Tag Archives: audio recording

Cables and Connectors

Cables and ConnectorsCables and connectors come in many varieties, and you may already know enough to get started. There’s one very important area, and I’d like to discuss that first.

There are basically two kinds of cables- balanced and unbalanced. The important thing about that is the fact that balanced cables reject electromagnetic noise. Unbalanced cables, if they are long, act as antennas for electromagnetic noise. That’s why professional studios use balanced cables as much as possible.

What makes a cable “balanced”? A balanced cable has two signal wires (along with one ground wire), but they are each sending the same signal. One is inverted from the other. Noise coming in affects both signal wires equally and in the same direction. When the two signal wires are summed at the other end the noise is zeroed out.

Balanced cables normally have a kind of connector called XLR. There are three pins at one end and three holes at the other end. Sometimes a cable will have an XLR connector at one end and what looks like a stereo connector at the other. That stereo connector may be a TRS (tip-ring-sleeve) connector which works like an XLR signal. Balanced cables only send one channel, they never send stereo.

Most of the cables used in non-professional settings are not balanced, but if you get a condenser mic you will almost certainly need to get a balanced XLR cable for it- and you’ll need a mic preamp that has XLR sockets and probably the +48 volt phantom power mentioned in the last section.

XLR Plugs (balanced)

XLR Plugs (balanced)

Unbalanced Plugs

Unbalanced Plugs

Once you get to this point I strongly advise finding a music store with somebody who has some expertise in electronic recording. There are even online stores that can advise you on making the right purchase. A well-informed technician can be worth his weight in expensive microphones for choosing the right mics, cables, and outboard gear. The next section will discuss the outboard gear.

However, if you are just learning how to do this, don’t get too distracted by the hardware details. You can get a decent recording of your group with a USB adaptor and a decent dynamic mic. Just keep the cable as short as you can, and make sure you use first class editing software like Blaze Audio’s RipEditBurn Plus.

There are a couple of other things to keep in mind when choosing a cable, especially an unbalanced cable. Many unbalanced cables do have shielding, which helps reduce the amount of noise they pick up. However, just because a cable is very thick does not mean it has shielding. Many cables, especially guitar cables, are made with very thick walls to protect them from people stepping on them.

Thick cables are not necessarily shielded, in fact one of the best shielded cables I’ve worked with was quite thin. We used it to record spoken words in a noisy room with the mic about 50 feet from the nearest place we could put the recorder. It wasn’t perfect, but it worked. In general you’ll want to have cables much shorter than 50 feet. If there’s a lot of traffic and people are likely to step on the cable, make sure it’s also thick enough to withstand the pressure.

In general, if you are having trouble getting a signal from a mic, take a look at the cable and make sure the connector is not getting loose. Mics fail, as do amplifiers, but cables are generally considered the most vulnerable part of your recording gear. Fortunately they aren’t very expensive, and it’s probably worth having some extra cables on hand.

Next- Getting the recording into your computer.

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 34 years. He studied with Charlie Schlueter as principal trumpet Minnesota Orchestra for four years. Charlie Schlueter went on to do 25 years as principal trumpet with the Boston Symphony Orchestraā€ˇ. Tom also played principal trumpet for the St. Paul Chamber Orchestra and principal trumpet for the San Jose Orchestra.