Question about XS30 vs Vtf-15h - Page 2

They are ground plane, but their are other factors which make their results incompatible. For instance, S&V is using the same testing standard, CEA2010, and look how his results differed from Audioholics. I would say its best not to mix testing results, even ones which adhere to CEA2010, although there is some debate on this subject. Those VTF15h test results from audioholics are converted number which were done with different equipment and different conditions.

I was told by Tom that the XS30 could hit 122db in the 40-120hz range, adding a second XS30 would increase that by 6db giving you a 128db. I haven't seen measurements on a Submersive but are you saying 128db still wouldn't hang with a Submersive?

6db is not a given, it depends on the room and placement. Doubt you will see 6db unless you placed the subs on top of each other or right next to each other. If you had one in the front of the room and one in the back it would be closer to 3db with smoother bass response.

2 XS30's would be awesome. I would probably take that over one Submerssive just to be able to smooth bass ore in the room.

I understand the possibility of differing results when different people use different gear etc, but how can we be certain that it wasn't the sound and vision measurements that were off by a smidge? My point is (if what you say is true) we will never really be able to use measurements from different reviewers since the circumstances will always be "different." Ricci better get busy and measure all subs under his identical circumstances or we won't ever have a common reference point. Please know I am not trying to be confrontational, I am just trying to rationalize things.

Are you saying that the PSA, XS30 is an improperly designed subwoofer package?


Well, it was in English. Maybe if you politely say you didn't understand. As we both know, the comment posted was in English and in the context of your comment. To better understand my comment, look to your comment that I was responding to.

"My view point is from the view point of a consumer of finished products and what my viewpoint is of the XS30 when compared to the Hsu, VTF-15H."

"My comments do not reflect that of one who's into building their own nor do they reflect my opinion of other available ID subwoofers."

"My comment that includes SubMersive and Funk Audio is intended to reflect the ever so important WAF (outer physical appearance) and to show that the PSA, XS30 does have the ability to run with the "Big Dogs."

"The Hsu, VTF-15H would be limited in that sense."

Sorry, that's as clear as I can make it. I'm sorry I can't do a better job..

When compared to the SubMersives or Funk Audio offerings? As no time in my comment did I suggest any subwoofer design wasn't attractive.

The context was running with the Big Dogs which means being able to keep up and no, the VTF-15H can't keep up with any of the SubMersive or Funk Audio designs nor do I feel it's capable of keeping up with the dual, 15" driver design of the PSA, XS30.

Your correct, placing them in the same corner would gain 6db and one in each corner of my front room was 4db. That's still a 126db, you still stand by your statement that dual XS30s wouldn't hang with a single Submersive?
And I'm certainly not saying it couldn't, i just don't know because I haven't seen any measurements on a Submersive.
Sorry ack_bk, I just realized Shadyj made the comment not you.
Edited by jbrown15 - 2/5/13 at 3:50pm

Sorry.

The AH review was skewed and the numbers didn't add up, gene did redo the numbers somewhere but not on the speadsheet iirc.

That's not true. I've found that simply turning a driver around with the box in the same location will cause change to the REW measurement. Having two drivers will change room response on many levels. If you have room analyzing capabilities, simply turn your subwoofer around and make a second reading and you'll be surprised at the difference you'll see in your measurement.


Not necessarily as it's a complex interaction of sound waves in a room that decides. Simply moving a subwoofer by a foot will make a noticeable difference to a room's measurement. In the meantime, you have the benefit of the a pair of dual driver subwoofers in the form of the PSA, XS30 and a room analyzing program to see how these four drivers are interacting with your room's acoustics. You'll have to forgive me but I'm suggesting a pair of XS30's, not a single unit and yes, a dual, 15' driver system will easily better integrate into a room's acoustics over that of a single 15" driver unit. I don't see the rub and don't understand the argument.


I'll give you that the SubMersive has a much more powerful Amp, but in the end, it's all about the amount of air a driver can move.

I find this "Piston Excursion Calculator" entertaining in conversations of this kind.

When you post that you doubt the veracity of my comment, are you comparing two 15" drivers to two 15" drivers; apples-to-apples?

Not knowing how the difference in amplifier capability would affect the final outcome, I think it would be an entertaining shootout, comparing a pair of Seaton Sound, SubMersive HP's to a pair of PSA, XS30's, inside a home, not a ground plane shootout.

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Edited by BeeMan458 - 2/5/13 at 4:08pm

Not at all. I am simply stating that putting two drivers in a box is an engineering choice, but is not magic. I have modeled two different designs below. Two Dayton DVC 385-88 drivers in 2 3cu ft boxes (6cu ft total) with each woofer getting 350 watts each (RMS rating of the woofer). This is the yellow line. I then modeled two dual opposed using the same Dayton drivers in a 4cu ft box (2 cu ft each) with each driver getting 350watts each (700watts total) in pink. Do you see the difference? The smaller dual box does not have an advantage vs the two slightly larger singles, it is actually at a 2db disadvantage in the lower frequency level. Now if we designed the DO box using the same drivers as above with the same wattage in 6cu ft vs 4 cu ft it would be identical to the yellow line if the two singles were stacked on top of each other.



So no, there is no magic pill for dual opposed vs dual singles from an engineering standpoint if drivers and amp is equal. But I can see why an ID company and customers like dual opposed. It might be a bigger box, but it is one box vs shipping two and would use less material. Dual opposed are solid designs, I don't have a problem with them at all, but they are not really superior it is just an engineering and design choice. All things equal I would personally rather have the 2 3 cu ft singles than the one dual opposed 6 cu ft box.


I guess I don't agree if you are talking WAF unless you are solely focused on size. The PSA only offers one rather industrial finish. All the other subs (and especially the Funk and Seaton) offer lots more custom choices and the VTF-15H offers a more smooth looking satin black and also a Rosewood. I am not knocking the PSA. Look at the price point for what you get and I think PSA will eventually add more finish options as they grow and mature, but I just don't see how you can say the PSA competes with Funk or Seaton in terms of WAF or even performance.

I would take a single 15" LMS driver in a box with 2K watts of juice anyway than two cheaper 15" drivers in a dual opposed box that had 1000 watts.
http://www.parts-express.com/pe/showdetl.cfm?partnumber=293-642

There is a reason why the Funk and Seaton subs cost more. They have much more robust drivers that can take a lot of power. It is not an apples to apples comparison and nor are the prices really comparable. If you want the higher performance drivers and beefier amps you will pay more.

But this thread is about the XS30 and the VTF-15H and I was commenting on the XS30. Not knocking your thoughtful efforts but wouldn't it be fair to model a XS30 and compare two XS30's against two VTF-15H's?

The drivers in the XS30 have an Xmax of 25mm. The Dayton DVC 385-88, has an Xmax of 15.1mm. I'm not bagging on your example of choice. Plug the Xmax differences into the calculator I provided and there's a 4dB difference between the driver used by PSA and the Parts-Express driver you mentioned. Again, unless the OP widens their choices, I'm keeping my focus to the two subs mentioned and nothing more.

I agree with you regarding the need to smooth out room responses and the need to properly integrate a sub into a room's acoustics as improper integration can cost an individual 3dB to 15dB in output due to cancellation.

All of my conversation has been about a pair of XS30's not a single XS30 and I agree, two lesser subwoofers is better than one subwoofer that's a class or two higher due to room smoothing. But again, my conversation has been about pairs, not singles and in the case of the comparison of the XS30 to a VTF-15H, one is comparing four drivers vs two drivers. Granted, size does matter and not everybody has room sufficient to hide a pair of XS30's so maybe a PSA, XS30 and a SVS, PC13-Ultra?

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Edited by BeeMan458 - 2/5/13 at 5:24pm

Suddenly PSA uses cheap drivers and amps?

There's no argument on my part. I'm in agreement with you but is it fair or valid to bring up random drivers when we're posting about two existing ID, subwoofers; the PSA, XS30 and the Hsu, VTF-15H. Please, reread what I've posted as all the points you're bringing up, I've discussed in my above comments.

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Edited by BeeMan458 - 2/5/13 at 6:10pm

At 20Hz, all things equal, one 15" driver vs two 15" drivers, 350w RMS vs 725w RMS, in the simple; absolutely.

Umm.. Maybe not. Look at the Epik Empire.. Dual 15" dual opposed drivers 600W RMS amp and it give up almost 3db at 20hz to the Hsu VTF-15H and that is using the very conservative Audioholics measurements. If you use the Sound and Vision CEA-2010 numbers I believe that number is close to 5db at 20hz. I would not be surprised to find that the VTF-15H was either the equal or superior to the XS30 at 20hz. The XS30 will have the upper hand above 40hz I suspect where the dual opposed sealed design helps.

Again, you are talking a large ported design vs a sealed design. You don't seem to grasp the engineering behind the two designs. There are pros and cons to each, but don't just look at the number of drivers and amp. The port tuning in a bigger box is a huge advantage and the reason why the amp is lower rated is due to the ported design and most likely the sensitivity of the driver.

The problem is, all things are not equal when comparing the XS30 and VTF-15H. One is sealed, one is ported. The VTF will have more output around tune that the XS30 because of it's design.

Cheap, no. Cheaper yes. Again, it is a design decision to keep the price down. Like I said, you pay for performance. I suspect a lot of people really like the XS30 due to price and performance combo. Like I said earlier, I myself would probably go for dual XS30's vs a single Seaton or Funk sub but that is just me. A bass head might feel totally different.

I was responding to your post where you claimed a dual opposed design was superior to multiple single sub design. It is not. There are pros and cons to both. If you want to start talking a pair of dual opposed subs, you should probably compare that to 4 single subs since we are talking 4 woofers and similar amp requirements.

It will above the tuning frequency most likely. They are different subs in terms of size as well. The VTF-15H is a larger sub. I would base my decision on the size of your room, and what size sub is acceptable to you and your budget. IMHO, there is no wrong answer here both subs are really solid at their price points, but if you are more size constrained I would say go with the XS30.

+1, much better explanation than I did.

 

Another good example, the XV15 has more output from 20-31.5hz (107.4db) than the XS30 (106.7db) according to the PSA site. The XV15 has a weaker amp and only 1 15in driver but yet has more output at the frequency range.

Okay, explaining it like that sounds better. The way you said it before sounded like you were implying that PSA uses cheap drivers and amps. You're right you get what you pay for, but I have to say that I'm VERY happy with the performance I've gotten from the dual XS30s that I have. I was going to go with either a Funk Audio 18.0C, and was also REALLY close to pulling the trigger on a JTR Captivator S1. But I thought for the price of the XS30s I would give them a try. And I'm glad I did, not to mention Tom from PSA has been great to deal with.

I believe below 20hz Tom has said that the XS30 has the advantage over the XV15 though, and above 30hz it has almost double the advantage in output.

And I agree with what you posted above, except for the part about what you said above, being what I posted. Below is a quote of what I did post:

" This gives one the equivalent output of a 18" sub and gives one the addition of two drivers in which to help smooth out a room's acoustical interaction with the sub's output."

And I followed up with this:

"And when one thinks about it, a pair of XS30's, by comparison, can be had for a very nice price. Now one has four 15" drivers (more sources) smoothing out the room's acoustical response."

And this:

"Not sure of your point. Two stacked, seal subs take up far more space then one XS30 and if you have two XS30's, you can split them, each to be placed in separate locations."

Note I'm posting about pairs of XS30's, placed in different locations and yes, a dual driver PSA system is superior to a single driver VTF-15H subwoofer. As I posted earlier, please take the time to reread what I posted in response to you as you're showing that you're getting further and further away from the original context of my comments.

My comments are focused comments and are about the PSA, XS30 and the Hsu, VTF-15H, ID, subwoofer and my original comments regarded the benefit of the XS30 over that of the VTF-15H.

Again, please reread my comments so as to reestablish context.


The XS30 comes with two drivers and the VTF-15H has one driver. And if someone buys a pair of XS30's, they'll have four drivers and if they buy a pair of VTF-15H's, they'll have two drivers. These are the two subs the OP asked about and these are the two subs I'm discussing.

Go with psa hsu constomers service sucks big time.

This is the same old argument that happens again and again. Everyone throws out raw numbers given by manufacturers or whatever source. Numbers really mean nothing. The questions are:

Will the sub fit into my setup?

Will the sub sound good in my setup?

The worse thing about this whole subject is that there is too much subjectivity. There are few if any absolute measuring tools. Sub testers use different methods of testing subs and then compare the numbers side by side. When we do get some kind of similar testing, the numbers come from the subs being tested outside. I have no idea how a sub being tested outside and feeding me numbers is actually going to help me. My room is going to have the final say unless I put treatments all over the place...which I will not.

I tell ya, ID subs are great....I own two but it's like the wild wild west. Until numbers are relative to each other in some real way, just buy what your gut says buy.

Oh, and why are we directly comparing a sub with one 15" driver that's ported to another with 2 15" inch drivers that's sealed again?

Never had a problem with them.

Hsu's customer service is at least as good as anyone's in the business.