What is the Hsu VTF-3 Mk2 crossover point with SVS subs? (1 Viewer)

[DavidG]

I'm in the process of upgrading my speakers and will likely upgrade my faithful ACI Titan mk1. I'm torn between Hsu and SVS. If I had sufficient funds, it would be PB2+ no questions asked. But, now that the Hsu VTF-3Mk2 is priced at $700 delivered (black on backorder), where does this cross over in performance with the SVS line? I prefer the box design over tube. I'm hoping to hear from people like Craig who have heard multiple Hsu and SVS models to give me their opinion. (For example, if the PB2-ISD were to be considered about equal to the VTF-3mk2 and the PB2+ the definite superior performer, then for the money the advantage would go to Hsu. If however, the PB1-ISD is considered the peer of the VTF-3mk2 and the PB2-ISD is superior, then it becomes getting the PB1 and saving a little money or trying to swing more money and get the PB2, etc.)

Thanks in advance,
DavidG

 

[Edward J M]

I've had an SVS PB1-ISD and an Hsu STF-3 running in my HT system for quite some time. The STF-3 is essentially a VTF-3 running in the Max Output mode.

Based on my research, testing, and measurements, it would be a fair statement that the PB1-ISD and the STF-3 (and by inclusion a VTF-3 running in Max Output mode) are performance "peers". Sure, there are measureable differences between them, but they are all in the same performance class. That is, a single 12" woofer, a 300-350 watt BASH amp, and similar enclosure volume, vent space, and tune point.

The PB2-ISD would be a big step up in output over any of the above three, and the PB2+ extends that margin even more.

Regards,

Ed

 

[BrianAe]

You may want to consider the 12" sub from Aperion Audio. www.aperionaudio.com. I have that sub now after upgrading from the 10". I compared the 10" in house against the HSU vtf-2 and it performed better then the HSU and looked much much better. My guess is that the 12" is similar in performance to the VTF-3 and PB1-ISD but priced at only 600 dollars shipped and with a furniture grade finish.

 

[CurtisSC]

Edward,

What kind of research are you doing? Are you doing your own shootout?

Lets also add that if you do not need the added output of max-output mode, you can give up about 2db of output and get a lower tune to 20hz conservatively speaking.

 

[Edward J M]

Hi Curtis:

There are a few guys in my general area interested in the $600 sub class, and I couldn't think of two more closely matched competitors.

So we all ponied up and bought them, with the understanding that they would both be at my place for a while to undergo instrumented testing under controlled conditions and also be available for back-to-back music and HT demos.

One of the guys is a long-time musician and is pretty picky about music peformance, so I used him as a sounding board (pun intended), and we did some blind music stuff with him because I respect his opinion and his ears.

Yeah, I guess you could call it a shoot-out, but I haven't pumped up the fact that both subs have been at my place for a while and were really pretty thoroughly evaluated and tested both objectively and subjectively.

I suppose I could post a formal report of our findings - there's certainly enough empirical data on both subs and a pretty good amount of comments/notes on music and HT performance (with time stamps and SPL stuff). I can just see it now......some cornball slant like "$600 Subwoofer Championship Of The World" with a pro boxing theme. :b

It's pretty rare when I'm not floating around the HT room with a pencil, notepad, SPL meter, or a test mic. It's a good thing the better half is so understanding. Hell, at one point this house was graced with a 20-39PC+, a PB1-ISD, an STF-3, a PB2+, and a PB2-Ultra - all at the same time! It was getting tough to find walking room, so a bunch of them were moved out to new homes and only the PB2-Ultra, the STF-3, and the PB1-ISD currently remain.

Ed

 

[CurtisSC]

That is great!!

Wait a second....do you have a real job?

 

[Edward J M]

Of course, silly! That's why it's "catch is as catch can" around here.

Due to other obligations, I might go a while without doing any formal testing or reviewing, and then delve into it with a passion over part of the weekend, save all the data and notes, and then pick it up again later in the week.

And it's tough to get the guys together for a blind demo or a HT review, so that can slow things even more. I figure what the hell, I'm in no rush; we're doing this for fun and as a hobby.

I really just wanted to answer DavidG's post honestly, since we've had on hand and tested a few of the models he mentioned. With that said, if you guys want to see all the test/review data on the PB1 and the STF-3, I can post it in a new thread; I'll just need some time to formalize it all (that boxing theme is growing on me...I can just see the Everlast gloves on top of each sub - LOL).

Ed

 

[steve nn]

Based on my research, testing, and measurements, it would be a fair statement that the PB1-ISD and the STF-3 (and by inclusion a VTF-3 running in Max Output mode) are performance "peers".
__________________________________________________ _________

Based on mails back and forth with another long time HT enthusiast who runs dual VTF-3s, I would agree with you fully Ed. He has brought into his home three or four SVS offerings to compare and his findings match up with what you state imo.

I myself have never thought for a second that a VTF-3 could hold it's own up against a PB2-ISD. This is no slam against HSU. My statement could sort of be compared to matching up a PB1+ to a PB2+. The 1+ is good but it is not a 2+.

I would really appreciate seeing what you have come up with Ed. Please do a separate Thread if you find the time while your out buying gloves. Go with the four ouncer's though. :wink:

 

[Edward J M]

Thanks for your input, Steve. 4 oz. it is - appropriate for a middleweight category like this. I'll throw it all together under a separate thread in a day or so.

Regards,

Ed

 

[Gabriel_Lam]

There's a guy (Craigsub) on the spot who compared a few subs. He found that two VTF3-mk2's were roughly 3dB or so down from a PB2+. This means that two VTF3-mk2's should be roughtly what a PB2-ISD would be. He was measuring with a pretty large room.

 

[Craig Chase]

Gabriel is about right - A pair of VTF-3/2's are about on a par with the pb2-isd...

And Curtis - Ed is a notch or two ahead of my testing... his research is as good as any I have seen...anywhere

 

[Gabriel_Lam]

Hey, there he is.

 

[Edward J M]

Thanks for the props, Craig. I wouldn't go that far; your brother's friend is using an extremely good test rig. I like to base my methods and standards after guys like Keele, Nousaine, Johnson, and Toole. It's good to have lofty goals and proven role models in any hobby. We can all learn a lot from guys like them, just by reading their tech papers and product tests. Imitation is the sincerest form of flattery, after all.

What I am a complete stickler on is consistent application of calibration, methodology, and test conditions. The most important piece of information is the differences between the two products, as measured under identical, controlled, repeatable and reproducible conditions.

6 months from now I could set-up my test rig and those two subs under the same original test conditions and generate a nearly identical data set for third party verification. If you can't generate consistent and repeatable test data, it's useless.

Anyway, I'd love to see some actual near-field and in-room FR sweeps of all those subs you've got floating around. You'll find that tweaking the CV 0-180 phase control on your PB2+'s will have a "major" impact on the in-room FR. You'll probably find a sweet spot over a very narrow range where the FR will suddenly smooth out.

Enabling the low pass filter if you have some response irregularities in the 60-100 Hz region can also help at times. Normally the low pass is disabled if you are doing BM at the pre/pro, but it can be a good tool if you have FR sweep capability and can evaluate its effect on the curve at various settings.

Making the most of these powerful tools can be as effective as employing a multi-band PEQ like your Behringer. It's key to first get the best FR you possibly can without have to resort to a PEQ, particularly if you will be boosting any nulls (usually met with limited or no success) or adding EQ on the bottom end. Most nulls can effectively be dialed out with the phase control and room placement.

I'll again concur with you guys on the PB2+, PB2-ISD, and VTF-3 comparo. A single PB1-ISD is a good match-up to a single STF-3 or a single VTF-3 in terms of clean output.

The PB2-ISD will have about a 6 dB advantage over either, and the PB2+ would stretch that to about 9 dB over either.

Your THD data confirms this; a single PB2+ has about a 3 dB advantage (even greater at the lowest frequencies) in clean output over dual VTF-3, so a PB2-ISD would be a very close match to dual VTF-3.

Question....did you test the VTF-3 in Max Output or Max Extension mode?

The current production (not the early Max Extension run) STF-3 is (by design) set to Max Output mode with both ports open and the EQ circuit is optimized for this tune.

Regards,

Ed

 

[DavidG]

Some excellent feedback guys - much appreciated. Brian, the Aperion subs do look very nice, but a concern I have is reading the 12" freq plot indicates that using 40Hz as a reference point, it looks to be down almost 7dB at 20Hz (104Hz @ 40 to 97dB @ 20)? And there's no info on how the freq plot was generated under what conditions, at what distortion levels, etc.

Ed - thank you for your inputs into this thread. Your approach and methodology is exemplary. I do question somewhat your assertion that the STF-3 is essentially equal to the VTF-3mk2 in max output mode. According to the specs on Hsu's site, the STF is +/- 2dB to 25Hz, while the VTF is +/- 2dB to 22Hz (max output mode). As well the VTF uses a different amp (350W vs 300W). I even wonder if the drivers are the same? That said, based on your tests with the STF and PB1-ISD, they are pretty equal but if the VTF were tested it might have a slight edge? I also look for real test results with accepted test criteria. However, I've been in the audio domain for too many years (including playing trumpet for many years and having a father who was a music director) to solely judge an audio component solely on benchmarks. That's why I'm also looking for the subjective comparison impressions from you guys as well. How does it sound in well recorded music reproduction (and not just warble tones playback)?

Now, if I consolidate the views so far, it appears the PB2-ISD would be a definite step up from the VTF-3mk2. Now you've got me looking at scraping up more money from somewhere. But then, hey look, the PB2+ is ONLY another $300 above that, sooooooooooooooo...........(thanks alot :frowning: ).

Cheers,
DavidG

 

[BrianAe]

Hey DavidG,

I can tell you from my own tests with an SPL meter that the Aperion graphs are pretty accurate. I get similar results once you take into account what you'd might expect from room gain. So, I guess what I would say is that in terms of extension and output that you can get a fairly flat response down to 20hz or so once you take into account room gain and especially if you use an eq. You'll get good output but not the insane levels that you'd get with a PB2-ISD.

I can't speak to the SVS (though the 2 times I've heard them I've been very impressed). However, compaing the Aperion to the HSU VTF-2 I will say that you get higher quality bass, especially in the mid and upper range with the Aperion. In other words, in my tests, it blended better with the rest of my system.

However, as I said before, I think they are all great options. If anything, we give these decisions too much thought. On the other hand, I think we sometimes over buy for our sub needs.

 

[Edward J M]

Yes, they could have a different tune point. In fact they probably do if the extension ratings differ by 3 Hz in Max Output Mode. The VTF-3 amp (in addition to being 50 watts more powerful) might also have a different looking EQ circuit (as compared to the STF-3) in Max Output mode too.

As for the woofers being different, I think Hsu employs the same 12" driver for both products, but the only way to be sure is to pull one and snap some macro digi pics up close from a few angles and also weigh it. Then maybe Craig can do the same with his VTF-3 MkII and we can compare notes on that point. Or you could ask Hsu tech support and take their word for it.

The PB1-ISD and the STF-3 were selected as being the closest match-up in terms of features and options. Both are fixed tune $600 box subs with similar amp configs and power ratings, enclosure volume, port area, and tune point. Can't get much closer than that.

I'm sure the VTF-3 would have different test results than the STF-3, particularly if the MO tune point and EQ circuit is different. Not to mention the variable tuning option. Of course it costs quite a bit more $$, and would probably be better matched up against a current production 25-31PC+ (with the gen 2 dB-12 woofer Craig mentioned).

While I'm probably getting ahead of myself, the PB1-ISD was really a bit more than a match for the STF-3 in terms of deep extension and distortion at the very lowest frequencies. Every where else in the spectrum, they were damn near equal. Hope this helps. The formal review will be more considerably more specific on test data and methodology, of course.

Regards,

Ed

 

[CurtisSC]

On the Hsu forum, it Sasha says the drivers in the STF line and VTF line are similar, but different.

Also, the matte black version of the VTF-3MK2 is $100 more than the STF-3. So for that $100, you get a slightly different tuning, variable tuning, and a slightly more powerful amp.

 

[steve nn]

While I'm probably getting ahead of myself, the PB1-ISD was really a bit more than a match for the STF-3 in terms of deep extension and distortion at the very lowest frequencies. Every where else in the spectrum, they were damn near equal. Hope this helps. The formal review will be more considerably more specific on test data .
__________________________________________________ __________

Bring it on Ed. I for one trust your analyses. You know what you Know.

TT

 

[DavidG]

Update: sold my ACI Titan and just ordered the SVS 20-39 PC+ Woot!!

Thanks again to all here for your informative posts and feedback and to Tom V. at SVS who was very responsive to all my email inquiries.

Will let you know how it works out

Cheers,
DavidG