I've been doing quite a lot of research on the 'static issue' that affects the new Santa Rosa MacBook Pros, and I have some things to report:
The Problem
The issue has three components, as described in this MacinTouch Report:
- A low hiss that is constant whenever the audio circuitry is on
- Static that occurs whenever anything is playing... even something quiet.
- A series of high-pitched noises that occur somewhat randomly. The best comparison I've seen is that it's like listening to those hearing tests where you raise your hand when you hear a tone.
The problem only occurs with low-impedance headphones (more on this below).
Some Facts
- The problem occurs on ALL Santa Rosa MacBook Pros, 2.2 and 2.4 GHz. It is a design flaw on Apple's part, and returning your machine for a new one will not help. There are plenty of people who say they can't hear the noise, but those people either have high-impedance headphones or speakers, or just don't have very good hearing.
- Only Santa Rosa MacBook Pros seem to be affected by this particular static problem. I've seen some reports of other machines having audio issues, but they are always different.
- The 'Audio Update 2007-001' that Apple released about two weeks ago doesn't fix it. It does fix a popping problem on all Intel Macs (including the SR MBPs), so it's worth installing, but that is a different problem than this one.
- It does seem to be an Apple-specific problem; I've been unable to find any other reports of non-Apple Santa Rosa notebooks having the same problem.
The Story on Impedance
The problem only occurs with low-impedance headphones, such as the Shure 3EC or the Etymotic ER-4P, which both have a 1KHz impedance of about 26 ohms. Impedance is a rather complicated subject, but roughly translated it is the resistance that the headphones exhibit to the audio circuitry when they are plugged in. The audio circuitry puts out a certain amount of power; a low resistance means more of that signal to be translated into sound, which means the sound is louder. A high resistance (impedance) means less signal is translated into sound, and the volume is lower at any given power level.
Why does all this matter? Well, because the flaw in the audio circuitry is always there, but is only detectable with lower-impedance headphones (remember, these are louder for a given power level.) The high impedance headphones mask the problems. You've still got the same static; you just can't hear it.
The Fix
The fix is actually surprisingly easy: all you need to do is increase the impedance of your headphones! To do this, you'll need to either buy or make an adapter. I chose to buy one, the Shure Level Attenuator Volume Control EA650. Cheapest I could find it was from some guy on eBay. Shure makes good quality products, and at $14 shipped it's not that expensive. It connects between your computer and your headphones, and only a quarter turn on the volume knob eliminated the hiss and static for me.
You can also make one of your own, following the directions on head-fi.org.
I do hope Apple will own up to this problem and fix the audio on the motherboards, but I don't think it's likely. With the yellow screen and whatnot, they've got bigger fish to fry.
The Problem
The issue has three components, as described in this MacinTouch Report:
- A low hiss that is constant whenever the audio circuitry is on
- Static that occurs whenever anything is playing... even something quiet.
- A series of high-pitched noises that occur somewhat randomly. The best comparison I've seen is that it's like listening to those hearing tests where you raise your hand when you hear a tone.
The problem only occurs with low-impedance headphones (more on this below).
Some Facts
- The problem occurs on ALL Santa Rosa MacBook Pros, 2.2 and 2.4 GHz. It is a design flaw on Apple's part, and returning your machine for a new one will not help. There are plenty of people who say they can't hear the noise, but those people either have high-impedance headphones or speakers, or just don't have very good hearing.
- Only Santa Rosa MacBook Pros seem to be affected by this particular static problem. I've seen some reports of other machines having audio issues, but they are always different.
- The 'Audio Update 2007-001' that Apple released about two weeks ago doesn't fix it. It does fix a popping problem on all Intel Macs (including the SR MBPs), so it's worth installing, but that is a different problem than this one.
- It does seem to be an Apple-specific problem; I've been unable to find any other reports of non-Apple Santa Rosa notebooks having the same problem.
The Story on Impedance
The problem only occurs with low-impedance headphones, such as the Shure 3EC or the Etymotic ER-4P, which both have a 1KHz impedance of about 26 ohms. Impedance is a rather complicated subject, but roughly translated it is the resistance that the headphones exhibit to the audio circuitry when they are plugged in. The audio circuitry puts out a certain amount of power; a low resistance means more of that signal to be translated into sound, which means the sound is louder. A high resistance (impedance) means less signal is translated into sound, and the volume is lower at any given power level.
Why does all this matter? Well, because the flaw in the audio circuitry is always there, but is only detectable with lower-impedance headphones (remember, these are louder for a given power level.) The high impedance headphones mask the problems. You've still got the same static; you just can't hear it.
The Fix
The fix is actually surprisingly easy: all you need to do is increase the impedance of your headphones! To do this, you'll need to either buy or make an adapter. I chose to buy one, the Shure Level Attenuator Volume Control EA650. Cheapest I could find it was from some guy on eBay. Shure makes good quality products, and at $14 shipped it's not that expensive. It connects between your computer and your headphones, and only a quarter turn on the volume knob eliminated the hiss and static for me.
You can also make one of your own, following the directions on head-fi.org.
I do hope Apple will own up to this problem and fix the audio on the motherboards, but I don't think it's likely. With the yellow screen and whatnot, they've got bigger fish to fry.
