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Recording Studios Need Playback Rooms

By May 24, 2012No Comments

Recording studios have many room types. Most rooms take on the name of the sound recording function that is going on in the room itself. They have vocal booths, drum rooms, control rooms, live rooms, and even mixing rooms. They can record a vocal or instrument and create a disc which that music is recorded upon. Where does the client go to hear his recording? Most of the time he goes to the control room and listens to his music back over the same monitors it was recorded and mixed with. This is not good for the music or the client. Recording studios need a playback room that is optimized acoustically for two channel playback to complete the most important phase of the recording process; the listening.

Monitors Near Field Only

Monitors that we use to monitor mostly near field are not designed for open space playback. They are designed for monitoring the recording, so every instrument and vocal is heard in its entirety and is evenly represented in the mix. All of this monitoring occurs in near field space. However, to be heard correctly, it needs to be expanded and placed on a sound stage that has a height, width, and depth to the presentation. Near field monitors simply can not and should not create this type of sonic presentation. Hi-Fi speakers are designed to create this sound stage illusion with two channels and a room with six room boundary surfaces. This is their job. It is what the designer intended them to do. They do not monitor the recording, that has been done. Their job is to playback the recorded digital data back into the analog domain. The waveform started analog at the mic position and then received conversion to digital. Now, in playback mode, it will be returned back to analog.

Comb Filtering

Sitting at the mixing board with the monitors on top the board, we get to experience comb filtering from the mixing board reflection off of the monitor. Any physical surface next to the monitors will receive sound energy from the monitors. Depending on the surfaces distance from the listener, we will receive comb filtering at the monitoring position. Comb filtering receives it name because of how it appears to an analyzer. It is a series of waveforms, grouped closely together in a saw tooth pattern. Needless to say it sounds as bad as it looks on the screen with blurring and smearing of the mid range and a total collapse of the sound stage.

That sound energy will then be bounced off the console and into the engineer’s ears at the monitoring position. With this single acoustical issue present we have lost our sound stage. We can not project our recorded sound energy back into the room and achieve a sound stage if the first reflection point only a few feet away from our speakers is the mixing console. We must have far field space for the waveform to fully form uninterrupted. A sound stage must have energy to be created and that energy must flow uninterrupted from the speakers to the listener.

Recordings Have Magic In Them

Recording engineers place numerous artifacts in the mix. They have the electronic ability to place instruments and vocals in different positions on
the sound stage. They can also create depth, width, and height. Unfortunately, the customer will never be able to hear all of this electronic effort without a playback room that is designed with the correct amount and type of acoustical treatment that will allow for our sound stage to properly manifest itself. Much thought and care was given to the recording of each vocal and instrument. We should complete the process and let the artist/customer hear their music in the best room and manner possible. It just seems right.

Playback Rooms

A playback room will have low frequency room resonances managed properly. The playback speakers will be room matched. They will have the correct size drivers and the correct number of those drivers that will produce the correct amount of energy to fill the room without over exciting room resonances. Amplifiers will be speaker matched. Amplifiers will be chosen that have the power output, impedance matching, and damping factor to compliment the speakers. Speaker cables will be speaker and amplifier matched with component interconnects receiving the same electronic consideration and attention to detail. All power sources will be noise filtered and dedicated power for all components will be provided.

Acoustics First

Acoustical treatment will allow for the sound stage formation in our playback room. Side wall reflections will be damped at the correct rates and levels to ensure that they do not interfere with the direct sound from our speakers at the listening position. Front and rear walls will be treated with two dimensions of diffusion to allow our sound stage to have a greater depth and length. Diffusion, especially two dimensions of diffusion, will render the surfaces they are placed upon acoustically “invisible”. The ceiling in our recording studio playback room will also be treated with two dimensions of sound diffusion and also a balance of sound absorbing technology to make it acoustically disappear.

The customer will hear everything the engineer placed in the recording. They will hear it in a room that has the same sonic care taken with it as the vocal, drum, or control room. I would argue that more care will be used in the playback room. The playback room will represent the best room sound that client will ever hear his music played back in. This experience will be appreciated by the customer and they will be realize that they have spent their money wisely.

Maybe the engineer will listen to the recording in the playback room before the customer does. After listening for awhile the engineer will hear things that he or she will want to change in the mix. Maybe the engineer will become better at his craft. He has the recording process trained into him. Now, lets really hear what you have when you listen to your creation in a room that will reveal everything you achieved or at least thought you did.


I am a structural engineer as well as a master furniture maker. I design cabinets for low frequency, activated carbon absorbers. Connect with me on Google+

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