The Acoustic Pressure Equalizer Ball for d:dicate™ 4006A Omnidirectional Microphone is a sphere shaped Acoustic Pressure Equalizer. It comes in three sizes and can be used for the microphone or the stereo kit.
Depending on the size of the Acoustic Pressure Equalizer Ball your microphone will impact your recording differently. The Acoustic Pressure Equalizer Ball comes in three sizes; 30mm, 40mm and 50mm.
APE30RS - The Acoustic Pressure Equalizer, 30 mm Ball
The APE30RS, a Ø30 mm sphere, gives a mild modification of your microphone's on-axis and off-axis frequency responses and a slight change in the direction-to-reverberation ratio. This will give your recordings greater presence, nearness and clarity on-axis (especially around 4 kHz).
An on-axis boost, between 2 kHz and 8 kHz, and high-frequency roll-off off-axis, will sometimes help you capture the subtle audible details of both musical instruments and voices.
APE40RS - The Acoustic Pressure Equalizer, 40 mm Ball
The APE40RS, a Ø40 mm sphere, offers a more noticeable on-axis boost between 2 kHz and 8 kHz. It also offers stronger off-axis attenuation than the Ø30 mm version. This gives a marked increase in the directivity of your recordings (at 4 kHz, the front-to-back sensitivity ratio is 8 dB). It also decreases the effects of reverberation and off-axis sources.
When using Acoustic Pressure Equalizer, 40 mm Ball, you can modify the spectral characteristic of a source by simply altering the angle of incidence to give a frequency boost, a flat response or attenuation.
APE50RS - The Acoustic Pressure Equalizer, 50 mm Ball
The APE50RS, a Ø50 mm sphere, offers a stronger on-axis boost and off-axis attenuation than the smaller APEs (Ø40 mm and Ø30 mm). Its larger dimensions accentuate the on-axis boost at lower frequencies and allow off-axis sources to be strongly attenuated above 1 kHz. This will give your recordings a more intense sensation of source clarity and presence and a marked increase in brightness. It will also extend the effective reach of your microphones.
You will also find that the APE50RS is particular useful for making recordings under reverberant conditions.
These accessories substitutes the former L30B, L40B and L50B, suitable for d:dicate™ 4003
and d:dicate™ 4006A
and their stereo kits. The L30B, L40B and L50B cannot be used with the modular d:dicate Series
but the APE30RS, APE40RS and APE50RS is backwards compatible.
More on acoustic modification
The Acoustic Pressure Equalizers – APEs – are passive acoustic processors functioning as both spatial and spectral modifiers. They use surface diffractions to modify the sound field near the microphone diaphragm. This technique is only possible on omnidirectional pressure microphones.
Two primary changes occur when using APEs:
1. An upper-midrange/high frequency boost (without changing the low end). This is due to the pressure build-up at certain frequencies depending on the element’s size.
2. More directionality at higher frequencies (focus).
A presence (upper-midrange) lift is often desirable in rhythmical genres, to make a voice or an instrument cut through a mix or simply to make it more intelligible or well defined. For symphonic music, the frequency response of certain legendary vintage types of microphones can be obtained using an APE. However, you will achieve a much higher degree of naturalness and detail when using a precision-handcrafted d:dicate™ 4006A Omnidirectional Microphone.
Please also refer to the Mic University article Acoustic modification accessories
– changing characteristics