Thursday, 20 March 2014

Mix that Mic, DAWg!

Two weeks done, 50 more weeks to go!

As I wrote in the last regular entry we started to learn about mixer consoles last week and I will elaborate a bit what we've learned so far about a mixer console and its components.

Let's start of with its purposes. What is a mixer for? Well, sounds like an easy question to begin with.
1. Summing up the single tracks to one stereo track
2. adjusting the ratio between the volumes of each track
3. frequency editing
4. effects
5. adjusting the balance/panorama or each track
Moving on to the mixer itself and its most important parts.
1. Gain (Eingangsverstärkung)
2. 48V Phantom Power (48V Phantomspeisung)
3. AUX Send
4. PFL (or "Pre", "Pre Fade"; = Pre-Fader Listening)
5. Insert Send/Return
6. EQ (= equalizer)
7. Subgroup Routing (Subgruppen-Routing)
8. Solo Bus (Solobus)
9. Pan(orama)
10. Faders
11. Faders for Subgroups (Subgruppenfader)
12. Control Room Pot(entiometer)
13. Phones Jack (Kopfhörerbuchse)
14. Master Fader
15. Talkback
16. Metering (VU-meter)
Of course, there are more components which differ from mixer to mixer, but at least those 16 components should be present.

We also had a short introduction into microphonics, the last topic on Monday.

Firstly, the purpose of a microphone is to converts fluctuations in air pressure (which we perceive as acoustic noise if the fluctuations are between 20Hz and 20kHz) into electric energy, so that a mixer console has something it can work with. Secondly, there are so-called "directional characteristics". They define in which area (front, back, left, right) a mic records and which frequencies it records in which area.
We've just been talking about 6 directional characteristics, but there are some more. So, what are those 6 directional characteristics?
1. Omnidirectional/Undirected (Kugel/ungerichtet!) [pic]
2. Cardioid (Niere) [pic]
3. Hypercardioid (Hyperniere) [pic]
4. Supercardioid (Superniere) [pic]
5. Shotgun (Richtrohr/Keule) [pic]
6. Figure 8 (Achter) [pic]

All of those directional characteristics have their fields of operation. Some are better for interviews, others work better with certain instruments. It really depends on what you want to record and how the room you're recording in is designed and sounds.

An important distinction for mics is whether your mic is a "condenser" or "dynamic" mic. You could say that this distinction isn't just important, but vital for the lifespan of it.

You might ask, "But Hörlöwe, 'vital' sounds pretty exaggerated. If it really is vital, why is that?"

That's a very good question and I'll gladly answer. Handling a mic incorrectly can destroy it. Simple as that. And if it's a very expensive mic, i.e. Brauner, Neumann, DPA - other expensive mics are available, it will probably gall you to no end.

So, why exactly is this distinction important?

Condenser mics are much more susceptible to vibrations than dynamic mics. If you drop a dynamic microphone, nothing much will happen. Hell, if you drop a dynamic mic from a height of 2m, it would still work fine just like before. But if you drop a condenser mic or just give it too much of a physical shock the diaphargm/membrane inside can go tits up. The microphone would be no more. It would have ceased to be. Expired and gone to meet its maker. Shuffled off its mortal coil, run down the curtain and joined the bleedin' choir invisible. It would be an ex-microphone. So, please, don't drop condenser microphones. Handle them and all other equipment with care.

Mass grave. RIP.

There are certain other differences between those two types of mics. While condenser mics need 48V phantom power, dynamic mics get along just fine without those 48V. Dynamic mics are more resistant to feedback and have built-in impact sound insulation. Condenser mics are more delicate. They can record smaller air pressure fluctuations (quieter acoustic noises), their frequency spectrum is more linear and the resolution is higher. But as I wrote earlier, they tend to break more easily if you handle them incorrectly.

This is just a short summary of what we've dealt with in class. Even so, you can see what the scope of those mics are: dynamic mics feel right at home on a stage, while condenser mics prefer the warmth and safety of a recording studio.

The last topic we touched on Monday was "interfering influences while recording with a microphone" and this concerns ALL directional mics, not the omnidirectional though. Oh, and dynamic mics compensate for those influences pretty well.
1. Proximity (Nahbesprechungseffekt)
Proximity effect comes into play if you get to close to a mic while speaking. The nearer you get, the more pronounced this effect will become. What's happening there? The bass or lower frequencies get boosted because the mic picks up in-phase sound in front of and slightly out-of-phase sound behind it.

2. Wind & Plosives (Wind & Explosivlaute wie P, T, K, ...)
Rushing of wind, plosives and other wind-related noises can disturb a perfectly good recording session. The most common way to prevent that is a pop filter or windjammer. Just place it in front of or over the mic and all's well that should be well.

After school we went to grab something to eat and since I wanted to do the first exercise today my lunch break was quite short. I started with my first "mini mixdown" where I had to mix 8 tracks. Getting the volume of each track in a good relation to the other tracks was the fist big task. After fiddling about with the gain pot and the faders I decided to send the drum set to a subgroup and all the string instruments (3x guitar and 1x bass) to a second subgroup, so I could simply raise the volume of each subgroup, since the relation among the tracks of each subgroup were good. Next up was the EQ. I took my time adjusting the EQ for each track, looking for frequencies to be brutally cut or gloriously boosted. Effects-wise I just used a vintage phaser for the bass guitar and two out of three guitars. I applied some final touches with some reverb and panning of the tracks. Voilà, the first mixdown was done... and now Supervisor Marco made his appearence and had to listen to what I mixed. Well as expected, some errors were made, especially a routing error. I double-routed some tracks via main L/R and via a subgroup, which boosted the volume of those tracks. But I also got praise for my choice of effects and the rest. I haven't done too bad for my first mixdown, if I may say so myself. But it was far from perfect and I still have a long way to go to become a good audio engineer.

Tuesday was the day of the "Recording Systems" or DAW (digital audio workstation). Michael explained in depth the two different recording systems that are in use today and that DAW is a very vague term, which only means a transducer with memory/storage and editing possibility. The two main recording systems are:
1. Standalone systems and
2. Computer-based systems
Standalone systems have a very sturdy casing and are extremely reliable. The software running this system is stripped down to a bare minimum to ensure maximum stabiliy. Plus, they are easy-to-transport.

Then there are the computer-based systems which are basically computers (Mac, PC, Linux) and maybe additional hardware. They can be divided into native systems and digital signal processing-based systems. Native systems run on a computer's CPU power alone, making it very resource-consuming. DSP-based systems require further hardware, either internal or external. It's a special hardware just to support the host computer and processes all signals. The computer is just using its computing capacity to display the GUI. The latter of the two systems is more reliable.

Besides that he explained some terms that have to do with recording systems:
linear/non-linear and destructive/non-destructive recording, audio interface, sequencer software and latency and how to avoid it through direct monitoring & buffer size. But that's something for you to look up. If you want to know more, leave a comment. =)

And Tuesday was, of course, aural training day. I started CD #4 and guess what the exercises were about. No, not frequencies. Well, not really. Who said "effects" just now? You! Yes, you over there! You're right. Effects were on today's agenda again. I should mix in some frequency exercises. It would make for a nice change and I would do better in the drill sets that involve the effect "equalization". Either next time or next week. I'll see.

Well, that's all for today. Cheers!

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