Loudspeakers
During our modules we have touched on loudspeakers and their role in audio production as both a piece of monitoring equipment and in live sound setups. Loudspeakers consist of the cabinet unit (enclosure) which is the main housing to the cone which is also known technically as the driver / transducer being the component to convert electrical energy containing the audio signal, into acoustic (kinetic) energy for listening. There are several different forms of transducers being : electro dynamic which utilising AC charged coils which then interact with a magnetic field which pushes the spider and subsequently the cone forwards / backwards (compressions & rarefactions), the cone being fixed the actual mechanical movement going on generating the sound waves is the surround rim on the cone.
There are also ribbon based loudspeakers in the electro dynamic grouping although differing with the coil being instead a metal ribbon between two poles of a fixed electromagnet, as well as separately electro static which are instead capacitor based over coil based, having a conductive sheet known as the diaphragm which is placed between two more plates completing the circuit between these components and the step-up transformer to drive the electrostatic speaker plate. With these types of loudspeakers the positive voltage is added to the centre plate and the external with the negative to cause the same forward / backwards function of the coil based loudspeakers, opposite in principle to condenser microphones.
When it comes to utilising speakers in practical applications, choice of an appropriate loudspeaker is important otherwise you can find yourself in situations where the gear setup is not working well for the task. With there being a vast range of types of loudspeakers, many are focused on specific applications: monitoring loudspeakers will typically aim to create a flat frequency response which is essential to mixing and mastering stages of post-production, these require the flat response in order to get as true of an understanding of a piece of audio, where no frequencies across the audio range (20Hz - 20kHz) are boosted or coloured creating discrepancies which may otherwise be interpreted as being in the mix (audio tracks and stems) themselves.
Another type of loudspeakers which would be unrealistic to swap out with mixing / monitoring loudspeakers would be something like a guitar amplifier, while the latter is essential to monitoring / recording / performing with guitars (and bass) and the too is similarly a powered speaker with an enclosure and drivers, swapping the two types in use of each others functionalities would be insane as guitar amps in no way can be used to monitor audio in a mixing or mastering environment as they provide lots of colour and tonality within themselves as they process and output sound. Similarly on the other hand, using a pair of monitoring speakers may work with a guitar if you have more equipment (interface / mixer / DAW) between the source and the speakers, however if you were in a live sound setup where you would typically find guitars plugged straight into amplifier loudspeakers and were trying to do the same thing with just a guitar / jack and KRK classics then you’re not going to get the job done as the speaker choice is just completely incompatible with what you’re attempting, even though they’re both technically loudspeakers.
Where loudspeakers have a clear distinction in type is with headphones, as with all technology decreasing in size as it develops, when miniaturised drivers were developed headphones emerged as a very practical piece of equipment for monitoring as the provide a near perfect stereo field and allow for near listening with any audio, doubling as equipment used in none professional and also consumer settings for leisure headphones again utilise the same aspects of cabinet and driver to generate sound waves.
Although using much smaller drivers, the much closer proximity to the ear drum means that the sound can still be perceived as a loud signal by the listener, with less acoustic energy lost over the travel from driver to eardrum the eardrum membrane can pickup this signal adequately. With the frequency response of headphones being typically flat the signal received by the ear can be considered a purer monitor to the original as it is not effected by external influence of a rooms acoustic for example, with none of the signal outputting into the room and bouncing around creating reflections and other unwanted signal response. Although very different in it’s form factor to monitoring loudspeakers, these aspects of headphones make them a very popular choice for mixing and especially recording situations.
