Beschreibung
Room reflections are best evaluated by using a storage oscilloscope to display the time response to a short duration toneburst (ADD2 on CD-download).
The response to short tonebursts from 20 Hz to 20 kHz can be measured with a fast, peak holding SPL meter, if available, or a storage oscilloscope. The Radio Shack sound level meters are too slow for the high frequency bursts and at low frequencies their response is rolled off. Accurate single burst measurements require instruments like the NTI Acoustilyzer.
For other tests using the toneburst signals see the more detailed description of the CD track contents below.
All signals are recorded equally in left and right channels. A voice announcements of signal type and of each upcoming burst frequency is added to the left channel.
1. 200Hz to 20Hz, 5 sweeps, 36s each, 5Hz/s rate, 3:18
2. 200Hz low-passed pink noise, 2:07
3. 200Hz to 100Hz, 3 bursts of 4x 20-cycles, large steps, 0:55
4. 100Hz to 50Hz, 3 bursts of 4x 10-cycles, large steps, 0:54
5. 50Hz to 20Hz, 3 bursts of 4x 10-cycles, large steps, 1:09
6. 200Hz to 160Hz, 3 bursts of 4x 20-cycles, 4Hz steps, 1:27
7. 160Hz to 120Hz, 3 bursts of 4x 20-cycles, 4Hz steps, 1:31
8. 120Hz to 100Hz, 3 bursts of 4x 10-cycles, 2Hz steps, 1:15
9. 100Hz to 80Hz, 3 bursts of 4x 10-cycles, 2Hz steps, 1:13
10. 80Hz to 60Hz, 3 bursts of 4x 10-cycles, 2Hz steps, 1:15
11. 60Hz to 40Hz, 3 bursts of 4x 10-cycles, 2Hz steps, 1:17
12. 40Hz to 20Hz, 3 bursts of 4x 10-cycles, 2Hz steps, 1:39
13. 20Hz to 10Hz, 3 bursts of 4x 10-cycles, 2Hz steps, 1:34
14. 4kHz, 4-cycle bursts at 100ms intervals, 3:09
15. 20Hz to 200Hz, 4 bursts of 4-cycles, 1/3rd oct steps, 1:54
16. 200Hz to 2kHz, 4 bursts of 4-cycles, 1/3rd oct steps, 1:47
17. 2kHz to 20kHz, 4 bursts of 4-cycles, 1/3rd oct steps, 1:52
18. 20kHz pink noise, 2:07
19-28. 12.8 kHz to 25 Hz in oct steps, five 5-cycle bursts each oct
ADD1 multi-burst test signal
ADD2 short duration toneburst
Tone Burst – How to use the different sound tracks
