Condenser vs Dynamic microphones for plug 'n play PC use

Question

I was comparing two AKG broadcasting/recording headsets, one with a condenser microphone (AKG HSC 271) and the other with a dynamic microphone (AKG HSD 271) but otherwise identical and approximately equally priced. Both headsets have removable cables. The cable is typically a 6-Pin mini XLR plug to 6.3 mm stereo jack and 3-pin XLR connector, but the condenser version is also available with a 6-Pin mini XLR plug to 2x mini jack (TRS), the so-called "PC Set", available for the purpose of directly plugging the headset in a PC (onboard sound-card), circumventing the need of a proper audio interface ( at the obvious cost of reduced audio quality ).

This surprised me, as condenser microphones typically require "better care", including phantom power, whereas dynamic microphones do not. Now, I understand that it is not advisable to connect any type of high-quality microphone directly to a PC, neither a condenser nor a dynamic one. However, if they'd offer the option to do it for one, I would have guessed it to be the dynamic rather than condenser microphone. As such, this makes me think I'm missing some understanding about the operation principles of either type of microphone.

Question:

Why would a condenser microphone be more suited than a dynamic microphone for connecting directly to a PC's built-in sound-card ?

Answer 1

There are two types of condensor mic - Electret condensor and true condensor. Both require a positive DC charge in order to function.

Condensor mics are based on capacitative plates which physically move in the presence of sound waves. This movement alters the static charge on the plates and thus the voltage between the plates changes. This voltage can be amplified by a small low-power preamp circuit and supplied back down the mic cable as a varying electrical voltage signal at audio frequencies.

A True Condensor requires external power in order to charge up the capacitative plates (the capsule). This is (today) traditionally +48v and is supplied up the mic cable as "phantom power". Other condenser designs use varying levels of power - some up to 120vDC and these require separate power supplies to work.

With Electret condensor types there are two main ones - statically charged and bias. The statically charged electrets contain a metal that is pre-treated to hold a static charge and thus do not require power. The bias type require a small (+5v) charge to "bias" one of the sides of the capsule.

Computer motherboards may or may not provide bias power for electret condenser mics. If bias power is available on the microphone in connector, then you can use either a static electret or a bias electret.

No motherboard I have ever seen will directly provide 48v phantom power on a 3-pin XLR connector. For this you will need a separate audio adapter device that specifically provides the correct connection and the correct phantom power supply.

Dynamic mics are an entirely different beast. They work on a moving coil which is attached to a moving diaphragm. The moving coil acts against a magnet to generate power which can be supplied back down the cable as the audio signal. They require no power at all to work as the microphone signal is generated by the movement of the coil. IF you can find a suitable adapter device to adapt the 3-pin XLR connection of most dynamic mics, to a 3.5mm jack connector, then the dynamic mic may well work adequately with the computer.