The key to professional sounding audio, especially in home recording situations, is to keep as much noise out of the audio as possible. The less noise (hum, buzz, hiss, lawn mowers, computer drive noise, etc.) you have mixed in with the sound you’re trying to record, the better. Prevention is best. That’s my story and I’m sticking to it.
Obviously there are lots of sources of noise. So let’s narrow our focus in this article on just one type of noise. How can we prevent the electricky (I think it’s a GOOD word) sounding noises such as buzzing and humming? Most of us will be stuck playing the role of engineer AND talent simultaneously, so our microphones will probably be quite close to all the electrics. So the key will be to minimize buzzing and humming that so often infect our pristine audio. The key to minimizing said buzzing and humming is to understand where it’s coming from. Hint: not the plant Zebulon 6…usually.
My computer died recently, and the replacement required me to put a new audio interface the M-Audio Fast Track, into my studio setup. I was getting an awful buzzing through the wires and try as I might I couldn’t get rid of it. It was too loud to remove with audio editing tools, such as noise reduction or gating. I simply had to find and eliminate the Fig. 1 – XLR Connector
source before I could do any recording.
The Fast Track Pro has inputs called “combo connectors” on the front that allow you to plug in either a 1/4-inch cable connector or a 3-pin microphone cable connector (called an XLR connector – see Figure 1). The way I had my previous interface connected was with a regular old 1/4 plug coming from my outboard microphone preamplifier (See Figure 2).
So I thought I could simply replace the old interface box with the new one, keeping the same cable connections. Are we making guesses as to how that turned out for me? “Badly” is the answer. That buzzing I mentioned was coming from or through the new interface. I knew this because it only happened when the interface was turned on. Clever huh? Fig. 2 – “Before” Pic With Unbalanced 1/4-in. Connection
It turns out that audio gear with amplifiers (like audio interfaces) in them are extremely sensitive to electromagnetic (EM) fields, which basically means that if there are electrons moving around anywhere near this gear, they are likely to flock to it like bees to honey, and create a very similar noise to that same mixed metaphor…buzzing! What causes electrons to fly around your stuff? Electricity is the main culprit. Anything that is plugged in and sucking juice is likely to be the cause of humming or buzzing. So what do you do?
First, check the cables running to and from the interface box. If there are any power cables touching it or its wires, separate them. Just get them the heck away from each other. Pay special attention to proximity to AC adapters, otherwise known as wall warts or power bricks. They cause lots of EM. Picture a big cloud of bees around one of these things. As in real life, steer clear of the bees!
Next, check to see if the wires running to and from the interface are balanced or unbalanced. You can usually tell by looking at the sockets in the gear which will usually say “balanced” or “unbalanced.” Go figure. Another way you can tell is by what kind of connector is at the end of the cable. If it looks like the one in figure 2 (with a single black stripe toward the tip), assume the connection is unbalanced. If the connector looks like those in Figure 3, assume you have a Fig. 3 – XLR Connectors…Again
balanced connection. Don’t worry about understanding what it means for electrical stuff to be balanced or unbalanced. I’ll write an article about that very soon. For now it is enough to know balanced connections can protect against electricky noise. So if your stuff is hooked together by unbalanced cables, check to see if the gear can accept balanced connectors. If so, try swapping your 1/4-inch pluggy cables with XLR ones and see if that doesn’t reduce or eliminate the buzzing noise. In my case it was exactly what was needed!
My old mic preamp (Peavey VMP-2) has two “output” sockets on the back, one with an XLR shape that had the word “balanced” cleverly written by it, and another with a 1/4-inch hole and the word “unbalanced” by it. Cryptic and confusing, no? No.
Anyway, the moral of the story is this. If you are hearing electricky- sounding buzzing or humming coming from your audio gear, try two things right off the bat:
1. Separate the cables as much as you can, and steer especially clear of the ones with big power packs on them.
2. Check to see if your connections are balanced or unbalanced. If unbalanced, try switching to a balanced cable connection. One of these two actions will likely solve or at least greatly improve your noise problem.
Good luck!
Ken
Wow, that’s a question that you’ll find answered all over the internet. And you might actually be able to understand some of them. It is almost an irrelevant question in this day and age, because it is the rare person who can even FIND analog (the opposite of digital) recording gear anymore…at least stuff you can afford on a really tight budget. If you want to start recording right now, for a budget of $5.00 or less, then you’ll be recording on computer, which means you’ll be creating digital audio.
OK, so I kind of hinted that I’d explain what digital audio was so that regular people can understand it, so I hope this will do the trick. If the audio is in a computer, it’s digital.
See? Was that so hard? Now you’re asking what I meant earlier when I said that “analog” is the opposite of “digital.” OK, how’s this? If the audio is on something physical like tape or on a record (those are the black, round, flat things your parents used to listen to music on) it’s analog.
Now there are some trouble-makers out there…I see you in the back! You want to get all picky and point out that “lots of audio outside the computer is still digital,” and just because it’s on tape, the audio could be digital.” The trouble-makers aren’t wrong, folks.
But ignore that! Yeah, forget about the fact that audio on phones and iPods is digital also. The smart ones out there knew that those things are just little computers anyway, right? And it won’t affect many of you to know that some digital media can be recorded to tape. But guess why you don’t need to remember that? Because if it’s digital tape, IT WILL SAY SO. It is rare enough that it will have a label saying something like DAT (digital audio tape) or something similar with the word “digital” in it.
So now you know the difference, right? Digital audio is “computerized” audio, and analog audio is recorded in some physical way onto records (all those little grooves) or tape (all those little magnetic particles).
Why should you care if you are going to be recording audio on your computer anyway? It’s digital right? Well…yes and no.
Getting Audio Into A Computer
It WILL be digital once it’s in the computer. But when it’s just a voice coming out of your face, it’s still analog. The physical medium is the air molecules your voice is moving. In order to make it digital, there has to be a machine that converts analog audio to digital audio. Amazingly enough, these are called “analog-to-digital” (A-to-D) converters. The converters play a large role in how good the audio sounds. If you’re just using the ones on the garden-variety sound card, the audio probably won’t be “high-end.” Audio interface boxes (mainly USB these days) typically have much better A-to-D converters.
One good example (and not just because I use one :-)) is the Focusrite Scarlett 2i2 or Focusrite Solo. These interface units are actually doing two main jobs – conversion, as I just discusses a bit (no pun intended :-)), and amplification (mic preamps). In the old days you’d have two units for this – a converter and a preamplifier. But mostly these days (updating this in 2018) these interface units combine many functions, including A-D conversion, D-A conversion, and preamplifiers.
So now you understand the difference between digital and analog audio. Go forth and use your knew knowledge well!
The key to professional sounding audio, especially in home recording situations, is to keep as much noise out of the audio as possible. The less noise (hum, buzz, hiss, lawn mowers, computer drive noise, etc.) you have mixed in with the sound you’re trying to record, the better. Prevention is best. That’s my story and I’m sticking to it.
These interface units are actually doing two main jobs – conversion, as I just discusses a bit (no pun intended :-)), and amplification (mic preamps). In the old days you’d have two units for this – a converter and a preamplifier. But mostly these days (updating this in 2018) these interface units combine many functions, including A-D conversion, D-A conversion, and preamplifiers.