The CE Mark - What Does it Mean, and Why Should I Care?
By John Siau
Many electronic products have a "CE" mark affixed to the product label. This mark is mandatory in European markets, but is not required on products sold elsewhere. Few people understand what this mark means and why it is important. It is often a good idea to look for this mark when purchasing a product outside of Europe.
The CE mark is the manufacturer's declaration that the product has passed a comprehensive set of tests to evaluate the ability of the product to operate in close proximity to other electronic products without causing interference. Today, our homes and offices and studios are filled with a variety of electronic gear. Some work well together, but some do not.
Interference
You are about to introduce one more piece of electronic gear to your audio system. Will it cause interference with other components? Will your existing components degrade the performance of the new component? If your new piece has a CE mark, it shows that the manufacturer has addressed some of these issues.
Advertised performance, (the performance of a product in an ideal environment) may not be possible in your environment. The ideal conditions of a manufacturer's test bench may not be replicated in your installation. If the product is a well-designed professional product it should still deliver the advertised performance. If the product is classified as a consumer product, the CE standards allow some loss of performance.
We have all experienced radio or TV interference caused by a power tool running in another room. We may be less aware of other interactions that occur between all of our electronic gadgets. Cell phones may cause bursts of low-level noise from speakers. WiFi signals may mysteriously drop out when certain devices are turned on. Your audio system may produce unexpected pops, clicks, and buzzes - all due to interactions between electrical devices. Audio products with a CE mark may be far less prone to this sort of problem, especially if they are classified as "professional audio products".
Consumer vs. Professional
The CE test standards distinguish between professional and consumer audio equipment. Professional products must withstand high levels of interference and must do so without a loss of performance. In contrast, consumer products are held to a much lower susceptibility standard. Consumer products are exposed to lower levels of interference during testing and are even permitted to malfunction in the presence of this interference - as long as no permanent damage is sustained. The CE standards recognize that a momentary burst of noise from a desktop computer speaker may be acceptable to consumers, but a similar burst of noise from a professional studio monitor would be unacceptable to a recording engineer.
Immunity and Emissions - Two sides of the interference problem
The CE standards define separate tests for "immunity" and "emissions". The immunity standards define how much radio, magnetic, electrostatic, and power-line interference a product must withstand. The emissions standards define how much radio, magnetic, and power-line interference a product can emit. The test limits vary by product type and by operating environment.
Operating Environment
The CE standards define five distinct operating environments. Products must be tested to operate in at least one of these environments.
CE test environments are defined as follows:
- E1 - Residential Environment
- E2 - Commercial and Light Industrial (e.g. theaters)
- E3 - Urban Outdoors
- E4 - Controlled EMC Environment (purpose-built broadcasting or recording studio)
- E5 - Heavy Industrial
Immunity standards increase as we progress from E1 to E5. In contrast, Emissions standards are more lenient as we progress from E1 to E5.
If we focus on immunity, E5 products have the toughest requirements. In contrast, if we focus on emissions, E1 products have the toughest requirements.
Products that are designed for a residential (E1) environment may fail to operate in a heavy industrial (E5) environment. Likewise, heavy industrial equipment often emits far too much interference for a home environment. Products must be designed and tested for the environment in which they will operate.
Questions
The differences between professional and consumer test standards may prompt the following questions:
- Should I buy a professional or consumer product?
- Is it OK to use a professional product in my home?
- Is it OK to use a consumer product in my studio?
The answer to all of the above questions is that the product needs to be designed for the environment in which it will be used. Benchmark products are classified as professional audio products. This classification subjects our products to much higher immunity standards than typical consumer products. But, we also test for consumer (E1) environments and this subjects us to the strictest emissions standards. This combination (professional product in an E1 to E4 environment) holds Benchmark products to the highest standards.
We could choose to only test for an E4 environment (recording studio), but we recognize that many of our professional products find applications in high-end home Hi-Fi systems. For this reason, Benchmark tests for environments E1 through E4.
What About Environment E5?
Please note that Benchmark products are not rated for environment E5 (heavy industrial). Beware, the performance and longevity of your Benchmark product may suffer if you try to operate it in close proximity to an arc welder.
Summary
Products must be designed and tested for the environments in which they will be used.
Benchmark products are tested to perform to professional standards in environments E1 through E4, making them well suited to professional and home applications.
Also in Audio Application Notes
Interpolator Overload Distortion
Most digital playback devices include digital interpolators. These interpolators increase the sample rate of the incoming audio to improve the performance of the playback system. Interpolators are essential in oversampled sigma-delta D/A converters, and in sample rate converters. In general, interpolators have vastly improved the performance of audio D/A converters by eliminating the need for analog brick wall filters. Nevertheless, digital interpolators have brick wall digital filters that can produce unique distortion signatures when they are overloaded.
10% Distortion
An interpolator that performs wonderfully when tested with standard test tones, may overload severely when playing the inter-sample musical peaks that are captured on a typical CD. In our tests, we observed THD+N levels exceeding 10% while interpolator overloads were occurring. The highest levels were produced by devices that included ASRC sample rate converters.
Audiophile Snake Oil
The Audiophile Wild West
Audiophiles live in the wild west. $495 will buy an "audiophile fuse" to replace the $1 generic fuse that came in your audio amplifier. $10,000 will buy a set of "audiophile speaker cables" to replace the $20 wires you purchased at the local hardware store. We are told that these $10,000 cables can be improved if we add a set of $300 "cable elevators" to dampen vibrations. You didn't even know that you needed elevators! And let's not forget to budget at least $200 for each of the "isolation platforms" we will need under our electronic components. Furthermore, it seems that any so-called "audiophile power cord" that costs less than $100, does not belong in a high-end system. And, if cost is no object, there are premium versions of each that can be purchased by the most discerning customers. A top-of-the line power cord could run $5000. One magazine claims that "the majority of listeners were able to hear the difference between a $5 power cable and a $5,000 power cord". Can you hear the difference? If not, are you really an audiophile?
Making Sound with Plasma - Hill Plasmatronics Tweeter
At the 2023 AXPONA show in Chicago, I had the opportunity to see and hear the Hill Plasmatronics tweeter. I also had the great pleasure of meeting Dr. Alan Hill, the physicist who invented this unique device.
The plasma driver has no moving parts and no diaphragm. Sound is emitted directly from the thermal expansion and contraction of an electrically sustained plasma. The plasma is generated within a stream of helium gas. In the demonstration, there was a large helium tank on the floor with a sufficient supply for several hours of listening.
While a tank of helium, tubing, high voltage power supplies, and the smell of smoke may not be appropriate for every living room, this was absolutely the best thing I experienced at the show!
- John Siau