you on a lot of threads.

You're forgetting or just ignoring the large increase in output around tuning frequency for the ported sub, which is entirely relevant to the discussion when comparing a sealed sub, the XS30, and a ported sub, the VTF15H. Especially when you say the following with no qualifications and no data to back it up.

I would not be surprised if the VTF15 has similar or more max output then the XS30 around its tuning, less below its tuning, and similar or less above its tuning.

This is assuming the xmax numbers you are using are correct and that the sub has enough power to push the drivers to reach that much excursion. If the sub is amplifier limited and not excursion limited at any frequency, that link is not useful for comparison. Just about all commercial subs are amp limited above about 30-40hz and many are amp limited everywhere. Do some modeling and look at the excursion. For example, look at a model of two eminence lab 15 drivers, in a sealed 68l box. With 3000W of power, each driver is below 20mm of excursion from 5hz and up. The link also cannot be used to estimate output of the driver in a ported box.

You do not get a 6db increase at all frequencies by just adding a second driver. You get a +3db increase adding a second driver if keeping power the same and get +3db by doubling the power. Again do some modeling and you can see what happens.

-Mike