Reply-To: "Kevin Aylward"
From: "Kevin Aylward"
Subject: Re: Acoustic Feedback reduction
X-Newsreader: Microsoft Outlook Express 6.00.2800.1106
Date: Wed, 15 Jan 2003 15:16:30 -0000
NNTP-Posting-Date: Wed, 15 Jan 2003 15:16:33 GMT
> Ok Phil
> I borrowed a 5Hz frequency shifter form a sound reinforcement company.
> We played the following notes concurrently on a synth.......
> E - 2, B - 2 and E +1. For the unititated these are the low E on a
> standard guitar, B a fifth up from this, then another E, 2 octaves
> higher. We recorded it and have posted it here....
> The file is called 5HzShift.wav The first 3 seconds are the 3 notes
> played direct. The last 3 seconds are the same notes played through
> the 5Hz shifter (we simply switched it on while holding the keys
> We also did the same thing an octave lower (still nowhere near the
> bottom of the music range) and the results were, as expected, even
> worse. However typical PC speakers won't even reproduce it so it
> seemed pointless posting it.
Well, my crappy PC speakers certainly showed the difference.
The reality is that you need to shift by a fixed ratio, not a fixed
frequency,as in speeding/slowing a tape recorder.
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.