Meaning of EQ bands?
Locked
 
|
A new question, probably for Lyle to respond:
How exactly are the EQ bands implemented in DSP, in terms of frequency response? Although the controls are presented in histogram form, what do the stated frequencies actually represent? Is the actual frequency response composed of overlapping sub-band filters, or what? -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In the KX3, the gain of the FIR filter at the specified frequency is set
to the requested value, and a linear interpolation is performed from the next lower specified frequency. At the highest frequency, sertting, all frequencies higher are set to the requested value. The K3 operates in a similar fashion. These are inputs to the FIR coefficient generator along with center/width/lo cut/hi cut and manual notch to create the FIR filter. 73, Lyle KK7P > How exactly are the EQ bands implemented in DSP, in terms of frequency > response? ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
Thank you for the clarification, Lyle. I hadn't seen that information
anywhere before. The existing K3 manual seems quite misleading in talking about 8 "bands" of audio equalization. We now learn that the EQ facility allows the user to set the relative levels at 8 discrete frequency POINTS, and that the rest of the frequency response is interpolated by "joining up the dots". That gives quite a different shape to the frequency response than many will have imagined. >> How exactly are the EQ bands implemented in DSP, in terms of frequency >> response? >In the KX3, the gain of the FIR filter at the specified frequency is >set to the requested value, and a linear interpolation is performed >from the next lower specified frequency. At the highest frequency, >sertting, all frequencies higher are set to the requested value. > >The K3 operates in a similar fashion. > >These are inputs to the FIR coefficient generator along with >center/width/lo cut/hi cut and manual notch to create the FIR filter. > >73, > >Lyle KK7P > -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
> The existing K3 manual seems quite misleading in talking about 8 > "bands" of audio equalization. We now learn that the EQ facility > allows the user to set the relative levels at 8 discrete frequency > POINTS, and that the rest of the frequency response is interpolated > by "joining up the dots". > > That gives quite a different shape to the frequency response than > many will have imagined. How so? That's the way "graphic" equalizers - whether they are octave or fractional octave - have operated for years. 73, ... Joe, W4TV On 6/21/2012 6:51 PM, Ian White GM3SEK wrote: > Thank you for the clarification, Lyle. I hadn't seen that information > anywhere before. > > The existing K3 manual seems quite misleading in talking about 8 "bands" > of audio equalization. We now learn that the EQ facility allows the user > to set the relative levels at 8 discrete frequency POINTS, and that the > rest of the frequency response is interpolated by "joining up the dots". > > That gives quite a different shape to the frequency response than many > will have imagined. > > >>> How exactly are the EQ bands implemented in DSP, in terms of frequency >>> response? > >> In the KX3, the gain of the FIR filter at the specified frequency is >> set to the requested value, and a linear interpolation is performed >>from the next lower specified frequency. At the highest frequency, >> sertting, all frequencies higher are set to the requested value. >> >> The K3 operates in a similar fashion. >> >> These are inputs to the FIR coefficient generator along with >> center/width/lo cut/hi cut and manual notch to create the FIR filter. >> >> 73, >> >> Lyle KK7P >> > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
Joe Subich, W4TV wrote:
> >> The existing K3 manual seems quite misleading in talking about 8 >> "bands" of audio equalization. We now learn that the EQ facility >> allows the user to set the relative levels at 8 discrete frequency >> POINTS, and that the rest of the frequency response is interpolated >> by "joining up the dots". >> >> That gives quite a different shape to the frequency response than >> many will have imagined. > >How so? That's the way "graphic" equalizers - whether they are octave >or fractional octave - have operated for years. > Please re-read what Lyle wrote. The underlying DSP does not use stepped frequency "bands" at all - not even as a concept. Whenever we use words to describe DSP, we are always at least one step away from reality. So let's not make that any worse than it has to be. A more accurate image of what's really happening is that the equalizers re-draw the frequency response curve by specifying its values at 50, 100, 200, 400, 800, 1600, 2400 and 3200 Hz. "Drawing a curve" gives a much more accurate picture of what is really happening, especially at frequencies in between those points. Fortunately, the K3 doesn't care about any of this. For the first time in almost 50 years I'm receiving unsolicited compliments about my audio - so whatever is happening in there, it works. -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
«
Return to [K3]
|
1 view|%1 views
| Free forum by Nabble | Edit this page |