Avoid the Hype (and Probably the Condensers)
I work as a teacher at a university. When the pandemic hit, I suddenly had to immerse myself into the world of audio/video streaming and producing online videos. To be sure, I was more prepared than most. In another life, I spent 8 years working as a television writer and producer for ABC and CBS affiliates back in Iowa. After almost 20 years of living overseas, however, I found myself a bit rusty. To catch up, I poured over hours of YouTube videos, bought several mics, and set out on a quest to find the best inexpensive mics and video editing programs to help me produce better quality videos. In truth, I was buying $200+ XLR condenser mics and $120 audio interfaces to power them. My setup sounds great, but I have since learned it was overkill. I'd like to save you some money, so I am adding this information to my radio blog.
I wasn't going to write this entry, until I searched "The best microphones for teachers" on Google, and found that many of the answers were conflicting. In short -- what were once blogs are now paid ad blogs selling microphones that I wouldn't recommend to anyone. For example, the #1 search on Google revealed the Blue Snowball to be a great value for teachers. Let this serve as a warning: the Blue Snowball is NOT a good option for teachers. It's a noisy option with a weak overall sound and it picks up a lot of room noise. It's one of the least impressive mics I've ever heard, and is completely carried by marketing to suckers who don't know any better.
Blue makes some really nice microphones, especially when you are talking $300+ XLR mics like the Baby Bottle SL, but they are also very slick at marketing hype on the consumer end. Another mic which everyone reads about is the Blue Yeti. A decent microphone? Yes... quite good. Would I buy it for teaching? No. Why not? It's complete overkill, is more money than a teacher needs to spend, and picks up a lot of noise off of your desk, unless you hang it on a boom arm with a shock mount (spending even more money to do so). Yes, it looks impressive on a desk, but you don't need all of those polar patterns, and it will hear everything in your room. Want to spend a lot more money and stop the thumps from your hands on the desk? Be forewarned -- on a shock mount the Blue Yeti looks positively idiotic. Blue also seems to have have an affinity for creating mics that are difficult to shock mount and look like a piece of male anatomy (see the Yeti hanging downward off of its ludicrous shock/boom system or the Blue Ember by itself to see what I mean).
So now that I've poked holes in two of the options you may have read a lot of hype about, let me mention a few mics that will sound great and save you money. I'll start with the cheapest, and work my way up:
Best Desktop Microphone under $35: Fifine K668 (USB Version)
Why is the Fifine excellent? This mic is a dynamic USB microphone that is pretty much plug-and-play. The microphone's cardioid pattern helps control echos and room noise, but is not TOO tight that you can't be away from it a bit. It comes with its own small stand, and as long as you move it as close to you as possible, it will work well. You don't have to worry about special settings or learn extra software. Plug it in, make sure the mic is selected, and bam. Excellent sound for the price. How good? Take a look at this video, which was produced by another gentleman. I will note that the K668 does have a smidge of that tell-tale cheap Chinese shrill top-end, but Zoom will remove that, anyway:
Best Smartphone Microphone under $50: Movo VXR10
A shotgun style microphone such as the Movo VXR10 is really a nice option if you want the freedom to move around a bit with a phone, yet keep room noise and echoes down. If you want a mic that sounds great, yet you don't have to see it in your video, a shotgun mic such as this is a top option. Just try to keep it within a distance of arms length to your face, for best audio quality.
Here's another review of the Movo VXR10, in detail:
Best Desktop Microphone at $50: Razer Seiren Mini
Best Desktop Microphone under $90: Samson Q2U
Best Value XLR mic for Interface Setup: Behringer xm8500
The Behringer xm8500 is an outstanding microphone. I've had one for 5 years, and it's still going strong. It makes an awesome budget choice for streamers, as well. It outperforms mics costing much more, and gives the $100+ Shure SM48 and even the SM58 a run for it's money. You will want to add a $2 sponge pop-filter to control the P-pop "plosive" sounds.
Here is my FAVORITE YouTube mic reviewer at Podcastage, talking about the xm8500:
Final Thoughts: What About Condenser Mics?
A dynamic mic, or even a simple high-quality headset mic, is usually a better choice for teachers because more outside sound is rejected. A negative of the dynamics, and one reason I like using a condenser with a treated room, is that I can move around more AND get that big sound. Without the room treatment, however, a condenser becomes a very bad idea quite quickly.
With a dynamic mic, the room sound becomes a bit less of an issue (but even still, hanging moving blankets or whatever you can get to break up the sound reflections on flat walls or floors will make a huge difference). What makes audio sound good is often not what you hear, but what you DO NOT hear. You want to remove those noise reflection echoes bouncing around, the motorcycle driving down the street, your kid's in the next room. A condenser such as a Blue Yeti will hear all of that, and it quickly becomes a problem. A cardioid dynamic mic like the xm8500 or the Fifine K668, or a Shotgun like the Movo VXR10 not so much, because they tend to favor what is in front of them. That's another quick tip for you -- get the mic close to you, as in a foot or less, for best audio. Adjust mic levels accordingly.
A parting note about the cheap Chinese condensers that are $40 or less, and come with a boom arm. The negative about these mics is often the shrill high frequencies they produce, as well as the room noise they draw in. That shrill sound is fatiguing on ears in long-form teaching videos. Fifine also makes a few of these, but personally, I'd avoid the condenser models due to the room noise they pick up.
Some further information about value condenser mics that I find work well for me in XLR format (with room treatment): Mackie EM-91C and Audio-Technica AT 2035. The even cheaper AT 2020 is also a good value option (note that they make a USB model for both the Mackie and the AT2020, although I am not sure if the USB Mackie is similar in sound). The Mackie is good for teaching, and allows you some room to move around. It comes with its own cable and shock mount (it is missing a 5/8 to 3/8" adapter piece for some booms or stands, which is cheap to get, but necessary). It does well against room noise, for a condenser, but I still treat the room. I also EQ it a bit, because it's a very "warm" mic. I roll-off frequencies below 90hz, and pull some down a bit at 250hz and 500hz. I also boost it about 2db from 3,000 to 5,000 hz.
I like the EM-91C, even though it's quite warm. I EQ to help it a bit. I like how it is forward in the midrange for bold yet clear sound. It's pleasing through headphones and tinny little notebook speakers. I took a poll of my students, and found that 70 to 80% of them prefer to listen to school videos this way. They are not listening on hifi stereo systems such as I grew up with. The EM-91C is clean enough without that shrill high-end that the cheap Chinese mics have. I also like how the EM-91C cuts off the excessive sibilant sounds that condenser mics often suffer from (especially after compression). I don't need to de-ess this mic, unless I am boosting with my EQ. This means most people can make a smooth, warm sound with it without a lot of post processing. I do recommend a low-cut below 90 to 100hz, to help remove some of that bottom end which is not needed for voice, anyway.
I also mentioned the AT 2020 and the AT 2035. The AT 2020 is a good USB condenser mic OR can be purchased as an XLR model -- BUT it's a condenser. Room treatment is a must. The more expensive AT 2035 is less shrill on the highs, and has better bass than the AT 2020. It sounds better on a pro level, but it hears a pin drop and is so sensitive. The 2020 and especially 2035 are more open, wide, and airy-sounding than the Mackie, so room acoustics are even more important. Both of these mics come with shock mounts, which are essential for condensers. I put a foam win screen on all of these. The Mackie will fit a cheap $2 XLR mic's foam screen. The AT mics work better against plosives than the Mackie does up close, but adding the foam and talking across the mic from a 45 degree angle makes it a non-issue. You can get very cheap $3 wind screens for them via Aliexpress.
Here is a video showing the Mackie vs. the budget AT 2020 (baby brother to my AT 2035):