Previous 1 2 Next 23 Replies Latest reply: Feb 11, 2010 7:58 AM by k4muro
David Hagan Level 1 Level 1 (80 points)
Hi everyone,

When I listen to certain audio, there's some distortion. I do not hear the distortion on the same audio with my iMac G5 and previous generation MacBook Pro. Is this something specific to my new MacBook Pro, or is it something specific to the new unibody models? It seems like the dynamic range of the headphone jack is limited.

Is anyone else experiencing this?

17" MacBook Pro 5,2, Mac OS X (10.5.6), 4 GB RAM, anti glare
  • iVmichael Level 6 Level 6 (13,725 points)
    Probably worth checking /Utilities/Audio MIDI Setup, select the Output/Headphone device then make sure the Format is set at 44Hz 2ch-16bit

  • sgginc Level 3 Level 3 (665 points)
    Any reason why it should not be 20 or 24 bit (also options)?

    Thanks ... Ken
  • David Hagan Level 1 Level 1 (80 points)
    Hi Michael,
    Thanks for your help here. I put the setting to 16-bit (from 24-bit) and it made no difference. Coldplay's "Lost?" is a good example. On my older MacBook Pro 2.2GHz, I can listen to the song at .74 (-9db) and it sounds fine, but on my new MacBook Pro it sounds scratchy especially with the piano. Basically anything where piano is the dominant instrument has the potential for distortion. Certain dialog scratches too at the higher volumes. I'm using Sony MDR-7506 headphones which I regard as pretty decent for monitoring sound. So I don't know if this is something that I need to call Applecare about or whether it's just how the new unibodies are? Regardless, it's disappointing.
  • Wills_Crump Level 1 Level 1 (0 points)
    I'm having problems too. I am using Sennheiser HD25s which are industry standard headphones and they work on my ipod touch. I find some audio is distorted and the balance in the mix when I have my headphones plugged in is changed - the mids are there, but it lacks the response in the bass and there is some distortion/volume level problem on spoken word audio.

    Any advice please?
  • Hunter09 Level 1 Level 1 (0 points)
    Yes, I play itunes on my MacBook Pro through a Bose L1 Model 2 PA system and it sounds generally horrible. I also have been using several macbooks and ipods through this system and they sound fine. I have adjusted all parameters with itunes output controls and system preference sound controls and it still sounds bad. It helps when I lower the input levels but the distortion is still present. It happens with recently purchased apple store music along with cd's copied to itunes. My iphone plays back with much better sound. Any solutions?
  • Hunter09 Level 1 Level 1 (0 points)
    Hi Again

    I would like to note that the sound coming out of my internal speakers sound ok. The sound quality is really noticeable when you send the signal from the earphone jack out to an external powered speaker system.
  • David Hagan Level 1 Level 1 (80 points)
    I'm wondering if this is a problem with the chipset?
  • David Hagan Level 1 Level 1 (80 points)
    No one else?
  • Wills_Crump Level 1 Level 1 (0 points)
    I've discovered it may have something to do with the Magsafe adapter. When the laptop's on battery there's no distortion. The distortion only starts when I plug the Magsafe in. Sounds like it's not grounding properly but I've had no electric shocks yet.

    Is this the case with everyone else?
  • handikap1210 Level 1 Level 1 (0 points)
    I'm having the same issue with my new MacBook pro. I bought it in December. It must be something with the output impedence. It only happens when I'm connecting to an external sound system/mixer. I will look into this immediately!
  • marco538 Level 1 Level 1 (0 points)

    I've recently bought myself a new MacBook Pro (alu body) and experienced the same problems.

    I've tried everything, but eventually I found out that it was a hardware probem (motherboard) and the Apple reseller had to replace the motherboard.

    I think that Apple did business with a questionable supplier, but doesn't want to publish this. I've seen a lot of similar problems on different discussion groups handling about the same (noise distortion), so I guess this is a typical production problem with a large number of MacBook Pro's .

    My advice: go back to your reseller and ask them to replace the motherboard.

    Kind regards,
  • David Hagan Level 1 Level 1 (80 points)
    I went to the Apple Store near me earlier this evening. I brought my Sony pro headphones. All of the other MacBook Pros on display had the same audio distortion problem. I called Applecare when I got home and explained the situation. The tech there said I should write to So I filed a bug report and left my contact information so they will hopefully get in touch with me. I hope that everyone here with the same problem files a feedback report with Apple.
  • Pancenter Level 6 Level 6 (9,055 points)
    Sorry to say that Apple is definitely using cheap components compared to their older machines.

    Antime you see Realtek audio, beware!

  • handikap1210 Level 1 Level 1 (0 points)
    Well, I finally went in to the genius bar to submit my Macbook Pro for this repair. I couldn't recreate the problem in the store? I never checked this issue after upgrading to 10.5.8. As far as I can tell, Apple has addressed the problem. The "genius" at the store had never heard about this problem before and I looked like an idiot. I was using apple earbuds in the store when I was trying to recreate so now I need to do some tests when hooked up to my mixer and sound system, as that is when it was most apparent. I also upgraded to iTunes 8.2.1 so I'm not sure which update helped.
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