Mobile Electronics Australia

There are a myriad of adjustments that need to be made or set before you can safely switch on your newly installed audio system, and the more complex the system is the more adjustments and settings need to be made.

If the following steps aren’t properly taken care, of not only will your system not give you its full potential, but you’re potentially putting certain components at risk of damage or, worse still, failure!

You don’t need to know much in the way of technical information to do these quick and easy steps yourself, and nor does it require anything in the way of advanced tools. Just your ears, a small screw driver (if that’s what’s required with your amplifiers) and a handful of modern, well recorded CDs are all you need.

Tools required

Various CDs
Screw driver set
 

Step 1: Everything to zero

The first step is to make sure all the settings throughout the system are set to a median or zero setting.  Begin by removing the fuse from the main power lead to your amplifier/s and turn the volume of the source to minimum. Cycle through the EQ portion of the source and ensure that everything is set to flat (no boost or cut to any band), while also ensuring that other things like LOUDNESS or any factory engaged DSP is switch to the off position. If you have a dedicated subwoofer level control built into the source set this to its middle position, while the fader and balance controls should be set to their centre positions.

Step 2: Initial amplifier settings

With the source unit switched off, reduce all of the input level controls (gains) of each amplifier to the minimum position. If there’s a remote level controller attached to your amplifier set this at roughly half way. Like the source unit, make sure any EQ built into your amplifier is set to the minimum position.

Step 3: Initial crossover settings

You will have crossovers built into either the source or amplifier or both. These are the filter networks that ensure each speaker is playing the correct band of frequencies (low for subwoofers, midrange and treble for other speakers). As a general guide it is ideal to start with a low pass/high pass intersect filter frequency of 100Hz. If you are using larger diameter midrange speakers (6 or 6.5-inch) you may start at around 80Hz. Set the low and high pass filters for the required amplifier channels to this frequency. You can now replace the main fuse.

Step 4: Tonal balance audition

Power up the system and leave the volume at minimum. Insert a modern well recorded CD (pop music works well) and find a track that has dynamic music that uses the full audio spectrum. Gradually increase the volume on the source until you have reached approximately three-quarters of maximum volume, as this is the maximum clean level at which most source units operate.

Step 5: Setting the tweeter levels

After comparing the relative levels between the midrange drivers and the tweeters you may find that the tweeters need to be increased or decreased in output to be better balanced. To adjust these you may have attenuation networks built into the passive crossovers that came supplied with the component sets. Adjust these levels until the best overall tonal balance between the midrange and tweeter sets is achieved. You also may find that varying the angle or placement of the tweeters will achieve a better tonal balance.

Step 6: Adjusting the main speaker levels

Decide on the pair of main speakers you wish to be more dominant in the mix (front or rear) and begin by setting the final level for these using the input sensitivity control on the amplifier channels being used. This must be done with the source unit’s volume on its three quarter volume level with the same dynamic CD track. Be careful to listen for distortion while gradually increasing the input level control (gain). If the speakers is distorting from too much bass you may need to raise the high pass filter point slightly to compensate. Leave the level at a point where the speaker is playing as loudly as possible without distortion.

Step 7: Adjusting the secondary speaker levels

Play the track again at three quarter volume and adjust the input sensitivity level control for the opposing pair of speakers until you arrive at the front/rear output balance that suits your tastes. Again be sure to listen carefully for distortion from bass output and adjust the high pass filter accordingly.

Step 8: Adjusting the subwoofer level

Play the system and experiment with the subwoofer level control built into your source unit or via the remote controller supplied with your amplifier. If there’s enough SPL the input level of the amplifier should be left where it is. If not then reduce the source’s subwoofer output level to around two thirds and gradually increase the input sensitivity level on the amplifier until the subwoofer reaches a distorted level, then back off slightly. If there’s too much upper bass you may consider reducing the low pass filter frequency point to between 60Hz and 80Hz to clean up the sound.

Step 9: Final system audition

Now try some other CDs and compare the sound balance. Your system should sound well balanced and will play as loud as possible without distortion at this point. While it may be tempting to start toying with the EQ or bass boost in the subwoofer amplifier please note that your level settings have been done based on no boosting of any kind. This means that if you add any boost at any frequency it is likely that the input sensitivity level of each amplifier will need to be reduced by the same amount to avoid distortion. If you find the system lacks treble or bass then adding boost won’t fix this. You’ll just have to add more tweeters, subwoofer and/or amplifiers to improve things further.