Newsgroups: comp.speech
Path: pavo.csi.cam.ac.uk!warwick!pipex!sunic!news.funet.fi!news.cs.tut.fi!pka
From: pka@cs.tut.fi (Kapanen Pekka Markus)
Subject: Audio filter for PC soundcard
Message-ID: <1994Mar22.082232.20398@news.cs.tut.fi>
Originator: pka@naakka.cs.tut.fi
Sender: usenet@news.cs.tut.fi (#Kotilo NEWS system )
Nntp-Posting-Host: naakka.cs.tut.fi
Organization: Tampere University of Technology
Date: Tue, 22 Mar 1994 08:22:32 GMT
Lines: 32


	I am involved in speech processing at low
	bit rates, and I am looking for suggesti-
	ons for an anti-aliasing audio low pass
	filter to be used between a PC soundcard
	and an amplifier.

	I am using a 16-bit Soundblaster PC card
	to play speech files at 8 kHz sampling
	frequency. At this sampling frequency,
	the sound card seems to provide poor anti-
	aliasing filtering, resulting in annoying
	high-frequency distortion.

	I would like to get the rid of this distor-
	tion, and it seems that an external audio
	low pass filter would be the solution. I am
	aware of the laboratory-grade equipment
	available, such as the Kemo VBF-8 dual vari-
	able filter, but I would prefer the price
	and quality level to match the price and
	quality of the sound card that I have.

	I assume there are people reading this news-
	group who have found a solution to this
	problem. Any pointers to the available pro-
	ducts would be appreciated, either by E-mail,
	or to this newsgroup.



	- Pekka
