Hi friends, I´m reading a lot about room measurements but I can´t figure out how it is done? I know there´s a special mic, an application for the results and a full spectrum noise, but where the mic is placed for the measurements? And the noise is generated from where, my monitors? Example: I put my drums in a "X" place in the recording room, this spot will generate and receive the reflection way different than the noise from my monitors and the results, IMHO, should not be valid for a equalization to record drums. I really don´t understand how it´s done, i have a room with minimal acoustic treatment and I want to improve my recordings, but doing without some science is a waste of money for me, that´s why I need to understand this subject.
Thanks!!!
Thanks!!!
Maybe I wasn´t clear, I meant that I don´t understand how to make the measurements of the room at all. Which source of noise I have to use? In which position on the room? My room have 7,0 meters x 5,0 meters (23' x 16') it´s a recording room with the tech room in the same place. I don´t know if this recording room have a adequated acoustic dynamics, that´s why I want to understand how to measure the frequency response, gain, etc...
You did not mention the vertical dimension of the room.
I would start with an Rt60 reverberation time measurement. Use a free software program like the Visual Analyzer. Correct the room deficiencies first.
Download the "Handbook for Sound Engineers" (all 1807 pages!), a lot of excellent info there. E
I would start with an Rt60 reverberation time measurement. Use a free software program like the Visual Analyzer. Correct the room deficiencies first.
Download the "Handbook for Sound Engineers" (all 1807 pages!), a lot of excellent info there. E
Read some about small room acoustics before you start measuring. Very short: the boundaries of a room reflect sound that mixes with the source sound. The result is a sound field that is varying throughout the room, as opposed to a sound field in the open from just one source.
The variations in the sound field can be divided in three regions. At low to medium frequencies the sound field is dominated by standing waves in the room. Even close to the source these standing waves are very obvious. Think of them as vibrating snares of a guitar, you pick it and it resonates for a long time.
This phenomenon is largely determined by the dimensions of the room. The higher the frequency, the more standing waves (eigentonen or room modes). Up to a certain frequency the frequencies of the standing waves can be perceived individually, above that they are closely spaced and togehter start to define a resonant sound field that is quite frequency independent.
Higher up in frequency, sound damping properties of boundaries cause the reflections to diminish, up to a certain frequency where the direct sound of the source is stronger than the resonant field. Enter the free sound field, where you hear the speaker, not the room.
The transitions between the different sound fields are not absolute but gradual. They are by no way constant when measured on different positions in the room. And only the free sound field could be predicted in a simple way.
Altogether measuring the acoustics of your room isn’t simple. RT60 in a relatively small room says bar to nothing (only for higher frequencies and away from boundaries). Do decide why you want to measure and what, before reading the graphs or even set up your microphone.
The variations in the sound field can be divided in three regions. At low to medium frequencies the sound field is dominated by standing waves in the room. Even close to the source these standing waves are very obvious. Think of them as vibrating snares of a guitar, you pick it and it resonates for a long time.
This phenomenon is largely determined by the dimensions of the room. The higher the frequency, the more standing waves (eigentonen or room modes). Up to a certain frequency the frequencies of the standing waves can be perceived individually, above that they are closely spaced and togehter start to define a resonant sound field that is quite frequency independent.
Higher up in frequency, sound damping properties of boundaries cause the reflections to diminish, up to a certain frequency where the direct sound of the source is stronger than the resonant field. Enter the free sound field, where you hear the speaker, not the room.
The transitions between the different sound fields are not absolute but gradual. They are by no way constant when measured on different positions in the room. And only the free sound field could be predicted in a simple way.
Altogether measuring the acoustics of your room isn’t simple. RT60 in a relatively small room says bar to nothing (only for higher frequencies and away from boundaries). Do decide why you want to measure and what, before reading the graphs or even set up your microphone.
The sound field in the recording room should be as diffuse as possible, so avoid parallell plain surfaces, patch the walls with materials of various acoustical properties and add diffusors/reflectors that reflect sound in various directions. One can also cover the walls with kind of Schroeder diffusers tuned to varying depths/wavelengths. For the measurements it is advised to put the sound source and the measuring mic in corners of the room to avoid sound pressure nodes and to amplify the sound emitted resp. te signal recorded.