X-Y interchangeable capsule heads
The X-Y system supports interchangeable capsule heads in configurations from two to four capsules:
- stereo: 120º
- three-channel: 90º
- four-channel 2D surround: 90º
- four-channel 3D surround (ambisonic): 120º
X-R capsules with male RCA plug output may be directly attached to the heads, or extended via RCA adaptor accessories or extension cables. A complete range of stereo and surround recording techniques are thereby enabled; including coincident, near-coincident, and spaced stereo, as well as combination of coincident and spaced microphone pairs, binaural, Blumlein, 2D, and 3D (ambisonic) surround.
Various stereo recording angles may be achieved by using RCA adaptor accessories between the capsules and capsule heads. The capsule spacings and stereo recording angles with each adaptor are as follows (click on spacing for image):
Stereo Recording angle
|Capsule on head||Coincident with
with Y adaptor
|With Y adaptor||With male &
90º, standard capsule
120º, standard capsule
180º, standard capsule
90º, short capsule
120º, short capsule
180º, short capsule
* omnidirectional capsules do not resolve a stereo recording angle of less than 180 º at less than 55cm spacing. However, when used with the equalization disc, the resulting polar response becomes subcardioid at frequencies above 3kHz. Thus, the recording angles shown for the omnidirectional capsule with equalization disc are derived for a subcardioid polar pattern.
Two X-R capsules may be connected to a single input with the RCA Y adaptor, which will mix the two signals from the capsules. When used with an RCA extension cable, the Y adaptor mixes two discrete sources into a single microphone channel. Also, the Y adaptor may be used to blend an omnidirectional capsule with a directional capsule. This technique is especially useful with the acoustic low-pass filter, yielding a hybrid pattern with a directional high-frequency response and an omnidirectional low-frequency response.
The X-Y capsule amplifier may be supplied with a TB4M input connector, which allows connection to the interchangeable capsule heads. The interchangeable capsule head output uses a TA4F connector with the following pin configuration (3D surround):
pin 1: white RCA jack, left (front left up),
pin 2: red RCA jack, right (front right down)
pin 3: black RCA jack, front (back left down)
pin 4: yellow RCA jack, back (back right up)
These pins will be routed to the output pins on the X-R or X-Y capsule amplifiers with XLR-5-M (-3-M) output, as follows:
pin 1(1): ground
pin 2: black
pin 3(3): white
pin 4: yellow
pin 5(2): red
When used on the four-channel 3D head, the short cardioid capsules have 4cm radius from the center of the head. The capsule head output given above is “A” format. This output must be mixed to “B” format (bidirectional response on three axes, plus omnidirectional) for further processing, using the matrix:
W (omnidirectional) = FLU + FRD + BLD + BRU
X (front to back) = FLU + FRD – BLD – BRU
Y (left to right) = FLU – FRD + BLD – BRU
Z (up to down) = FLU – FRD – BLD + BRU
The resulting ambisonic frequency response requires correction. The recommended filters (low-frequency shelving, notch, and high-frequency shelving) to decode to B format are as follows:
W filters: +9dB shelf @ 120Hz; -7dB notch (Q=1) @ 5kHz, +9dB shelf @ 11kHz.
XYZ filters: +9dB shelf @ 120Hz; -11dB notch (Q=1) @ 4.5kHz.
Note that the low frequency shelving boost is not recommended for recording distances of less than 1m.
|Dimensions||1.5 × 1.5 × 1.5 in|