avatarvorti.blogg.se - Parabolic sound reflector

Because the gain increases with increasing frequency, the output of a parabolic microphone has a high-pass characteristic. Note that the D and gain G provided by a dish are proportional to the square of the ratio of its diameter to the wavelength. It’s often expressed as the Directivity Index (DI), which is the ratio D expressed in dB. The Directivity (D) is defined as the ratio of the on-axis response to the response averaged over all directions. Therefore, if a microphone element is mounted at that focal point, it will receive all of the acoustic power received by the entire dish, which results in significant acoustic gain and directivity:įigure 1: Sounds arriving along a parabolic reflector’s axis of symmetry are concentrated at its focus

This is possible because, as shown in Figure 1, a parabolic reflector (or “dish”) has the property that a sound wave striking it from the on-axis direction-regardless of where on the dish it strikes-will be reflected to a specific focal point determined by the shape of the dish. This attribute is called directivity, and it’s the key to long-range pick-up because it attenuates off-axis noise that competes with the target sound.

More importantly, the acoustic gain decreases as the sound’s angle of arrival deviates from the axis of symmetry.

It provides acoustic gain for sounds arriving along the reflector’s axis of symmetry.

The reflector increases the microphone’s pick-up range in two ways:

References How parabolic microphones workĪ parabolic microphone consists of a microphone element mounted at the focus of a parabolic reflector.

Parabolic microphones versus other directional microphones.

Parabolic microphone design considerations.

What's the maximum useful range of parabolic microphones?.

The Klover MiK 09: can a small parabolic microphone outperform a shotgun microphone?.

I bought a small parabolic microphone for just 40 dollars off the web, and it really works…sort of.

The complete guide to parabolic microphones.

A deep look at how shotgun microphones REALLY work.

Predicting microphone performance-Part 3: microphone range prediction.

Predicting microphone performance-Part 2: using the SINR.

Predicting microphone performance-Part 1: what is microphone SINR?.

The 4 key microphone specifications and why they’re important.

The 7 best microphone elements for cost-effective DIY microphones.

Why you shouldn’t rely on microphone plug-in power.Basic DIY microphone design-Part 3: microphone back-end design.Basic DIY microphone design-Part 2: microphone front-end design.Basic DIY microphone design-Part 1: the microphone design process.