Rhintek LLC is the
US / Canadian representative
for ELAC Technische Software GmbH.

Test-CD - For Room Acoustics

The CARA Test-CD for Room Acoustics is a terrific tool for helping you understand the characteristic sound colorations of your room and properly identify deficiencies in sound quality you may have already noticed.
"My new loudspeaker has no bass response!"
With this CD, you will be able to wander the room and hear the variations in sound quality.  You can use this information to find better listening positions and improve the placement of your loudspeakers.

The CARA Test-CD for Room Acoustics contains 59 test signals, with a duration of 70 seconds each. These digital signals were computer-generated and captured to CD using top-of-the-line mastering techniques to create the best audio signals obtainable from a CD source.
The test signals are subdivided into three groups:

  • 28 pure sine wave tones from 16 to 200 Hz (distortion < -80 dB)
  • 27 narrow band pink noise signals (bandwidth about 1/18 octave) within the range of 20 to 200 Hz. The center frequencies equal those for the pure sine wave tones mentioned above (except 16 Hz)
  • 4 special bandwidth limited pink noise signals, 2 * "CARA-Noise" (to analyze midrange sound colorations), "Polarity-Noise", and a standard pink noise signal flat between 20 and 20,000 Hz.

  • Room Acoustics

    Room acoustics describes how room shape, size, and contents influence the sound experienced by a listener within that room.  A sound source produces frequency-dependent sound waves travelling from the source to the listener.  These waves are reflected and absorbed by the furniture and walls of the room.  The reflecting waves interact with subsequent oncoming waves, resulting in interference patterns greatly modifying the sound the listener actually experiences.

    A surprising fact in room acoustics is that the size of the room greatly changes the importance of certain acoustic phenomena.  Large rooms such as churches, theaters, or conference centers, are characterized by long reverberation times.  This effect may considerably deteriorate speech intelligibility and syllable articulation if not corrected by manipulation of the room elements.  Things such as loudspeaker positioning, delayed signal lines, addition of absorptive materials, and general room shape are examples of techniques used to improve the listener's perceptions in large rooms.

    By contrast small rooms suffer from too many reflections.  The frequency dependence of the interaction between direct and reflected sound waves adds undesired sound coloration. These sound colorations depend not only on frequency, but also on the actual position within the room. 

    In small closed rooms, the sound field forms standing sound waves characterized by nodes (sound cancellation) and antinodes (sound multiplication) which may have as much as a 1000 times (30 dB) volume difference between them. Because these standing waves occur over small frequency ranges, the difference in volumes is not noticable as a whole, but rather as if some vital part of the sound is unbalanced (e.g. - the piccolo is too loud while the bass drum is barely heard).

    Click here to Order Now!


    call: (410)730-2575

    Email Rhintek!

    MC/Visa Accepted!

    Copyright ©1977-2022 Rhintek LLC