It is what it wants to be. You want equal power per Hz. When you
adjust our equalizer filters on TX, you will see the entire response
floor of the filter rise and fall in the power spectral display. Bill
is correct that since each filter is wider than the last, the total
energy that goes through the later filter is larger but we do not
provide an "energy in that filter" measurement. We give you a visual
aid so you can tune the filter up and down for transmit. When you "see"
the noise floor from that filter at the right place, you will have it
adjusted correctly. There is no visual aid for receive yet because are
not yet doing the power spectrum calculation on the audio.
I am working on the polyphase FFT now for us, GnuRadio, etc. When that
is done I will show you a few pixel wide line for a good CW tone in
the1000 Hz display and then the audio display will make sense.
Bob
Eric Wachsmann - FlexRadio wrote:
The internal generator does white noise. This could probably be
modified to easily add pink noise though.
Eric Wachsmann
FlexRadio Systems
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
radio.biz] On Behalf Of Bill Guyger
Sent: Tuesday, November 15, 2005 3:16 PM
To: flexRadio@flex-radio.biz; [EMAIL PROTECTED]
Subject: Re: [Flexradio] Feature request - white noise generator for
receiveEQ
OK I've actually slept simce my rock and roll days, but IF I remember
correctly, white noise has equal energy per hertz which means that it
has
a rising frequency responce plot as frequency rises. Sound systems are
more properly equalized with "pink" noise which is white noise
filtered to
yield equal energy per octive or a flat frequency response.
If you set up EQ with white noise you will have a "hotter" high end
than
you might want. Does the internal generator create pink or white
noise?
Bill AD5OL
"Tim Ellison" <[EMAIL PROTECTED]> 11/15/05 11:47AM >>>
I was setting the receive EQ this morning and had an idea that I
wanted
to share with the Flex-Radio virtual neighborhood.
Back many moons ago when I was much younger, I played in a rock band
(for all the reasons you would join a rock band) and one of my jobs
was
to help the sound man set the final EQ specific to the speakers we
were
using and the geometry of the venue we were playing. We did this with
a
white noise generator and an audio spectrum analyzer.
My thought was we have most of those components already in the
PowerSDR
application. If you added a white noise generator you could direct
the
output to your speakers and while using your microphone to measure the
output, you manually (or with an automatic software routine) adjust
the
receive EQ until you flat line the response. This would allow you to
compensate for room acoustics and non-linear speaker response.
Wadda ya think?
-Tim
---
Tim Ellison <mailto:[EMAIL PROTECTED]>
Integrated Technical Services <http://www.itsco.com/>
Apex, NC USA
919.674.0044 Ext. 25 / 919.674.0045 (FAX)
919.215.6375 - cell
PGP public key available at all public KeyServers <<<
_______________________________________________
FlexRadio mailing list
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
_______________________________________________
FlexRadio mailing list
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
_______________________________________________
FlexRadio mailing list
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
