STF3 -- "popping"...

[sputnikv8]

Ok. I got my stuff setup up. Its not optimized yet, but, I just couldn't wait. Here's my initial problem:

1. I tried the darla scene....works fine, I don't hear a "rattle". So thats good.

2. Tried a few jurassic park scenes and some top gun. Worked great. Sounded incredible. Bass with authority.

Now the bad...

Both Star Wars Ep1 & Ep2 have space ships floating across the screen at the beginning which emits TONS of bass. When it gets to the crescendo of the bass I hear a "pop" from what seems to be the driver. I turned the thing on its side and played/replayed the scenes and it is DEFINATELY a pop from the middle of the driver or behind it.

My receiver is barely at 9'oclock and the sub is set as follows:
- Using "sub in"
- Crossover set to "out" (tried in as well - same deal)
- Volume barely at 9'oclock (lower and the bass isn't as authoritative, as soon as I reach that point on the dial -- the pop will happen during the intense scene)

I don't feel like I'm even pushing the system here but that sound should only happen if I stress the thing, right?

HELP! I'm calling tech support too, but, the line was busy.

First time HSU owner.

[cschang]

what is the sub level set on the receiver?

Have you calibrated? Maybe you are bottoming out the sub?

[sputnikv8]

Originally posted by cschang
what is the sub level set on the receiver?

Have you calibrated? Maybe you are bottoming out the sub?

I have it at the "0db" setting. I guess I could turn it down. Seems like if I turn it down here, I'll have to turn "up" the volume on the sub and I'd get back to the same level?

I don't have an SPL meter yet, so, nothing is calibrated yet. I guess it just shocked me that I never stressed my little klipsch 10" 50 watt sub at these levels. (of course, it didn't go as low either). :)

I will go turn down the DD LFE on the receiver and retry the scene -- i will have to adjust the sub's gain though.

[cschang]

I was actually thinking turn the gain down on the sub and turn it up at the receiver.

[sputnikv8]

Well... here is what I did. (As you can tell this is my first "real" sub). The Klipsch was nice, but, its a toy compared to this.

Anywho...

I turned my DD LFE down to -10db on the receiver. I then turned the sub's gain up to about 10 o'clock. The bass on the starship scenes is still thunderous and the driver is not bottoming out.

That kinda went against my logic, but, it seems to work.

I've never really calibrated everything, so, I was starting with the settings I had to use to get any bass out of the previous sub.

What exactly is happening when a driver "bottom's out". Its a horrendous sound that really sounds destructive. Did I harm anything?

[cschang]

It seems to me you actually turned down the overall volume of the sub. You really need to get an SPL meter and calibrate properly. I suspect you have the sub too "hot" or loud.

With the rumble you hear on those scenes, or other scenes, what is the volume like on the rest of the system?

By using the gain control on the sub, you should try to get the receiver to just a few db above zero on the sub volume.

Bottoming out happens when the excursion of the driver exceeds the limit and hits the structure behind it.

[Lwang]

If you don't calibrate with an SPL meter, and adjust by ear, you would most likely have the sub level way too high. Even with music, one generally want to hear the sub, but by then, your sub would be at least 10dB too hot.

[sputnikv8]

Thanks for the help guys.

I'll be getting an SPL from one of the sound guys at church. (Ok, so what...I want to save the $30 bucks!) and will try to set it all correctly.

I think you're right though. With the new big sub I wanted to make sure I heard it so I had everything set hot.

The sub is incredible though. Wow... powerful. It moves SO much air.

[Ddavidson]

The initial reports coming in for the STF-3 are excellent. I was especially impressed by a few people that have had the VTF-2 and reported performance relative to the their VTF-2. All STF-3 owners seem very impressed with the STF-3, which is how I expected things to work out once it shipped.

As far as setting it up by ear, its just always going to end up way too hot. We humans have funny judgement when it comes to balancing up bass with our ears. Remember when using the RS meter with bass you neeed to do the corrections because its not accurate.

10Hz add 20dB
12Hz add 16.5dB
16Hz add 11.5dB
20Hz add 7.5dB
25Hz add 5dB
31.5Hz add 3dB
40Hz add 2.5dB
50Hz add 1.5dB
63Hz add 1.5dB
80Hz add 1.5dB
100Hz add 2dB
125Hz add .5dB


Ddavidson

[sputnikv8]

I did a calibration using the SPL last night.

The sub was set WAY too hot and that is why it bottomed out. It is taking some getting used to listening to everything properly set up. All these years of miscalibrated equipment (not to mention a "toy" Klipsch 10" sub) .... and now this.

Very impressive to say the least.

[Ddavidson]

It's rather a shock when you realize how far out your ear settings actually are. But sound like you have it alll worked out now and can get on enjoying your STF-3. Keep us posted on how things are going.

Ddavidson

[vbjeff]

It shouldn't be too surpising that setting a sub by ear will be too high since it takes a higher SPL for lower frequecies to sound "equally" loud (assuming this study is accurate).
http://www.silcom.com/~aludwig/images/Fletcher-Munson.jpg
http://www.silcom.com/~aludwig/EARS.htm#Subjective_vs_objective

[Lwang]

vbjeff,

That study does not mean we cannot set a sub's level by ear. What you are assuming is that we cannot set level with wide bandwidth and 20-120hz bandwidth pink noise that are available in discs like ones that include THX Optimode.

We are talking about adjusting the sub level based on prior knowledge of how the music track should sound. Since most people want to hear the sub they just bought, they will either turn it up until they notice the sub (6-10dB too high), or until they have a satisfying thump (++10dB).

It is not impossible to adjust the level by sub, as long as you have to push away one's inherit bias into wanting to hear the sub, no matter how much you tell yourself that you shouldn't.

Since the low bass might never have existed in the main speakers, it would be hard to adjust the sub purely on how loud those levels are, so we have to adjust the level from the mid-bass, especially in regions in which the main speaker use to occupy before being rolled off. You just have to hear the relative levels of notes from instruments that are prominent in that region, with and without the sub. Once you got it close enough, you can play a track with a repetitive bass rhythm that goes up and down across the crossover region by an instrument that has roughly constant level (e.g. bass guitar or double bass). Then you listen for level difference as the notes goes up and down and adjust accordingly.

Many audiophiles many years ago adjust their sub's level by ear, and rarely end up with the level higher than it should. It's all based on what you expect the sub to achieve and how you go about it.

[Mlee]

sputnikv8,

Unfortunately, I too have had the same experience, the good thing is that there seems to be a solution. Do you by chance have a Yamaha receiver? Mine is set to 0db for the LFE and my sub was at 9 o'clock similar to what you described... The noise is very unnerving...

When you turned down the receiver and then turned up the sub did it net out to the same volume our did you actually get an increase in volume? I just can't believe that the STF-3 would be bottoming out at such low volume levels, I too could not bottom out my cheap 10" velodyne.

I have faith - just looking for guidance, anyone?

[cschang]

MLee,

Have you calibrated the sub using an SPL meter?

Many folks trying to set an accurate, clean sub by ear oftern set the sub way too hot.

[Michael Bain]

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

Careful setup and tuning is very important. What settings are you using (in detail), and what placement options do you have?

[Mlee]

Thanks guys for the quick reply - I want to become an HSU believer!

No SPL meter, sub in corner of room, speakers set to small, xover set to out, receiver (Yamaha5560) LFE set to 0db (max) it goes down to -20db... I can place the sub at my couch/armrest but then it would be out from the corner 3 or 4 feet.

I just don't understand the idea of too hot, that means too loud to me and I can't imagine that these things aren't meant to be louder without distortion - I guess I need to get a meter but I want my ears to tell me that it Rocks - not a meter.:(

[Michael Bain]

The SPL meter is very important for calibration. Dr. Hsu should be able to give you some more tips once he knows all the other variables in your setup.

[Mlee]

We'll just a quick update - thanks for both your replies...

I have turned down my receiver (-10db) LFE and adjusted the volume slightly higher on the sub - what a difference!!:D

I have even tried it with the xover set to in even though my receiver suggests that it sends less than 80hz to the sub when the xover is set to 80hz on the sub it seems to filter out a fair amount of higher freq. sound - even more improvement here, perhaps because of the tuning.

Needless to say getting more impressed with this Sub the more I learn how to use it. I totally understand now what hot means.

Thanks again.

[eddy13]

Well I to bottomed out my vtf2. I had the sub voluem set to 50 percent and receiver at 0 db I have a yamaha rxv1400 and in the matrix reloaded feeway sene when agent smith jumps on the car and crushes it I was bottomling out all the time when i had it in max output. Funny thing is when i put max extension it never bottomed out.
Actually what i did is i got a spl meter and i lowered the sub now to 30-35 percent and run it on max extension. I did not claibrate it exactly to my speaker levels as this would of given me way to little bass. I have it a tad higher but still not running so hot. readign the posts above what does one get out of lowering the lfe sub level to -10 db and turning the sub volume out. Would you hear the same thing if you turned the sub volume down and kept the receiver volume at the same level which i had it before which is 0db. Actully my sub is probably calibrated to about 3 to 4 db higher. can anyone help me out here and by oen bottomlign out there sub does this mean that it got dmaged

[fanuminski]

Quote:
_________________________________________
As far as setting it up by ear, its just always going to end up way too hot. We humans have funny judgement when it comes to balancing up bass with our ears. Remember when using the RS meter with bass you need to do the corrections because its not accurate.

10Hz add 20dB
12Hz add 16.5dB
16Hz add 11.5dB
20Hz add 7.5dB
25Hz add 5dB
31.5Hz add 3dB
40Hz add 2.5dB
50Hz add 1.5dB
63Hz add 1.5dB
80Hz add 1.5dB
100Hz add 2dB
125Hz add .5dB
____________________________________________
It seems that no one has been able to supply the answer to this question:
Do these adjustments also apply to the
digital version of the RS meter? (Unfortunately) I bought
the newer, digital version and need to know if there are
any adjustments needed.
thanks:)

[Mlee]

Eddy,

My take is that the volume gain is exponential so that by turning it down at the source (Yamaha) you are able to tune it in easier at the sub - it worked for me & some of the other Yamaha owners you may want to try it. I have not been able to even make it bottom out since - my much less powerfull system get's too loud.

Good luck!