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  #1  
Old 05-26-2010, 02:51 AM
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Nausicaa Nausicaa is offline
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Default Rockbox CPU noise?

I'm not sure if anyone else finds it a problem or even noticed it, but can you hear a mechanical sound (soft beeps and clicks is the closest thing I can compare it to) when using the Clip to play music? It doesn't appear in the Sansa firmware. Is this even considered a problem enough to correct via software? If not, is there an easy way to get rid of it? It is a lot more apparent when listening to quieter tracks or parts with silence.
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  #2  
Old 05-26-2010, 05:26 AM
funman funman is offline
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I think it's a problem on all Clipv2.

The noise is
  • regular
  • independent of volume (you can hear very well when volume is muted)
  • absent when playback is paused
  • absent when listening to FM radio
  • completely absent in the OF
  • not present on rockboxed Clip+ / Fuzev2
  • dependant on the CPU frequency, the fastest the CPU is, the more frequent the noise is.
saratoga suggested it was a power management issue rather than a DAC problem, if you have an idea on how to track down the problem suggestions are welcome (here or on rockbox forums/irc).
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Old 08-01-2010, 11:38 AM
orby orby is offline
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Quote:
Originally Posted by funman View Post
I think it's a problem on all Clipv2.

The noise is
  • regular
  • independent of volume (you can hear very well when volume is muted)
  • absent when playback is paused
  • absent when listening to FM radio
  • completely absent in the OF
  • not present on rockboxed Clip+ / Fuzev2
  • dependant on the CPU frequency, the fastest the CPU is, the more frequent the noise is.
saratoga suggested it was a power management issue rather than a DAC problem, if you have an idea on how to track down the problem suggestions are welcome (here or on rockbox forums/irc).
furthermore, noise is different for different codecs. (i used the attached files for testing)

I hope this problem can be solved sometime - some tracks are unbearable to listen to with rockbox.
that makes me switch to OF, but then again navigation and all the comfort and functionality of rockbox is missing.
Attached Files
File Type: rar Silence Tracks.rar (1.74 MB, 20 views)
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  #4  
Old 08-17-2010, 09:00 PM
orby orby is offline
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can someone please answer this question:

- is there no noise at all when using clip+ OR sansa v2? that is _really no noise at all_?

thank you for answering. :-)

Last edited by orby; 08-19-2010 at 04:55 AM.
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  #5  
Old 08-19-2010, 06:59 AM
orby orby is offline
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Quote:
Originally Posted by orby View Post
can someone please answer this question:

- is there no noise at all when using clip+ OR sansa v2? that is _really no noise at all_?

thank you for answering. :-)
anyone..?
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  #6  
Old 05-26-2010, 10:08 AM
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Nausicaa Nausicaa is offline
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I don't think its absent when the playback is paused. I hear a distinct 'fizz'. Its happily nonexistent while traveling as the background noise cover it well. Is it on the clip v1 as well?

My version is 26241-10052. Is there a way to alter the CPU frequency? I looked in the debug menu and I'm not smart enough to figure out where it is.

I should have mentioned: Thanks for all your (Rockbox developer's) hard work. I bought an iPod mini because of you guys, and have been using it for three years. Rockbox makes the player for me, if it has Rockbox, I buy it. Although I jumped the gun on the D2, and its been sitting unused because of the horrible touchscreen (It took $250 to convince me to never buy another touchscreen product again, haha). I have other iPods and refuse to buy another Apple product unless it has Rockbox on it, and Zune isn't even an option because of the lack of Rockbox.

Last edited by Nausicaa; 05-26-2010 at 10:18 AM.
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  #7  
Old 05-26-2010, 12:24 PM
funman funman is offline
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You're right, some noise is still present when paused, but not the regular "tick".

Clipv1 is all right afaict
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  #8  
Old 05-26-2010, 04:33 PM
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It's not absent in Rockboxed Clip+ either. While I haven't heard a "regular tick" there are definite little beeps and whirs during playback and when paused. I don't notice them while playing music but only audiobooks and podcasts as they are much quieter and have more silence. It's not ruining my player but it is a bit annoying sometimes.
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  #9  
Old 05-28-2010, 12:22 PM
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Artmuzz Artmuzz is offline
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Quote:
Originally Posted by Rockin Munki View Post
It's not absent in Rockboxed Clip+ either. While I haven't heard a "regular tick" there are definite little beeps and whirs during playback and when paused. I don't notice them while playing music but only audiobooks and podcasts as they are much quieter and have more silence. It's not ruining my player but it is a bit annoying sometimes.
Hmm, I cannot say I hear any noise, beeps or whirs when I play music on my Rockboxed Clip+. How I know is because when I play certain tracks that have a quiet middle bit there doesn't seem to be any noise.

So I am happy to say the noise is absent on my Clip+


Art
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  #10  
Old 05-29-2010, 09:07 AM
Hirsch2k Hirsch2k is offline
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I also noticed beeps when using fade in/out on play/pause with rockbox on my clip+
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  #11  
Old 08-18-2010, 05:16 PM
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Quote:
Originally Posted by Hirsch2k View Post
I also noticed beeps when using fade in/out on play/pause with rockbox on my clip+
Me too. That's why I have fade in/out turned off. It would be really nice if it could get fixed.
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  #12  
Old 05-26-2010, 05:31 PM
Kenaneu Kenaneu is offline
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Quote:
Originally Posted by funman View Post
Clipv1 is all right afaict
I hear tons of noise during playback of quiet passages on both my Clip v1 and Fuze v1. This noise is absent on the Clip+ (other than when paused/navigating folders, etc.).
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  #13  
Old 08-19-2010, 10:33 AM
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I listened to your silence tracks on a Clip+. Both in Rockbox and the stock firmware they have the same faint background hiss on maximum volume, same for all three codecs. At normal listening levels it's basically inaudible (at least with the phones I used for testing).

I checked the FLAC track in Sound Forge, and it's SPL is apparently -71.2dB. So I assume it's not digital silence in the tracks?

EDIT: Made my own silence file, FLAC with -96dB digital silence. In the stock firmware it does hiss a bit at maximum volume (but less than yours), in Rockbox it's dead silent.
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  #14  
Old 08-19-2010, 10:39 AM
saratoga saratoga is offline
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The noise doesn't change when you increase the volume, so its probably not amped. I think thats why you only hear it on some headphones, they have to be really sensitive and easy to drive, else it doesn't get picked up.

I played with it for a while on my v2 and couldn't really see a pattern. Its obviously dependent on something being on in the CPU since it goes away with the radio, but other then that I'm not sure what it could be.
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Old 08-19-2010, 05:36 PM
orby orby is offline
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Quote:
Originally Posted by dfkt View Post
I listened to your silence tracks on a Clip+. Both in Rockbox and the stock firmware they have the same faint background hiss on maximum volume, same for all three codecs. At normal listening levels it's basically inaudible (at least with the phones I used for testing).

I checked the FLAC track in Sound Forge, and it's SPL is apparently -71.2dB. So I assume it's not digital silence in the tracks?

EDIT: Made my own silence file, FLAC with -96dB digital silence. In the stock firmware it does hiss a bit at maximum volume (but less than yours), in Rockbox it's dead silent.
thanks for testing.
mmh. so it seems the clip+ isn't completly silent as well.
bad :/.
most likely it will be the best thing for me to get my hands on a clip+ / sansa v2 to try myself and hear, if it's sufficient for my tracks.

however, thank you very much for your time and effort.

my silence tracks were created using audacity. maybe that's not the best way to do this.
however if i listen to them on anything but my rb-clip, these tracks are dead silent, using normal listening volume.
so my conlusion was, that if i can hear something with the clipv2 and hear nothing with my home rig, noise must source from the clip.
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  #16  
Old 08-19-2010, 12:23 PM
McMusic McMusic is offline
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There is CPU noise on the Clip+, e.g. when browsing through the library and choosing a song. Obviously the ability to hear the noise depends on the sesitivity of the phones you use. With my JH13 I can hear the noise clearly. I would also appreciate, if this noise could be avoided in future RB releases.
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  #17  
Old 08-19-2010, 05:51 PM
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I re-tested your silence tracks on Foobar2000, feeding an AudioFire4 over ASIO, using Ultrasone HFI-780 phones. This is a rather revealing high-quality setup. Same thing as on the Clip+ - they do hiss at very high volume levels, while my -96dB silence track is completely silent. Still, the hiss with yours is only apparent at ear-shattering volume levels where it's totally negligible, same as on the Clip+.

I also loaded the tracks onto my Cowon J3. Same results - your tracks hiss, mine doesn't.

I think your files aren't the best to test such things with. Attached is my -96dB silence track, if you want to re-test. With this file, Rockbox's way of amping/playback actually surpasses the stock firmware (with yours both perform the same).

BTW, I normalized your tracks to 0dB, and they do contain a certain amount of white noise. Normalizing mine still results in a silent track.
Attached Files
File Type: rar silence-dfkt.rar (1.6 KB, 26 views)
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  #18  
Old 08-20-2010, 11:19 AM
orby orby is offline
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thanks for your effort, dfkt.

i'll test again with your files as soon as i can find time to do so.

however, as you said yourself:
Quote:
Still, the hiss with yours is only apparent at ear-shattering volume levels where it's totally negligible, same as on the Clip+.
i'd conclude my files are not perfect, but sufficient for this purpose.
cpu noise of the clipv2 is much much louder than any noise on this files.

thank you very much anyway.
as said, i'll test as soon as i can.
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  #19  
Old 08-25-2010, 08:46 AM
orby orby is offline
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so finally.

i got my hands on a clip+ and can now answer my question myself:
The noise one can hear in silent parts if listening with clipv2 is not audible with a clip+.

Great news for me, i'm going to buy one.


and well, dfkt, your right. my silent tracks are hissing (they where produced using audacity/create silence), your track is considerably more quiet.
however, and as said before, for the purpose of detecting the CPU noise, they were absolutely sufficient.

I'm not at home right now, that means i can't play your file through my home rig. But at least the Clip+ isn't totally quiet with any of these files. In fact there is even hissing, when playback is paused.



summa summarum: clipv2 CPU noise is horrible with some quiet tracks if i want to enjoy music.
clip+ is sufficiently quiet. i can enjoy all my music without beeing disturbed by clicl click beep beep etc.

wow, great news.
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  #20  
Old 08-25-2010, 03:46 PM
Kenaneu Kenaneu is offline
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Glad you found the Clip+ to be acceptable. I struggled with the same noise issues on my v1 Clip and Fuze. Not a problem for most music, but quiet passages in classical music were painful with the bubbling noise going through them. The Clip+ may not be perfect, but my imperfect ears are happy.
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