From aweber@mindspring.com Wed Feb 21 22:57:41 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!mindspring!aweber From: aweber@mindspring.com (Anja Weber) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Feb21.225741.6614@mindspring.com> Date: Wed, 21 Feb 1996 22:57:41 GMT Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: WinVN 0.99.5 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? -- Anja Weber | aweber@mindspring.com PGP Key fingerprint: 9F12 8A81 6B62 CEBC "Keep the channels open." From kschneider@cam.ac.uk Fri Feb 23 21:03:41 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!cam!kschneider From: kschneider@cam.ac.uk (Kirsty Schneider) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Feb23.210341.6027@cam.ac.uk> Date: Fri, 23 Feb 1996 21:03:41 GMT References: <1996Feb21.225741.6614@mindspring.com> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Feb21.225741.6614@mindspring.com>, aweber@mindspring.com (Anja Weber) 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Kirsty Schneider Practical Peripherals 14.4 @ 28,800 bps "When every node is whole, the channel opens." From jsilva@unam.mx Sat Feb 24 12:37:41 1996 Path: ashpoly!cascade!brgate!saturno!unam!jsilva From: jsilva@unam.mx (Jens Silva) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Feb24.123741.7041@unam.mx> Date: Sat, 24 Feb 1996 12:37:41 GMT References: <1996Feb21.225741.6614@mindspring.com> <1996Feb23.210341.6027@cam.ac.uk> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Feb23.210341.6027@cam.ac.uk>, kschneider@cam.ac.uk (Kirsty Schneider) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Jens Silva Opinions expressed are solely my own and not those of Universidad Nacional Autónoma de México (DGSCA). ------------------------------------------------------------