• April 21, 2004: I reported this problem to Logitech Support (via phone). I was asked to send my MX310 and MX510 mice to Logitech in Fremont, California. Shortly after the report, I had the opportunity to test a MouseMan Dual Optical, only to find that it also exhibited the noise problem, but sounded a bit different (the noise sounds remarkably like a mix of bus noise and the "high pitch" tone some people hear coming from televisions).
• April 28, 2004: I received my original mice, in addition to a typed letter from a Logitech manager stating there was in fact no problem. In lieu of having my mice back, I decided to void the warranty on my Logitech MX500 (which exibited "cursor jitter" anyways) and open it up to try and find the noisy part.
• May 2004: [section about Customer Support Manager unprofessionality removed per request of Logitech]
• May 13, 2004: I purchased a Microsoft IntelliMouse Explorer 4.0 (yes, with the tilt wheel). Giddy with hope that it wouldn't emit an identical noise, I plugged it in to find that it didn't. This confirms that the noise being emitted is specific to Logitech mice, and that the noise has nothing to do with the host PC, faulty USB ports, or end-user error.
• April 28, 2005: Tested Logitech MX518 Gaming-Grade Optical Mouse (first generation P/N).
• April 29, 2005: Filed an official Support Request with Logitech Support (Case #050429-000058). However, due to the previous dealings I had with Logitech and the Support Manager who denied there was any problem with the mice, I am unable to communicate with Logitech in any way. I am being asked to fax all communications through Logitech's legal department in Fremont. I am also not allowed to publicly disclose the aforementioned Support Managers' name or divulge any of his contact information. At this point, I have now done everything I can to bring this matter to Logitech's attention. My hands are tied; I cannot communicate with Logitech due to their legalities and strict communication policies. I urge users and owners of any of the aforementioned Logitech mice to contact Logitech Support, open a support case, and put pressure on Logitech to acknowledge this engineering flaw. Document everything you do, in the case that what happened to me happens to you (re: legal threats and what not). Please be respectful and kind to Logitech's telephone and online Support staff — the flaw has nothing to do with them, they're just doing their job. But please make it clear to them that this issue is quite major, as it could possibly lead to a class-action lawsuit due to the health problems it can cause (damage to hearing, induced headaches, and possible nausea).
• November 22, 2005: Tested Logitech G5 Laser Mouse (single side button version).
• September 29, 2006: Good news! I've had two electrical engineers (one mid-level, and one professional) examine multiple Logitech mice. Both engineers agree that the noisy part is the IR transmitter (not receptor) that is being used inside of these mice. See the Workarounds section for details.
• May 2, 2007: Tested Logitech MX400 Performance Laser Mouse and Logitech LX3 Optical Mouse.
• June 6, 2007: Tested Logitech G5 Laser Mouse (dual side button version). This seems to be a good alternative; the noise is still there, but decreased greatly.
• June 7, 2007: I've decided to keep the Logitech G5 Laser Mouse (dual side button version) to see if the level of noise increases over time with scroll wheel use.
• July 7, 2007: Logitech G5 Laser Mouse (dual side button version) still being used; noise remains at a tolerable level. For those wanting an MX510/518 replacement, consider this mouse instead. However, there are two major negatives to this mouse: the side buttons are incredibly soft and are easily pushed (I prefer the MX510/518 buttons), and the tracking/speed is very different from the MX510/518. I've also had issues with this mouse moving on its own (my screen saver turning off without anyone at the computer), which appears to be caused by my mouse pad.
• August 22, 2007: Tested Logitech MX518 Gaming-Grade Optical Mouse (second generation P/N) and Logitech Optical Mouse.
• August 23, 2007: Attempt at surgery: replacing LD1/LQ1 in an MX518 with parts from the Logitech Optical Mouse. Findings: using LD1/LQ1 from the Optical Mouse does not solve the problem. Noise is definitely being emitted by LD1, but the reason the noise is being emitted is still unknown. I really need some a low-level EE person to find the reason for the noise, and a proper solution. If you're someone with an EE background who wants to make some money on the side researching and engineering a workaround for this problem, contact me. I will be more than happy to pay you a more-than-reasonable amount (US$30+/hr) assuming you're skilled and are dedicated. I will also purchase the mice for you to work on and repair.
• August 27, 2007: Tested Microsoft Habu Laser Gaming Mouse (for comparison). Completely silent, as all of Microsoft's other mice are. It also has some awesome features (relocatable side buttons); too bad I *hate* the tracking speed, and refuse to install the incredibly bloated Habu configuration utility.
• August 29, 2007: Tested Microsoft Natural Wireless Laser Mouse 6000 (for comparison). Completely silent. The mouse is fairly atrocious to hold, though; it's comfortable in the hand, but the side buttons are nearly impossible to reach (placed too high). I also have a great dislike for mice with scroll wheels that move horizontally, and I'm not very fond of wireless mice. Regardless, this just goes to show that even the wireless ones from Microsoft do not emit noise.

Read the article IGN wrote about this problem.

From my experiences with some other manufacturers' speakers (such as Klipsch), I can attest to the "idle hiss" problem usually being the result of the default gain (either hard-wired, or possibly controlled via a potentiometre inside of the amplifier) being set WAY too high. Another example of the "louder is better" mentality that the audio industry has been pushing for many years.

Members of the forum Gathering of Tweakers, specifically Het Logitech PLOPJES probleem topic Deel 4, started this topic in the Netherlands due to an overwhelming number of complaints concerning noise issues regarding Logitech Audio Systems. This involves, in particular, the Z-5500 and X-530 speaker set, but other Logitech audio models may suffer from these issues.

The issues are as follows:

1. "Popping" noises from the speaker system. When light switches, blenders, fridges or other electrical appliances are switched on or off, a very loud and disturbing "popping" noise is generated in the audio systems. Sometimes the volume of this "pop" is at such a loud level, that you do not want to be in the same room when it occurs.
2. An irritating permanent 'humming noise' coming from the subwoofer.
3. And in some occasions the speaker picks up radio signals that can be heard, without any other appliances connected.

Since most people do not realize that the problems are part of their Logitech speaker system, they usually blame their indoor electrical system or other electrical appliances. This idea was (and still is) stimulated by the things mentioned in the customer support (FAQ 3629 and 3630) section on Logitech's website. As a result, many people are buying EMI filters, which of course do not provide a solution. Some members have started the initiative and contacted Logitech about these issues in order to solve the problems. At first, Logitech even denied that a problem existed which affected their speaker systems. However, a few members, who are qualified engineers, did investigate the Z-5500 and some other audio models and figured out exactly what is causing the noise problems. With some minor modifications they managed to solve almost completely the noise issues.

It became very clear that the noise problem is a result of a design error and affects not only the Z-5500 and the X-530, but also other Logitech audio models. There is no doubt that the Logitech design staff has repeatedly underestimated the importance of a proper shielding of the respective audio units. May we point out that it is common knowledge that a proper shielding of audio equipment is essential, in order to avoid noise problems.

However, it took an incredible 5 months for Logitech to accept this fact. Due to our efforts Logitech was not able to deny any longer that a serious problem exists regarding their audio units. Since Logitech showed no initiative at all to change their FAQ section, we had to press hard for Logitech to do so! As a result the FAQ were somewhat altered and a refund policy, concerning the Z-5500 as well as the X-530, is offered.

Logitech claims this problem is a "manufacturing issue", and not an engineering design flaw.

Now, 10 months later, after many emails, phone calls, meetings, prototype testing and even some visits of members of Logitech's Technical staff (to test some experimental units at the homes of members), the aim of this matter, a popping free Z-5500 speaker system has been obtained!

For X-530 Surround-Sound Audio customers who experience this problem and have not found a suitable solution with our Customer-Support staff, Logitech is offering the option of a refund on the purchase price.

Logitech believes that the noise (popping) problem is very localized and only concerns The Netherlands and Belgium. However, this is a far cry from the reality. By using Google it is not very hard to find many, many, forums (worldwide) that are related to this "popping" problem.