Anyone who works with voice recordings knows how much a room can shape the sound. Besides the voice and the microphone, the shape and size of the room or vocal booth you record in play a very decisive role in the sound of the recording. Generally that is not a good thing: you do not want to hear the room, only the voice. Some of the problems caused by the room can be solved with a well-set equaliser.
Why does every recording room sound different?
Every room, big or small, has its own sound. Simply put: certain frequencies (pitches) fit exactly between two surfaces. The walls left and right, front and back, and certainly do not forget the floor and the ceiling. The dimensions of the room cause a resonance at some frequencies: a tone that sounds louder than others. Anyone who likes a good sing in the bathroom will know this.
Does an acoustically treated vocal booth help?
Many voice-overs have an acoustically treated vocal booth, which limits those reflections to some extent. But to really tackle this for all the frequencies that matter for speech, you would need constructions that do not fit in a vocal booth.
Because I also work a lot with music, I had my studio built by an expert (Jelle van der Voet, Pinna Acoustics) who calculates and builds very precisely what is needed to make the room sound perfect. In places, the isolation and the wall construction inside the isolated room are more than a metre thick. In practice, for speech recording alone, a well-built vocal booth or recording room combined with some equalising afterwards is enough.
What should you set on such an equaliser?
How do you know which frequencies play a role? The fun thing about sound (OK, fun is subjective, but I am a sound nerd after all) is that you can calculate quite well with it. Of course an audio engineer with a trained ear is the best final judge, but if you are not sure how to approach this, you can already make a targeted start by identifying the problems in the room.
You can determine which resonances will occur in a room whose dimensions you know. That is what this calculator does: enter the dimensions of your room and you will see which frequencies will resonate, with a concrete EQ suggestion per frequency (cut and Q factor).
Does it matter whether you record a male or a female voice?
Yes. Frequencies you do not produce will not resonate either. That is why you can set whether you have a male or a female voice, or whether you want to take both into account. The calculator then only shows the resonances that are relevant for that vocal range.
Does it matter where you stand or sit during the recording?
It does, that has an effect too. In one spot in the room a resonance builds up much more pressure than in another; corners and spots close to a wall are especially unfavourable. Click on the floor in the diagram to indicate where you will stand or sit: the calculation and the EQ suggestion adapt to that position.
How do you use the calculator's results?
You can copy the resulting curve in the EQ tab into the software you work in. You can also print the tool’s output or save it as a PDF, including the full report with an assessment of and advice about your room. The points shown are a starting point to work with. The main goal is to understand the influence of a room.
In the end, you will always get the best result by recording in a well-built studio.
