Problem with Hsu STF-2

[Vinnces]

Bought a STF-2 off craiglist about a month ago. I notice that whenever I play something with really low bass the subwoofer starts distorting if what I'm hearing is correct. Like there's a shaking sound coming from the subwoofer. I tested the same video/music with my parent's Infinity Entra Sub II and did not hear the same problem. Is something wrong with my STF-2?

[Pete_Hsu]

Hi Vinnces,

May I ask what settings you have on the subwoofer for volume and crossover, and what settings you have on the receiver for channel level and crossover for subwoofer/speakers?

Are you hearing distortion with both music and movie program material, at low/moderate/high playback levels?

Are you using the subwoofer with spiked feet on any hard flooring surface?

Thanks

Sincerely,

[Vinnces]

Hi Vinnces,

May I ask what settings you have on the subwoofer for volume and crossover, and what settings you have on the receiver for channel level and crossover for subwoofer/speakers?

Are you hearing distortion with both music and movie program material, at low/moderate/high playback levels?

Are you using the subwoofer with spiked feet on any hard flooring surface?

Thanks

Sincerely,

Sub Vol. is at the 9 or 10 o'clock position. Crossover is set at 60 on the sub but the crossover is set to "out" on the sub. Receiver is an Onkyo HT-RC180 so the setting was set by Audyssey. I remember Audyssey have the front at 40hz and the surrond at 60hz. Think the front and back was set to -7dbl while the sub was left at 0 dbl. I just got the Onkyo this week, was using a H/K avr-235 before but had the same problem if your wondering.

The louder I crank up the volume the easier I hear it. But then I have no idea what really is consider low bass since I'm still a newbie to HT.

The Sub is sitting in the corner opposite where the TV is in a 10x10x8 room. It's on carpet with the spiked feet that came with it.

Was wondering if there was any sound file I could use to test to see if my sub is broken or not. I don't really have any thing to compare with beside my parent Infinity Entra Sub II and that's why I got suspicious that something is wrong with my sub. That and it was still doing the same thing after I change the receiver and ran Audyssey.

[Pete_Hsu]

For simplicities sake, on the receiver disable Audyssey, set crossover frequency for all speakers and subwoofer to 80Hz (all speakers 'Small'), set the channel level to +0dB for all speakers and subwoofer, and set the distance settings appropriately. On the subwoofer, set the volume knob to ~ 11 o'clock, and keep the crossover switch set to 'Out' (which bypasses the internal crossover on the subwoofer).

How does it sound after making these changes?

[JerryMeeker]

If the speaker trims are -7 and the sub trim is zero, something is very wrong.

You don't mention whether you ran Audyssey calibration or not. If you run the Audyssey calibration, then the levels for your speaker and sub will be automatically set. If you set your sub's level to 10 or 11 O'clock, then the suggested sub trim set by Audyssey should fall between -3 and +3. If outside of this range, the sub's level is set too high (if the trim is lower than -3) or too low (if the trim is higher than +3). Adjust the sub's level and re-run Audyssey until the sub trim falls in the -3 to +3 range. Once Audyssey calibration has completed, set all speaker crossovers to 80 Hz and test the system out again.

You should not be hearing the sub "bottom out", if that is what the noise is.

[Vinnces]

For simplicities sake, on the receiver disable Audyssey, set crossover frequency for all speakers and subwoofer to 80Hz (all speakers 'Small'), set the channel level to +0dB for all speakers and subwoofer, and set the distance settings appropriately. On the subwoofer, set the volume knob to ~ 11 o'clock, and keep the crossover switch set to 'Out' (which bypasses the internal crossover on the subwoofer).

How does it sound after making these changes?

I can still hear the distortion after making the changes. It's slightly better but I tested it again with the music I was listening to and you can still definitely hear it at parts.

I went and borrowed Wall-E from my parent and used the bass list from avsforum:

"WALL-E" DTS-ES Blu-ray
1. Chap ? (0:12:40) WaterFall (http://img175.imageshack.us/img175/7474/75964007hd1.jpg)
2. Chap ? (0:55:00) WaterFall (http://www.imagebam.com/image/8a73ec21081848)
3. Chap ? (1:23:10) WaterFall (http://hdimage.org/images/vuoamjjgztmnuznrz8z3_a.jpg)

Can hear the distortion from the sub at those scene when the sound isn't drowning it out. For example around 13:46 when the spaceship lands I can clearly hear the sub distort with a vibrating sound. Volume was set at -12.5db with the setting you provided.

Can I send ya the mp3 I was listening to to test the sub with? I can clearly hear the distortion playing those at certain points.

[Vinnces]

You don't mention whether you ran Audyssey calibration or not.

The setting above was provided after I ran Audyssey calibration. The thing I'm worrying about mostly is that I don't hear this kind of distortion from the Infinity Entra II sub that my parent use. I thought at 1st, like you said, it was maybe the sub bottoming out cause it can't go low enough but after testing the same music on my parent setup I began to suspect that wasn't it. I don't know how I can describe the distorted sound accurately and I'm not sure I can record it either. I think the best way I can describe it atm is like the woofer cone is producing an extra sound by vibrating. As you can see the description sucks. :confused: Like I said I don't hear this type of distorted sound when I check the Infinity Entra II sub playing the same music.

[Pete_Hsu]

Volume was set at -12.5db with the setting you provided.

I'm not sure I follow. Are you referring to the master volume level on the receiver here?

For simplicities sake, make sure to disable Audyssey, manually set the channel level to +0db for all channels, and manually set crossover frequency to 80Hz for all speakers and subwoofer.

After that, at what master volume level do you start to hear audible distortion with various music/movie program material? Could you clarify in more detail what program material you are listening to when you hear distortion?

Did you hear distorted sounds starting from day one after you received the used subwoofer?

What are your room dimensions (HxWxD, including openings to other areas)?

Make sure that the spiked feet are snugly screwed on, and make sure that all the screws around the perimeter of the driver and amplifier are snug.

Note that the Infinity sub may completely roll off the lower frequencies and/or have strong limiters to prevent the woofer from running into overexcursion. Or there may be a problem with the STF-2 driver. After clarifying the above points, I will give you instructions on how to test the driver by itself.

Thanks

[kinggimp]

I also owned a stf-2 and thought that it was distorting. Before that I had never owned a nice subwoofer. I kept thinking I heard distortion from the sub but it turned out that the wall behind it was the culprit. Maybe you should play a bass sweep to see if there are any room rattles that you are mistaking for distortion in the subwoofer. That might have nothing to do with it but it can't hurt to check it out.

[Vinnces]

I'm not sure I follow. Are you referring to the master volume level on the receiver here?

Yes, I meant the receiver master volume. I reset everything according to your instructions. Audyssey is disabled, channel level all at 0db and all crossover at 80hz.

Using Wall-E as the source material for the test.

At about 13:47 at volume of -21db when the ship just finishes landing.
At about 54:10 at volume of about -19db when the projectile is in flight.
At about 1:24:50 at volume of -19db when the ship is landing.

Did you hear distorted sounds starting from day one after you received the used subwoofer?Yes, heard it since day one but assume it was just bottoming out/can't go deep enough. I just assume maybe it was me playing material too loudly.

What are your room dimensions (HxWxD, including openings to other areas)?Room is basically 10x10x8 with a 30inch close able door and 1 window on the 2nd floor.

Make sure that the spiked feet are snugly screwed on, and make sure that all the screws around the perimeter of the driver and amplifier are snug.Yup, double checked all the feet and screws. The only problem I think I found was that the most left side screw in the picture. When I turn it it will just keep turning, can't be tighten. It still can be unscrewed back up but when I screw it back in it just keeps spinning after going back in.

Pic link: http://img156.imageshack.us/img156/2217/img2102.jpg

Thanks for all the great support Pete! Hopefully I'm just being paranoid. :rolleyes: Guess suddenly deciding to spend close to a thousand bucks on a HT system will do that to you. :(

[Vinnces]

I also owned a stf-2 and thought that it was distorting. Before that I had never owned a nice subwoofer. I kept thinking I heard distortion from the sub but it turned out that the wall behind it was the culprit. Maybe you should play a bass sweep to see if there are any room rattles that you are mistaking for distortion in the subwoofer. That might have nothing to do with it but it can't hurt to check it out.

I actually tried about 3 different position in the room and still hear it coming from the sub. I tried planting it right in the middle of the room just now and yup it's exactly coming from the sub itself. Thanks for the help though!!

[Pete_Hsu]

Thanks for the clarification Vinnces. So if you have the master volume level on the receiver set lower than -21dB, then you don't hear distortion? What about with other music and movie program material?

I recommend that you leave the door open that leads to your room, and place the subwoofer in the front corner that is furthest away from that doorway.

Feel free to email sales<at>hsuresearch<dot>com , and I will give you some instructions on how to test the driver by itself.

Sincerely,

[Vinnces]

Thanks for the clarification Vinnces. So if you have the master volume level on the receiver set lower than -21dB, then you don't hear distortion? What about with other music and movie program material?

I recommend that you leave the door open that leads to your room, and place the subwoofer in the front corner that is furthest away from that doorway.

Feel free to email sales<at>hsuresearch<dot>com , and I will give you some instructions on how to test the driver by itself.

Sincerely,

From the listening position, yes. If I like turn down the master volume down another db or 2 I can only hear it if I put my ear close to the subwoofer. Like I said that why I thought at 1st it was just me having material being play back too loud.

Yup, already placed it in that position. It's infront of a bookshelf but basically I can hear the same thing at any position from the sub in the room. Opening and closing the door produced no difference that I could tell with my ear.

If you don't mind can I also email you the music mp3 I was using to test with? Thanks again!!

[Pete_Hsu]

If the noise basically goes away once you back down on the master volume level one or two dB, then it may be a case of the unit being overdriven where the driver runs into it's excursion limits.

Do you have an SPL meter and test tone CD at home so that you can check to see what is the subwoofer level relative to that of the main speakers?

Also, it is still unclear to me if you are hearing this distortion on just Wall-E, or other movies and music too.

Nevertheless, feel free to email us at any time

Thanks

[Vinnces]

Nope, other music and movies/shows that have deep bass like the Pacific. I just use Wall-E as an example since I have it on hand and avsforum had those play time for bass.

Don't have a test tone CD but I can grab a SPL meter from Radio Shack.

If it's just the STF-2 hitting it's excursion limits, would it be better if I sell this and grab a VTF-2 instead? Would I notice an improvement?

Thanks!

[Pete_Hsu]

I feel that in your room, it is difficult to get a flat response with just one subwoofer. I would add a second STF-2, and put one in each front corner of the room.

Sincerely,