Amplification 103

Amplifying Classical and Flamenco Guitars with PA Systems

A thorough description for how to use PA systems will require more than one chapter.  This first chapter will start with describing the various components required, or are optional, with basic modern PA systems, and how these components can be operating together. Get ready for a lot of technical talk, but do not be afraid. Learning how to navigate the world of amplified “pro audio” is much less difficult than learning to play classical or flamenco guitar. It just takes some patience, and awareness of how PA systems are configured and operate.

The word PA system is a short version for “public address” system.  The first PA systems were used mostly for amplification of the spoken word at large gathering of people… conventions public speeches, demonstrations, etc.  The equipment used was functional, but crude, and the sound quality reproduced was decent, at best. The 1940’s, 50’s, and 60’s saw the emergence of the modern PA system, and the increased application of low impedance  signals to microphone and PA designs. From the 1980’s until the present day, technological advances for the design and manufacture of microphones and PA equipment continues at a rapid pace.

A basic modern PA system, in its most common configuration,  consists of the following: a mixer that receives the electronic signals from microphones, electronic instrument, playback devices (tape, CD, smart phone) and send these signals on to  speakers for reproduction.

A typical PA configuration will have two or more “main speakers”, with an equal number on either end of the stage and pointing towards the audience. Main speakers are usually located in front of the performers to minimize problems with feedback. Usually Main Speakers are elevated above the height of the performers to best disperse sound around the hall.

One or more “monitor” speakers at the leading edge of the stage pointing back towards the performers.

A mixer that receives the electronic signals from microphones, recorded devices, electronic instruments, or other  possible electronic sound signal sources, can process these signals to adjust for volume, tone, equalization, and possibly add desired sound effect qualities,

Some type of amplifier to increase the strength of the output signals from the mixer sufficiently to power speakers for broadcast of the amplified sound.  Such an amplifier can be located within the mixer, within the speakers, or be a separate component between the mixer and the speakers.

In small venues, all of the PA equipment may be located on the stage and operated by the performers. This permits the performers to make certain the sound is great on stage but creates a difficult situation for getting the best sound quality for the audience.  

In larger venues, a component termed a “snake” is added so  the mixer can be located towards the rear of the audience and operated independent of the performers by a sound engineer.  This helps to insure better sound quality for the audience, as the operating sound engineer is hearing the same sound quality as the audience, and cam make adjustments to the mix as needed.  Using a snake permits the output signals from any microphones or amplified instruments used on stage to be sent to the mixer towards the rear of the audience, and the output, or mixed signal returning to the stage to connect with the speakers.   .

Mixers can be very simple, or very complex.  For most classical guitar performances, simple works very well.  For flamenco guitarists playing in ensembles with electronic instruments, a more complex mixer may have advantages.  But more complex mixers require greater skill to operate properly, so one is encouraged to not always view big & complex as better than small & simple when working with PA mixers.   Having a properly scaled and easy to operate mixer with the most essential features is often the best course of action.

The most important features for PA mixers to have for classical and flamenco guitarists using the2Mic are:

  • Phantom power (between 9 to 48v)
  • Good equalization features  (more on equalization in a follow up chapter)
  • Line out to a separate mixer, or other speakers

Other useful features for mixers:

  • Digital interface for equalization
  • Effects loop
  • Recording playback device input (1/8” ad/or RCA)
  • Monitor out

To sum up, a basic PA system consists of a mixer that receives electronic input from microphones & electronic instruments, and speakers which receive and broadcast the final mixed signal….  main speakers for broadcast to the audience, and monitors for broadcast back to the performer.