Sub distorting - help please

[Simpleton]

Hello.

I have this problem with my sub and don't knwo what's all about.
The sub is a Vieta PWS-12., powered by a Blaupunkt GTA-200. The box is sealed, of triangular shape, with internal volume of 30l (manufacturer recommendation for optimal performance).
Still, the subwoofer has a lot of distortion, which is not that audile at the front (a bit more at the rear)but makes the bass very unclear.
BTW, my car is s Citroën C5 Estate.
Should i put some fiberglass whool or pillow foam inside the box? What can i do?

Attached is a pic of the subwoofer.


Thank you so much!

[simon5]

If the distortion is caused by overexcursion, filling the box will degrade the sound further.

If distortion is caused by vibrations, then filling the box might help a bit yes.

At first, I'd guess the subwoofer is not powerful enough for you.

[silviuvlt]

I don't think either that you subwoofer driver is the right one for you. As it looked it isn't a performance woofer, more less a subwoofer. If you can the only solution is to put in to the box sintetic or natural wool.

Goodbye and have fun.

[Cal Weldon]

Simpleton,

Can you describe the distortion a little more? Just what kind of sound is it making and at what volume? How much power are you feeding it from what amp etc.?

Cal

[Simpleton]

Sorry for the late reply.

Well, it distorts...
I mean, the bass is very fuzzy, it hurts the ears and the sub can't take up much volume without appearing to desintegrate. I'm sorry i can't explain myself any better.
I've connected it to my mom's home stereo, a 45W per channel Technics amp, and at little less than half volume it starts do go uncontroled. Even the JBLs speakers of the stereo can go louder than it at half volume!
It seems the problem is the subwoofer itself...

I'll probably buy a new one...if i do buy one again.
The sub is 250Wrms, the amp in my car is a Blaupunkt GTA250, at 125Wrms. I don't use it as a ghetto blaster, so the volume is moderate...

Thanks guys

[ThomasW]

Check the box and driver for air leaks!

Yes adding some damping material will help any sealed design

[Simpleton]

no air leaks, as i sealed it all around the subwoofer with bathroom type silicon and the box is built like a brick too, no leaking from it.
I added some stuffing but to no avail...

[Bull]

Well is the distortion coming from the actual cone or is the box vibrating???

Enclosures for subwoofers should be properly braced to stop them buzzing.

But if the cone is buzzing either the driver is going over excersion or the driver is damaged, or you are clipping the amp.

And a 45w per channel amp is way too weak to drive a 250w rms sub if you are cranking it. So you are probably clipping the amp, so it sounds distorted.
As bass makes the amp clip easier.

[lonelyposto]

I did not see anything about how the amp is hooked to the speaker. I would agree that it sound like an amp/signal problem. I would ask what load your amplifier is seeing from the subwoofer 2ohm etc.. Then I would check signal (crossovers or other boost circuits). Also some times if the amp cannot get enough current it will sound like it is laying down.

I dont believe it is the speaker as long as it moves freely and has the same amount of excursion in both directions.

About the home technics receiver: 45Watts into 8 ohms probably.
It would not want to see a car type speaker 4 ohms or lower.
If the other speaker was louder it is because it is more efficient or has a higher SPL output-- But that doesnt mean that home speaker is capable of good low frequency output.