Monday, June 11, 2007

Macintouch review: audio noise in the new MacBook Pro

Thankfully we have Macintouch to warn us about these product design defects...
Macintouch Review: MacBook Pro (15" LED)

... Noise from the headphone port (first identified by a MacInTouch reader) is a real problem, which has three components, as we confirmed with sound-isolating headphones:

First, a very quiet hiss is present whenever the laptop is awake with headphones plugged in. It's on the same scale as the hiss we noted in the aluminum iPod Shuffle, so many people will never notice it.

A greater problem is a quiet but ubiquitous static. It is present only when the audio circuitry is working, and ceases within a second of pausing iTunes or QuickTime player. It is easily masked by music but shows itself during quiet passages.

The last component is an intermittent high-pitched noise. We've heard four distinct pitches, but never more than one at a time; it varies from a high tone to a faint whine. It goes away within five or six seconds of pausing iTunes; we believe this is when the audio circuitry turns off to save power. We cannot consistently cause the high pitched noise to happen, nor affect the pitch. We cannot trigger it with hard drive activity, spin-up or spin-down, display or keyboard brightness, or display activity. We assume it is caused by interference from other components within the machine.

These audio problems probably can't be solved without a hardware redesign, which is disappointing, given Apple's previous audio quality. If audio playback (or recording) is critical to your work, you'll need something like an external USB or FireWire audio interface...

A significant step backwards! The complexity of these RF environments must be daunting. I wonder if we'll eventually need to move the (power-demanding!) D/A converters to the headphones or stereo systems, so there's no analog output from the complex RF environment of the laptop ...


  1. The same noise that was described occurs with the new MacBook 2.2. Its specifically the second noise described, its very irritating

  2. I bought some new Sennheizer MX200 and the noise is very obvious! I've never really noticed it in my Unibody (Late 08) but now it's very irritating.

    Have you found any solution yet? Nowadays I'm rather listening music on my iPhone instead of the Macbook Pro.