The Sanken CUB-01 offers a totally new design that overcomes the limitations of previous boundary microphones. Generally speaking, most boundary microphones have almost the same sound characteristics, heard as "thin," "solid," and "metallic." Using Sanken's advanced technology, the CUB-01 has resolved this problem with its unique square-shaped cardioid capsule. This proprietary design significantly enlarges the effective area of the diaphragm, resulting in a boundary microphone whose sound is rich and natural, with a flat response to 70Hz. Now it is possible to capture a "full bodied" and "clear" sound - human narration and dialogue are clearly caught while excluding unnecessary background noise.

The CUB-01 is available in gray or beige and in two versions - the standard high performance CUB-01 which runs on 48volt phantom and the CUB-01-PT ( pigtail ) version. The PT version will operate on 3 to 10 VDC for wireless applications.

Theory of Boundary Microphones
There are at least two paths of sound waves from a sound source to a microphone. One is a direct route from the sound source ( D1 ), while another is sound reflected from the floor between the sound source and the microphone ( R1 ). Obviously, sound D1 reaches to the microphone earlier than sound R1. As a result, sound waves through the R1 route have a "time delay." The sound waves via D1 and the "delayed" sound wave (R1) will be combined at the microphone. In this case, the delay of mid and low frequencies will not be as heavily affected because of the their long wavelength. In case of high frequencies, the time delay between D1 and R1 is critical because of its much shorter wave length. In the high frequency range, the time delay of two sound waves creates a cancellation between the two. This is known as "comb filtering." When we think about this phenomenon as rms sound energy, we can see that energy in the high frequency range decreases considerably when compared to the mid and low frequencies. As frequency increases, energy decreases.

When we place a microphone "on the floor," with virtually no distance between the microphone transducer and the reflecting floor surface, most of the sound waves from the sound source to the microphone follow the one direct route. Theoretically, there is no reflected route with this type of mic positioning, and thus no time delay and, consequently, no comb filtering even in the high frequency range. This means that sound energy in the high frequencies is identical with the mid and lows. This is the basic theory of a boundary microphone.