From bkang@stanford.edu Tue Mar 08 01:01:40 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!stanford!bkang From: bkang@stanford.edu (Brian Kang) Newsgroups: comp.dsp Subject: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Mar08.010140.8998@stanford.edu> Date: Tue, 08 Mar 1994 01:01:40 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Brian Kang Hayes Optima 288 @ ISDN 64k bps "In theory there is no difference between theory and practice." From rkarlsson@illinois.edu Tue Mar 08 07:00:40 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!illinois!rkarlsson From: rkarlsson@illinois.edu (Raj Karlsson) Newsgroups: comp.dsp Subject: Re: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Mar08.070040.3635@illinois.edu> Date: Tue, 08 Mar 1994 07:00:40 GMT References: <1994Mar08.010140.8998@stanford.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: WinVN 0.99.5 Lines: 12 In article <1994Mar08.010140.8998@stanford.edu>, bkang@stanford.edu (Brian Kang) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Raj Karlsson Practical Peripherals 14.4 @ 19,200 bps "Tape doesn't lie at 02:14. Ears do."