The "N+2" Rule: How to Choose a Mixer with the Right Number of Channels

You’ve decided to buy an audio mixer. Immediately, you’re faced with a dizzying array of choices: 6-channel, 10-channel, 12-channel, 16-channel… The number of channels is the single biggest factor in the size, complexity, and cost of the mixer.

Choose too few, and you’ll outgrow it in six months. Choose too many, and you’ve wasted money on features you’ll never use. So, how do you find that “just right” Goldilocks number? Let’s ditch the guesswork and use a simple, future-proof formula.

The Travel Analogy: Pack for the Trip You’re Taking

Think of the number of channels like the capacity of a suitcase. You wouldn’t pack for a two-week international expedition using an overnight bag. Conversely, you don’t need a giant steamer trunk for a weekend trip. The key is to realistically assess your needs.

First, let’s learn how to count. “Channels” refer to the number of individual sound sources you can plug into the mixer at one time.

Step 1: Count Your “N” - What You Need Today

Be brutally honest about your current, most common setup. Let’s count the inputs for a few common scenarios:

• The Solo Podcaster/Streamer:

  • 1 for your main vocal microphone.
  • Maybe 2 more for a stereo input from your computer for sound effects or music.
  • Your N = 3

• The Singer-Songwriter:

  • 1 for your vocal microphone.
  • 1 for your acoustic guitar microphone (or direct line-in).
  • Your N = 2

• The Two-Person Podcast:

  • 2 for the hosts’ microphones.
  • 2 for a stereo computer feed (intro/outro music).
  • Maybe 2 more for a phone call input via a specific device.
  • Your N = 4 to 6

• The Full Band (Basic):

  • 1 for lead vocals.
  • 1 for backup vocals.
  • 1 for bass guitar.
  • 1 for electric guitar amp mic.
  • At least 2 for drums (a simple kick mic + one overhead mic).
  • Your N = 6

Step 2: Apply The “N+2” Rule for the Future

Now that you have your number “N,” here’s the rule: The minimum number of channels you should buy is N+2.

Why? Because something always comes up. * A guest unexpectedly joins your podcast. * Your duo becomes a trio. * You decide you want to add a dedicated reverb pedal, which uses up a stereo return (2 channels). * You want to mic both the speaker and the direct out of the guitar amp.

That “+2” is your buffer. It’s your “just-in-case” insurance policy. It’s the small bit of extra room in your suitcase for a souvenir you didn’t plan on buying. It prevents you from having to sell your mixer and buy a bigger one the moment your needs evolve slightly. For the band scenario above, their N is 6. Applying the N+2 rule means they should be looking at mixers with at least 8 channels. A 10 or 12-channel mixer (like a Yamaha MG12XU) would give them even more comfortable room to grow.

A Quick Word on “Stereo Channels”

Be careful when reading the specs. A “12-channel” mixer doesn’t always mean 12 microphone inputs. Often, some of those channels are “stereo pairs” that share one set of controls and use quarter-inch line inputs, not XLR mic inputs. For example, the MG12XU has 6 dedicated XLR mic inputs, with the remaining channels configured as stereo line inputs. Always check the number of mic preamps if you plan on recording with many microphones.

Conclusion: Invest in a Little Wiggle Room

Choosing the right number of channels is about finding the balance between your current reality and your future aspirations. By carefully calculating your “N” and applying the “N+2” rule, you can make a smart investment. You’re not just buying a piece of hardware; you’re buying the capacity for your creativity to grow. A little extra room in the suitcase is never a bad idea.