Live streaming, recording, online classes, how to choose a microphone and sound card without stepping into the trap

As live broadcasts, home recordings, and online meetings become more and more popular, the demand for "buying a good microphone" is growing rapidly - but there are many pitfalls in this category, and the difference can be several levels within the same budget.

Microphone type: first figure out the purpose

USB microphone (no sound card required)

The microphone has a built-in A/D conversion chip, which can be directly plugged into USB and used without the need for a separate sound card.

Advantages:

Plug and play, zero threshold
Better sound quality than 3.5mm microphones in the same price range
Suitable for video conferencing, podcast recording, and live streaming

Disadvantages:

Unable to connect multiple microphones (the same USB port cannot connect two)
Limited upgrade space (cannot change to a better microphone head)
The delay is relatively high (for people who are sensitive to real-time monitoring)

Suitable: Introductory live broadcasts, podcasts, online courses, and video bloggers recording alone

Dynamic microphone (condenser microphone comparison)

Type	Principle	Advantages	Suitable for scenarios
Dynamic microphone	Magnetic induction vibration	Durable, not afraid of high sound pressure, no need for phantom power	Live performances, high sound pressure recording, podcasts (environments with poor sound insulation)
Condenser microphone	Capacitor plate vibration	High sensitivity, rich details, clearer high frequencies	Recording studio, indoor recording with good sound insulation environment

Key differences:

Condenser microphones have better pickup details, but they also record all room background noise, air conditioner sounds, and outdoor car sounds.
Dynamic microphones are less sensitive and have relatively less background noise (suitable for home environments where sound insulation is not done)

Cardioid vs Omnidirectional vs Figure 8

The "directivity" of a microphone determines which directions it can receive sounds:

Type	Main radio range	Application
Cardioid	Directly in front, suppressing the rear	Recording and live broadcasting alone (most commonly used)
Supercardioid	Narrower in the front and a little behind	When stronger isolation is needed
Omnidirectional	360° omnidirectional	Multi-person conference, environmental recording
Figure 8	Right in front + Right behind	Two-person conversation, AB stereo recording

Sound card: When do you need to buy a separate sound card?

If you are using a professional condenser microphone (XLR interface), you must have a sound card (audio interface) because:

XLR condenser microphone requires 48V phantom power (provided by the sound card)
The microphone signal is very weak (mic level) and requires a preamplifier (built-in in the sound card)

Sound card (audio interface) key parameters:

Parameters	Description
Number of input channels	Channel 1: Single person recording; Channel 2: Duo or instrument + vocals
A/D conversion bit depth	24bit standard, 32bit better
Sampling rate	44.1kHz is enough for music recording; 96kHz is higher quality
Phantom power (+48V)	Required for condenser mics, not required for dynamic mics
Delay	The lower the better (affects real-time monitoring)

Direct monitoring: A good sound card supports "Zero-Latency" direct monitoring (monitoring the input signal directly from the sound card hardware, without going through the computer, with extremely low latency).

Supporting equipment

Blowout net (windshield)

The price is low, but the effect is obvious - it eliminates the airflow impact caused by mouth plosives (sounds starting with P, B, F).

Condenser microphone: a must For dynamic microphones: It is recommended to prevent saliva/airflow from directly spraying on the diaphragm.

Microphone arm (cantilever bracket)

It is easier to adjust the position than a desktop tripod, allowing you to place the microphone in the best position and free up space on the desktop.

Key parameters: The maximum load capacity is greater than the weight of the microphone.

Acoustic treatment (sound absorption)

The bottleneck in recording quality is often not the microphone itself, but the room acoustics - reverberation reflected off the walls that makes the recording sound like a "bathroom" sound.

Low cost solution:

Surround the recording location with thick curtains, bookcases (books absorb sound very well), and sofas
Hang a quilt or thick towel behind the microphone
Purchase a simple sound-absorbing panel (sponge sound-absorbing foam) and place it behind the recording position

Video conferencing/online classes: no need to buy so expensive

Video conferencing and online classes have much lower sound quality requirements than live broadcasts/recordings. Recommendations:

Option A (lowest cost): Headphones with microphone (wired)

Close to the mouth, low background noise, completely sufficient

Option B (Advanced): USB desktop microphone (cardioid pattern)

More natural than headphones, no need to wear headphones

Plan C (High-end): USB condenser microphone + sound insulation treatment

Suitable for people who have frequent meetings and have requirements for image presentation

Live recording budget reference plan

Budget	Recommended plan	Suitable scenario
Getting started (200–500 yuan)	USB condenser microphone (heart-shaped)	Basic live streaming and podcasting
Advanced (500–1500 yuan)	Sound card + dynamic microphone (XLR)	Live broadcast with higher quality requirements
Professional (more than 1,500 yuan)	Sound card + large diaphragm condenser microphone + acoustic treatment	Professional recording, high-quality podcasts

*The technical parameters in this article are derived from Audio Engineering Society (AES) specifications and industry evaluation standards, and do not represent recommendations for specific brands. *