Car Stereos: Subwoofer connection without amp

Question
I have a Kenwood dpx-u5130 not Kenwood dpx-u5130BT which is installed in my car it has pre-amp output. Can i connect a 3 inch sub-woofer without a extra car amplifier. If i do so will it be a problem.

Answer
Hello,

An amplifier is needed to drive a subwoofer.  The pre-amp output on the head unit does not have the power to drive any sort of speaker.  It's a low-level output, meant only to provide an audio signal for an amplifier.

You could make a subwoofer work by connecting it to the head unit's speaker output, but this is not ideal.  If you did this, you would not be able to connect four speakers and the subwoofer together; you would need to disconnect a speaker to connect the sub.  Also, the speaker outputs cannot be filtered to send only low frequency sound to the subwoofer.  This means the sub would be playing full-range audio, instead of just bass, which will degrade the overall sound quality.

You can purchase a powered subwoofer, which is simply a subwoofer with a built-in amplifier.  This would work with the head unit's pre-amp output.  Otherwise, if you wish to use a subwoofer you already own, then you'll need to buy an amplifier for it.

Hope this helps!

Brian