First and foremost, this article is geared towards beginners to home recording who are still trying to figure out what gear they need to start their home recording studio. This article has nothing to do with high end mixing consoles such as Neve, SSL, Trident, or API.
Let's Define Our Home Recording Needs
As illustrated in my much more comprehensive guide Getting Started With Home Recording we have the following requirements for any relatively serious home recording studio.
We need a way to control the level of our microphones or line level instruments going into our soundcard / computer interface. This is done with a preamp.
We need a way to monitor what we are hearing while tracking and we need a way to control the the level of the recorded instrument vs that of the already recorded music (if applicable).
That's it! Except for the stuff happening inside the computer, this is all we need. In fact, if you monitor with your recording software, you can eliminate the third requirement all together.
Do I Really Need A Mixer To Do This?
The answer is no. All you need is a preamp and a soundcard that you can run to a headphone amplifier before going to you studio monitors. That's it! In fact, there are quite a few soundcards that come with built in preamps and even more have headphone outputs. Do a search on the Home Recording Soundcard Wizard?for soundcards with built in preamps. You will see there are quite a few!
So What Will A Mixer Do For Me?
I realize that with all those knobs, a mixer should be doing something extra.
Let's break it down.
Preamp – The preamp on most mixers is adequate for home recording. A preamp on the mixer is probably of no better or worse quality than any other preamp of equal price. You can hear how Mackie preamp compares to a $1,000 per channel preamp at my Preamp Shootout.
Why A Soundcard solution is better: In this case, a preamp is a preamp more or less and the soundcard solution isn't better than the mixer. The preamps built into a name brand soundcard are probably very similar to the preamps of a mixer (again, assuming the price of the preamp is about the same). So there is no benefit to using a mixer preamp vs using a soundcard's preamp.
Aux Sends – Aux sends allow you to send a signal out of a ? jack of the mixer into whatever you want. This can be a headphone amplifier, effects processor, compressor, monitor wedges (for live sound), etc. Every single channel has a level control for each aux so you can send out 4 totally different mixes. This is convenient in situations where 4 guys are using headphones and they all think they need separate headphones mixes.
Why A Soundcard solution is better: Not all soundcards come with powerful control of multiple monitor mixes. So, a mixer with 4 aux sends can be better than a soundcard that has no aux sends. However, this only effects engineers who need more than one monitor mix. If you are doing mostly overdubs, you could do just fine with a soundcard with no fancy sends.
Soundcards that use multiple monitor mixes often allow you to control this within software on your computer. This allows you to save your mix settings, which can be very powerful.
If you eventually upgrade to better preamps, you will still have to run that preamp through your old mixer if you want to monitor using the mixer. If you choose to monitor with the software, you can go straight to the soundcard without any trouble.
So before you decide which is a better route, make sure you need aux sends in the first place. You may not.
EQ With Limited Capabilities – The mixer on the Mackie 1604 has a low, mid (with sweep), and high. This means that if you want to cut 80Hz but boost 120Hz, you are out of luck. The mid does allow you to change the frequency you are boosting or cutting, but the Q (width) is fixed. So if you wanted to notch out a narrow 4Khz problem, you can't do it with this EQ. You'll be stuck cutting a very wide hole. The high is the same way as the low. For recording, I consider this EQ “near-useless”.
Why A Soundcard solution is better: I know of no soundcard that offers built in EQ. However, the EQ in recording programs like Cubase, Sonar, Logic, Vegas, and Pro Tools are vastly superior to anything in a Mackie console. The ability to boost or cut just about any frequency you can imagine with fully parametric EQ is a billion times more powerful than the EQ with limited capabilities in the Mackie.
Why You Don't Need A Mixer
So, if you are looking to record a single instrument a time, you only need one headphone mix and you don't need the aux sends. You will need a preamp, but you don't need 4,8, 12, or 32 that may come in a mixer. You could buy a soundcard with a built in preamp or buy a soundcard with no preamps and an external preamp like a M-Audio Audio Buddy ($50) or Neve 1073 ($2,000). If you monitor using your software (which is what I do), you don't need a mixer at all.
If you are recording a full band live with 16 microphones and 4 different headphone mixes, you could do it with 2 soundcards (each with 8 built in preamps) as long as they also include 4 monitor mixes. (There are several out there. Check the Home Recording Soundcard Wizard )
The biggest problem here is the all those knobs look fancy and impressive but don't really do anything for recording that you can do with a nice soundcard.
I hate the fact that I'm paying for components in a mixer that aren't going to benefit my recordings. I'd rather put that money into something else that will improve my recording quality just a tad bit than put into extra preamp capacity, busses, aux sends, etc that I will never use.
Software Has Replaced Mixers
You'll notice that the only real feature a mixer provides (besides monitor...which can also be handled by many soundcards) is getting the signal up to line level and into the computer. After the signal is into the computer, we are home free. Audio recording software like Cubase SX3 (my favorite), Logic, Pro Tools, and Sonar are all extremely powerful. In fact, their capabilities completely blow away what can be done with low cost mixer.
Because recording software is so powerful, it is recommended that take the simplest approach to getting audio into your computer. The less components you run your audio signal through, the more likely you are to keep the fidelity of that audio signal.
What A Mixer Can Do That A Soundcard Can Not
Just to hit this from a different angle, I'd like to discuss what a mixer can do that a soundcard can not do.
Live sound – So far soundcards aren't being used for live sound. So if you have a use for all the sends, preamps, busses, and any other features found in a mixer (that may not be that useful for recording) than it may be smarter to get a mixer.
The live stuff is where the routing capabilities really comes into play with a mixer. I didn't even mention that on the recording side of things because the routing is essentially useless.
Analog mixing – When using a soundcard and computer, if you don't have a mixer, you can not mix with an analog mixer (because you don't have one). I never recommend analog mixing unless a person has at least a $500,000 budget. In that case, you can get a huge console like a SSL, Neve, Trident or API and a slew of mega $$$ outboard compressors, Eqs, and effects.
So, if you go the same route I have you must mix in the box with your recording software. I consider this a huge advantage to anyone who doesn't have 30 channels of outboard compression and a billion dollar console. The highest of high end engineers sometimes say they prefer analog mixing, but they are working in $zillion studios.
For 99% of all home recording people, the mixer isn't necessary in a modern home recording studio. You can bypass it altogether. If you don't need the extra components in a mixer, don't buy them. Instead go with a better quality soundcard. If you would prefer to have the ability for live sound or whatever, then a mixer may be exactly what you need. It's up to you to decide what your needs are what you are trying to achieve.
Some people try to do too much with too little gear. If you want a recording rig that is equally good at live sound, you may end up half assing both the live sound and the recording rig. Generally speaking, it's best to specialize or go with dedicated components.
In the end, just remember that a mixer is not required for home recording. If you don't need the extra features a mixer provides, don't buy one!