Best Paper in Show

Positive Feedback Online has named Audio-Technica’s presentation at the 125th Audio Engineering Society (AES) conference Best Paper in the Show.


Positive Feedback Online has named Audio-Technica’s presentation at the 125th Audio Engineering Society (AES) conference Best Paper in the Show.

Scott Dorsey writes in the online audio journal: “Down in the papers sessions, a team of folks from Audio-Technica consisting of Mark Zaim, Tadashi Kukutani and Jackie Green, were talking about a study called 'Phantom Powering the Modern Condenser Microphone: A Practical Look at Conditions for Optimized Performance.' This is a great study, because it looks at something ‘everybody knows’ and defines what is really going on. … This is precisely the kind of thing that I go to the AES show to find out about.”

Audio-Technica’s Senior Process/Product Design Engineer Mark Zaim summarizes the A-T findings:

The basis for this study stemmed from complaints by industry as well as amateur recording engineers regarding poor performance when multiple phantom powered microphones were used at the same time. While this was not a factor years ago, modern live-sound reinforcement setups now use many condenser microphones in settings that were previously dominated by dynamic microphones. We felt the need to study this further and really understand what is happening between the microphone and mixing console phantom power interface. We accomplished this by studying the requirements of microphones in typical multiple-mic and high-sound pressure level (SPL) settings in order to gain understanding of circuit and design requirements for maximum performance.

In this study we examined five popular live-sound mixing consoles supplying 48 volt phantom power and five condenser microphones frequently used in live-sound settings. These covered a wide price range from a few hundred dollars to almost $20,000 for the mixers and the hundred dollar range to almost $1500 for the mics. We wanted to cover the wide spectrum of available equipment.

We looked at the following important parameters essential to optimum performance: current draw, phantom power stability, common mode noise, and equivalent input noise.

We found some very interesting and surprising results. The biggest performance variation involved equivalent input noise (EIN). Tests showed a large discrepancy between manufacturers’ published EIN figures and measured values so we recommend that console manufacturers should specify equivalent input noise figures in a more meaningful manner and under real world conditions.

All of the consoles, including the most expensive, had high common mode noise figures in the range of 60dB higher than microphone self noise levels (a thousand times higher). One console even had a tremendous amount of crosstalk. So our recommendation is that console companies should focus on improving common mode noise figures and minimizing crosstalk in their designs.

Another interesting discovery was that some mics performed better under the same conditions so microphone manufacturers should take note: diligent circuit design can help minimize the effects of weaknesses or variations in the phantom power supplied to their microphones.

We also did some measurements relating to phantom power supply performance and input impedance. We saw a significant variation in dynamic range and Max SPL figures but this topic was too large to cover in this paper and will be covered in detail in an upcoming paper.

We feel this is an important first step in understanding real-world conditions under which many modern condenser microphones are used and improving the overall experience for the end user.

Access the entire paper through the Audio Engineering Society website at http://www.aes.org/publications/preprints/. Locate the article at that site by searching its number (7594) or title (Phantom Powering the Modern Condenser Microphone: A Practical Look at Conditions for Optimized Performance). The cost: $5 for members; $20 for others.