Recording Audio Into Your Computer

After reading the other blogs I hope you have a better idea of how to set up the room and choose mics and cables to record your church or school group. Let’s move on to how you get the audio recording by the mic or mics into the computer.

Your computer almost certainly has a sound card, and you can just feed the signal into the mic inputs for the sound card. The input may be different for each sound card. You will need to look at your owner’s manual for the details.

Sound cards are inside the computer, and the inside of a computer is very noisy electronically. There will almost certainly be a level of noise injected into your audio signal. The best way to eliminate that noise is to use an external USB audio unit. The analog signal, which is subject to noise, is converted to a digital signal which is much less subject to noise outside the computer, and the resultant sound is much better. We sell a nice USB 5.1 External Sound Card on our site.

If you have two mics, and I encourage you to use two so you can get a stereo recording (although RipEditBurn Plus has an effect in that allows you to create stereo sound with only one mic), you probably have two cables, each with a plug at the end, and you will need a device that will combine the two mono signals into one stereo signal. I could write two pages of instructions about how to do that, but there’s an easier way. Take the cables to your local electronic parts store (Radio Shack or something similar), show it to the staff, and have them put it together.

Whatever you are using for a sound card, an internal one or an external USB audio unit, you should connect the output from the mics into the jack labeled “mic” or “microphone”.

If you have more than two mics you’ll need to invest in a mixer. I strongly suggest you find a mixer that converts the signal into USB before sending it to your computer. There are also some Firewire devices if your computer has a Firewire port. Over the years Singing Electrons, Inc, the parent company to Blaze Audio, provided drivers for many of the USB and Firewire chips, so you might end up with our software both in your computer and in your mixer!

Mixers range in price from under $100 to many thousands of dollars. The number of channels is important, as is the quality of the electronic hardware. I suggest getting the best you can, with at least a couple more channels than you immediately think you will need. Many mixers have effects like reverb and EQ built in. Reverb can give you the sound of a big concert hall, but you may already be recording in a room that has reverb. EQ (equalization) allows you to set the level for each frequency band. In other words, if you listen to the recording and it just doesn’t have enough bass, you can increase the level on the lower channels to give your recording a more satisfactory sound.

Some mixers may offer the option of outputting more than 2 channels, but in general I suggest mixing the signal down to two channels, left and right, before bringing it into the computer. Pro studios have hardware and software that can deal with many tracks, but both the expense and the learning curve are high.

You may be using the mixer to record not just microphones, but also guitars, electronic keyboards, or other instruments that produce a line-level signal (as opposed to the levels that microphones put out). Most mixers have jacks for both balanced (XLR) and unbalanced plugs. Plug your guitar or electronic keyboard into the unbalanced jack.

With most balanced XLR inputs you will need to turn on something called “phantom power”. Phantom power is the 48 volts that are used to turn one conductor in the cable into the opposite of the other conductor, which allows you to have long cables without noise.

There should be a control marked “trim” on each XLR input (and sometimes on all inputs). Use that to get each input set to approximately the same level, and then use the pan sliders (or knobs) to set the final level for each channel. The output should be controlled by two sliders. Try to avoid red-lining the output- in the old days, with analog gear, a little red-lining was good, but because of the nature of digital audio going past the max means you will be adding nasty, unremovable distortion to the sound.

It is very important to spend time setting the level for each channel before you record. I suggest getting a good pair of headphones (the kind that are sealed so that you are listening just to the signal, not to what’s going on in the room) and having your group play while you move the sliders up and down until you get the right mix. With most mixers you’ll be able to select which signals go into the left channel and which signals go into the right channel. Do that with some care so that the eventual recording will sound realistic and clear.

So now you have the room set up, the mics chosen and connected, and the sounds going into your computer, all ready to record.

Next- Recordings of your musicians.

by Tom Jeffries, Chief Blazing Officer at Blaze Audio

Tom is a former professional musician who has been running companies that develop audio software for 33 years.

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