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