Audioholics Ultimate Subwoofer Shootout Planned

Sepen said:

Snowed in for the day. Eagerly awaiting this.

Click to expand...

Same here

gene said:

The HSU review has been completed and is under peer review. It should post on Wednesday of next week.

Click to expand...

So where is it?....

HSU Review Posted

http://www.audioholics.com/reviews/speakers/subwoofers/vtf-15h

Sounds like HSU are claiming there is something faulty with the measurements taken. Gene - if you still have the sub any chance these can be redone?

http://www.avsforum.com/avs-vb/showthread.php?p=19947178#post19947178

pbc said:

Sounds like HSU are claiming there is something faulty with the measurements taken. Gene - if you still have the sub any chance these can be redone?

http://www.avsforum.com/avs-vb/showthread.php?p=19947178#post19947178

Click to expand...

Another member has already linked Pete's comments here in the VTF15H review thread.It sounds like they(Hsu) are planning some redo's down the road alongside others to see what gives.... His explaination gave us some insight as to why...but the 2 sets of measurments don't appear as close to the ones provided by Svs....

i love the smell of subwoofer wars in the morning

billy p said:

Another member has already linked Pete's comments here in the VTF15H review thread.It sounds like they(Hsu) are planning some redo's down the road alongside others to see what gives.... His explaination gave us some insight as to why...but the 2 sets of measurments don't appear as close to the ones provided by Svs....

Click to expand...

Maybe SVS measures their subwoofers in a manner closer to how Audioholics measures subwoofers. With these sorts of things, where the subwoofer is will matter, and the exact positioning of the microphone will matter. It is also important that one knows the frequency response of the microphone, and compensates for any deviation from perfection.

As there are many ways where various errors may enter into a measurement, there should be no surprise if someone gets different results from someone else. But if we are looking at the results from different people who all pretty well know what they are doing, then the ones most likely to be making a mistake are the outliers (i.e., the ones who disagree with everyone else). Of course, if we were talking about a group of incompetent buffoons, then being an outlier would not indicate any such thing. But that does not appear to be the case in this instance.

Our measurements are NOT faulty. All of the subs were measured according to our CEA 2010 Subwoofer Shootout Protocol article which all of the participants agreed upon before entering our shootout. Dr. HSU was personally there witnessing Paul taking the measurements and seemed OK with his methodology. Rythmik and SVS did NOT dispute our measurement results, and SVS actually confirmed our results were within 1dB of theirs.

It's possible HSU does report different #s based on how they measure their product and how the plug or not plug their ports. The point is, the way we measured, directly compared each sub in the exact same manner. If we were to measure the sub as HSU prefers and it did yield extra output, that would also mean we'd have to measure the other contestants like that as their output levels would also increase by that amount.

Having Paul retest all of the subs would involve me paying him a retest fee for each product again. This is not something that I can budget at this moment. If HSU want's a retest, they are more than welcome to work that out with Paul directly as some of the other participants did when Paul found issues with their products. At that point, I would have Paul write a review addendum with the new measurements to supplement his review.

I'd rather not debate this with HSU fans or HSU directly. We stand by our review. The product is an excellent value per dollar. HSU makes a damn fine sub and offers excellent customer service. I like Dr. Hsu and Peter very much. I don't think anything else needs to be said on these points.

Gene. I think the issue is that the svs and rythmik subs' measurements are indicative of real world performance. HSU's claim is that the triangular port geometry, in an on-its-side application is creating counterproductive interference which does not occur in an upright situation.

now I am having difficulty understanding the logic behind this but if this measurement method doesn't reflect real world performance then obviously it's worth examining as hsu appears to be about to do. if simply turning it upright gives a 3-4db increase in low end output then potential buyers deserve to know that.

i hope hsu and paul work this out. all anyone wants is a good reflection of real world performance. sometimes testing method consistency can bite you in the ***... there is a nearfield summed measurement of a dipole/electrostatic magnepan speaker on stereophile which doesn't begin to describe its performance at an actual seating position for example, where for a monopole it does so very well. if the triangle ports are truly creating measurement irregularities it should be examined.

Gene. I think the issue is that the svs and rythmik subs' measurements are indicative of real world performance. HSU's claim is that the triangular port geometry, in an on-its-side application is creating counterproductive interference which does not occur in an upright situation

Click to expand...

Sorry but that is a tough pill to swallow (3-4 dB is alot, 1 dB maybe). Had that been the case, it should have been brought up prior to the measurements being conducted.

We always desire to accurately reflect the true performance of products in our reviews to the best of our abilities. This is why manufacturers are given our full review and measurement data at least 2 business days prior to publishing to ensure accuracy.

For future sub reviews, I will try to get our reviewers to conduct measurements to test all viable port modes that consumers may use for the product.

gene said:

Sorry but that is a tough pill to swallow (3-4 dB is alot, 1 dB maybe). Had that been the case, it should have been brought up prior to the measurements being conducted.

Click to expand...

I don't disagree with you at all. With regards to HSU's claims, they were moreso conjectures. His statement

Dr. Hsu said:

I don’t know the answers to these questions. We do plan to have a measurement session in the near future at a park to examine differences in max clean output when measuring these subwoofers upright vs. on the side, with and without any averaging techniques.

Click to expand...

pretty much suggests that there's still a lot to be learned, at least by one party if not the other. At the end of the day all I really want is the fully story... the "truth". Not he said she said etc. Once a consensus has been reached we can know how it correlates to Paul's review. In that respect Paul's review didn't do anything wrong. Just that there's some irregularity between the HSU measurements and his, and I'd like to know more.

Personally my only issue with the review is that Paul subjectively didn't describe its sound in the sealed and low tuned modes as those are actually things I think a lot of people would use (it appeared all of these sub reviews are being done strictly with the shootout in mind, whereas the usual review normally toys around with things like this a bit more). I mean he alluded to it, and I can make the assumption myself, but I'd have liked to see that in practice.

GranteedEV said:

HSU's claim is that the triangular port geometry, in an on-its-side application is creating counterproductive interference which does not occur in an upright situation.

Click to expand...

My understanding is that Hsu plans to test this theory in a public venue. If they measure upright, then on side and can establish such a change in output between the two positions, I believe they will have made their case and see no real need for Gene or AH to use their resources. Hopefully whatever results they reach might be addressed by a "Manufacturer's Comments" addendum to the review.

From HSU's response

Was there any difference due to the triangular port geometry where the top port centroid is pushed far away from the mic compared to round port geometry? Was there any issue due to different measurement sessions, calibration, etc. from one measurement session to another? Why were the stepped harmonic distortion limits not reached with the 20Hz test tone when this unit is supposed to be excursion limited at that frequency? I don’t know the answers to these questions. We do plan to have a measurement session in the near future at a park to examine differences in max clean output when measuring these subwoofers upright vs. on the side, with and without any averaging techniques. We hope to invite members of the SoCal HT group for that session too. At the end of the day, it’s nice to look at max clean output capability at any one frequency, and you all know that we believe in CEA2010 standard, but we also need to recognize that this won’t tell us about frequency response linearity nor overload behavior nor performance with multiple frequencies playing at the same time.

Click to expand...

KEW said:

My understanding is that Hsu plans to test this theory in a public venue. If they measure upright, then on side and can establish such a change in output between the two positions, I believe they will have made their case and see no real need for Gene or AH to use their resources. Hopefully whatever results they reach might be addressed by a "Manufacturer's Comments" addendum to the review.

From HSU's response

Click to expand...

I'd feel better if HSU paid someone else to do the testing, even if it is a "public" venue.

Further, I can't imagine that turning a subwoofer on it's side would impact output 3 to 4 db, regardless of the "patent pending" triangular port design, or circular ports, or square, rectangular or pentagonal (is that a word?).

Unless the sub was a defect, it's hard to believe that 1 sub's measurements were off by that much while the others were within 1 db. Especially if Dr. HSU himself was there for the measurements and nothing odd was noted at the time?

BTW, when HSU first came out with the sub, didn't they post intial CEA-2010 figures, then a few weeks later post slightly higher numbers and mention "the previous were from a prototype model"? Curious if the AH numbers are closer to the previous ones?

I don't know about the sideways measuring but I moved my sub 5' and had a drop of 9db at 20hz and an increase of 6db at 45. You can go mad with measuring and eq'ing!!!

Also it is said that he dropped the sub off but did he really stay for the testing? If he did wouldn't he have mentioned/seen the discrepancies and also said to test it with one port for the extension? I don't know, it just all seems so odd to me.

Regardless, I still may order one, but I would like to clear up the return shipping if I am not satisfied. It would cost me $179 to ship it back but he gets a break, I wonder if he would do the return shipping on his account as it is at least $50 cheaper.

pbc said:

I'd feel better if HSU paid someone else to do the testing, even if it is a "public" venue.

Further, I can't imagine that turning a subwoofer on it's side would impact output 3 to 4 db, regardless of the "patent pending" triangular port design, or circular ports, or square, rectangular or pentagonal (is that a word?).

Unless the sub was a defect, it's hard to believe that 1 sub's measurements were off by that much while the others were within 1 db. Especially if Dr. HSU himself was there for the measurements and nothing odd was noted at the time?

BTW, when HSU first came out with the sub, didn't they post intial CEA-2010 figures, then a few weeks later post slightly higher numbers and mention "the previous were from a prototype model"? Curious if the AH numbers are closer to the previous ones?

Click to expand...

Sepen said:

I don't know about the sideways measuring but I moved my sub 5' and had a drop of 9db at 20hz and an increase of 6db at 45. You can go mad with measuring and eq'ing!!!

Click to expand...

In a room, yes makes sense. Outdoors, that wouldn't happen.

pbc said:

In a room, yes makes sense. Outdoors, that wouldn't happen.

Click to expand...

Ahhh, I learn something new every day.

Well with all the bantering back and forth between users I would like to say THANKYOU very much for the in depth reviews your company had done, it is greatly appreciated by many people. This is my first post here however I have been a long time reader of the forum and site.

Im proud to say that I am the new owner of a SVS PC12-Plus and your great review made my decision very easy.

I am looking foreward to the Funky Waves review.

Once again Thank you.

FW12 review...time & date specifically?

Thanks...

HSU Retested, review supplemental coming

B/C of all the feedback we received on our HSU VTF-15H review both on our forums, AVS Forum and from HSU directly, Paul did a complete battery of measurements and just finished a 20 page test report that I am peering. We will be posting this after HSU has a chance to peer it. To date this is the most comprehensive testing we've ever done on a single subwoofer. I hope it clears up any doubt about our measurement results and assessment of the product. Stay tuned for the results...

gene said:

B/C of all the feedback we received on our HSU VTF-15H review both on our forums, AVS Forum and from HSU directly, Paul did a complete battery of measurements and just finished a 20 page test report that I am peering. We will be posting this after HSU has a chance to peer it. To date this is the most comprehensive testing we've ever done on a single subwoofer. I hope it clears up any doubt about our measurement results and assessment of the product. Stay tuned for the results...

Click to expand...

The assessment was made by a AH professional tester and reviewer there is nothing more to be add and say...20 pages of what?.....lmao...like i said on avs....How can two professional reviews be SO drastically different?....must be one of the 2 who was high or something??..........