@erik_squires . Interesting research-- AES preprint 3207 by Oohashi et al. claims that reproduced sound above 26 kHz "induces activation of alpha-EEG (electroencephalogram) rhythms that persist in the absence of high frequency stimulation, and can affect perception of sound quality." |
@erik_squires . More from same research- Oohashi and his colleagues recorded gamelan to a bandwidth of 60 kHz, and played back the recording to listeners through a speaker system with an extra tweeter for the range above 26 kHz. This tweeter was driven by its own amplifier, and the 26 kHz electronic crossover before the amplifier used steep filters. The experimenters found that the listeners' EEGs and their subjective ratings of the sound quality were affected by whether this "ultra-tweeter" was on or off, even though the listeners explicitly denied that the reproduced sound was affected by the ultra-tweeter, and also denied, when presented with the ultrasonics alone, that any sound at all was being played.' |
@ptss Very interesting!!! My speakers are flat to 30kHz, i wonder how much of that I’ve been experiencing?? I’ve also read positive things about damping ultrasonic resonances in tweeters during crossover design, but I thought that was because of distortion artifacts being introduced at a lower frequency. |
