Level setting is regarded by some as a science; others approach it as an art form. One thing is certain, proper level setting is fundamental to maximiaze dynamic range and optimize your signal-to-noise ratio for a hiss free syetm. Below are a couple of methods I have used to setting gain controls. They range from a method using no outside equipment (reasonably accurate), to using test CD`s and outboard listening devices (much more precise).

The idea behind level setting and matching is to maximize output from the source unit and deliver as much signal from the front of the vehicle to the back (where you keep those ultra important amplifiers). The amp is ideally the only place where we reduce the level.

Whenever adjusting gains, make sure your head unit`s tone controls are set flat (middle setting) and all EQ`s and pre-amps are either in bypass mode or defeated.

Method 1

1. Turn on the amp`s input level controls to minimum positon (usually fully counter-clockwise)

2. Set source unit volume to approximately 3/4 of full volume.

3. While playing dynamic source material, slowly increase the amp`s input level(s) until a near maximum, undistorted level is heard in the system.

Method 2

This method of setting levels does require an outboard tool, but the accuracy is noticeably greater than with the technique listed in method 1. One such tool is a RADIO SHACK "Mini Amplifier Speaker" (catalog number 277-1008c). You will also need a 1/8" male to female RCA adapter. In addition, you will need a test CD with a 1 KHz test tone. Autosound 2000`s Test disc #101, track 99 is perfect, but there are others available (be sure to read the liner notes).

1. To start, plug the headunit`s output DIRECTLY into the amplified speaker and insert the disc with the 1KHz test tone. Slowly raise the volume control until you begin to hear the tone distort. 1KHz tone distortion is fairly easy to detect, but you may need to expermiment a bit before making final settings. You may nned to adjust the level on the amplified speaker so you do not overload it. Set the headunits volume control to the point just beneath where the distortion begins. This is your maximum unclipped output from the headunit.

2. Connect the headunit to the next device in the chain, be it a processor ( eq or etc), crossover, or amplifier(s). Plug the amplified speaker into the outputs of the next device and adjust the levels in the same manner as step 1.

3.  Repeat step 2 until you are left with only the amplifier(s). Connect the system to the amp(s).

4. Turn amplifier gains to their maximum setting. Play the system with music, the more dynamic the better. Begin by adjusting the subwoofer amplifier level so that you reach either the amplifier`s or speaker`s limit at approximately the level determined from Step 1 on the headunit. From there, adjust the levels of the satellites relative to the subwoofer level, which will be based on personal preferance and overall system response.

If your system consists of products with fairly high output (4 volts or greater),you will probably be able to operate your amplifiers with their gains at relatively low settings. Level setting via these means will yield maximum undistorted output from all devices at the same time and maximum signal to noise ratio.

Method 3

This method requires an oscilloscope in place of the amplified speaker. Obviously this is a more sophisticated process, but instead of listening for the distortion, you are looking for it on the screen. The process is otherwise similiar to Method 2. Remember, when your gains are finally set and you reactivate your equalizer or processor, you may need to make slight adjustments-----particularly if you have substantial cut or boost.

Well I hope this has helped you out to some degree. Kinda hard to explain it any simpler..........

                               Good luck TOYRANTULA