what is a lowpass filter?

[brian10161]

i read somewhere that if you put a wave file through a lowpass filter it will make the file sound better at a lower bit-rate. if anyone can tell me what a lowpass filter is and where i can get one for free it would be greatly apreciated.

cheers

[adaywayne]

Re: what is a lowpass filter?

i read somewhere that if you put a wave file through a lowpass filter it will make the file sound better at a lower bit-rate. if anyone can tell me what a lowpass filter is and where i can get one for free it would be greatly apreciated.

cheers

~~~~~~~~~~~~
A low-pass filter is simply an audio filter which allows only frequencies below a certain value to pass through....thus cutting out most or all of the higher frequencies. Since many people can't hear any frequencies above, say, 16,000Hz (the highest note on a piano is at about 4200Hz ....Hz = cycles per second) then many compression programs simply discard those higher frequencies before compressing the rest. This is particularly true at lower bitrates. Lame 3.96.1 at 64 bitrate , for example, discards all frequencies above about 11,000Hz.

The free audio editor program, Audacity, has both low and high-pass filters, as well as many other interesting features to play with.

http://audacity.sourceforge.net/

Also, if you want a simple test of your hearing frequency range, try

http://www.engr.uky.edu/~donohue/audio/fsear.html

Arnie

[brian10161]

Re: what is a lowpass filter?

thanks for the response. i got the program and put the file through the lowpass filter and it worked, but sounded horrible :o lol. oh well, i will just use the default bitrate. i guess my hearing is really good, because below 128kbps anything sounds horrible. well thanks for the links.

cheers

[adaywayne]

Re: what is a lowpass filter?

thanks for the response. i got the program and put the file through the lowpass filter and it worked, but sounded horrible :o lol. oh well, i will just use the default bitrate. i guess my hearing is really good, because below 128kbps anything sounds horrible. well thanks for the links.

cheers

The default setting for the lowpass filter is 1015Hz. If that is what you used then it would sound horrible!! Try something in the 10,000 to 14,000Hz range.

Note, however, that cutting out the high frequencies before converting to a compressed format is really just something to do to pass the time and have a bit of fun with. Believe me, the various compression programs will do the job for you, especially at low bitrates! I think the best result for 64Kbps is mp3PRO (played back on a player that has the proper playback codec). A very close second at 64 bitrate is OGG (VBR). Just my opinions, of course.

[brian10161]

Re: what is a lowpass filter?

i tried 10000hz and it still sounded bad to me, it was all muffled and stuff. so im just going to stick to 128kbps high quality lame encoded songs, they sound really good, yet i can still here some distortion. does that mean that my hearing is really good? lol well thanks for the responses.

cheers

[ChristinaS]

Re: what is a lowpass filter?

i tried 10000hz and it still sounded bad to me, it was all muffled and stuff. so im just going to stick to 128kbps high quality lame encoded songs, they sound really good, yet i can still here some distortion. does that mean that my hearing is really good? lol well thanks for the responses.

cheers

Either that or your soundcard/speakers are really bad :D

If mp3 @128 kbps is ok, try wma at 64kbps for the same result and half the size, or wma at 128kbps for possibly much better at the same size.

[brian10161]

Re: what is a lowpass filter?

i seriously doubt my speakers are bad, :vmad: because they are the Logitech x-230. 4 tweeters :D

(im not being mean )

[Thulemanden]

Re: what is a lowpass filter?

~~~~~~~~~~~~
Also, if you want a simple test of your hearing frequency range, try

http://www.engr.uky.edu/~donohue/audio/fsear.html

Quite interesting. It showed why I always adjust the high pitch up, as my plot showed specifically a 10db drop in the range 6-10Khz.

[brian10161]

Re: what is a lowpass filter?

ok, i've been looking everywhere and everone seems to be saying that WMS at 64kbps is as good as mp3 at 128kbps. i decided to try it. first with dbpoweramp with the second pass thing enabled, and then again with without the second pass. then i tried it in windows media player 10 at 64kbps both variable and constant bitrate. i put it on both my mp3 player and pocket pc with my sony headphones and beleive me, they all sounded like crap. well if anyone has a different idea about this please help me with it

cheers

[ChristinaS]

Re: what is a lowpass filter?

ok, i've been looking everywhere and everone seems to be saying that WMS at 64kbps is as good as mp3 at 128kbps. i decided to try it. first with dbpoweramp with the second pass thing enabled, and then again with without the second pass. then i tried it in windows media player 10 at 64kbps both variable and constant bitrate. i put it on both my mp3 player and pocket pc with my sony headphones and beleive me, they all sounded like crap. well if anyone has a different idea about this please help me with it

cheers

Sorry dear, I must conclude either your equipment is crap or your hearing has been seriously damaged by something. I'm not even kidding here.

[brian10161]

Re: what is a lowpass filter?

why? what is wrong with my hearing then that when listening to a low bit rate file that it still sounds like crap, meanwhile all my mp3s are encoded at 160kbits a second and they sound perfect there. please tell me why my hearing is bad because it doesnt seem that way to me. :(

oh, and i doubt that, my phillips cd player, pocket pc, laptop, desktop, and mp3 player are all poor quality.

[adaywayne]

Re: what is a lowpass filter?

why? what is wrong with my hearing then that when listening to a low bit rate file that it still sounds like crap, meanwhile all my mp3s are encoded at 160kbits a second and they sound perfect there. please tell me why my hearing is bad because it doesnt seem that way to me. :(

oh, and i doubt that, my phillips cd player, pocket pc, laptop, desktop, and mp3 player are all poor quality.

Try OGG and mp3PRO at around 64Kbps. Make sure the player you use for playing back the mp3PRO file has the mp3 decoder, otherwise everything above 8000HZ will be cut off.

High-frequency cutoff for mp3PRO and OGG at 64Kbps are at 16000Hz and 15000Hz respectively, versus 13000 for WMA. Lame at 128Kbps is at 17000.

Sorry I can't post the spectra.

[brian10161]

Re: what is a lowpass filter?

AHHHH! why cant this stuff be easy?

btw is there anyway that i can upgrade my mp3 player to play OGG vorbis? ogg vorbis seems to be the best at 64kbps

[LtData]

Re: what is a lowpass filter?

AHHHH! why cant this stuff be easy?

btw is there anyway that i can upgrade my mp3 player to play OGG vorbis? ogg vorbis seems to be the best at 64kbps

No, ogg vorbis has to be supported via the hardware, you cannot manually add support.

[adaywayne]

Re: what is a lowpass filter?

AHHHH! why cant this stuff be easy?

btw is there anyway that i can upgrade my mp3 player to play OGG vorbis? ogg vorbis seems to be the best at 64kbps

Buy a new player that supports OGG! AlliRiver and Rio Karma ones do.