Testing freerunner's audio quality
Dr. H. Nikolaus Schaller
hns at goldelico.com
Thu Sep 23 06:47:10 CEST 2010
the problem is the bass. Initially, It was difficult to hear differences
by playing two sounds one after the other. So until you have listened
music on a bass fixed Freerunner, you would say it is quite ok.
I was only able to hear the difference after taking one original Freerunner
and one with Bass-Fix applied. After a while you get that there *is* a
difference in low frequencies.
What I have done is this test: create a sinus sweeping from 10 to 100 hz.
Without bass fix you can't hear it before it comes to the 50 hz range.
sox -n -t wav - synth 10 sine 10-100 >file.wav
This can be seen on scope outputs as shown here:
Can you please compare you device?
One effect may also be the input impedance of your line card. Did you connect
it in parallel to a headset?
Am 22.09.2010 um 23:57 schrieb Gennady Kupava:
> Hi, list,
> Many gossips flying around about bad fr's audio subsystem quality. I
> promised to proove that FR audio subsystem is good, just default
> headphones quality below anything.
> As today finally i overcome my lazyness and soldered 2.5mm->3.5mm jack,
> and i am almost content with high sound quality of my Sennheiser CX300
> II+FR, i decided to do some basic testing.
> Test environment
> I got 2 recodings - 60 seconds of white noise and 120 seconds of piano
> +voice, audacity to do spectrum analisys, cable 3,5mm<->3,5mm to connect
> my old m-audio revolution 7.1 card to line-in to freerunner.
> White noise
> 1. White noise were generated by audacity original file:
> 2. Same noise recorded then audio-out were connected to audio-in of
> sound card:
> 3. Same noise played on FR, connected to line-in of sound card:
> Conclusion on white noise:
> I see no frequency cut-offs. spectrograms look very well and close to
> original file. Only exception is fall below 20Hz in fr case, but i am
> unsure if any headset can reproduce such frequences very well.
> Real song
> 1. Original piece of song (piano+voice):
> 2. Same file played on freerunner and captured on line-in of sound card
> Conclusion on piano+voice:
> I can't distingush difference in quality while replaying original file
> or file recorded from freerunner. Spectrum show almost no difference.
> Overall conclusion
> Seem audio quality completely depends on quality of headphones. You may
> try to distiguish original song and song from fr youself, only do not
> forget to normalize volume before attempting to do this.
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