The Media Technology Department (DTM) has several equipments and facilities, which allow performing a large variety of audio, acoustics and vibration measurements.

Concerning to the equipments, the DTM has at its disposal, a 24 multichannel real time spectrum analyzer with its corresponding transducers (microphones and accelerometers), an impact hammer, a tapping machine, a vibration exciter and a dodecahedral speaker, among others. Regarding to facilities, the DTM has a full anechoic chamber, a reverberation chamber, a full equipped recording studio and a tank for underwater acoustics. A more detailed description of these facilities is next provided. 

Full anechoic chamber:

The anechoic chamber is used to conduct acoustic measurements in free field conditions. All sound energy emanating from a source inside the chamber propagates with non-reflecting back. This is achieved by recovering the room with pyramidal acoustically absorbent material. Vibration isolators separate it from the rest of the building to avoid any structure-borne noise path that could alter its anechoic properties. 

Anechoic chamber main features:

General data:
 Volume without absorbent material: 517 m3
 Volume with absorbent material: 215 m3
 Total suspended mass: 120•103 Kg

 Width: 6.13 m
 Height: 4.4 m
 Length: 8.9 m

Acoustics characteristics:
 Ressonant frequency: 11 Hz
 Cutoff frequency: 70 Hz
 Transmission Loss at 1KHz: 80 dB
 Residual noise: 15 dB(A)

Reverberation chamber

The reverberation chamber is used to perform acoustic experiments in diffuse field conditions. It has been designed to have a high reverberation time (TR60) for all frequency bands. All inner sides are recovered with acoustically reflecting materials and it has non-parallel walls and an irregular roof. Consequently, only a very small percentage of energy is lost at each reflection, and the chamber presents a good distribution of eigenmodes. 

Reverberation chamber main features:

General data:
 Volume: 231 m3
 Total surface: 211 m2
 Floor surface: 44.6 m2

Acoustics characteristics:
 Residual noise: 40 dB SPL, 16 dB(A)
 Transmission Loss at 1KHz: 50 dB

Reverberation time:

Freqency (Hz) / TR60 (s)
125    11.5
250    11
500    10.5
1000  10
2000  7.25
4000  5
8000  2.25

Recording Studio

The recording studio consists in two separate spaces: a control room and a recording room. The control room hosts the hardware that the sound engineer uses to perform sound recording and mixing tasks. The studio is based on a digital sound platform and allows simple intercom between control and recording room. The room is acoustically treated with perforated wooden panels and with absorbent materials on the inner side. The objective of these panels is to make the room’s frequency response as neutral as possible to ensure maximum transparency for the monitoring of recorded audio signals.

Control room equipment:

 1x AKG D112
 4x Shure SM57
 4x Shure SM58
 2x AKG 414 ULS
 2x AKG C1000B
 2x AKG C391B
 2x Audiotechnica 4033
 2x Shure Beta 91

Recording system:
 Focusrite Octopre Preamp
 Digidesign Protools HD96I/O + Apple MAC G5
 Digidesign Control 24 Mixing Desk and Controller

Editing & mixing:
 Protools 7.4 + Pro-tools HD|3 plugins
 Digidesign Control 24 Mixing Desk and Controller

 Dynaudio AIR15 Stereo Pair
 Behringer Powerplay HA4700 Headphone Amplifier
 AKG Headphones

Backline and additional gear:
 Roland A30 MIDI Keyboard
 Roland XV-3080 GM Module
 TC Electronic M-One Multi FX Processor
 Alesis 3630 Compressor / Gate
 ESI Miditerminal M8U MIDI Switch
 Yamaha Stage Custom Drumset
 Hartke 5500 Bass Amp + VX115 Cabinet
 Ibanez MIMX150H Guitar Amp
 Native Instruments KOMPLETE

The recording room is where musicians, speakers and other artists are recorded. To reduce the impact of room modes on the recording, the room’s ceiling has been made non-parallel to the floor. The absorbent curtains, together with the installed resonators allow having different acoustic environments that can be easily configured. There also is an acoustic door that connects the recording room to the reverberant chamber, which can be use to record special reverberation effects.

Tank for underwater acoustics

The DTM also has a small water tank (about 8m³) to carry out underwater acoustics measurements. Hydrophones can be positioned using specially designed guides and an annex room is used to record all measurements. The tank can be used for example to make studies on water sound speed or reflection phenomena.