Meeting 6/9/2024 - John F. Allen, CEO of High Performance Stereo

[@paulsartana1785]

Thanks for posting this. John Allen seems truly ahead of his time and extremely knowledgeable when it comes to Symphony and Movie theatre sound.

[@andysummersthxcinemaandmyc7748]

58:15 check the amplifiers being used with frequency sweep see which ones have flat response of a high pass filter rolling off the high frequencies ones with a roll-off maybe look into schematic diagram to locate the high-pass filter put a switch on it so can be set to flat response a bit messy lot of hassle or simply use the loudspeaker management crossover system , use high pass filter boost the level at roughly where it rolls-off and compensate the level until flat with RTA direct connected , with cinema booth monitor , then do frequency sweep until all amps being used show flat response , the type of HF horn being used tested without projection screen and with projection screen see which type of roll-off there is and then how to go about compensating with it , do you use some extra high pass boosting providing there is enough headroom on the amplifier won't clip on the higher highs and that the HF horn doesn't have any issues with strange sounds when sine wave or filtered pink noise customised pink noise for higher high frequencies that will sound like a sort of whistle effect just at upper high highs of course and how much of it can we actual hear in the higher highs ? film soundtracks often have sci-fi like high highs up to around 18KHz for 70mm and digital 20Khz but rarely do i see higher highs or some are at low mix level can barely hear it at the fader level and needs adjusting cos i think all of sudden i lost hearing range when i test with sine wave tones with relief all is fine with my hearing its the soundtrack that that is at issue here