There was once a time when any credible mixing studio would not be seen without a pair of Yamaha NS-10 monitors. They are the black speakers with the white cones and are well recognized even by lay persons, in fact many people still swear by using them today. However another very common but less well known loudspeaker was the Auratone 5C. This speaker was very unassuming, a 5 inch single circular driver in a small wooden box. The goal of this speaker was to allow an audio engineer to have a focus on the critical mid range frequencies of an audio mix.
Almost all instruments and voices have mid range components and it is a frequency range which can easily get cluttered and such a speaker as the Auratone 5C allowed the engineer to reference the mid range without the ambiguities of multi driver loudspeakers. This type of speaker also approximated the reproduction characteristics of television sets, small radio receivers and other small devices from which sound would be reproduced.
Firstly, the Auratone was a sealed box enclosure, this meant it did not have the resonant port issues that are related to bass reflex designs common of todays low cost studios monitoring solutions. The speaker had a very respectable spectral decay. (Low resonance when a sound source is abruptly stopped) In addition there was a sole driver, this meant that there was no crossover components to add distortion or bad crossover frequency choices. A sole driver means that you have a point source of sound as opposed to 2 drivers which could easily be reproducing the same part of the audio spectrum at and around the cross over point creating possible delay/filtering issues. This kind of loudspeaker was not used for hearing the high frequency details of the mix down or getting a picture of the stereo imaging. (To the contrary as often they were used as a single mono loudspeaker as opposed to a pair) They were used to simply understand how the important mid range would translate to a small sound system.
In no uncertain terms they would allow the mixing engineer to hear if the snare was interfering in a negative way with the vocal or if the guitar was too strident in the upper mids vs the vocal. It was a secondary but highly useful reference to the near field monitors that would have donned the mixing console bridge. The Auratone also had it’s purpose in the field of broadcast, often found in TV and radio transmission studios as a means of getting an idea of how audio program would sound upon reception and reproduction on domestic equipment.
These days people are wising up to the value of these type of loudspeakers and are employing them again, although the original Auratone is no longer manufactured. (available second hand on auction sites) However there is a speaker that is made as of today with a strong nod to the characteristics of the Auratone called the Avantone mix cube. They are quite reasonable in price and a very functional and cost effective tool for both a home or professional studio. For those who are a little more practical a similar speaker can be made with some basic DIY skills that could have you clarifying your mid range for a very small sum of money.