Last time we ended with adjusting the crossover settings, this time we’ll be taking a quick look at the Gain Structure. This is a very important step since most systems are unlikely to have had this optimized for best performance.
Gain structure and crossover settings can definitely affect eachother so it’s important that we do both on any system we are working on. To achieve minimum noise and maximum output levels we need to set the gain structure properly.
First, make sure you have some high quality recordings that you are familiar with so that you can identify what sounds best. Start the adjustments with the subwoofer relative to the higher frequency speakers. While listening at a moderate level, change the subwoofer and high frequency amp’s gain levels until the balance between the two sounds about right to you.
Next, go to the crossover frequency and adjust it up and down to see if effects the sound quality. Turn off the subwoofer for the moment so we can find the lowest frequency for the mid range speakers. These often vary from the specifications from the manufacturer, altough not by huge amounts. Listen to the low frequency response from instruments such as drums, bass guitars etc as you vary the crossover point. At some point you will notice that the sound doesn’t change when the crossover point is. This marks the lowest spot that the mid range speakers should be set at. Make sure this level is not below the manufacturers recommended setting though as it may cause problems.
Now, make adjustments to the crossover slopes, if possible. Try steeper and shallower slopes, and even try different slopes on the highpass and lowpass sections if possible.
The final thing to look at is to try reversing the polarity of the subwoofer and see how that effects the quality.