Even the most expensive studio monitors are not worth much if they are not in an acoustically treated room in which acoustic problems caused by the poor position of the speakers in relation to the walls and furniture in the room will not occur, as well as phase nulling and signal build up due to sound reflection on parallel surfaces in the room.
Very often the price of acoustic treatment exceeds the price of studio monitors several times, so it is not surprising that some professional studios do not have adequate, acoustically treated room where it is listened to what is being recorded, so resort to some other, far more affordable solutions to equalize frequency curve that the listener gets in his listening position.
Whether it is a professional studio, our living room or some venue in which we perform live, it is desirable to treat acoustic problems with adequate resources at hand.
To begin with, it should be said that flat frequency curve is a very controversial topic, primarily because not everyone agrees with what suits their ears the best, some like V or U shaped curve with more or less slightly raised LO and HI SHELF, while others like a seemingly boring but clinically precise curve that allows them to hear all frequencies more neutrally. In addition, it should be added that the frequency curve is not determined solely by mathematical measurement, but the psycho-acoustic effect must be taken into account, due to which certain frequencies are logarithmically corrected due to the way we humans perceive sound and frequencies so include the correction in the measurement in order to get a pleasant result and what we humans subjectively perceive as correct.
This topic is very complex and we will not go into further technical details because basically, it is not necessary for us who use arranger keyboards, whether it is for personal entertainment at home or for professional work, for which arranger keyboards are certainly capable.
The meaning of acoustic treatment is precisely in obtaining a flat or as flat as possible frequency curve in the position in which we listen to music or play. As already mentioned, this is a psycho-acoustic effect, so a simple change in the frequency curve can affect our brain to perceive the sound it hears and characterize it completely differently, regardless of the fact that nothing has changed in the audio material.
For example, if we have too much low frequencies in our listening position, it may seem to us that the vocals and certain instruments playing in the mid spectrum are less audible, that they have spatially gone back even though technically nothing happened to the audio material we listen to. Also, if we have more middle frequencies, we can perceive it as a good separation of instruments, even if the vocals became more nasal, and again nothing technical happened in the mix itself, so the material is always the same. Excess of high frequencies in the listening position can be tiring after some time, it can also be characterized as the definition and details of instruments and vocals.
The frequency curve can also affect our perception of the spatiality of the material itself, the so-called sound stage, as well as many other aspects of our perception of sound.
How to fix bad acoustics in a room
When the room is treated acoustically then the frequency curve is changed by acoustic aids, by using various diffusers and by changing the position of the speakers in relation to the walls, also a room is made inside the room so that there are no parallel surfaces from which the sound would bounce and add up in our listening position and that process is, as we have said, very expensive and complex. Even when it is completed, the frequency curve is not ideally flat, but digital correction can be approached further, and that is what we are most interested in.
Digital correction involves measuring the frequency response of the speakers in combination with our acoustically treated room and then using digital EQ to further flatten the frequency curve in our listening position. This process is not perfect and is best as an addition to acoustic treatment, but as we have already found it to be too expensive and complex, we can only use digital correction for relatively very good results. It should not be forgotten that digital correction corrects only frequency problems, while reverberation and phase issues due to the reflection of sound on parallel walls remain and there is nothing we can do about it.
It is very difficult to talk about a flat frequency curve because we rarely come across it in most situations in which we normally listen to music. In addition, our brain adjusts quickly to various conditions, so very often we get used to what we hear and it becomes new normal. The fact itself that we need a measuring microphone and software that measures the frequency response of the combination of speakers and the room itself speaks in favour of the fact that very few musicians understand this topic at all, and the general population knows almost nothing about it.
But, mostly it’s just about the will to learn something new because the price of a measuring microphone is relatively very low, and the software with which it is measured is practically free, so in the end, it all comes down to whether we want to improve our hearing and the way we perceive music.
For example, one of the cheaper measuring microphones is the Behringer ECM8000, which is the order of magnitude of $50, which is a very small price for what it offers, and even cheaper models can be found. Also, REW, the software used to measure with this microphone costs nothing and can be downloaded for free from the official website.
However, you don’t always have to use a measuring microphone. In the studio or at home, we can make measurements without problems, but in the places where we are for the first time and where we came to play, it is not possible to do the whole process and that is why it is important to calibrate our brain to what is correct and this is achieved exclusively by listening to the corrected system at home and getting our brain used to what it hears, and that takes several months. That way, we will be able to play a song we know well from home anywhere else as a reference and listen through the PA system on the location and immediately hear where the problems are and solve them by simply using an equalizer.
It should be kept in mind that digital equalizer correction refers to the position from which we make the correction, so it is recommended to listen to several different places in the room and find the middle value to make everyone comfortable. Of course, there can be additional problems on stage due to the monitors and the fact that the stage is very often close to the walls and behind the main speakers, so this complicates the whole process because we have to decide whether we want the correction to be in relation to the audience or musicians, but with using digital mixers that have an independent equalizer for the Master Out and Monitoring section this is very easy to fix.
This is probably new and seems too complicated for many, which is understandable. But the fact is that it is a relatively simple and not at all expensive process that can bring big changes and progress in how we perceive sound, also teach us to listen properly and make it easier for us to deal with acoustic problems in various locations with easy use of equalizers, I believe it’s worth a little effort.