independent testing

[tgrisham]

I was wondering if the VTF-3 Mark 1 or 2 has been tested independently in a lab. I noticed that Audioholics reviewed and tested the Axiom 500 ($1150) and concluded that it is "King of the Deep". I posted there that the VTF-3 II is less expensive and boasts the same frequency response (and I own one). The reply was, "show me an independent labs test of the VTF-3, not manufacturer claims". Now, I really am a nice guy and I don't want any arguments or comparisons of products on this forum. I am curious as to the measurements of the VTF-3, even knowing that what counts is the sound. And I won't discuss the fact that Axiom is an advertiser on Audioholics. So...is anyone aware of independent testing? Thanks!

[Dudley]

Try this. Not the MKII, but the rosewood model is very similar.

http://www.hometheaterhifi.com/volume_11_1/hsu-vtf-3r-subwoofer-1-2004.html

[craigsub]

I was wondering if the VTF-3 Mark 1 or 2 has been tested independently in a lab. I noticed that Audioholics reviewed and tested the Axiom 500 ($1150) and concluded that it is "King of the Deep". I posted there that the VTF-3 II is less expensive and boasts the same frequency response (and I own one). The reply was, "show me an independent labs test of the VTF-3, not manufacturer claims". Now, I really am a nice guy and I don't want any arguments or comparisons of products on this forum. I am curious as to the measurements of the VTF-3, even knowing that what counts is the sound. And I won't discuss the fact that Axiom is an advertiser on Audioholics. So...is anyone aware of independent testing? Thanks!

tgrisham - The purpose of pointing out the "independent test" quip was not to try to start an argument, nor was it intended to come across as "mean".

For its intended purpose (high output, deep bass, and excellent SQ) the VTF-3 Mark II is my favorite subwoofer in its price class. I wish I still had mine, and was ready to order another pair, but Peter convinced me to wait for the VTF-3 HO.

Is it "better" than the EP-500 ? Hard to say. Until someone does a direct comparison, who knows ? What I was trying to convey to you was comparing a spec sheet on product "A" to an actual test on product "B" is difficult.

As for Axiom advertising on Audioholics - Hsu Research has received excellent reviews from publications in which it advertises. This does not make the review invalid.

Oh - and look for a complete review, with measurements and all (outdoor groundplane at two meters), on the Axiom EP-600 vs. the VTF-3 HO with Turbo option in the near future. A Velodyne DD-18 and a subwoofer from svs will be here, too ... :)

[tgrisham]

Thanks, Dudley. I am familiar with that test and it helped me to decide to buy mine. I was hoping for any others that might be more specific with SPL/frequency response graphs, etc. But, it really is just for fun anyway. I don't really trust magazines to tell the truth! I have measured my VTF-3R with the Mark II amp in room to -3 dB at 20 Hz. It actually gave me a weird feeling in my gut, almost sea-sick! And much better than what I normally experience in the movie theaters.

[Michael Bain]

Has the VTF-3 been said to achieve it's frequency response rated extension numbers? Let's see what the reviewers have said.

In the Secrets review:

http://www.hometheaterhifi.com/volume_11_1/hsu-vtf-3r-subwoofer-1-2004.html

In terms of frequency response, I can safely say that the specifications that Hsu published do not lie a bit. In my room with the maximum extension mode, I got relatively flat response down to 20 Hz with still plenty of energy down to 16 Hz (about 3 dB down). With the same volume setting and in the maximum output mode, I got louder output with usable response down to about 20 Hz (3 dB down).

From the Audiophile Voice review:

http://www.hsuresearch.com/reviews/index.php?id=6

In a test-tone face off against a Velodyne F1800RII, with their outputs matched at 40 Hz, the two systems were subjectively identical down to about 30 Hz. At 20 Hz, the Hsu was 2dB louder than the Velodyne

From Stereophile review:

http://www.hsuresearch.com/reviews/index.php?id=9

What I found surprising was that the response stayed flat between 20 and 26 Hz, with no indication of a rolloff at 20 Hz, and less overall frequency-response variation from 20 to 100 Hz.

I also did a brief test of the VTF-3’s frequency response below 20 Hz with a Hewlett-Packard sinewave generator (the R.A.B.O.S. test signals don’t go below 20 Hz). This showed that Maximum Extension mode did. result in greater response below 20 Hz, with strong response evident down to 16 Hz (albeit with some doubling), but the cost of the increased extension was a peak in the response at 20 Hz.

Back in December 1999, my comparison of the VTF-2’s Maximum Extension and Maximum Output modes showed that sub dropping sharply below 31 Hz in Maximum Output mode, which led to my recommending use of Maximum Extension. In the case of the VTF-3, the situation was reversed: At least in my room and with my subwoofer placement, Maximum Output mode resulted in more even response and still-excellent low-end extension, even down to 16 Hz. This is better than Hsu Research claims

[craigsub]

Michael - While those are excellent reviews, none was on the VTF-3 Mark II. In order to truly discover whether or not a VTF-3 Mark II is superior ro the EP-500 it would require a direct comparison.

By the way, Calling the EP-500 "King of the deep" seems a pretty big stretch -Audioholics is still working out a consistent test method, and only has a couple subwoofers tested in its most recent methodology.

And I can say confidentally that there is nothing in this review which would lead me to believe the EP-500 is vastly superior to the VTF-3 Mark II.

[Michael Bain]

There is really no reason to believe that the VTF-3 Mark2 behaves any differently than the first VTF-3 in frequency response. Same port tuning, 3" ports, 12" driver.

And it can accept a turbocharger ;)

Nothing against Axiom of course, if their sub goes super low then swell, but Hsu always meets and exceeds specifications (and I do not believe a review exists showing otherwise on any Hsu product).

Of course the Audioholics website has not reviewed any Hsu products, so how can they use it as a basis of comparison? It's not their fault.

[craigsub]

There is really no reason to believe that the VTF-3 Mark2 behaves any differently than the first VTF-3 in frequency response. Same port tuning, 3" ports, 12" driver.

And it can accept a turbocharger ;)

Nothing against Axiom of course, if their sub goes super low then swell, but Hsu always meets and exceeds specifications (and I do not believe a review exists showing otherwise on any Hsu product).

Michael - I also believe the Mark II will perform as well as the original. MY only reason for bringing up the review point was the original thread on Audioholics was about the review of the EP-500.

We can both believe the Mark II will perform as well as Mark I, but it has not actually been tested, so, for now, it is our belief.

On a related front - Peter was REALLY adamant that I need to get a VTF-3 HO with the turbo option. In 15 years of reading about Hsu products, I have never seen this level of excitement from Hsu Research about a product ... :)

I cannot wait to hear this beast ...

[Michael Bain]

HO does sound interesting. I get the feeling that Hsu Research is holding back something, the way he has been dropping hints.

[tgrisham]

Thanks to all for your responses. And thanks for keeping a high standard of professionalism. This promotes understanding and better discourse so we all may learn and enjoy our hobby more. I don't believe there is a need for more discussion on this topic. Thanks again.

[tafguy]

For its intended purpose (high output, deep bass, and excellent SQ) the VTF-3 Mark II is my favorite subwoofer in its price class. I wish I still had mine, and was ready to order another pair, but Peter convinced me to wait for the VTF-3 HO.


Wow, VTF-3 HO must have something and probably it is the only thing I'm waiting now besides the turbocharger. To beat VTF-3 MK2's already awesome performance, there is great chance it will become next HSU flagship killer sub. If Peter convinced you to hold and knowing that the next generation HO sub could only be better products, it is also pretty wise at this stage to wait!. The question is would one know the difference of the twos if you happen already have the VTF-3 MK2? We will probably need a specific test CD containing specific tracks to be able to judge the performance between the two's. And probably the lower the frequency, the one which can play it and how great musicality the sub will produce, will tell us the difference. But there is more to this, how good the new sub will measure up with movie sound track and from poll we have so far, movie seems to be greater usage among users than music. So, craigsub, what made you change your mind to wait based on Peter's advice?

[craigsub]

Wow, VTF-3 HO must have something and probably it is the only thing I'm waiting now besides the turbocharger. To beat VTF-3 MK2's already awesome performance, there is great chance it will become next HSU flagship killer sub. If Peter convinced you to hold and knowing that the next generation HO sub could only be better products, it is also pretty wise at this stage to wait!. The question is would one know the difference of the twos if you happen already have the VTF-3 MK2? We will probably need a specific test CD containing specific tracks to be able to judge the performance between the two's. And probably the lower the frequency, the one which can play it and how great musicality the sub will produce, will tell us the difference. But there is more to this, how good the new sub will measure up with movie sound track and from poll we have so far, movie seems to be greater usage among users than music. So, craigsub, what made you change your mind to wait based on Peter's advice?

When a man tells me "Be patient, you will be glad you did" .. and those words also prevent that man from making an immediate sale, (The VTF-3 Mark II's - and I was buying 2), THAT gets instant respect.

Peter's saying "wait" is what did it for me.

[Pete_Hsu]

Dear Craig,

On a related front - Peter was REALLY adamant that I need to get a VTF-3 HO with the turbo option. In 15 years of reading about Hsu products, I have never seen this level of excitement from Hsu Research about a product ... http://www.hsuresearch.com/forum/images/smilies/smile.gif

I cannot wait to hear this beast ...

As good as Hsu Research subwoofer designs have been over the years, there has been some criticism too. This criticism has come not only from our closest competitors, but also from our staunchest supporters! Dr. Hsu has listened, and at the same time he has analyzed his own designs. The man knows best, after all! He always knows the limits of his products. So, that said, the Doc has pinpointed weaknesses, and has tried to make them strengths. He has looked at concerns about port area per given low frequency tune, amplifier power demands, driver excursion demands, internal volume considerations, minimized footprint considerations, floor interface solutions, sealed versus ported methods of operation, driver radiation pattern, digital signal processing, flexible and cost-effective ways towards upgrading performance for existing and future models, and so on.

I believe that Dr. Hsu will be addressing all of these issues with the VTF HO series at some point down the road.

Stay tuned my friends!

Sincerely,

[tafguy]

Dr. Hsu has listened, and at the same time he has analyzed his own designs. The man knows best, after all! He always knows the limits of his products. So, that said, the Doc has pinpointed weaknesses, and has tried to make them strengths. He has looked at concerns about port area per given low frequency tune, amplifier power demands, driver excursion demands, internal volume considerations, minimized footprint considerations, floor interface solutions, sealed versus ported methods of operation, driver radiation pattern, digital signal processing, flexible and cost-effective ways towards upgrading performance for existing and future models, and so on.

I believe that Dr. Hsu will be addressing all of these issues with the VTF HO series at some point down the road.


Thanks, Peter. That is what I wanted to hear besides craigsub's feedbacks. By the way, craigsub, thanks for your response. It must be tough for you to wait but in the end, it is surely worth the wait.

Peter, actually, through your sayings of what has been going on, this is a truly quality that not everyone has and personnally I do admire people like Dr. Hsu who goes beyond what has been done to make things better and what Dr. Hsu is doing to the HO products just shows who he really is: simply a perfectionnist!

No wonder, how good HSU's sub is knowing that there is always someone behind who pays attention to owner's inputs. And not everyone, but someone which has his signature in the subwoofer you own in your HT room.

[Pete_Hsu]

Hello tafguy!

Thank you for the very sincere thoughts and comments. I agree with you, Dr. Hsu is a perfectionist. There are certain areas where he is willing to compromise when it comes to subwoofer design, but there are other areas where he is absolutely not willing to compromise. Always for good and sound reason, of course!

The basic technology and design ideology that debuted in the original TN1220HO, VTF-2, and VTF-3 is remarkably still running strong to this day. This is a testament to a visionary designer. Now we are finally getting ready to evolve and create something new again. You can see this pattern in Dr. Hsu's work over the years. Each design has always been very unique and creative.

In addition to what you already know, please be aware that there are several very exciting developments that we still have yet to share with you all. We have really just begun to scratch the surface of what can be done in the future with the HO series. When the ideas are closer to fruition, then I will speak more about it.

Sincerely,

[subadubdub]

Is one of the developments a rotary woofer? That would be interesting to incorporate into a Hsu box. 5Hz might be pushing it inside a box.

http://www.eminent-tech.com/RWbrochure.htm

I guess with a frequency response of 1Hz – 30Hz +/- 4dB, this would be an addition to a Hsu/SVS/Velo/etc sub. I wonder what 5Hz feels like.

[Michael Bain]

$13k and does not include an amplifier or crossover, and still another sub needed for signals above 30Hz? That is the price to pay for such exclusive technology.

[tafguy]

I wonder what 5Hz feels like.

It is important to get the maximum from the room. In our room, when you play Jurassic park cinema track, when there is the dynosaurous coming, you orribly feel all the walls crashing down (many people got scared, now I normally ask if they are ready to be scared) is something that you cannot even get in a cinema show, this is because all the frequencies (low bass also) are focused all to the listening point, while in any cinema show you normally are not able to do it. The full 10 Hz frequency response depends on this. 5 Hz we cannot measure, but you can feel them easyly on your body. 30 Hz is lower in amplitude because of the phase of the emission made by the frontal speakers bass horn. Nothing in this Audio room has been done by a case and this is one of the topics that has been well thought before building it.



Subwoofer from extract of link below probably will do the job!

http://www.royaldevice.com/custom.htm

[craigsub]

Is one of the developments a rotary woofer? That would be interesting to incorporate into a Hsu box. 5Hz might be pushing it inside a box.

http://www.eminent-tech.com/RWbrochure.htm

I guess with a frequency response of 1Hz – 30Hz +/- 4dB, this would be an addition to a Hsu/SVS/Velo/etc sub. I wonder what 5Hz feels like.

Does that thing look like a fan to anyone else ? I am pretty sure it would have been a Lirpa Labs joke 10 year ago ... :D

[Lwang]

This kind of stuff use to be from Lirpa Lab, now it is just PR by every company

[bacobits]

Martin DeWolf from BFS mentioned something about that ET Sub.

[subadubdub]

Speaking of Lirpa, do you think we will see a purchaseable HO before next Lirpa?

[Lwang]

Hope HO has not been sold off to Lirpa.

[subadubdub]

Wow, I didn't know how right I was about a purchasable HO until Lirpa since Lirpa is here and may come and go before most of the people get their HO.

[Lwang]

Maybe there will be a big announcement tomorrow about the status of the HO.

[JimLely]

Wow, I didn't know how right I was about a purchasable HO until Lirpa since Lirpa is here and may come and go before most of the people get their HO.

My Lirpa is scheduled to arrive on April 1st. It is being securely packed in 20th century discontinued Audio magazines.