Recently, the microphone maker Blue announced a professional $ 100 studio microphone, Ember. So the question arose: What is this XLR case, and how do I use it? Let's talk about what the XLR is and why you might want to use it in your studio.
XLR is pro audio. That's what all recording and radio studios use, and that's what you'll see live artists on stage. This is why XLR cables have balanced sound, which is essential for sound.
What is XLR?
First things first – let's define what XLR means. It is a fairly simple abbreviation for X Connector, L ocking Connector, R ubber Boot. The rubber section of the connector is not always a part of the equation these days, but it is no longer necessary. Despite the small design change, the name has been the same.
There are currently several different versions of XLR cables available with a variety of pins (XLR3 – XLR7), but what we are talking about here is XLR3 or the three pin cable. This is the most common type of cable.
In short, the XLR is the go-to standard for high quality audio inputs, such as microphones. This is because they send a balanced signal that isolates sound. It is simply a better type of connector for that type of application, but it is also so robust that it is not necessarily something that the average consumer really needs to think about if it is not of high quality for audio recording or streaming.
Apart from an XLR microphone and XLR cable, you need a kind of audio interface or mixer so the computer can see the microphone. A decent audio interface is available for as little as $ 40-50, but nicer devices can go much more. The average enthusiast will likely want to spend somewhere in the $ 150-200 range for a good interface. As if Focusrite Scarlett 2i2 is a great place to get started, for example.
If you are planning to do home recording, I also need a DAW Digital Audio Workstation to capture your recording. You can use something free as Audacity, but there are also good options out there that don't cost much, like Reaper. You can read our pictures for the best DAW here.
The technical side of what makes XLR so much better than other audio inputs is good, quite technically.
If you've ever changed the batteries in the flashlight, you've probably noticed that there is plus +. When you just hook one side of the battery to the torch light bulb, nothing happens. You need both the positive and negative connections so that the lamp lights up. This is an electrical circuit. The electrons must make a complete loop from the battery's negative pole, through the wire, through the light and back to the battery again. The sound is no different: you need the positive and negative sides of an audio signal for something to happen. A microphone pushes electrons on one side of the cable, the electrons are sent to an amplifier and then back to the other side of the microphone.
The problem is that most audio systems treat the circuit as if there is only one wire, usually the middle conductor of a piece of coaxial cable, and they simply combine the other line with all other electronics in the system. This creates an opportunity for several different types of sound to get into an audio signal chain:
- Ground loop noise: In my 35 years of experience in pro audio and video systems, this is the most common and disturbing problem, especially when computers are involved For the most part, you hear this as a low hum, although it can also occur as static or irregular buzzing sounds. Earth loops occur when the sound takes two different paths to get to the amplifier: a path through your audio cable and a second path through the lead's lead.
- EMI and RFI : Transformers, motors and high-frequency electronics can create magnetic fields that induce a current in your audio cables. This creates buzz, hum, and can even carry audio signals if you are placed too close to an AM transmitter.
- Crosstalk : This happens when a signal on the same system crosses to another.
Do you fix this? The solution seems quite obvious afterwards: you isolate both wires in the signal chain so that the positive and negative halves of the signal are carried separately from everything else. The main advantage of a balanced audio signal (when it is finished right) is that the audio signal never touches the ground plane of the amplifiers or other instruments in the system. So there is no opportunity for crosstalk or earth loops.
For example, I work with a live band and a few weeks ago we had a problem with the "click track" which was produced by the music equipment one of the practitioners used at stage. The sound from the click bar leaked through to other outputs on its audio interface, so you could hear "beep beep" in the PA system. It was quiet, but there. We disconnected the unbalanced audio cables he used and switched over to balanced XLR cables. The problem went away.
The other advantage is sound rejection. EMI and RFI work because a moving or altered magnetic field creates a voltage on a wire. In unbalanced signals, the magnetic field creates a voltage on the positive side of the signal, but not the negative (or perhaps the other way around). In a balanced cable, the wires are next to each other and so a magnetic field creates the same signal on both sides.
On the broadcast side, an XLR device creates a second copy of the sound, inverts it. On the receiving side of the signal, the inverted copy of the signal is summed back to the original copy of the signal. And just as in mathematics, where -2 + 2 = 0, a balanced audio signal rejects sound from from external sources.
Finally, your cruise opportunities significantly decrease when the signals do not share a ground plane. High-end equipment that uses a completely balanced audio chain internally has virtually no crosstalk.
So how can you put all this into practical use? What good is it?
If you look at Ember, you might be thinking of streaming to Twitch, recording a podcast or some music. In either case, you can connect the Ember to a USB mixing console (such as the Mackie Pro FX8) and use the mixer as an amplifier for the microphone and a USB audio interface. You can also add another microphone for your Internet co-star and plug in other equipment, perhaps a musical instrument, another computer running Skype or Discord or just your smartphone.
The most important thing to remember is that you need a mixer or audio interface that includes phantom power (this is often indicated by a switch that says + 48V). Because the microphone needs power to work, you need something that can generate that power. This is one reason why a mixer is a good choice for an audio interface because it contains phantom power right there in the device. High-end microphone amplifiers can also have phantom power, and some XLR computer accessories have built-in phantom switches.
Finally, there are other options for sending balanced sound besides XLR plugs.  TRS Phone Plug "width =" 352 "height =" 385 "data-creditext =" Tom Wilson "src =" / pagespeed_static / 1.JiBnMqyl6S.gif "onload =" pagespeed.lazyLoadImages.loadIfVisibleAndMaybeBeacon (this); " onerror = "this.onerror = null; pagespeed.lazyLoadImages.loadIfVisibleAndMaybeBeacon (this);" />
TRS Phone plugs can also carry balanced signals. amplifier, as well as connect outboard effects, such as reverb processors, equalizers, compressors and audio recorders. While the connector is the same (and the same part) as plugs used in high quality headphones, the ring is used for the negative side of the audio signal.
You can also get some of the benefits of a balanced audio cable with a device called a ground loop isolator. It generally looks like a small box with two pairs of RCA sockets on it, or sometimes mini-headphones. : 1 sound transformer inside, which breaks ground loops. If you connect a computer to a mixer or cable box, you are almost guaranteed to get ground loop noise and AC mood. This almost always fixes the noise problems. You might also have this problem in your car when you plug your smartphone into your car stereo, so a ground loop isolator with 3.5mm phone cords is a great help.
Why not a USB microphone?
Finally, probably wondering why the reliable USB microphone is not good enough.
It is actually only good when you just need to record one thing at a time. I have a good Samson USB microphone on my desk for podcasting or streaming, and it works fine. But capturing with USB microphones is that you can't use more than one at a time. USB audio devices all have their own clocks to drive the digital audio converters, and if those clocks go out of sync, you get pops or dropouts in your recordings, as the software on your computer is trying to fix these errors.
It's also harder to mix this way because you don't have the physical knob to work from. So when I want to do something with more than one person at a time, I go to my desktop mixer and my reliable XLR-connected study microphones.