Monitors

In the home music studio block diagram, I had reached the computer and the digital audio workstation software where the music recording, editing, mixing, and mastering occurs.  I will return to talk much more about these music production processes in future posts.  But now it’s time to complete the “hardware” in the studio with the monitors  used to hear the playback of the music tracks.

Typically, there are two types of monitors used – headphones and powered speakers.  These are connected to the analog signal outputs in the rear of the audio interface unit, as shown in the photo above.  My Sennheiser HD 280 pro headphones are connected to the stereo TRS ¼” jack.  Yamaha HS5 powered speakers are connected to the left- and right-channel balanced TRS ¼” jacks.

The balanced TRS ¼” cable connection in the rear of the speaker enclosure is shown in the photo above.  The speaker system incorporates a power amplifier to boost signal voltage and current to levels sufficient to drive the speakers.  (This power amplification of line-level signals was discussed back in the post on analog signal voltage levels. )    The speaker system consists of a two-way active crossover network that splits the line-level audio signal into high- and low-frequency bands.  Each frequency band is then fed to its own specially-designed power amp, which in turn is used to drive the respective bass (woofer) and treble (tweeter) driver elements.

These speakers are designed to be “near field” monitors and to have a flat frequency response over the audible frequency range.  “Near field” refers to the propagating sound pressure waves being fully formed in a short distance from the driver element.  This is important because the home music studio space is typically small, and the direct “line of sight” distance between speaker and listener may only be on the order of 3 – 6 feet.  The flat frequency response characteristic of the speaker is necessary so that the tonal balance of the music is not “colorized” by the speaker itself.  As an example of why this is important, consider that a particular monitor over emphasizes the low-frequency content of the signal.  The recording engineer will apply equalization in the mixdown to reduce the too-bass-heavy sound that he is hearing.  But this actually leads to a tonal balance in the recording that is deficient in the low end.  Not good !  The monitors are mounted on IsoAcoustics stands that isolate the speaker cabinets from the Gator Frameworks platforms on which the speakers are placed in the studio (see photos above).  Natural resonances can occur between the speaker and the surface that the speaker rests on.  These resonances can add a distinct coloration to the sound from amplitude peaking at the resonant frequencies.  The isolation stands act to decouple vibrations in the speaker cabinets from the supporting surface, thereby reducing the unwanted tonal coloration.

Finally, the sound waves emanating from the monitors interact in a complex way with the room acoustics and with the human hearing process itself.  The public will listen to recordings over a very wide range of playback systems and speaker types, and under an infinite number of listening conditions.  It is only possible to record and mix music that sounds “just right” on your sound gear, in your studio space.  But by having quality sound gear, conditioned room acoustics, and a good ear, you can make recordings that will sound great to a majority of listeners.
 
Next time, I’ll take a look at the science, and art, of setting up the monitors in the studio space.