Sound Production and Music Recording

Sound Production Skills / Music Recording

Lesson 1 - Monday 3/9/12

Signal Flow

Today we started to have a look at signal flow. Signal flow is how the sound travels through the equipment. It's important to understand signal flow so you can identify problems (and solve them) and also so that you can change where the sound is going.

Firstly the vocalist sings into the mircophone. The microphone converts the acoustic sound energy into electrical energy that represents sound.

We use a XLR (grounded left right) balanced lead (as a balanced cable enables hums and buzzes the lead picks up to be removed) to connect the microphone. If we used an unbalanced rca cable that would pick up interference.

In the college this then goes into a snake box which connects to a wall box that takes the signal into the control room. Not every recording studio has a snake boxs but all will have a wall box. The snake box is numbered and this matches up with the patch bay and mixer.

The sound then goes into the patch bay which is wired in to the corresponding channels on the mixer.

A Stereo out from the mixer will go into an amp and speakers for monitoring.

The mixer is also connected to an audio interface AD/DA which converts electricity into binary so that the information can be processed by a computer (mac or pc) running music sequencing software. The Box can emulate instruments, equipment and is also used for mixing.

After discussing signal flow as a group of 6 we attempted to connect up a microphone to see if we could get a signal going through from the live room to the control room.

We set up a stand with microphone connected an xlr cable between the microphone and snake box, then went to the control room where logic was loaded on the pc.

We came across several problems while trying to set this up. We managed to get a microphone sound to come through the mixer and the speakers but there was a problem getting the signal into the computer and Dan Morgan had to come and have a look. It was apparent that there is usually some sort of problems happen usually occur and that sometimes these are not fixable in a short amount of time. This can lead to recording sessions having to be abandoned.

Setting up a Microphone Stand Correctly  

We was then shown how to set up a microphone stand and asked to set one up correctly.

A Microphone stand consists of the base and the microphone boon (holder). The first step is to set up the base. There is a knob which releases the central pole and allows it to be raised. It is important that the central pole be extended all the way out so that the tripod feet can rest flat on the ground. This is important because sound can travel along the ground and up the metal shaft and cause interference. The tripod feet have rubber stoppers to prevent this but these also stop bass sound escaping to the floor which would cause a loss of signal. With the feet folded out and the central pole fully extended we adjust the mic boon. There is another knob on the boon which allows us to raise or the lower the mic boon. This is loosened and is used to adjust the angle of the boon. The boon is adjusted and rotated so that it extends and is in line with one of the feet, this makes sure that the microphone is more stable and less likely to fall over and cause an accident. 

We then attach a microphone clip onto the end of the boon and it's time to set up the cable.

First we slot the xlr female side through the mic clip and (unlike the photo!) wrap the cable around the microphone boon. We then wrap the cable around the main pole of the stand and make a small coil of cable at the stand base and tuck it a little underneath it. This is in case we need to move the stand in future and to prevent accidents. We then clip the cable to the stand with a cable grip and we are ready to attach the microphone. 

The microphone slots into the clip and the female end of the xlr cable is connected to the male socket on the mic and we have a correctly set up microphone stand.