Topic: Sanken css-5 vs mkh30/8040 ms

[idelgas]

Hello,

Anybody out there has experience using the sanken css 5 and an ms rig using an mkh30 with an mkh8040?


Would like to know if anybody has any thoughts on the difference between these two setups.

Thanks.

[John Willett]

Hello,

Anybody out there has experience using the sanken css 5 and an ms rig using an mkh30 with an mkh8040?


Would like to know if anybody has any thoughts on the difference between these two setups.

Thanks.

See my reply in your other thread.

As you are going to the Jungle which is hot and humid, the only microphones I would take for safety are RF condensers - and that means MKH mics.

However good the Sanken is, it's not an RF condenser - take it in addition if you want, but I would not rely on it as the main mic. in those conditions with out an MKH rig as a back-up.

The explanation of the differences between RF and AF condensers is:-

Question:
Can anybody give me a quick explanation of why RF modulated microphones are less
susceptible to humidity problems than are AF microphones?

Answer:
Basically, AF capacitor microphones use the capsule as a capacitor to store charge. With
one fixed plate and the other free to vibrate in sympathy with the sound, the capacitance
varies, and the charge moves in or out of the capsule accordingly. This is measured by the
head preamplifier and an audio signal results. All well and good, but the capsule is
inherently in a high impedance circuit (over 1Giga-Ohms) – it has to sit there with stored charge
until the diaphragm moves and any changes in the charge are perceived as audio. In a
humid atmosphere the stored charge finds it easier to escape on water molecules in the air
rather than through the input of the preamplifier, hence noisy and reduced output, and
misery all round. The high biasing voltage also attracts dust particles to the diaphragm,
reducing its efficiency and linearity.

The RF system (as used in Sennheiser MKH microphones) uses the capsule (a low
impedance capsule) in a completely different way: as a tuning capacitor for an RF oscillator
– which inherently employs it in a low impedance circuit where a high frequency signal is
being passed through the capacitor all the time. Changes in capacitance (caused by sound
moving the diaphragm) alter the resonant frequency of the circuit (circa 8MHz) and so its
frequency becomes proportional to the audio signal. A simple RF demodulator restores the
output to a conventional audio signal. More complex and sophisticated (but still very
rugged), this system is highly immune to the effects of humidity and is thus the preferred
design to be used out of doors (or when moving from outside to inside on a cold day!).