My Little Test

[cboyd1]

I reposted this from a thread where I originally posted, hope someone finds it useful or interesting.

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Well, for anyone reading this thread, I did a little experiment yesterday and all last night. Keep in mind I'm no super duper audiophile, but here is what I did.

I went and purchased the following

Sony 12" 150-Watt Powered Subwoofer - Model: SAWM500 - $199.99

HSU STF-2 - $349.99

Definative ProSub 100TL - $404.99

Now before I go on, check this out. I was scouring the forum here, and I saw someone mention that CompUSA sells HSU subs in limited quantities. Well I did a local search in the Dallas Texas area where I live and actually found some, and for $349.99 at that, 50 dollars cheaper than the website . So I drove out and picked one up.

Now you may be saying, why the hell did this guy buy THREE subwoofers. Well, I'm doing something I really don't approve of, but I am having a hell of a time shopping for a subwoofer. They sound nothing at home like they do at the store display, you simply can't get a good feel at a store. BestBuy and UltimateElectonics (where I got the Sony and DefTech have 30 day return policy) CompUSA has a 15 day with 15% restocking fee return policy (more on that later, ugh).

So I got home yesterday about 3pm with all 3 subs and began my testing, I've made some categories to divide up my comments.

FIT and FINISH
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The Sony has a decent finish, but all in all seems alittle cheesy. The driver seems abit flimsy, paper cone with no good coating.

The Definative was a nice solid sub, it was significantly smaller in size versus the other two, and once again has your typical black laquer woodgrain exterior. The speaker itself is made of a polymer instead of a paper base, it seems alot more durable, and I think that is one of DT's selling points.

The HSU had the overall best fit and finish. The knobs and stands on the back, just the overall feel seemed to have the highest quality, and it is definately the most handsome looking of the 3. With the down firing setup and the smooth plastic coating with rounded edges, it just looks the best.

Controls and Tuning
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This is an odd category but thought I'd briefly touch it.

The sony has your typical volume and high cut knobs, plus a norm/rev mode

The Definative merely has volume and high cut knobs, no reverse

The HSU has a few nice options, volume and high cut knobs, forward and reverse settings, and an interesting crossover setting that was worth playing with.

Overall Performance (of course this is my cheesy opinion)
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I did my testing with DVD movies in Dolby 5.1 mode. My setup is as follows. (please dont' laugh, I know its nothing special)

A Kenwood Receiver, puts out 100 watts per channel (basically a 400 dollar Kenwood Receiver from Summer 2000)

Up front Two Cerwin Vega Floor speakers up front, the top of the line model that has a 12" sub, 6" mid and tweet, purchased in 1997 for about $600 for the pair, they are still in really nice shape.

Sony 150 watt center channel, two 5.25" mids and one 1" tweet.

In the rear, two Sony bookshelf speakers, 150 watt, 5.5" mid and 1" tweet.

I dialed the subwoofers into the following config (approximately)

I set the high cut to ~65Hz
I set the volume to 50% (some tests done with volume set to ~70%)
I set the receiver to a nice semi-loud setting, typically the volume I watch a good action movie.

Let me preface the test with this also. I use my system for movies only, I rarely listen to music at home. Also, I'm really into booming bass, I like to be shaken abit in a loud movie should I be in the mood and want to turn it up, I like having that option (I know its not for everyone).

My roomie and I did the following tests

Test 1 - Matrix Reloaded

I picked 3 scenes. Two fighting scenes with good music and nice bass hits from the fighting. We also used the trailer for Matrix Revolutions at the end of the flick. My roomie blindfolded himself and I played each of the three scenes on each sub, and he made his picks.

The HSU won 2 out of 3 times, it seemed to have the most full sound, but in all honesty they were all so very close. You could tell that the Sony wasn't as "tight" but if you were on tight budget, you can't go wrong with the Sony if you want some booming bass.

We did similar blindfolded tests with Hackers (I know silly movie but has alot of deep bass music for testing), Gone In 60 Seconds, Gladiator, and ONE MORE MOVIE.....here is where things went wrong...

At this point I was sold on the HSU, I liked its fit and finish the most, it was $50 bucks cheaper than the Definative, and it seemed to barely edge out the Definative with a slightly more "full" sound (maybe because of the downward firing).

Now back to that last movie. Our last test was with Titan A.E. the final scene where the Titan (the ship) forms the planet. This scene has alot of very deep extended bass, meaning instead of quick hits, it does more of a roar, long extended bass tone. This time I was the one blindfolded. The HSU really fluttered under this scene, it didn't sound too hot. Now when I say fluttered I mean the sound a sub starts to make when its getting too much juice, like you have the volume turned up too high. This disturbed me because this was the one I thought I was going to keep. I checked the settings and I had it at ~65Hz and abit over half volume, I dropped it to exactly half volume and it still fluttered. I dropped it to about 40% and got rid of the flutter but at that point, it wasn't as deep and booming as I wanted, this sucked, since I liked the HSU the most at this point. I tested the other subs with this scene, from 50% up to ~70%, they all handled it fine. Hrm..what to do.

At this point I went and grabbed a test CD I have which has some bass test tracks, deep hitting bass songs, and some sine wave outputs that do the 20Hz to 20,000Hz range. I put on the bass track, a 3 minute deep hitting song. Holy smoke did the Definative come alive, it by far was the most powerful, I could crank it to near max and it stayed clear, the sony did a nice job too, mainly because of the 12" i think. The HSU simply couldn't handle the deep bass at the levels the Definative could. Read on for my conclusion.

Conclusion
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Let me begin by saying all 3 subs were very good. The Sony for its price I think was very nice, but couldn't hang with the other two. All the way up until the end of my testing I preferred the HSU. And quite honestly I'd imagine that for the majority of people out there, the HSU is probably the best choice, I think it has abit (albeit slight) fuller sound versus the definative. When considering total all out power and booming (yet still crisp, when I say booming I'm not talking about washed out crappy sounding boom, I mean nice solid hits) the Definative takes the cake. Now I realize that 99% of the time, the HSU is gonna be just fine for me, but for those nights when I come home late with some friends, we've had a few beers and we just wanna watch something super loud and knock our socks off, I like to be able to do that, I know that isn't the norm, but I can't help my preference, I want to have that option, to go all out with my sub. The HSU simply couldn't handle what I threw at it (I'm sure the STF-3 could though). So at this point, I think I'm going to keep the Definative, but by all means the HSU is an amazing subwoofer. Now, folks, here is my problem...read on.

My Problem (heehee)
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Okay, as I mentioned before I got the HSU for $349 and the Definative for $404. Problem is, I got the HSU at CompUSA who has a 15% restocking fee, so if/when I return it, I have to pay ~$50 dollars in a restocking fee, effectively making me pay $404 for $454 for the definative (OUCH). So here is what I'm going to try to do. I'm going to try to sell the HSU STF-2 for $350 plus shipping (buyer pays shipping of their choice). If I don't sell the HSU in time, I'm going to have to decide to either keep the HSU and return the Definative in order to save money, or return the HSU and eat the 50 bux (ouch). So, if you know anyone out there who wants an HSU STF-2 for 350 plus shipping (I still eat 28 bux on the tax I paid on it ) let me know. Its brand new, I've had it for less than 24 hours and I have all boxes booklets etc..

P.S.
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HSU folks, if you have any suggestions that I can try to "tune" the HSU better let me know. I experimented with the crossover and norm/reverse like the manual suggests, no luck when playing my "Titan A.E." test.

Thanks guys, I realize my testing was not very "official" but I hope this post is interesting to some folks. I'd love to hear comments and questions.

Thanks,

Charlie

[Nigel_Pl]

Hey cboyd,

Just wanted to know how you calibrated the subwoofer volume in relation to the rest of the system. Did you use a home theater setup disk or the receivers pink noise to make sure the subwoofer levels were the same using a sound pressure level meter? Did you measure the SPL of your system with the forward and then the reverse phase setting to make sure the Hsu sub was in phase with the rest of your system? Were all the subs placed at the same position prior to each audition?

Without proper calibration and setup its close to impossible to evaluate the performance of each sub.

[cboyd1]

Nigel,

I openly admit that this was a very un-official test, and also i am a novice for sure.

Concerning position, i did reposition each sub prior to each test, the sub would sit just left of my front left speaker.

Concerning setup, I have no setup disk, my receiver did not come with one.

Concerning trying to get the subs to all the same level, during later tests if one sub sounded louder than a previous test I simply had to make adjustments by hand/ear, I realize this is not the way to do things, but it's all I had available to me.

Concerning forward and reverse phase on the HSU I tried both, and really didn't notice much difference between the two settings on identical tests. (granted everything was done without any measuring tools).

Bottom line though, the HSU sounded more full and precise, yet couldn't handle the low deep long extended bass like the Definative. For the Titan A.E. scene I mentioned and the deep bass music I tried (I listen to rock btw , not deep bass type music) it had to be turned way down to keep it from fluttering. The actual speaker on the sub was fluttering, I didn't like the way it sounded (this was at 50% volume on HSU sub)

I probably seem like a big newbie dork to you guys with alot of experience and gear, but this is the best I can come up with. It tried to be very sure to keep things in norm, not cranking up either the receiver or sub too high on any testing.

And like I said before, if I wasn't into having super huge boom on occasion, I'd choose the HSU, but if and when I wanna blow the house up, I like having that extra oomph there

[Nigel_Pl]

Hi Cboyd,

Don't worry no one is out to make you feel bad. I just wanted to know a little more about your setup and calibration procedures.

The problem with not having a sound pressure level meter is that it can be difficult to set the levels in relation to other subwoofers. The sound from some subs are "clean" with low distortion and free of additional harmonics. These additional harmonics can be perceived as stronger bass. This is because sound at a higher frequency is perceived as louder than sound at a lower frequency even if both sound waves are at the same volume levels. Hsu subs have a reputation of playing very clean.

The phase switch can be very important when you calibrate the subwoofer. If the subwoofer is playing out of phase compared to your other speakers the volume around the crossover frequency will be reduced....in your case the 65hz mark where most of the "boom" is. So no matter how high you turn the subwoofer volume up that "boom" may still be lacking.

Anyway I'm curious about the fluttering you've mentioned. I guess we'll have to hear more from other STF owners and the Hsu team. I just hope your Hsu Sub isn't damaged. Maybe the Definative ProSub 100TL can really dig deeper.

[cboyd1]

Concerning damage on the HSU, I don't think so, because it sounds flawless in all sorts of situations. It was just that one scene that it seemed to have trouble with, even when set down to 50% volume.

The flutter is hard to describe. I've experienced what I call flutter for years, for instance in friend's cars who have systems with aftermarket subwoofers in boxes, etc..I can cause my cerwin vega house speakers to "flutter" with enough volume on the receiver, its that threshold where the sub goes from max to "hey this is just to much"

picture a car stereo with subs in the back, etc..u put on a song with nice low bass and slowly beging to crank the volume on the deck. There is a point at the top where the sub quits putting out nice solid hits, and switches over to a not so ideal vibrating type sound, you realize you've raised the volume too much and u lower down to get back to that solid hit you had before, hope that makes sense.

also keep in mind this "fluttering" only occured in the one scene in Titan AE, when view the matrix films, gladiator, hackers, saving private ryan, i didn't experience this. Titan AE was the only film with long duration bass, meaning the low "note" hits and remains "on" for awhile (i.e. a rocket booster firing and roaring", versus Neo hitting the ground with a quick "thud" in the Matrix).

If I had never put in Titan AE I'd likely have never started this thread and would for sure go with the HSU. I still have more testing and considering to do...fun stuff :)

[Michael Bain]

The STF-2 should handily outperform these other two models in low bass output, low bass extension, and tonality. The STF-2 should match up pretty well with a VTF-2, and we already know how many larger and more expensive subs that this product has outperformed.

One cannot set an arbitrary volume level on each subwoofer and go from there. This will not work because of the different sensitivities of the amps.

You should look at this page so that you can get setup help directly from Hsu. Proper setup and calibration of a subwoofer is critical with low bass performance.

http://hsuresearch.com/support/index.php?id=36

[cboyd1]

I mentioned the volume settings more as reference points. Using my ears and my roomies ears only (no tools available). During various tests we'd set the volume on the subs to where they sounded equal, then try to listen for the fullness and tightness of the bass and overall quality. Typically in any test the HSU would be turned up about 10%-12% more then the DefTech to create what we considered a match....so no...I'm not just putting them "both" on say 50% then comparing, I try to dial them in the same. Its just when dialed in on the high range, the DefTech handles the sound better. This is of course pretty hard hitting at this point...at the settings I'd say 75% of listeners would use, the HSU probably does sound abit more clear and full, its just the top end suffers versus the DefTech, at least in my living room with my setup....audio is so intersting to discuss because we all hear things so differently and our setups are all so diverse.

[Sasha_G]

Thanks for your input. We usually like it more when we come out the clear winner ;) In particular, I was pleased that we came out high on fit and finish, considering that people used to think all our subs were ugly. However, we really care the most about audio quality. Regardless, there are a couple points I should mention:

The number 1 rule of subwoofer comparison is to use a SPL meter to match levels. As you may know now, setting the volume to 50% does not help, because each amplifier has different internal gains. Each sub should be volume matched, preferably at around 40-50 Hz. Level matching by ear just doesnt work well because the ear is less sensitive in those frequencies, and also might focus on certain frequencies.

Send me your address (sales@hsuresearch.com) and we will mail you a test CD with test tones so you can match the volume levels.

We get people all the time that say that our subs are not as loud as the ones they used to have, and almost always its because they didn't hear all the bloating and boomy sound. Really, our subs are generally in the top percentile when it comes to loudness. That is, they have the capacity to get loud when tested with a SPL meter.

In car audio, a lot of people like that "fat" sound, and that is what they think real bass sounds like. In almost all cases, within a month HSU customers come back happy to have discovered realism and more even bass. So, while with their initial impression of bass loudness is most important, in the long run it is the realism that makes them fans.

I would suggest going down to radio shack and getting a SPL meter.

Also, all the subs should be placed in the same are of the room, preferably a good area for bass. I won't get too nitpicky, but even a foot or so difference in location can change the bass response dramatically.

Also, the crossover should be switched to OUT on the HSU. You were cutting out a bunch of the bass. Especially if the other subs you mentioned don't have low pass filters, this is unfair. You mentioned that you had it to 65 Hz.

[Ddavidson]

You definitely have something wrong because there is no way that ProSub 100TL will play deeper and louder than the STF-2. You must be confusing bloated distortion for loudness. Perhap's that type of sound is to your liking, but its not accurate, deep or louder than the STF-2 can reproduce.

One of the easiest ways to see how good the Spl result is to do it within distortion limits. So look at Tom Nousaine testing where he places each subwoofer in the best corner of the room and measures its clean output capability. He places the SPL mic at a 2 meter distance and uses a 10% total harmonic distortion limit.

In TN's testing even the small Hsu has proven it can compete with the much bigger Def Tech (500w + 15") which by the way is rated to down to 14 Hz (by a lotto lucky dip rating system they use)

The $699 Definitive Tech PF15TL+ from 25-63Hz maxxed out at 104dB and at 20Hz recorded 88dB.

Now look at the STF-2's twin sister the $499 VTF-2 which measured from 25-63Hz at an average of 107.1dB and at 20Hz it recorded 93dB.

I notice this site has TN's test results in logical readable form.
http://members.cox.net/frankcarter/Tom%20Nousaine%20Sub%20Data.htm

Please do not take it as a negative dig. Subjective results can be somewhat variable and people need to know the conditions and set-up. That's why TN's testing is good because he has the one 7500 cu ft room and uses a 10% cut off to keep things even and relative.

It is just that clean output is the goal and the sub should not be changing or adding its own signature. Loudness perception in low bass can fool human ears. Also excessive distortion tends to draw attention to the sub which may be perceived as loudness.



Ddavidson

[cboyd1]

Fill me in on the SPL, how much do they cost, where can I purchase one, I might get one if they are semi-affordable, I'm interested to do some more in-depth testing.

[cboyd1]

I just read Sasha's reply. I'm going to get an SPL meter this weekend and do some real testing. I'll write a detailed post of my procedure and results. I also agree there may be some merit in Ddavidson's post, it is quite possible that some element of bloating and/or distortion to some, may be what sounds "good" to me, and if thats the case, I can't change what I like. Anyways, thanks for all the awesome replies, I'm looking forward to my testing this weekend. I think I'll even get out my digital camera and take pix of my setup and post em just for fun :)

[Sasha_G]

We'll, the long time enthusiast favorite, the RadioShack analog SPL meter, was discontinued last month :( I just found out about it now. I can't believe they did this! Everyone used that. We'll, thats RadioShack for you--they also discontinued their best remote control about two years ago. The analog SPL meter might still be available in some stores. If anybody has any suggestions for a similarly inexpensive replacement (~$25), let me know.

Radio Shack currently has their digital SPL meter, which was considered less accurate. Oh well, it still works:
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=33-2055 Not sure what your local return policy is.

Also, I just realized that if you had the internal low pass crossover switched to "IN" and set to 65 Hz instead of "OUT", that would mean that you would most likely turn the HSU sub way up to compensate for all the missing, punchy bass in the higher regions. If it was turned up too high, that would explain the "fluttering".

[cboyd1]

Sasha, I did the majority of my testing with the Crossover on OUT and the frequency set to 65Hz. The instruction manual mentioned trying the CROSSOVER on IN with 90Hz, I tried this a few times and didn't see much difference. Pretty much 95% of all my testing was Crossover on OUT and 65Hz setting.

[cboyd1]

also, I think I like the word "rattling" versus "fluttering" heehee, i think thats a better description :)

[jwygal]

Originally posted by Sasha_G
We'll, the long time enthusiast favorite, the RadioShack analog SPL meter, was discontinued last month :(

Ugh. No wonder I wasn't able to find it in stock, and they kept trying to foist the digital model on me.

[cboyd1]

Sasha, or anyone else. The testing CD you refer to. Is there anyway you could post it in .mp3 or .wave format for download, that would be awesome, and I'll just make my own copy at home? Does anyone have this test CD and has a means to post it?

Thanks,

Charlie

[cboyd1]

Sasha, or anyone else. The testing CD you refer to. Is there anyway you could post it in .mp3 or .wave format for download, that would be awesome, and I'll just make my own copy at home? Does anyone have this test CD and has a means to post it?

Thanks,

Charlie

[Ddavidson]

if thats the case, I can't change what I like.
No you can not, and no one is blaming you for your choice. But if that is the story then I think its best to make it very clear to anyone reading this thread. Of course they may agree or disagree with your subjective opinion, but at least everyone is talking on the same wavelengh.

That is really why Tom's tests are regarded as a good relative guide. Of course 3rd party controlled Spl, FR and extension measurements are not the only things to look at when comparing a sub, but it helps get you a starting list of potential subs.
also, I think I like the word "rattling" versus "fluttering" heehee, i think thats a better description
That sounds scary and a very wrong thing for a sub to be doing. What does your term "rattling" actually mean? Give us an example of "rattling" and then the term "fluttering".

You need to work out what happening here, do you have either Avia or the VE Dvd discs. You should go and buy it and then run some test tones and sweeps measure and locate the problem area called "rattling".

Some business in the field of meters should buy the design and get the analog RS meter made in China. Its like an industry standard and you have another industry modifying them to measure much more accurately. Tie it altogether and I am sure it still be selling till doomsday. Sad to see that model end as I have several myself and would not trade them for the world.


Ddavidson

[cboyd1]

"picture a car stereo with subs in the back, etc..u put on a song with nice low bass and slowly beging to crank the volume on the deck. There is a point at the top where the sub quits putting out nice solid hits, and switches over to a not so ideal vibrating type sound, you realize you've raised the volume too much and u lower down to get back to that solid hit you had before, hope that makes sense."

that is a quote from one of my earlier posts in the thread, thats the best way I can describe it. The "flutter/rattle" sound is slight by the way, its not loud or highly noticeable. And so far I've only been able to reproduce it in Titan AE with its long and loud explosions, most other movies have more of a quick hit, not extended. I think I'm going to put in Lord of the Rings tonight, when Sauron dies in the introduction you get a rather long bass blast, see if I can recreate the issue I get in Titan AE.

Keep in mind this is slight but noticable, and its when I'm really playing the movie loud, I normally wouldn't have things set this loud unless I was just really in the mood to rumble.

[Ddavidson]

the sub quits putting out nice solid hits, and switches over to a not so ideal vibrating type sound,
Sounds expensive.http://www.hsuresearch.com/forum/images/icons/icon10.gifhttp://www.hsuresearch.com/forum/images/icons/icon10.gifhttp://www.hsuresearch.com/forum/images/icons/icon10.gif

After reading through all of your descriptions, it is quite clear that we are not talking about clean real output and real frequency depth. As you have said above, if that's your perception of being louder and better then all the more power to you......for it's "your money" after all.

One thing I will say is if you get a chance try to accurately balance the system and subs up and then also listen to various music as part of the comparision.

Unlike a special effect most music needs balance and clean output or else a bad subwoofer ruins the music. Try to listen for longish periods, for I can almost gaurentee that you will find the Def Tech will make you want to keep getting up and turning it down, until finally you will "give in" to the headache and turn it "off" whenever playing music.

The reason of course is its not balanced over its FR and its tonality is pushed toward that hollow and bloated feeling almost like a car audio guy driving around with 70/75 Hz playing twice as loud as any other frequency (thumping up the street). The excessive distortion also forces you to grow very tiered very quickly. Not only that but all your music regardless of type quicky sounds like "Thumpy Pumpy" the Rap God.

The whole idea of a subwoofer is not to change the sound but to represent what is on the disc and replay it balanced accurately at the same relative level that your main speakers are reproducing the higher frequencies.

The sub should not be the one to decide to play back some frequencies louder than others.

But back to clean output, I bet a pound of peanuts that if you could get a hold of an Spl meter and a test disc and run some tests between the two subs, the STF-2 will be outputting "much more Spl" over "any" frequency or average combination of frequencies. (its designed operational frequency range)

Ddavidson

[tdekany]

Originally posted by cboyd1
"picture a car stereo with subs in the back, etc..u put on a song with nice low bass and slowly beging to crank the volume on the deck. There is a point at the top where the sub quits putting out nice solid hits, and switches over to a not so ideal vibrating type sound, you realize you've raised the volume too much and u lower down to get back to that solid hit you had before, hope that makes sense."



That simply means that the gain is turned up too much.
try lowering it a bit maybe cross it over at 80 or so.
I know what you mean about boomy bass. I like it too, but once you dial it in properly, you will not want that kind of bass.
Try it. Also could you put the HSU behind your couch?

The problem has to be with the position of the Hsu sub as well. However the Hsu is an acurate sub so it will only reproduce what is given. No coloration. Colored sound will make feel fatiqued in the long run too. Hope this helps.
Play around with placement.

[Sasha_G]

Originally posted by cboyd1
Sasha, or anyone else. The testing CD you refer to. Is there anyway you could post it in .mp3 or .wave format for download, that would be awesome, and I'll just make my own copy at home? Does anyone have this test CD and has a means to post it?

Thanks,

Charlie

Matter of fact, we have the test tones here (ripped with Exact Audio Copy and encoded with LAME encoder):

http://hsuresearch.com/mp3/

[horts32]

Sasha_G or anyone else - do you know the model number for the old analog SPL meter from Radio Shack. I am looking for one online, and the model number would really help!

[cboyd1]

Question, should the HSU be able to play a 20Hz sample solidly? I bought this little Dolby 5.1 Test DVD from Radio Shack today while picking up an SPL, I found an analog :) When I play the sub test, the 20Hz signal goes off 3 times in a row. The HSU sorta just wheezes, while the Definative gives me a solid bass hit. Comments anyone? I'll be doing some tests over the next few days with the SPL and will let you know the results.

[Michael Bain]

The STF-2 should have some usable output at 20Hz, albeit with somewhat reduced levels compared to 25Hz and above. It should really have much louder and cleaner SPL levels at lower frequencies than the other subs in question. What are your results when playing a 25Hz, 30Hz, 35Hz, and 40Hz test tone through the STF-2? If you are not getting very loud output at these frequencies, then something is wrong and you should troubleshoot with Hsu.

[Lwang]

Hsu's subs are vented design with a designated low end extension, and his subs are designed in such a way that signal below that point are attenuated so that it would not try to produce sound in which it is not optimal at doing. So signal below 25hz has been intentionally decreased in level on the Hsu subs.

The Definative subs, being a sealed design, does not encounter a point where it becomes un-optimal in the same way a vented sub does. So they could atrificially equalize the sub to be flat to (in this case) 21hz. So even if you hear something at 20hz, how much of it is useful? Does it go to any significant SPL level? And if you actually hear the 20hz sound, you might not be really hearing the 20hz signal at all, but its upper harmonic distortions. 20hz sound could rarely be heard. It should be felt instead.

[cboyd1]

Hey Gang,

Well first I'd like to thank Sasha and the rest of you for all the constructive comments as I entered the world of subs, and started to learn a few things. At the start of this thread you'll recall I was testing a Sony 12", a STF-2 (rated at 25Hz), and a Definative Prosub 100 (rated at 18Hz).

I had once concern, which was a rattle or flutter as I described it with the HSU. I like the overall build quality and the crispness and tightness of the HSU, but the flutter on really low bass areas on movies was bothering me, and the other subs weren't giving me this flutter or rattle noise.

I met a nice guy named Kevin Chen here on the here on the message board who lives and works close to me, and we spent our lunch break today playing with the DefTech and HSU subs, using the SPL i bought recently and his testing DVDs.

I calibrated both subs with a 50Hz tone, setting each sub to output 70db. We listened to some low bass scenes, and he too heard the "vibrating/rattle" noise as my roommate and I had heard before on the HSU

THEN

We popped in his test DVD and began running some sweeps, there was one nice sweep that went from 100Hz down to 20Hz, and constantly updated its reading on the TV, so you knew where you were.

Sweep with the DefTech ProSub 100 - Rated at 18Hz
-------------------------------------------------------------------
As we swept down from 100Hz, at about 27Hz, basically all sound and vibrations were gone, it was like you turned it off more or less, at about 32Hz you definately got more of a rattle than a pleasing solid sound.

Sweep with the HSU STF-2 - Rated at 25Hz
-------------------------------------------------------------------
As we swept down from 100Hz towards 20Hz, at about 31Hz I start to get faint hints of my rattle, and from 30-20Hz I get my "rattle" I tried to describe to everyone throughout the range of 30-20Hz.

Conclusion, the DefTech rated lower simply can't pick up the lows like the HSU, thats why the rattle I was hearing was actually the technically better HSU doing its job, and picking up the low frequencies, while the DefTech just did nothing, it couldn't handle it.

Also, during the flutter ranges....things in my kitchen were vibrating, yet we couldn't hear much in the home theater area.

I am solidly convinced that the HSU is a better value and can handle deeper frequencies. Also, to prove our point, the SPL meter showed no db reading at 20ish Hz for the DefTech, while the HSU showed a solid 60-70db reading at the low frequency.

Now I'm faced with one problem, haha, while I fully agree and accept that the HSU is a far better sub, I must admit, in low frrequency scenes, I don't like that rattle I hear, and I can't hear it with the other subs because they simply can't reproduce as well as the HSU. Unfortunately my receiver does have the option to set how low of a frequency I send to the sub, its all or nothing.

With this in mind, I know I'll be upgrading my receiver in a year, the HSU is cheaper than the DefTech and is obviously better.

Thanks to Kevin and everyone here at the board for putting up with me, teaching me, and giving me all the great suggestions, I'm an HSU owner and enthusiast now, I've been sold :)

Later all,

Charlie

[tdekany]

I love to see posts like yours (honest). Welcome to the world of HSU.

[cboyd1]

One more quick question. As my receiver is abit old (it was a 300-400 dollar Kenwood Model in summer 1999, it does have dolby digital 5.1 though, and has 100W per channel RMS, it does a "decent" job). I just posted a few mins ago that the HSU is picking up the low low frequencies that my other test subs weren't. On the newer receivers, do they typically have settings where I could set it to not send out anything lower than say 30Hz to my sub (or whatever I set it for?)

Thanks,

Charlie

[cschang]

bad info....please delete the post.

[cboyd1]

From what I understood from Sasha, the optimal setting on the STF-2 is to set the CROSSOVER switch to OUT, which nullifies the CROSSOVER on the Sub, or do I have it backwards?

[cschang]

I'm sorry...I stated it in correctly. You would need a filter of some sort to achieve what you want.

Is this rattle coming from the sub? The sub should not rattle.

[cboyd1]

i'm convinced it's not so much a rattle but simply how this sub sounds when it's recreating low frequencies in the range of ~30-20 Hz. As mentioned before the Sony and DefTech couldn't even go this low, at 27Hz you simply hear and feel nothing, and register 0 db. The HSU puts out abotu 70db in my testing environment all the way down to the lowish 20'sHz. It isn't as solid to the human ear, resulting in a humming type sound, but you can still "feel" it. Can anyone who has been keyed in on this thread back this finding up with their own experiences?

[Nigel_Pl]

Hi Cboyd,

I am really glad that you took the time to conduct a proper test.

As for the 30hz and below cut off I am not aware of any receiver that can do that...but I'm sure some of the more expensive ones will be able to do it.

If you are using the receiver crossover then there is no need to set the crossover of the Hsu Sub to IN....that is if your receiver does not redirect a full range signal from the centre, front and rears to the subwoofer. I know that some of the older receivers would pass a full range signal to the sub instead of just the lower frequencies. If this is the case then you will have to set the crossover of the sub to IN.

[cschang]

Even so, it should not be making an unusual sound.

I have a VTF-3, and yes, that low, you feel more than you hear......but I do no hear anything like you describe.

[cboyd1]

My receiver has a crossover in it, and it's doing its job :)

I will also add that Kevin, the guy I met through this forum in my area didn't seem to be bothered by the "rattle" I have been describing, it didn't bug him in the slightest. In fact I think he has ordered an STF-3 already :).

Man, I wish I could just zap you guys into my living room so you can hear what I've been trying to describe for days. Anyways, now that I understand "what" I'm actually hearing I'm totally fine with it. The reason I'm hearing it is because the HSU is so much better than the DefTech and Sony I tested, they put out 0db at these frequencies, the HSU is definately shaking things, and I can hear and measure the ~70db it's putting out at the low range, it just doesn't sound solid, like a 45Hz tone. Make sense? Like Sasha said, low frequencies don't sound all that nice, its more of a feeling, and I think he's right.

[cboyd1]

Also, I hear people mention that their receiver has "bass management" or bass option. The ONLY thing I can adjust on my sub via my receiver when in dolby 5.1 mode is the +/- db going out to the sub, default is 0db, and it can be adjusted to -10db up to 10db (this just adds more or less to the sub via the receiver). I have no high and low limit settings or anything of that sort.

[cboyd1]

For anyone interested, here is a link to the manual of my Kenwood receiver, its a .pdf from the Kenwood site.


ftp://docs.kenwoodusa.com/manuals/OM-VR-309-1999-KUSA.pdf

[Dudley]

Have you checked to see if it is something else in the room rattling besides the sub? Is the rattle a different frequency than the tone the sub is playing, or is the rattle the tone itself? Could it be port noise (some call it chuffing). A lot of air goes through the port at the tuning frequency.

[cboyd1]

I can definately tell the sound is coming from the driver itself, i can turn the sub on its side and tell its from the driver area, not the air hole in the back and not something in my room/house.

[Ddavidson]

I imagine you are hearing the (for lack of a better word) "flapping" of the driver at 20 Hz or so. If you have a 15-18 Hz test tone turn your STF-2 upside down (volume at 0) and with the 15-18 Hz tone playing bring the volume slowly up while listening if this is the noise you are hearing. (do not over-drive and cause audible driver distress)

Test tones locate the frequency where it happens. As mentioned below....... playing a slow frequency sweep is good if you have no idea where to start looking.

The other issue down this low is port "chuffing" which on a Hsu sub is normally one of the lowest in the industry. (that's why Dr Hsu can get away with using /recommending the "close couch positioning", where other ported brands have too much port noise). Still people have variable tolerances to noises so while your running the low test tone check out the noise from the port. Basically all the low frequency output comes from the port and the higher frequencies the sub is capable of comes from the driver.

My bet is your hearing the mechanics, physics of the driver as its working very hard at 20Hz.

Also running a slow freq sweep from 0-120Hz helps find all those annoying internal and external subwoofer noises. It's amazing how many things both internal and external can start buzzing away at a certain frequency.

Ddavidson

[Nigel_Pl]

Ddavidson,

You are definately on the ball with that reply. Most other drivers will hardly move at frequencies that low.

Cboyd,

It doesn't look like your receiver has an adjustable crossover for SMALL speakers but setting them to SMALL will still redirect bass to the sub. So your receiver has "simple" bass management. Some receivers allow you to adjust the crossover frequency for SMALL speakers and the subwoofer...others allow you to adjust the crossover frequency for each individual speaker which is very handy if you want to crossover your FRONT speakers at 40Hz, your centre channel at 50Hz and your surrounds at 80hz.

[cboyd1]

Ddavidson you described my "rattling" or whatever the heck I've been calling it, to a tee. That is exactly it, and while I don't "like" that sound, I am thinking I should be able to eliminate it with a more advance receiver. Additionally it's rather rare, only certain scenes.

Man, after I used my SPL to dial in all my speakers and subs, I watched Bad Boys 2 (which by the way is decent at best, and thats considering you sorta like the first one) last night, the car and chase scenese, with all the gunfire was AMAZING.

Thanks again guys for all your help and patience.

-Charlie

[Dudley]

Nigel_Pl

Which receivers let you have variable crossover. That is a feature I want in my next receiver, but can't seem to find. I suppose I may have to wait for it to trickle down.

[kevingchen]

Hi, cboyd,

Glad to see that you decided to keep the STF-2. And glad I could help you on this.

Yes, I think the what you call 'rattle' sound from the HSU is indeed the actual sound between 20~30Hz that Hsu can play and the Definitive cannot. And I actually like the sound. It make me feel the air is shaking.

Frankly I am also a newby on this. I am yet to get my first sub (STF-3 on order). I gained all my knowledge from Web forums like this and AVS forum, etc. I, too, learnt a lot from the nice guys here and on other forums.

After seeing the STF-2 playing in your home, I am more convinced about HSU and also more convinced that I want the STF-3 or even VTF-3Mk2, since I have a large (19x19x9) room.

To everyone else, what cboyd wants is a receiver with a filter that can limit the LFE signal sent to the sub between ~30Hz and say 80Hz, so he can remove the sound below 30Hz from the sub. I don't think such a receiver exists. You may be able to achieve this with a external filter.

Kevin Chen

[Nigel_Pl]

Dudley,

The new range of mid level pioneer, sony, onkyo and yamahas have it...I am sure many other brands have it too. I think even the cheaper sony range has variable crossovers for each individual channel.

[Dr_Hsu]

Sounds like you don't want a subwoofer, but a woofer :) I suspect that you will get to enjoy and appreciate the deep bass later.

If you like, ship your STF-2 back to us and we can check out the sub for you.

[Todd B.]

cboyd1, have you checked to see if the screws attaching the driver to the enclosure can be tightened any further? If they're loose, the driver very well might be rattling around. Just be careful not to strip out the screw holes.

[Hawkson101]

i think i may be in the same boat as the original poster. The stf-2 makes everything vibrate and shake, but i dont think it is very loud. Maybe i do like the booming bass(not too much, but enough).
huh
so much for being an audiophile.

anyways, how much better is the TN1220 then the stf-2 or am i just going to be in the same boat? I do like a little boom in my bass

[cschang]

if you like boomy bass then Hsu is probably not the place to look.

You could also try to reposition the sub as well.

[tdekany]

Originally posted by Hawkson101
i think i may be in the same boat as the original poster. The stf-2 makes everything vibrate and shake, but i dont think it is very loud. Maybe i do like the booming bass(not too much, but enough).
huh
so much for being an audiophile.

anyways, how much better is the TN1220 then the stf-2 or am i just going to be in the same boat? I do like a little boom in my bass

I learned this from Dr Hsu. (I know most of you know this).

Put the sub where you sit when listening/watching. Start walking around the room. Where ever you hear the sound that you like, (kind of boomy) is where you will put the sub.

[Ddavidson]

The stf-2 makes everything vibrate and shake, but i dont think it is very loud.Actually high distortion and boomy bass is only a habit of our listening nature. It's a little like having lots of sugar in your coffee where in the end you wonder why your drinking coffee when it's actually more like hot chocolate.

Position the STF-2 near your listening chair and adjust to suit the new position. (once again it takes a little trial and error) This will give you some more Spl sock and punch close to your body. Either that or fill in the position diagram for Dr Hsu to answer. Ask about an ideal behind the sofa position to gain you some Spl impact you feel you miss from boomy subs.

To get used to what the soundtrack / music really sound's like without the artificial overhang you have to change your listening habits (which is not hard once you see what your missing). Funny thing is by you not listening to the fine detail you are now getting with the STF-2, you now feel like you are being cheated..... but that's only because you think that overhang and distortion is how it should sound. Its not that you can not tell but you just do not know what to listen out for.

Most of my friends initially thought similar things of my VTF-2 and VTF-3 until I sat them down and then actually measured Spl and played really deep bass. One day they all came over with their subs and we directly compared and measured in my two listening rooms. Their clear initial opinion after a short listening session was that both of my Hsu's could not play as loud (at the same frequencies) as their subs could.

But once we actually measured with my trusty old RS meter (modified for the corrections) all of their negative thoughts disappeared . To cut to the chase they suddenly realized that the Hsu's not only played louder and deeper but they obviously did so at a much lower distortion level which meant they where a whole heap cleaner in their bass reproduction. It was night and day in direct comparisions. That's how they pretty much all ended up with Hsu subs.

The whole idea of a subwoofer is to add weight and depth to the bottom end, it is not to over power the mid and treble sections. People have gotten far too used to the mentality of tone controls, and they think that by consistantly adjusting them they will somehow make it sound better than the actual recording. By listening to boomy subwoofers for so long it's sort of like suddenly you have the tone controls set back to "0" .... and to you at the moment it just doesn't sound normal.

We all can get used to having 4 sugars in our coffee and turning the tone controls all the way up, just as people have got used to listening to boomy subwoofers. We just take that as the way it should be. Take away the boomy subwoofer and our ears no longer know what they are hearing so it all seems wrong.

Which its not of course.

The only solution when you find it sounds like you should have more bass coming from the subwoofer, is to go over and turn the subwoofer off (then take a good listen) then repeat the same section except this time with the subwoofer on. Adjust the level to where you can not tell where the bass is coming from (even though you can see or know where the sub is located) then play the track with the sub off...... then on..... then off..... then on .... e.t.c.

After a while of deep listening you will get the feel for the subs balance and turning it off while you are playing any track will make you realize just how much detail the sub is allowing you to hear.

It is much easier to show people in real life what I am talking about than to try to explain it in words ...... but in summery it's all about getting a balance which comes from positioning, acoustics and system set-up. You do not miss boomy subwoofers after you hear the detail of the real soundtrack. Gunfire just is not a test of a subs ability.

If all else fails then maybe the Hsu is just far too correct. Perhaps then a more artificial subwoofer tonality is needed for your ears. Unfortunately there are lot's of them on the market, which is why we have to try to explain what is correct and what is not.



Ddavidson

[wjficken]

cboyd1,

There is a thread in the STF Series Central > Driver & Cabinet section titled "STF-2 defective?????" posted by raider73. Does the issue described here sound like yours? Do you have access to Finding Nemo, and if so, could you try the scene that he refers to?

Here's a direct link to it: http://hsuresearch.com/forum/showthread.php?s=&threadid=419

Wes