USB microphones have become ubiquitous in the world of digital audio. Boasting plug-and-play simplicity and affordable pricing, they‘re an enticing option for budding podcasters, YouTubers, and musicians. However, as someone who‘s spent over a decade recording and mixing audio for music and film, I‘m here to tell you that USB mics are rarely the right tool for the job. In this article, I‘ll dive into the technical details of why XLR microphones are a better long-term investment for anyone serious about capturing quality audio.
The Basics: How Different Microphones Work
Before we compare USB and XLR mics, let‘s review how the two main types of microphones function:
Condenser Microphones
Condenser mics are the most common type of studio microphone. They have a thin, electrically-charged diaphragm (hence the name "condenser") suspended close to a metal backplate. When sound waves hit the diaphragm, the changes in distance between it and the backplate create fluctuations in capacitance, generating an electrical current that mirrors the acoustic waveform.
Condensers are known for their ability to capture delicate high frequencies and quick transients, resulting in a detailed, articulate sound. However, the low mass of the diaphragm also makes them more susceptible to noise from vibration and wind. Condensers also require external voltage, known as "phantom power", to charge the diaphragm.
Dynamic Microphones
Dynamic mics generate audio through electromagnetic induction. They have a thin diaphragm attached to a coil of wire suspended in a magnetic field. When sound waves move the diaphragm and coil, it creates an electrical voltage in the coil that corresponds to the acoustic waveform.
The heavier diaphragm assembly of dynamics makes them less sensitive to high frequencies but also more durable and resistant to loud volumes, wind, and moisture. This makes them a go-to for live vocals and instruments. Dynamics‘ moving coil design also eliminates the need for external power.
The Problem with USB Microphones
Now that we understand how different mics work, let‘s examine the issues with USB microphones:
1. Inferior preamps and converters
The primary appeal of USB mics is their simplicity: the microphone, preamplifier, and analog-to-digital converter (ADC) are all contained in a single unit, outputting a digital signal that can plug directly into a computer.
The problem is, to cram all of those components into a mic-sized chassis, manufacturers have to cut corners. The preamps and converters in USB mics are almost always inferior to those in even entry-level audio interfaces. For example, the popular Blue Yeti USB mic has a signal-to-noise ratio of 70dB, whereas the Focusrite Scarlett 2i2 interface has a mic preamp SNR of 106dB. That‘s a massive difference in terms of noise floor and dynamic range.
Additionally, most USB mic preamps are not designed with gain staging in mind. Many only have a single analog gain stage, making it difficult to optimize levels for different sources. This can lead to noise and distortion that can‘t be fixed in post-production.
2. Fixed polar patterns and lack of positioning flexibility
Another limitation of USB mics is that they typically have fixed polar patterns, meaning you can‘t adjust the directionality of the microphone to suit different recording scenarios. For example, the Blue Yeti has selectable cardioid, bidirectional, and omnidirectional modes, but you‘re stuck with those preset patterns. With an XLR mic, you can choose from a wide variety of polar patterns to fit your specific needs, from supercardioid for noisy environments to figure-8 for capturing two sources simultaneously.
USB mics also tend to be larger and heavier than XLR mics due to the extra circuitry inside. This makes them more cumbersome to position on mic stands and booms, limiting your placement options. With an XLR mic, you can easily use a shock mount to isolate vibrations and put the mic wherever you need it for the best sound.
3. Latency and driver issues
Since USB mics rely on your computer‘s drivers and processing power, they are more prone to latency (delay) and compatibility issues than XLR mics. The analog-to-digital conversion process takes time, and if your computer is struggling to keep up, you may notice a slight lag between what you‘re hearing and what‘s being recorded. This can be incredibly frustrating and throw off the timing of your performance.
Additionally, some USB mics have known issues with certain operating systems and USB chipsets. Focusrite has a whole article dedicated to troubleshooting USB audio problems on Windows. With an XLR mic and interface, you have a dedicated audio driver that is less likely to conflict with other devices and software.
4. Lack of expandability and customization
One of the biggest drawbacks of USB mics is that you‘re stuck with the components and features built into the mic itself. If you want to upgrade your preamp, use a different polar pattern, or add a compressor or EQ to your signal chain, you‘re out of luck.
With an XLR mic and interface setup, you have endless possibilities for expansion and customization. You can use the same mic with different preamps and converters to shape your sound, or add outboard gear like limiters and de-essers to fine-tune your recordings. And if you need to record multiple sources simultaneously, you can easily add more microphones and inputs to your setup.
The Benefits of XLR Microphones
Now that we‘ve covered the downsides of USB mics, let‘s look at some of the advantages of XLR microphones:
1. Higher quality components and design
XLR microphones are designed first and foremost for audio quality. They use premium components like gold-plated connectors, low-noise transformers, and high-grade diaphragms to capture every nuance of your sound. They also have more robust shielding and grounding to reject electromagnetic interference and hum.
Many XLR mics also feature interchangeable capsules, allowing you to switch out the diaphragm assembly for different polar patterns and frequency responses. This level of modularity is simply not possible with USB mics.
2. Longer cable runs and phantom power
Another benefit of XLR mics is that they can support much longer cable runs than USB. XLR cables can extend up to 100 meters without signal loss, whereas USB cables are limited to around 5 meters. This gives you much more flexibility in terms of mic placement and studio layout.
XLR mics can also be phantom powered, meaning they can receive the 48V DC voltage needed for condenser mics directly from the mic preamp or interface. This eliminates the need for separate power supplies and batteries, making for a cleaner and more reliable setup.
3. Direct monitoring and zero latency
When recording with an XLR mic and interface, you have the option to monitor your input signal directly, without any latency or processing. This is known as "zero-latency monitoring" and is crucial for avoiding timing issues and hearing yourself in real-time.
With a USB mic, the signal has to travel through the computer‘s audio drivers and DAW software before it reaches your headphones, introducing some amount of latency. Some USB mics have a "direct monitoring" feature that routes the signal back to the headphone jack on the mic itself, but this is still not as low-latency as true hardware monitoring.
4. Better resale value and longevity
Finally, XLR microphones tend to hold their value much better than USB mics over time. Because they are not tied to any particular computer or software ecosystem, they can be used with a wide variety of audio gear and will continue to work with future technology.
Many of the most popular XLR mics on the market today, like the Shure SM57 and Neumann U87, have been in production for decades and are still considered industry standards. In contrast, USB mics are often designed with planned obsolescence in mind, with limited driver support and non-replaceable parts.
XLR Microphone Recommendations
If you‘re convinced that an XLR mic is the way to go, here are some of my top recommendations for different price points and applications:
Entry-level: Audio-Technica AT2020 ($99)
The AT2020 is a great starter condenser mic for home studios. It has a full, balanced sound and low self-noise, making it suitable for vocals, acoustic guitar, and other instruments. It‘s also built like a tank, with a metal chassis and heavy-duty mesh grille.
Mid-range: Shure SM7B ($399)
The SM7B is a legendary dynamic mic used on countless hit records. It has a smooth, broadcast-ready sound with excellent rejection of room noise and proximity effect. It‘s a top choice for podcasting, radio, and voiceover work, as well as recording loud sources like guitar amps and drums.
High-end: Neumann TLM 103 ($1,099)
The TLM 103 is a classic large-diaphragm condenser mic with a sweet, airy top-end and unmatched clarity. It‘s a favorite for recording lead vocals, piano, strings, and other acoustic instruments. The TLM 103 also has a low-cut filter and pad switch for handling loud sources up to 138dB SPL.
Conclusion
While USB microphones may seem like a convenient and cost-effective solution for digital audio, they simply can‘t match the quality and flexibility of XLR microphones. From the superior sound of dedicated preamps and converters to the expandability of modular components, XLR mics offer a level of performance and customization that USB mics can‘t touch.
If you‘re serious about capturing professional-grade audio, whether for music production, podcasting, or video, investing in an XLR microphone and audio interface will pay dividends in the long run. Not only will you get better sound quality and more control over your recordings, but you‘ll also have a setup that can grow with you as your needs and skills evolve.
So next time you‘re in the market for a new microphone, skip the USB hype and go for the tried-and-true XLR. Your ears (and your audience) will thank you.
Additional Resources
- The Beginner‘s Guide to Recording Studio Microphones
- Dynamic vs Condenser Microphones: Which to Choose?
- USB Microphone vs XLR: Which is Better for Podcasting?
- Why you shouldn‘t use a USB microphone (video)
I hope this article has helped shed some light on the differences between USB and XLR microphones and why investing in an XLR setup is the way to go for serious audio work. As always, feel free to reach out with any questions or comments. Happy recording!
