HSU VTF3R or SVS PB2 ISD (1 Viewer)

[Zack_R]

I'm thinking perhaps laying the SVS on its side (suitably supported at the top with a small block of wood to keep it level with the baseplate) so its woofer and ports are at the same height as the HSU.

You may want to consider taking the HSU measurements from the side of the speaker also. This way it would be as close to identical match as you can probably get with one mic.

 

[John Robert]

If the VTF-3 is used, need to differentiate between it and the VTF-3R, as the latter latter's down firing design and wood cabinet may yield different results...

 

[Zack_R]

Also, when testing at 40Hz ground plane, you can probably test this signal with both subs in a normal postion as 40 Hz should be well above port output. If nothing else, it may show you what effect (if any) testing the sub sideways has on output at ground plane.

 

[Edward J M]

Sasha/Curtis - I like the tube vs. tube and box vs. box idea. It would certainly make mic placement issues easier to deal with.

Zack - I agree; boundary gain can be quite significant and I was taking an educated stab at what the SPL would/could be with ground plane. If the subs hit 10% early, I'll scale back the overall volume.

Test rig will basically consist of:

- A professionally calibrated Behringer ECM8000 ultra linear omnidirectional microphone. Calibration yields a data file of over 200 correction factors, which are then inputted into the RTA software program.

- A Behringer UB1002 mixing board with 48v phantom power and studio grade ultra low noise/distortion mic preamps.

- A professionally calibrated B&K 2205 sound level meter for calibrating the RTA software on the SPL scale.

- A commercial grade digital volt meter for calibrating the RTA software program on the dBu scale.

- A CPU with 2.0 GHz Pentium 4 and 512 MB DDR SDRAM.

- True RTA Level 4, Version 3 software. 1/24 octave resolution, accepts mic, sound card, dBu, and SPL calibration. Generates wide gate digital FR sweeps and sine waves.

After inputting correction factors for the mic and sound card, the rig theoretically has a FR of approximately 10-20,000+ Hz +/- 1 dB. It does not in any way compare to the stuff being run by the big dogs, but it does the job for me. Regardless, any response anomalies, noise, or distortion introduced by the test rig itself will be pretty minor and will affect both subs equally, thus becoming a non-variable.

 

[Rick Hilst]

Looks like you have put up what looks to be a good test, and as "scientific" as we can hope for

I don't know what your definition of "scientific" is but this doesn't even come close to mine.

I will be glad to contribute to this process but not if it's going to be done this way. As far as I'm concerned, what will come out of this approach will be very little, if any, more "scientific" than a whole host of other "comparisons" that I have read.

Part of being scientific is being methodical, clearly identifying the goal, being thorough in identifying all factors and how they will be accurately and reproducibly measured, clearly identifying all factors that need to be eliminated and how to eliminate them, seeking input from all parties involved, adjusting based on these inputs, etc.

If you want to do this analysis correctly, I'll be glad to be involved and contribute. However, if this analysis is going to be done using the slipshod approach identified by the postings in the last day, then leave me out of it. In no way do I want my name associated with it.

 

[TanT]

Look at what I got for asking a simple question. I didn't mean to open up a can of worms guys

Anyhow, what's happened to the SVS PB2 ISD? Did it get lost in the shuffle somehow?

 

[Tom Vodhanel]

>>>Anyhow, what's happened to the SVS PB2 ISD? Did it get lost in the shuffle somehow

 

[CurtisSC]

Tom,

What are you proposing for the first round? Which subs?


Rick,

I hope you stay involved.

 

[Edward J M]

If you want to do this analysis correctly, I'll be glad to be involved and contribute.

By all means, fire away, Rick.

You have been asked for your input and all you have offered is a generic definition of the "benchmark approach" (which I have no objection to), and then criticisms and insults of any proposed testing, methodology and equipment.

Instead of being a sideline critic, why don't you cut to the chase and help flesh out the actual testing protocol instead of spouting nebulous descriptions of scientific methods.

While the testing equipment will be calibrated against known sources wherever possible, we are not looking for - nor do we need - absolute data in order to generate a valid comparison. We are looking for the differences between the two products, as measured under identical conditions using the same equipment and test methodology.

You indicated you were originally intending to buy a PB2-ISD but now you are leaning toward a VTF-3. What changed your mind Rick? Word of mouth, rhetoric, and half truths over at the HSU forum? Wow - that's real scientific. And you have the stones to turn around and criticize my proposal of instrumented testing? Gimme a break you hypocrite.

If you don't want any part of something that - while not perfect - will be orders of magnitude more informative and scientific than trying to make a purchase decision by sifting through outdated test data generated using completely different test methodologies - then you have just shown your true colors. I'm sure you will enjoy your HSU - they are good subwoofers.

SVS has just offered to send out a PB2-ISD. Maybe HSU will pony up with a VTF-3 and we can proceed with instrumented testing of both under the same conditions and see how the numbers crunch out. Helpers and witnesses are welcome; no one is out to cook the numbers - the objective is to generate some decent data about how these two subs peform and post it for the HTF community to read/use in making purchase decisions.

Regards,

Ed

 

[CurtisSC]

Wow Edward...where did that come from? Thought this was going kind of smoothly as far as SVS/Hsu threads go until the name calling. Is this going to be able to happen impartially without any policing?

OK....so lets get this straight:

SVS has offered the PB2-ISD and would like to see it tested with the VTF-3.

Sasha is working on getting you a TN1220HO with the 250watt amp and would like it tested with an SVS tube sub in the same price range.

or

The STF-3 tested along with the PB1-ISD.

Maybe we should just figure out a way to get Tan a listen to the subs he is interested in.

 

[Rick-S]

Ego time again.
For those of us on the sidelines trying to learn, the "name calling" and "my opinion is better than your opinion" is so distracting. I know I will probably get slammed by the ego people for writing this email....I appreciate everyone's input regardless!!

 

[Edward J M]

Curtis - Perhaps you should first be asking Rick where his post came from before you accuse me of name calling.

In the spirit of information sharing and advancement of knowledge, I extended an offer to use my equipment, my home, and my time to voluntarily test some competitively priced and highly regarded subs in a controlled fashion, write the report, and share it with the entire HTF community.

Instead of accepting my open hand and offering constructive comments, Rick comes out of left field with a mean-spirited and condescending ("I don't know what your definition of 'scientific' is but this doesn't even come close to mine") and insulting ("...if this analysis is going to be done using the slipshod approach identified by the postings in the last day, then leave me out of it.") post.

And yet this same individual - who by all outward appearances holds scientific data and methodology in high regard - has admitted to being nearly convinced that the VTF-3 is a better sub than the PB2-ISD without so much as a shred of empirical data on the SVS product.

Was my response really that much of a surprise to you?

Yes, I still want to do a shoot-out. And yes, I agree that in deference to the thread starter, a PB2-ISD vs. a VTF-3 should come first.

If the test report is well received, then maybe we can try it again with some other models.

With the advent of powerful CPUs and RTA software for the masses, enthusiasts are doing some pretty neat stuff on the testing and analysis end of things. The capabilities of even modest test rigs are so far ahead of the RS meter and test tones, it's not even funny. I bought my test rig ostensibly to better evaluate my own system and fine tune it. While I don't expect the report to be published at ScientificJournal.com the test methods will be well-controlled and fair, and the data will be repeatable.

I won't force feed my report to anyone; I just wanted to raise the bar a little and improve the quality of test data that the average enthusiast can generate and share with his friends and peers. They can take it at face value, and either use it, or not.

Regards,

Ed

 

[CurtisSC]

From reading that quote, I can see how it can be taken as being mean spirited. But if there is one thing we have all learned on these forums, it is to give someone the benefit of the doubt.

If it was meant to be mean spirited, then I have lost some respect for Rick.

And yes...your response was a surprise to me. And, it was meant to be mean spirited.

Would your response have been any different if Rick said he was leaning toward SVS?

Am I a Hsu advocate, absolutely. I won't hide that. But for 7 months or so I wondered about SVS. So I listened for myself. Exactly what I did with my speakers. And that is what I always advocate....listen for yourself.

OK...with all that aside, I was wondering if there was one test that would be possible for you to do. Can you measure how fast the driver starts and stops when it is given a signal?

 

[Edward J M]

Rick's post cannot be construed as anything but condescending and mean-spirited. And I don't regret defending myself or my post. He had it coming to him. And that's all I want to say about it.

Regardless, I feel we have a collective obligation to each other as an on-line community to go the extra mile and share data and impressions and test results. All my equipment was purchased as a result of forums like Club Polk, HTF, SPOT, AVS, etc.

I really appreciated the input and guidance from more experienced owners, and I want to give something back to the community in return. Hence my PB2+ review (you don't want to know how many hours are tied up in that report). And hence my latest offer to conduct an objective sub shoot-out with my latest test rig.

I just wanted it to be a fun way we could all get together (even those across the country) and participate in a cool project and inject some objectivity into what has heretofore been a very subjective issue. Aren't these forums all about separating hype from fact and making informed decisions?

Regards,

Ed

 

[Edward J M]

OK...with all that aside, I was wondering if there was one test that would be possible for you to do. Can you measure how fast the driver starts and stops when it is given a signal?

No, I can't measure transient response. How quickly a driver stops moving after the electrical signal terminates is a function of the moving mass of the cone/suspension, and the forces which act upon it to arrest its motion. Forces like the stiffness of the suspension, and the electromotive force of the motor. I think damping factor of the amp comes into play also (see Crown's website).

A question like that is best posed to true designers like Vodhanel, Hsu, Seaton, Wiggins, Janowitz, Hall, etc. When they talk, we should all shut up and listen.

 

[CurtisSC]

Edward....mean spirited or not, when I read Rick's quote, I didn't even think it was directed at any one person.

Subjectiveness is what makes it fun IMO. Getting everyone into together to listen to subs/speakers is fun. Getting everyone together to get test measurements is interesting, but not as much fun.

Anyways, lets see if this can be pulled off. And what subs can be shipped to the cause.

 

[CurtisSC]

A question like that is best posed to true designers like Vodhanel, Hsu, Seaton, Wiggins, Janowitz, Hall, etc. When they talk, we should all shut up and listen.

Would be nice to get all of them together for a Q and A session!

 

[Paul_Ptaaty]

Curtis and Ed,

I respect both of your opinions and seem to be both on the level. Ed more an SVS fan, Curtis for HSU. I hope we don't let Rick's comments grind down what looked to be a very solid test. It would be far beyond any of the normal comparisons we have seen for these subs, and past most professional reviews IMHO.

*edit removed part about transient measurements and freq response*

One of the few direct comparisons by someone who should be unbiased was the 3 way shootout by Ecoustics CEO and founder (I can't post links yet). With a PCi vs a VTF3 and Axiom E350. The PCi and VTF3 were neck and neck with the PCi ending up with what seemed a slight advantage price not considered and more sizable if it were.

Where this comparison lacks is that it had too much subjective and not enough objective data. Also based on the older VTF3 and not matched against a more direct competitor the PC+ 20-39 for comparable tuning. With SVS's recent boxes the competition becomes even more balanced.

I think the newer VTF3R with the PB1+ (not yet released) would be a heck of a shootout. The PB2-ISD is just a much bigger sub which should be able to win on most objective tests anyway...but it has serious drawbacks of size and weight.

For my 2 cents, this won't be as good a comparison as the subs should be appealing to a different market anyway. There was a reason SVS was so quick to offer the PB2-ISD for the competition....it just isn't fair, and would have no worries about winning the competition. Yes, fair from a "bass for buck or best under $1000" but I truly feel the PB1+ and VTF3R are more similar subs from a market point of view. Of course, the PB1+ is not out at the moment.

Take the above with a grain of salt, any test with decent objective data will be great to benefit the community, esp those who are looking to buy a new sub. I will be the first to donate $5 (paypal)to help defray any costs if needed.

Stating my bias, I have owned a PC+ and my PB2+ arrives next week, but I have recommended both the VTF3 and VTF2 for people for whom it was a better fit. I hope everyone can get the sub that best fits their needs, and in overlapping product areas to try both if possible.

I hope some of this post too isn't out of date...it has been a slow process during breaks at work

 

[CurtisSC]

I'm not the PB2-ISD would have an advantage in every aspect, but it does have definite advantages in others.

When is the PB1+ due out?

I am actually the most interested a $600 box sub shootout.

 

[Paul_Ptaaty]

The $600 box shootout would be great, my only point was to keep the comparison as even as possible for both $$ and market.