Yamaha E1010 E1010 Owners Manual Image - Page 10

FLANGING a 2 o 4)' N.-7W TUNNEL ft v:Fr irvInava .7T • 0 4)Y M85 Lj iii)YAMMA L PHASE SHIFTING INPUT 9 OUTPUT Frequencies cancelled out at • • O Harmonics • „ 6' 6 Harmonics • o Lj • • DISTRIBUTED SPEAKER SYSTEMS& THE HASS EFFECT While the E1010 is designed primarily for creative signal processing, it can be used in conventional delay line applications. For example, when an extension speaker is placed remotely from a main stage speaker, the sound may be perceived as coming from the remote speaker and not the stage, depending on the relative distances between the l istener and the speakers. With the E1010 one can ensure that sound is perceived as coming from the main speakers. If the remote audience loudspeaker is 25 or more feet from the main stage speaker, a listener near the remote speaker will either not hear the main speaker or will hear it as the source of an echo. However, if the E1010 is used to delay the signal to the remote speaker* so that its sound actually arrives at the audience 5 to 20ms later than the sound from the main speaker, then the perceived localization of the sound will be from the stage; the remote speaker still reinforces the sound from the stage, but is not heard as a distinct sound source. Our localization of a sound "image" based on the sound source which arrives first at our ears is known as the Hass effect. (Refer to Figure 8 for a graph of delay times, speaker-listener distances, etc.). In using the Hass effect and delaying the sound to the remote speaker(s) with the E1010, the delay line can actually eliminate echoes rather than create them. *The E1010 must operate on line-level signals fed to the remote power amplifier, not on the amplifier output. 350 - 300 e 250 1 200 2w E LL 150 2 6 100 O 50 - 300ms max. delay (338 ft.) Dark line represents delay required for main and remote speaker output to coincide at remote location. -4- 5ms extra delay (333 ft.) (remote lag) Area to left of dark line is range wherein main speaker is heard as echo to remote 20ms extra delay (316 ft.) (remote lag) speaker (confused image localization) Shaded zone is range wherein hass precedence effect makes sound 41romr image move to main speaker. Area to right of shading is range wherein remote speaker is heard as echo to main speaker. Hi) Based on speed of sound at sea level, 25° C at 1130 feet/second (1 foot in .885ms). 50 100 150 200 250 300 Time Delay To Remote Speaker (MILLISECONDS) Fig. 8 - Delay Times required for hass effect correction of sound images at various main speaker/remote speaker/listener distances.