What are the basic checks to do to make sure I have a good quality installation for accurate monitoring of my music?

Here is a basic checklist of things that you should do to ensure that you have a good environment for accurate monitoring. There are links to other answers that will give more details if you are unsure what to do.

Basic Monitor Positioning Checks:

  • Ensure that the monitors are all placed at the appropriate angle for the reproduction channel, e.g. in stereo left monitor ia at 30° from centre, etc.
  • Measure the distance to the side walls and the wall behind the monitors of the left/right stereo pair and ensure they agree to within 1 cm (0.4"). Do this for the front AND rear left/right pairs in a 5.1 surround system
  • For the best stereo imaging ensure that the side walls and the front wall behind the left and right monitors are similar. If not, this may affect the response
  • Ensure the furniture and equipment in the room has precise left/right symmetry
  • Clear the space between you and the monitors from all unnecessary equipment, e.g. computer screens and piles of rack equipment, so that there is a clear view from all the monitors to the listening position

Simple Measurements:

  • Use pink noise and a sound level meter to check that all monitors are reproducing the same input signal at equal sound pressure levels.
  • Use a measuring tape to check that the monitor to listening position distances are all the same. This ensures that all monitors (except subwoofers) have an equal time-of-flight
  • Listen or measure to check that all of the monitors have similar frequency response. Use the tone controls to make adjustments to give a flat frequency response.
  • Ideally the frequency response should fall into a ±2.5 dB window. If it does not then try to find out why - often it is the room or monitor positioning and not a fault with the monitor itself
  • If there is a lack of bass level then check the distance to walls for low frequency cancellations

Test signals:

  • Use pink noise to check that all monitoring levels are equal. Also if the tone of noise is different, use measurement tools to determine why the frequency responses are not similar
  • Use male speech, preferably someone you know, to evaluate tonal naturalness. If you spot something strange in the tonality then check the frequency response

Subwoofer tests:

  • Use a sinusoidal sweep to check if the level from the subwoofer is different to the level from any other single monitor. Move the subwoofer and adjust the controls to give a flat frequency extension down to the subwoofer low frequency cut-off
  • If there are notches anywhere in the frequency response check the distance to nearby walls and check the subwoofer phase adjustment