Why Set Gain?


People end the lives of their subwoofers everyday and one of the most reoccurring reasons is due to improper gain settings on their amplifiers.  A majority of people mistake gain to be nothing more than a volume knob but that misconception can lead to horrific subwoofer murders.  Knowing exactly what gain is and how to set it will not only prevent your precious power-pushing woofers from meeting their maker, but will also give you the cleanest output possible.  Gain is basically defined as input sensitivity and is used for matching the output from different sources so that they reach optimal performance and minimal damage.  The main thing you are trying to avoid is clipping your signal. Clipping is the distortion that occurs when an amplifier is pushed beyond it’s limits.  At high volumes the music will sound muddy and will cause unpleasant sounds.  If you avoid clipping your signal,  then you will give both your amplifier and woofer a longer lease on life.


With all of that being said, here is a quick way to set your gain:

  • Insert a CD into your headunit that you know to be fairly loud.
  • Play a song and set the volume on your headunit to about 75%.
  • Set the gain all the way down and slowly raise until you experience clipping (audible distortion).
  • Once you reach the clipping point, set it back down so you no longer experience a clipped signal
  • The volume that your headunit was set at during this procedure is now your head unit’s MAX volume.  This is the loudest it will play without clipping and will sound good and clean if you have done it right.

Please note that this is not the most accurate way of doing this but it will get you very close.  If you’re looking to get the most absolutely accurate result then you’re going to want to use an Oscilloscope or Digital mutimeter.  Just make sure you know how to use them!  Another alternative is getting an amplifier such as the JBL GTO-751EZ which features gain LED indicators that will tell you if you signal is being clipped.  For a more in-depth analysis please read our knowledge base article here.

Have you guys ever experienced issues with your gain settings? Comment below and tell us about them!