Mixers

[dogcop]

Afternoon Blue Room

 

First, please forgive my ignorance , the purpose of this post is for me to learn. I do not knoww a lot about sound but I wish to increase my knowledge on the subject

 

After a discussion at church yesterday about mixers the question arose as to "what are you getting for your money"

This page picked at random http://www.thomann.de/gb/search_dir.html?g...;sw=mixing+desk

 

It shows the same amount of channel desks but the prices range from 300 pounds to nearly 3000.

 

Now I appreciate you get what you pay for and in any piece of equipment. you get the Lada and the Ferrari, BUT, what is the differences in these models?What will the more expensive units do better than the mediorcre priced units?

 

What does a mid range price have that a cheapo doesn't?

 

When the question was put I didn't really have a clue other than I'm guessing some are digital desks as opposed to analogue. But does that mean that analogue desks are on their way out and digital is the fromat to use for the future ?

 

Questions questions Questions

 

Many thanks for your time and thoughts

 

Andy

[paulears]

An interesting one - I'm sure there will be plenty of answers

 

Features

Capacity

Reliability

Sonic quality

Build quality

Operation style

 

At the most basic, a mixer allows you to merge/balance two or more inputs to one or more outputs. Mixers at the other end of the complexity scale can mix dozens of input channels to large number of outputs. Most, on the way through, allow gain to be adjusted to cope with low output mics, right through to line level equipment such as CD/MD/Computers etc. Equalisation (posh or clever tone controls) allow more tweaking. Simple mixers don't offer the range and accuracy of adjustment that more complex ones do. Reliability - well they go from 'damn good job it has a guarantee' to 'never been looked at in 20yrs'.

 

Sonic quality is a good one. This involves avoidance of noise and distortion, and having as higher quality sound as possible. As few people can put this 'sound' into words, I won't try.

 

Some are flimsy - reliable, but flimsy. Knobs break off rather than bounce back. Some are designed to be toured, others are better at being in one place for ever.

 

Some small size mixers with decent specs are very complex - lots of switches buttons and knobs that take a bit of getting around. Some lager mixers have plenty of space for grouping common buttons together, or having some system of overall control - making life easier for the op.

 

The new digital systems work very differently from old fashioned analogue - most now sound great, but have a different operational philosophy. Knobs no longer have to have single functions - different users can have their own set ups stored and recalled.

 

 

In practice, this means that you need to work out what you need one to do - then look at the list and assess each individual one.

 

Expensive may no longer equal best - just different.

 

Just a ramble, really.

[Bobbsy]

An interesting topic indeed, and Paulears gives a very good basic overview--good enough that I'm going to steal his topic headings!

 

Features/Capacity: Features and capacity are very inter-related. At the most basic, the brochure headline about a mixer is going to be the number of input channels and obviously this is important. You need enough inputs to handle the largest project you can foresee. Indeed, it's generally worth going for about 50% more inputs than you can ever see yourself needing because you needs ALWAYS grow in ways you can't predict.

 

However, there are other features you need to consider, particularly for live work.

 

Foremost amongst these is how many outputs you have. These outputs can take the form of "Aux" channels and Mix Buses. Auxes tend to be some of those rows of little knobs on each channel are have two main uses. First, they are a way of sending the signal from each channel to some form of effects unit to be brought back into the board with reverb or whatever. Second, they allow you to do a customised mix of multiple channels for things like stage monitors, feeds for video relays, the "quick recording" the director wants or a multitude of other things. Cheap mixers tend to have few auxes and the ones they do have can be inflexible in terms of how they're routed. Expensive mixers tend to have more...and allow more selection of things like whether the aux is before or after the fader. The other form of output tends to be a mix bus. Cheap mixers often just have the main stereo output; slightly better ones give you a mono output as well while big mixers allow multiple different routings. Again, this is useful in live work, allowing you to (for example) put the vocals on the main outs and spot sound effects to dedicated speakers in the "right" location around the auditorium.

 

As Paul mentioned, a feature where there are big differences is in the EQ section of the mixer. EQing a live microphone is difficult to learn but is part of the real art of sound mixing. The difference in quality of EQ between the cheapies and the expensive desks is huge; you can be far more accurate and precise with a better EQ while the knobs found on the less expensive mixers are often next to useless. I've heard the analogy of it being like trying to do surgery with a butter knife instead of a scalpel!

 

Another feature you may or may not find, depending on cost, is built in effects. It may cost extra to have these on the desk but, on the other hand, it's often cheaper in the long run to have them built in than to buy an extra "outboard" box. Conversely, by buying a separate unit you might get better quality.

 

That's the main "big" features but there are lots of other things that can vary, usually affecting flexibility and ease of use. Some differences you may find are things like the quantity and quality of metering, polarity reverse switches, built in provision for intercoms, sockets for lights, etc. etc. It would be impossible to go over everything in a post of manageable length and, frankly, until you start using a mixer you don't realise what you need and value. (As an aside, I still remember many years ago my horror at the beginning of the first show I mixed when they turned out the house lights and I couldn't see my script or mixer. It never occurred to me that it would get dark!)

 

Reliability/Build Quality: This can be a big area of difference between the low and high end of the market, though spending money is no guarantee of reliability. Generalising horribly, most cheap mixers are built with one big circuit board inside while more expensive ones are modular with each channel (or at least groups of channels) plugging in separately. This, to a large extent means that, when something goes wrong, the cheap mixer is not economic to repair while the more expensive one can be maintained. Over the years, this can make it a better investment to spend a bit more up front.

 

One other point worth making on reliability is the power supply. This is a component where, if you're going to have a problem, it'll likely occur. On a cheap mixer you only have one and, if it goes, you lose your show. More expensive mixers generally allow the use of a backup or dual power supply so if one fails, you keep going. In a studio this might not matter, but for live work it can be a big issue.

 

Sonic Quality: Like Paul, I'm not going to try and describe sound with words, other than to say some mixers simply sound better than others. Words like "open", "natural" and "warm" crop up all the time--perhaps a bit "audiophool" in nature but they do reflect some of the differences.

 

Beyond that, three things are worth mentioning in terms of sonic quality.

 

The first is the EQ section, already discussed under features.

 

The second is the quality of the microphone pre-amps. The signal from you microphones enters the mixer at an extremely low level and is immediately amplified by the mixer up to a working "Line" level. Because of this, the mic preamps can have a major effect on the way things sound. It is very easy to find a specialist mic preamp that costs more than a whole 16 channel cheap mixer so it's obvious there are some compromises going on in this area. Suffice to say that the mic preamps in cheaper mixers can be prone to noise (being "hissy") or adding distortion when levels get a bit high. The better the mic preamp, the less noise and less tendency to distort.

 

The third issue in sonic quality (or should it be build quality?) is headroom. As you mix more and more signals the overall level the mixer is handling keeps going up and eventually hits a level where it can't cope and adds distortion. On better mixers, there is more headroom (i.e. more space between normal operating levels and the point at which you hit distortion). Also, the onset of distortion on good mixers tends to be more gentle and less noticeable.

 

(It's worth stating that, with a digital mixer, clipping is NEVER gentle so they tend to be built with oodles of headroom...which poor operators then use up by pushing the system farther than they should!)

 

Operation Style: It's hard to be specific here, but better mixers tend to be better designed for ease of operation. Knobs and faders are smoother, switches fall to hand better, labelling makes more sense and so on. As always, more money doesn't always mean better...but chances are that it will be that way in most cases.

 

Also, cheaper mixers tend to be purely manual, while the "big boys" have exotic forms of scene memories, remote controls, Voltage Controlled Amplifiers (which let you group channels together and control them from one fader) and so on. Again, there's too much to explain but once you start mixing you'll start saying "I wish I could....". Fulfilling those wishes is where the more expensive mixers come in. (Can you tell I'm a gear ####?)

 

Finally, a note on your question about digital mixers. The situation is slightly opposite to what you're guessing: most people move to digital to save money. I better explain. The cheapest digital desks still cost more than the low priced analogue ones, but they tend to have far more features. For example, they tend to have things like compression and limiting on every channel...doing this with separate boxes on analogue would cost a fortune. They also tend to have more and better effects built in. Finally, (often by using layers) they tend to cram far more channels into the same size package. In the professional world, where audience seats are taken out to make room for a mixer, every seat you can save makes the producers more money.

 

For these reasons, there IS a trend in the live sound world to move to digital. It's still far from universal (and hasn't filtered down to the low end of the market yet) but that's the way things are moving.

 

Anyhow, hope this helps.

 

Bob

[dogcop]

Fantastic posts guys- worthy of a thesis methinks !!!!

 

Thankyou very much for taking the time I am much clearer now.

 

I feel I can at least sound as if I know what I'm talking about rather than waffling like a 5 year old with too many E numbers in his system!!!