mrw wrote: > Perhaps your sampling frequency steps are too large to accurately > capture energy per octave at the low end. Also seems to show up with > your White noise plotted against octave.
Good point! The FFT size and sampling frequency were set to 4k and 44.1kHz respectively (spatial resolution = 10.7Hz). If I increase the size to 64k, which corresponds to a spatial resolution of 0.67Hz, then I get a nice flat response with pink noise (see below). Even with a FFT size of 32k I still get some uplift below about 50Hz. TBH I am a little surprised that the effect is so pronounced and am not quite sure exactly what is going on, esp as I am doing a lot of averaging! 30538 +-------------------------------------------------------------------+ |Filename: 2020_06_01 Pink noise played on Pi-Mesh, sample size=64k.jpg| |Download: http://forums.slimdevices.com/attachment.php?attachmentid=30538| +-------------------------------------------------------------------+ SB3 -> Quad 909 -> Quad Electrostatic speakers, Quad 405 -> TBI subwoofer 3 x SB3s + SB Radio Rotel RSP1068 surround processor, Quad 99 -> B&W surround ------------------------------------------------------------------------ rbl's Profile: http://forums.slimdevices.com/member.php?userid=4517 View this thread: http://forums.slimdevices.com/showthread.php?t=112265 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
