Thursday, 19 July 2012

Mixing 101 - Making Gains - Part 2 of Many

Last week I discussed how to set-up a mixing desk properly but left you in the lurch on the 3rd step which is setting the gain on each channel. This subject deserves an entire post on its own due to the influence it will have on how well things will turn out.
Firstly, there is a lot of quite complex physics and maths related to this topic which I have purposefully left out. Hopefully my crude metaphors will explain the topic a little more easily than a physics or maths class.

Lets first take a look at what gain actually is.
For starters, the level of the signal that comes out of a microphone is tiny. It is so small that you can't really do anything useful with it at all.
In order for us to be able to do some useful things (like EQ and effects), we need to make the signal 'bigger' or 'louder' than what a microphone can produce.
We do this with something that is built into every single mixing desk called a pre-amplifier or pre-amp.
The gain knob simply controls how much we amplify the microphone signal so that the mixing desk can do useful things with the signal. Think of it as just like a tap that can open up or reduce the flow of water going into a sink (our mixing desk). If the tap is too high, then the water comes in faster than it can go down the plughole and the sink overflows. If the tap is too low, then the water drains away before any collects in the sink.

If the signal coming into a mixing desk is too weak, then we have to turn the faders up really high to get it loud enough, this results in noise or hiss because we are also turning up all of the unwanted signal that gets generated inside the mixing desk by all the electronics.
If the signal  coming into a mixing desk is too strong, then it will begin to hit the operating limits of the electronic components in the mixing desk and the sound quality will degrade with distortion. (the sink will overflow).

What we need is every single signal coming into the mixing desk to be like Goldilocks porridge... just right.

The gain knob can be used to increase the 'volume' of a weak signal, or decrease the 'volume' of a strong signal so that each instrument is the exact same level.

We call this 'ideal' volume Zero (technically this is called 0dBu but don't worry about what the U means too much) and it is usually marked about 3/4 of the way up the meter scale. Anything below Zero has a minus in front of it, and everything above Zero has a plus in front of it. The 'space' above Zero is called Headroom and means just what it sounds like it means....

If 50 people get on a bus, then they will be all different heights, so they build buses with a bit more space above everyone's heads so that the tallest people do not have to duck down. Headroom in a mixing desk works the same way as a bus roof and generally the more headroom a desk has, the more expensive it will be. Just like a bus with 2 meters of headroom would be expensive. However if occasional you carry very tall people, that extra Headroom can be very handy.

Lots of headroom is a good thing and is worth paying a premium for.
Cheap desks will only have +6dB to +9dB (I have left off the U to avoid explaining some complicated stuff) above zero, while expensive desks could have +18dB to +24dB (or even more) headroom.
All that additional headroom gives you much more control and will contribute directly to the sound quality of the end result.

You can see in the photo of the Allen and Heath Zed mixing desk above, this desk has +16dB of headroom above zero which makes it pretty good for a small desk. Take a look at your own mixing desk and see what it goes to before it peaks out (note sometimes desks go a little bit higher than the meters show just in case).

Gain also goes in the other direction (minus) and how a desk behaves at the other end of the spectrum is just as important as what it does with very strong signals. This is because gain is directly related to noise.
Every single audio device generates noise. Noise consists of hiss and is not unlike the sound that cassette tapes used to make (showing my age now). We measure the amount of noise a device makes relative to its distance from our 'ideal' Goldilocks level. This is called the noise floor and we want the noise floor to be as far away from 0dB as we can get it. The closer the noise floor is to 0dB the more hiss we will hear in our sound system. When you are buying audio equipment, always make sure you look up its noise floor (again, it is worth paying a premium in this area). This information is usually buried in the technical specs at the back of the user manual, but is actually more important than most of the headline features that you see on the glossy brochures.

To give you a bit of a feel for what is good and bad:

  • A cassette tape has a noise floor of around -65dB. That means in the quiet bits when there is nothing recorded, the volume of the noise will be -65dB. We all know how bad the hiss was on cassette tapes, so if you buy audio equipment with a noise floor around this level it will have as much 'hiss' as a cassette tape.
  • The noise floor on a cheap mixing desk from an un-named manufacturer beginning with the letter B is -85dB. Obviously better than tape, but don't forget that sound systems are generally much louder than home stereo's which means the noise will also be louder. Equipment from this manufacturer is notoriously noisy.
  • The noise floor on a typical home stereo is between -80dB and -95dB (for a good one). Obviously CD based systems sound much better than cassette tapes, so this gives you a good reference but often you can hear the hiss in your home stereo.
  • The noise floor on our  Allen and Heath Zed reference desk is -100dB. This is what I would recommend as an excellent noise floor for a mixing desk without getting too expensive, at this level, when you turn up the volume to full and have no music playing, the hiss will be barely noticeable.
Now onto the fun stuff...

Once you have completed the line check I described last week, the next step is to set the gain on each channel.

Get your helper to play each instrument and check each microphone once again, it is imperative they do this at performance levels. The classic bad example of this is saying "Check 1,2" into the microphone at a whisper, then peaking out all your channels later on when someone actually sings into the microphone at performance levels.

To set the gain, press the PFL button on the channel you are setting and slowly turn up the gain knob until the signal on the meter sits nicely around zero and occasionaly peaks to +3dB for only the loudest parts. (If you have a realluy good desk and are a competent sound engineer, you make like to make 0dB the average and have your peaks go considerably over 0dB).

If your gain knob is turned all the way down and the signal is still way over 0dB then press the PAD button on that channel which will reduce the signal by 20dB, you can now start turning up the gain again until you get the signal just right.

When you have done this for all of your channels you have now completed setting up your mixing desk and you are ready to move onto the next step which is the actual sound check.

Thursday, 12 July 2012

Mixing 101 - Line Check - Part 1 of Many

This week we start a new series of posts that will concentrate on mixing desk fundamentals.
I'll be using the Allen and Heath Zed series of desks as a reference for this series, mainly because they are probably the best quality small format analog mixer on the market right now and also because they have all of the most important functions we will be talking about in this series and none of the unimportant ones that often clutter desks up.

Lets say you have just un-wrapped a brand new mixing desk and are about to use it for the very first time.
Where do you start?
Its tempting to just dive in and plug stuff in, and rather than be a killjoy who tells you to read the manual from A to Z whilst 'familiarising yourself with your new mixing desk's layout", I'm actually going to suggest its not actually such a bad idea.

But here are a few suggestions to make the process less painful..
Before you plug in anything, zero all the faders, slide them all the way down to nothing so that no audio signals can come out of the desk.
Next find the gain or trim knobs (usually right at the top of each channel strip) and spin them anti-clockwise all the way down to nothing.

The rest of the channel strip knobs also need to be set to zero, where zero is will depend on what the knobs function is. It is important NOT to set them all fully anti-clockwise.

The following knobs are zero'd in the full anti-clockwise position:
- Anything with AUX written on it
- FX sends

The following knobs are zero'd when in the 12 oclock position (pointing straight up):
- EQ  (usually labeled HF, HM, LF etc)

If your desk has a phantom power switch (usually labeled with '48v') on each channel, make sure it is off for now.

Now you are ready to begin, I'll take you through the process of getting ready to use your desk. You go through this same process every time you use it, for every gig, no matter how big or small. The same process should be used when playing on a Thursday night at the Cossie Club or at an 80,000 seat stadium show.

Step 1 - With all the faders and knobs zero'd, plug in all your instruments into the channels you want. Set them up in a layout that is easy and quick to access and try and use the same layout everytime you play. The 'unwritten' soundguy standard is to put drums first, bass, then guitars, then other instruments and vocals last. Plug your PA or speakers into the desk outputs.

Step 2 - Line check. This step is just to make sure that everything is plugged into the right channels. One person taps each mic or makes a noise on the line while the other person checks the desk. Most desks have a PFL button that helps with this process. While a helper taps the kick drum mic, press the kick drum PFL button on the desk and slowly turn up the gain / trim knob until you start to see the signal on the signal meter. If you don't see anything, check the microphone does not need phantom power (turn on the phantom button if needed). If there is still nothing, you have something plugged incorrectly, or you have a faulty cable or microphone. Get this sorted before moving on. Work your way through all of the rest of the channels until everything is where it should be.
Note: You haven't turned up any faders yet, and no sound has come out of the speakers.

Step 3 - Setting the gain. This is the most important step, in fact it is so important I am going to dedicate an entire post to it next week. Getting the gain right is the single most important thing you can do to ensure whatever you mix sounds great so it is worth spending a bit of time understanding what this misunderstood little red knob actuall does.

Thursday, 5 July 2012

The Value of Live Music.

A deviation from technical subjects today to discuss a topic near and dear to me.
What is the value of live music?
How much should your band charge?

The answer to this question is that "It depends".
One of the problems with live music is that from a musicians perspective, its is a pretty fun thing to do.
Getting up on stage is an exhilertating and satisfying experience and that has a nasty side effect in that it often clouds a musicians judgement on what is a wise thing to do.

When you have a fun job and you get offered an opportunity to do it, of course you want to accept every opportunity that comes along because you don't really see it as a job. The problem is that many of these opportunities are to perform for free and by agreeing to perform for free you are basically shouting out at the top of your voice that your performance is not worth anything.

Think of it this way....
As you walk into a McDonalds, someone hands you a voucher for a free Big Mac. Mmmm nom nom nom you think.
So you go to the counter and get your free Big Mac.
Just as you are walking away from the counter, your Big Mac slips out of your hand and smashes to bits on the floor.
Oh crap you think, but how upset are you really? Chances are you will just shrug your shoulders and say "Oh well, it was free anyway".

Now if you paid for that same Big Mac, you are going to be a whole lot more upset about it because you made the concious decision to part with some money in order to get it. Really think about that for a second and about how you may have used the words "Oh well it was free anyway" at some point in the past.

They are the same Big Mac and they cost exactly the same to make, however, we don't value the free one at all, while we place a higher value on the one we paid for. The free one is nice to have and we certainly enjoy it. But if we didn't have it or we lost it we wouldn't really care at all. When you pay for something, you enjoy it more and generally the more you pay for something the more you tend to associate it with quality. Think of wine and how much people pay for a 'good' bottle of wine.
Its just wine, but for some reason, some people think that a bottle that costs $500 tastes better than a bottle that costs $20.
Really the only thing that is different is the price. The wine still came from grapes on vines and probably cost around the same to produce. Its just they probably made a LOT of the $20 bottle and not very much of the $500 bottle.
Still, wine 'people' will swear black and blue that the $500 bottle tastes better.
It doesn't taste better, it just tastes different.

Unfortunately for us music works the same way.
If you play for free, your performance will not be valued, you will not be valued and you are effectively telling people that your product is worthless.

So how much should you charge?
Well again, it depends.

If you are a huge international star and a promotor is selling tickets for your show, then your value is quite high for obvious reasons. But how much is a band playing in a pub worth?

If a band just turns up and plays 3 hours of covers, does no promotion for the event, doesn't bring any followers and doesn't encourage people to spend money at the bar, then the value of that band is quite low. Its simple economics, if a bar has to pay you $1000 but the bar only makes an extra $500 by having you there, then you are overcharging.

However, if you promote to 5000 facebook fans, you print posters, you generate a huge buzz about your gig and bring an army of followers to the pub that all spend a small fortune at the bar, then you will quickly find the demand for your band goes through the roof and your ability to charge a high rate goes up accordingly.
The pub will also not care if you play covers, originals or the theme songs to childrens programs because they are making significantly more money than what they would if you were not there.
This same model works for any type of event but pubs are the easiest and most common example to work with.

Musicians often complain about being poor or only being able to charge a couple of hundred dollars for their whole band to perform.
This probably means you are doing something wrong.

If a pub says to you "We only pay bands $300" then you are doing something wrong.
If a pub says to you "How much do you charge" then you are doing something right.
If your answer is $2000 for a 3 hour show at a pub, then you are doing something really right!

In order to maximise how much you can charge, my advise is to:
- sort out your marketing and promotion and make sure it is top notch
- generate a following and a huge buzz around every performance.
- create a reason for people to come to your shows (new songs, giveaways)
- Actively pursue a large facebook following
- Make sure you have a top quality website with all your news and gig info
- Name a drink after your band and get the bar to do a special on it then get everyone to buy one.
- Book gigs in blocks, give pubs a discount for booking you for 5 gigs in advance over the next 6 months.
- Actively promote the pub during your gigs, actively promote the bar and any drinks specials.
- Actively promote your next performance at the same bar, say when you will be back.
- Actively tell everyone your band name at least 5 times during the show so it sticks and they remember.
- Make sure your audience has an awesome time!!! (don't just play for your own satisfaction)