Power Mac Noise Analysis

The new Apple Power Mac dual processor machines are getting to be notorious for being noisy. Unfortunately, the reports have not been consistent. None of the professional reviews that I have seen mention a noise problem. Some users report a problem, others don't notice anything unusual. Obviously, noise is a subjective issue, but I think part of the problem is likely that some machines truly are noisy.

After buying my own Power Mac MDD DP/1Ghz, I was shocked to find out how truly annoying these computers can be. It didn't take long before I was getting constant headaches. I started researching the noise issue on the second day. I put up this web page to share the information I have found.

I would highly recommend that everyone download the Amadeus tool from HairerSoft and record their own Power Macs. The resulting spectrum analysis may help you understand:

Whether or not you have a problem.
If you do have a problem, whether it's the case fan or the power supply fan. After all, what's the point of getting Apple to replace your power supply when it's your 120mm case fan that is making all of the ruckus?

There are instructions below for recording your own Power Mac, and then analyzing the results.

Recent Changes

02/08/2003	Added noise samples of my PowerMac MDD before and after mods.
12/20/2002	Added description of my experience with PAX.mate noise insulation.
12/15/2002	Added step-by-step instructions for power supply fan insert. (Warning: lots of graphics)
12/09/2002	Added analysis of second power supply fan insert.
12/08/2002	Revamp and add analysis of relativel decibel levels
12/01/2002	First web page.

Noise Analysis

Links to information and research that I have done on the noise issue:

Recording	Step-by-step instructions for recording your Power Mac noise for analysis.
Analyzing	Analyzing the noise that you recorded.

My Modifications

Describes modifications I have made to my Power Mac:

Fan Mods	Describes power supply and case fan replacements. Leather inserts to dampen vibration.
Insert Instructions	Instructions for putting in the power suppy fan insert. (Warning: lots of graphics)
PAX.mate	My experience with PAX.mate noise insulation.
History	A summary of what I have tried with my Power Mac

Noise Samples

MP3 recordings of my MDD before and after modification. Decide for yourself if it's worth it.

PowerMac 2 Before	Second PowerMac MDD unmodified. Quieter than first MDD.
PowerMac 2 After	With Thermaltake fans, leather padding, PAX.mate noise insulation, and Papst 120mm fan.
PowerMac 1 Before	First PowerMac MDD with Thermaltake fans. I never measured the original unmodified.
PowerMac 1 After	With Thermaltake fans, leather padding, and Panaflo 120mm fan.

Resources

Links to additional information about the Power Mac noise issue:

Amadeus	Shareware tool that I have been using for noise analysis.
Yahoo G4Noise	New Yahoo group to discuss Power Mac noise issue. Best place for discussion.

Retailers

Some web sites that I found useful for locating fans and such:

Directron.com	Lots of fans plus a section for quiet fans.
KD Computers	Where I bought my Panaflo 120mm case fan and PAX.mate noise insulation.
Plycon	Home of Magic Fleece noise insulation.
Silicon Acoustics	Carries quiet fans, although not a lot of selection.

Goal

It's very frustrating to spend thousands of dollars on what is supposed to be a no-compromise computer from Apple and find such a major flaw. The noise was so annoying that I frantically searched for solutions the very day after I purchased it. I don't know that I would have been able to use the computer the way that it was. It was that bad. Luckily, I found some an excellent description of a power supply modification to quiet my beast. Within a few days, I was able to start enjoying my Power Mac.

This web page is my contribution and a thanks to those who helped me out. I realize a lot of the work here is speculation, but hopefully it will generate the discussion necessary to get concrete solutions. If we are lucky, hopefully all of these web pages will be obsolete someday. Wake up Apple and listen to our computers!

Contact

If you would like to discuss the results or let me know about your own experiments, you can email me at (Chun Hsu) hsuc@centurytel.net.