Extending Quasi-Anechoic Measurements to Low Frequencies

Benjamin E. Extending Quasi-Anechoic Measurements to Low Frequencies. In: AES Convention 117. Audio Engineering Society; 2004. Paper 6218. Available from: https://aes.org/publications/elibrary-page/?id=12875

@inproceedings{Benjamin2004_12875,
  author = {Benjamin, Eric},
  title = {{Extending Quasi-Anechoic Measurements to Low Frequencies}},
  booktitle = {AES Convention 117},
  note = {Paper 6218},
  year = {2004},
  month = oct,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=12875}
}

TY  - CPAPER
TI  - Extending Quasi-Anechoic Measurements to Low Frequencies
AU  - Benjamin, Eric
T2  - AES Convention 117
M1  - Paper 6218
PY  - 2004
DA  - 2004/10/06
UR  - https://aes.org/publications/elibrary-page/?id=12875
PB  - Audio Engineering Society
LA  - en
AB  - It is frequently desirable to make electro-acoustic measurements in ordinary working spaces. These measurements would normally be performed in anechoic chambers, since it is the response of the device under test that is needed, not the response of the room reflections. In the past 35 years various techniques have been employed to make what are commonly referred to as “quasi-anechoic” measurements. These techniques make use of the fact that the initial signal from a loudspeaker-microphone system is anechoic, until the first reflection arrives. By analyzing only that portion of the signal which arrives before the signal, an anechoic measurement is achieved. However, these measurements as a class suffer from a low-frequency limitation due to the shortness of the reflection-free time window. Time-frequency tradeoffs in the transformation of the impulse response to the frequency domain make it difficult to obtain an accurate estimate of the response of the device under test. We first characterize the nature of the errors induced by the short time window, and then propose methodologies for reducing the error.
ER  -