SR MBP, do you have audio hiss?

Discussion in 'MacBook Pro' started by Sopranino, Aug 11, 2007.

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Can you hear audio hiss or bleeps on your SR MBP when using the audio out jack?

  1. Yes, I can hear a hiss.

    76 vote(s)
    63.3%
  2. No, my audio is clean.

    44 vote(s)
    36.7%
  1. Sopranino macrumors 6502

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    Alberta, Canada
    #1
    When using headphones or earbuds connected to the audio out jack on your computer do you hear a low level background hiss and/or other strange tones not part of whatever sound you are listening to?

    The audio hiss is present even when the volume is muted and doesn't change in volume as the computer volume is increased.

    The tones or bleeps can best be described as random in nature over about four different tones and seems to occur either when audio stops or when the audio levels are adjusted.

    These audio artifacts are only present on the SR MBP so please don't respond unless you have the new SR MBP.

    The audio artifacts can be best heard when in a quiet room and when using low impedance earphones or headphones. They do not seem to audible when the impedance goes up past 45 ohms.

    Sopranino
     
  2. hexonxonx macrumors 601

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    Denver Colorado
    #2
    I haven't noticed any hiss yet, but then I have only had my MBP for about a month. I have only had external speakers connected once or twice.
     
  3. Sopranino thread starter macrumors 6502

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    Alberta, Canada
    #3
    The audio artifacts are only audible using headphones. I suspect that your external speaker connection has a fairly high impedance and thus filters out the hiss and bleeps.

    Thanks for your reply

    Sopranino
     
  4. rodman109110 macrumors 6502

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    Jun 7, 2007
    #4
    i hear the hissing but thats it. i had the hissing on my old hp so it doesn't bother me much but then again i rarely if ever use my headphones.
     
  5. polycat33 macrumors 6502

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    Alexandria, VA
    #5
    I hear it, however the solution as has been posted on these boards seems reasonable, there's a device you can buy for like $15 to adjust the resistance and get rid of the his and beep sounds. I'm hoping my external speakers are high impedance, they also have a headphone plug so I'm hoping if they are high impedance that I can use that headphone plug when I want to and get rid of the hiss that way. Speakers are in storage now, won't find out for another month if they work. It's not that big of a deal to me though.
     
  6. Sopranino thread starter macrumors 6502

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    #6
    Thanks for the reminder about the other posting which contains the information regarding a solution. Credit for this information goes to dordal who did a fair amount of actual research into this.

    Here is the link dordal's solution to audio hiss

    Sopranino
     
  7. lucasc896 macrumors member

    Joined:
    Jul 30, 2007
    #7
    I've noticed this with my SR MBP. No beeps but I did occassionaly get strange buzz at random intervals every 5-10 minutes or so.

    I looked at the other thread briefly - but how does this all translate when you're using a hi-fi as an audio output?
     
  8. Sopranino thread starter macrumors 6502

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    #8
    I am going to assume that by 'hi-fi' you mean that you have your computer connected to an amplifier and speakers. If that is the case you probably won't experience any of the audio artifacts as the audio in on most amplifiers has a sufficiently high impedance.

    If I have not correctly interpreted what you meant then just repost with a bit more detail.

    Sopranino
     
  9. lucasc896 macrumors member

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    Jul 30, 2007
    #9
    It's not a seperate component system, it's just a regular off the shelf stereo system. So yes, in it there is an amplifier, but I still get the hissing sound. It's not a particularly expensive setup, so it's no way by far a pro audio system.
    Any ideas?
     
  10. chex macrumors regular

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    May 17, 2007
    #10
    i get the hiss when there is nothing playing, but it stops as soon as something starts playing.

    maybe it has something to do with the computer cutting power to the sound card when nothing is playing.
     
  11. DHagan4755 macrumors 6502a

    DHagan4755

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    #11
    Do you think that this might be adjustable in a firmware update? Does any one hear this hissing while booted into Windows via Boot Camp?
     
  12. Sopranino thread starter macrumors 6502

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    #12
    Okay, if you're getting hiss on the speakers then the impedance on the audio in line of the stereo is too low. An inline impedance gain device as mentioned in the article posted by dordal (see post # 6 above) will filter out the hiss.

    Sopranino
     
  13. Sopranino thread starter macrumors 6502

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    Alberta, Canada
    #13
    Actually the hiss is still there but it exists at a fairly low level so you probably won't hear it when playing back other sounds. Try turning the volume down while playing something back, as you get lower in the volume the hiss will more than likely become noticeable.

    Sopranino
     
  14. Sopranino thread starter macrumors 6502

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    #14
    Hmmm, I can't answer this with any sort of certainty. If I had to guess I would venture to say not likely, as a firmware update probably wouldn't have anything to do with the impedance level at the output jack. However I'm not an expert on this so anything is possible.

    As far as hissing when booting into Windows I can state with a reasonable degree of certainty that yes the hiss will be there as well simply because the issue is hardware related, not software. (I haven't run Windows myself so this is still just speculation...... anyone out there able to test this?)

    Sopranino
     
  15. aliquis- macrumors 6502a

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    May 20, 2007
    #15
    Scary that 50% says yes, is it there in all machines but only just a few hears it?
     
  16. Sbrocket macrumors 65816

    Sbrocket

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    #16
    I haven't noticed any audio distortion in but one song, and I have a feeling that's the audio file rather than my headphones. The headphones have an impedance of 32 ohms, so I doubt I would get the distortion anyways. I'm betting that everyone voting "Yes" on here has <32 ohm impedance on their headphones. You may want to try looking for a new pair with higher impedance if you're going to be using the MBP's built-in audio with headphones for a long time.
     
  17. aliquis- macrumors 6502a

    Joined:
    May 20, 2007
    #17
    I have the Alessandro (Grado) MS-1 which is 32 ohm. Guess I'll see how it goes. I don't expect perfect performance for integrated audio but on the other side it's a very new chipset so I still think it should had performed decent.
     
  18. Sopranino thread starter macrumors 6502

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    Alberta, Canada
    #18
    The sound should be a lot better than it is, my old PB G4 1GHz has an absolutely quiet audio output. I suspect that the cause behind this issue is hardware related and in specific probably relates to having incorrectly spec'ed resistors in the audio circuits output path.

    I do find it very interesting that so far the respondents to the poll are spit equally.

    If we get enough replies I will be able to send this to Apple support as an indication of a potentially wide spread problem.

    Sopranino
     
  19. Sopranino thread starter macrumors 6502

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    Alberta, Canada
    #19
    Using a higher impedance headset definitely filters out the audio artifacts, however the fact that the hiss and bleeping sounds are present on lower impedance headsets indicates that something in the audio path is not right. You should be able to use any headset/ear phones without getting extraneous sounds.

    Do you have a pair of lower impedance headphones that you can try? I would be interested in the result.

    Thanks

    Sopranino
     
  20. aliquis- macrumors 6502a

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    May 20, 2007
    #20
    I don't want ****** noice.

    Thought this AC97 **** on this msi ms-6702 sounds ok now when I'm used to it, but sounded like utter **** when I stoped using the audigy because ... uhm.. I guess I could say driver issues ;D
     
  21. vicious7 macrumors 6502a

    vicious7

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    #21
    Yeah, I also get some buzzing just before my cell phone rings but no hissing unless Im using earbuds.
     
  22. lauph macrumors regular

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    Jun 29, 2007
    Location:
    30 mins from Cupertino
    #22
    i plugged in my ipod headphones, and what i hear is like a tone generator, randomly generating a sine tone.
    After any kind of REAL audio, the tone would be random for like half a second, and will stay at that tone, kinda like alien spaceships in cartoons.

    so i would hear something like this after pausing some music:

    be di da de biiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii........

    and all the tones are within audiable range so i can hear them, and no matter what volume the master volume is at, the tones are at the same volume.
     
  23. XheartcoreboyX macrumors 6502a

    XheartcoreboyX

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    #23
    it only happened once to me while playing a game with loud voice under bootcamp..
     
  24. Sopranino thread starter macrumors 6502

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    Alberta, Canada
    #24
    Thanks vicious7. The buzzing from your cell phone is caused by RF interference and is actually not a flaw in the design of the computer, just about anything with an amplifier and a speaker attached will pick up a cell phone 'handshake' just prior to the phone ringing. You shouldn't have that problem with the phone moved a few feet away.

    As for the hiss that you are hearing that is a flaw in the computer audio hardware. I suspect that the impedance at the output jack is a bit too low. Are you also getting the 'R2D2' noises? (sort of random tones)

    Sopranino
     
  25. Sopranino thread starter macrumors 6502

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    Alberta, Canada
    #25
    Well, you definitely have the same symptoms as myself. Are you also hearing a hiss in your headphones?

    Sopranino
     

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