From: Martin Grainger
E-mail: martin@graingercommunication.com
Date: 29 Nov 2004
Time: 07:49:54
I have been using Acoustic tools to measure STI but can never obtain readings greater than 0.7 even though when I use other software (WinMLS) and measurement tools (Norsonic)to measure STI I can get better results. For example I have set up tests using WinMLS and Norsonic to measure RASTI and STIPA respectively. The test was set up in a small room with a midrange RT60 of 0.3 secs. I would expect that the results in this situation would be excellent using the STI scale. As expected both sets of results returned "excellent" values of 0.88 and 0.86 respectively. The value returned by Acoustic Tools was 0.69 (good) In the case of the WinMLS software the test was carried out using the same measurement microphone and Laptop as well as the same source loudspeaker. The Norsonic setup (Norsonic 118 with STIPA) used the same source loudspeaker but uses its own microphone and processing within the meter. Why does the Acoustic tools software consistently yield lower values of STI.