Distortion only at low volumes?

[tatsuha]

I just picked up my FiST and was pleasantly surprised at how strong the bass could get without distorting. I lowered the treble some and the mids a bit and then increased the bass so that it would still sound full at the moderate volumes where I listen. When getting out of the car, I turn the volume down to 2 or 3 and noticed that the bass notes are tremendously distorted. Listening a bit harder, it sounds like there maybe is still that little amount of distortion at higher volumes as well, it's just a lower percentage of the total audio output, so it isn't as noticeable.

Is this normal? I assume that a sub won't be able to fix this because it's a processing issue and not a hardware issue. I haven't gotten around to testing with lower bass levels in the EQ. And I know it's not the source because it happens over Bluetooth and USB with my reference tracks. If it is normal, is there any way to fix it?

 

[cversion7]

I noticed the same exact thing, only in a bit less scientific manner. When my phone is turned all the way up, the distortion goes away at 14 on the car volume. Taking the phone down 2 notches seems to remove the distortion, but I have to turn up the car volume to 20 to get a similar volume.

 

[Intuit]

It's possible that the distortion may be introduced at the pre-amp level.

Regardless the speakers aren't designed to handle bass output below a particular Hertz and the result is distortion.

If that's the case, a (good and properly powered) sub-woofer should bypass the issue; provided the factory radio has a cross-over that allows you to filter bass output to the door speakers.

Since I may transfer the subwoofer setup from my previous vehicle some day, I'm curious to know if there are built-in provisions on the factory system for adding the subwoofer and filtering bass output to the door speakers.

 

[tatsuha]

Regardless the speakers aren't designed to handle bass output below a particular Hertz and the result is distortion.

I don't believe it's hardware related. If it were a limitation of the speakers, then the distortion would occur at all volume levels and not just at low levels (and frequency response only relates to efficiency). If it were the amp, it would have the problem at high volumes also.

If that's the case, a (good and properly powered) sub-woofer should bypass the issue; provided the factory radio has a cross-over that allows you to filter bass output to the door speakers.

Since I may transfer the subwoofer setup from my previous vehicle some day, I'm curious to know if there are built-in provisions on the factory system for adding the subwoofer and filtering bass output to the door speakers.

From all that I've read, there are no provisions for a subwoofer or external amp, though a sub/amp set can be spliced in using the rear channel signals without much difficulty. I worry that this would still carry the distortion though. It shouldn't be hard to even add a high pass filter to the door speakers, but I don't think that would solve this problem either.

 

[Intuit]

Heat damages speaker coils by increasing their resistance (slightly blown), and/or melting them (really blown). The speaker coils' ability to conduct electricity efficiently is what produces movement against the stationary magnets. From what you're saying, your speakers could be slightly blown... internal resistance has increased enough to cause problems at low volume. Their efficiency has been reduced and can no longer generate sufficient movement with lower power throughput. /theory

 

[Intuit]

Yes, without independent channels and preamp-level filtering, sound quality is going to be degraded. Not good. The tight integration of the radio into the vehicle's systems will make it difficult to replace, without sacrificing some functionality.