-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Raj Mathur (राज माथुर) writes: > On Monday 10 Jan 2011, Linux Lingam wrote: >> gora is correct. >> also, have you tried to check the dell's internal circuitry is not >> causing this problem? >> depending on the level of hiss, here's a quick workaround: >> >> 1. ensure the recording has a few seconds of silence recorded: >> without voice/music/whatever. >> 2. open audacity, select this portion, and through the filters menu, >> look for the 'remove noise' option. >> the first click will load this pattern as the 'hiss' that has to be >> elminated. 3. now select the entire track, and again go back to the >> same filter. clicking it again will eliminate >> the noise/hiss from the entire track. >> 4: optional: adjust the EQ to correct other possible problems with >> the recording's balance of each channel, >> add salt, pepper, oregano, and other seasonings to taste.
> Thanks for all the advice folks. Some more background: > 1. This machine is going to be used for VoIP, so post-facto editing of > audio isn't possible. If you know a (say) 1000Hz filter that can be > implemented at the ALSA level I'd be glad to give it a shot. > 2. I've tried all settings. Yes, the hiss (obviously) decreases when I > push down mic gain. However, an obvious side-effect of lowering mic > gain is, you guessed it, voice volume goes down and the person at the > other end of the line has to strain to make out what I'm saying. > 3. I've tried recording without a mic attached and the hiss is still > there, so it's not an impedance mismatch (or whatever other technical > stuff sound engineers like to bandy about). > In my view, a properly-configured sound system should not be generating > hiss from the input at all, at any mic gain value, and this is confirmed > by running Winduhs on the machine where, lo! the hiss disappears. > Hence my conclusion that this is purely an ALSA issue and needs to be > tackled at the ALSA configuration level. > More advice/offers for help/commercial offers welcome. Ofcourse you probably have tried this, but let me mention this: 0. Have you tried passing various values for "model" option[1] corresponding to your snd-hda-intel chipset (ALC269). 1. Trying with latest ALSA sources 1.0.23 instead of 1.0.21 ? 2. Not ALSA related, how about ditching ALSA and going with OSSv4[2] stack which is also getting fairly good support, work great and its mixer is as confusing/complex (or maybe more) as ALSA. And ofcourse it's licensed under GPLv2 and BSDL, which makes it free software as well. References: [1] http://lxr.linux.no/#linux+v2.6.37/Documentation/sound/alsa/HD-Audio-Models.txt#L82 [2] http://opensound.com/ HTH - -- Ashish SHUKLA “We've so many people in India, that all of our time is spent doing Census only.” (abbe) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (FreeBSD) iQIcBAEBCgAGBQJNK90IAAoJEMdGz6nnT6SwsqIP/0Mgtg0QlJ+c6L8dmeuEYghy eMIwHL5gBs6wm2CrNUrHxQfjrbgkyKfaUtJm5l8FApwyAi9m/DbG30wLJVtS21Sg 9zQ6ssTSaiNSpl9eMJrgVEJlvrBuin2WbSSRUqJfQ4cZVYC1f+JqKOPXlj3bospn mvC2rPvtKZNE2rSKRpaQGQmB5ahsCQhkFamJbiX9Us6ysg4pN1mvnRXDG0GwX6+c 9fmvHdu+w5MAoW1tSDn39RyYBkh9cEIZ6F/X2RZhwbYdKAndH1NvhM+fb56f+X3Z pDcQXkSoOqeYxABC3Yfi8ln/XL48v5U8wu6ZTd5lPZYkr8IOmNPR9amOTfdgY7Ig 7YZs+71roJWm3d1K3YH5dty3ZlxCcgl5po5/loLOexygquHHpIXKsFxvFzdVfsl1 UOU7rtMY7/SDzrXKaNFc8YBluZUxmvGQ1d0whejIMdaEbZ8FEAww3LGc9TkJmbTq kFilNj+J7jCVU4QvaZbqcAjrLvwSJt1dv4eOy73K12iIQYiy8Uo+DitY5LFb42oW XPihrjPlSmuwPhqDJiu7jruqj1YvLDvOimDnyYjn6Lpy94TO2x9lfntExnvgShbe NXsG3OaBx3e0GRq3WKlG3E68OhxPIf7GUO5kUN1VuckwDrcSsTaFzW3mjcwL7FPt Ny5g4K1K+LmfdmptBJnv =isn2 -----END PGP SIGNATURE----- _______________________________________________ Ilugd mailing list Ilugd@lists.linux-delhi.org http://frodo.hserus.net/mailman/listinfo/ilugd
