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How to Hookup an Analog Mixer
To a Soundcard or Audio Interface
by Tweak

So many newbs think you need to connect the main outs to a soundcard and can monitor off the control room outs too. Is that you? Hah! Enjoying that high pitched whine
every time you want to record? That's called FEEDBACK. You are getting it because you hooked up the mixer improperly. Here's some better ways. First with a cheap mixer (which I don't recommend) and second, with a mixer with an alt 3-4 bus or direct outs (required if you are serious!)

One Way Communication: Mixer to Soundcard
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Here's all you do is connect the
main outs of the Mixer to the soundcard line input(s). You then connect your speakers to the
line outs of the audio interface or soundcard. That's all you do. Yes, you will need adapters if you have a
Soundblaster type 1/8th inch input on the soundcard and typical 1/4 inch phone jacks as outputs of the mixer. You may also need adapters to connect your powered monitors to the soundcard's output.
Advantages:
Any stereo mixer will work
Its easy
Disadvantages:
Monitoring directly off a soundcard with active monitors means you have to control the volume in software on your computer. This is less than ideal. If you have multimedia speakers it's not so bad because there is a volume control on the speakers. Active monitors may not have that and your monitors may occasionally blast you with full volume (that's loud!)
You cannot monitor your external MIDI synths while you record or they will get recorded too. There is no way to
separate the signal. If you are just using soft synths this is not a problem.
You can't monitor the mix at the mixer.
Two Way Communication: Mixer to Soundcard AND Soundcard to Mixer with ALT 3-4 Bus
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Here's what an
ALT 3-4 bus looks like on the back of a mixer. The Mixer shown is the
Mackie 1402 VLZ3

This is for people that want to connect their
active monitors to the mixer, as it is done in advanced studios.
Note the following:
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You need a mixer with an
ALT 3-4 output (sometimes called a subgroup out, or group out) You can also use direct outs (see below) from two channels. Don't go cheap if you want this bi-directional communication between mixer and soundcard/audio interface.
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The subgroup (ALT 3-4) connects to the soundcard line in. The soundcard
line out connects to any two available line inputs. The can be aux returns, tape ins, or channel line inputs (preferred).
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The active monitors (or cables to an amplifier) go to the CONTROL ROOM OUTS.
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NOTE: Though it defies newbie common sense wisdom, you do not have the main outs connect to anything. The Control Room outputs act as the main outs and acts as a volume control for the whole system.
- You simply press the ALT 3-4 button (often the "mute" button) to send the channel to the soundcard.
Advantages:
- You can monitor both the signal you are recording and the playback signal from the computer. You can use the headphone jack and this will keep the studio quiet and the recording clean.
- You can adjust the level of your monitors from the mixer.
- You can put processors like compressors in between the alt3-4 out and the soundcard input.
- You can
monitor your external MIDI synths and modules without recording them to audio
and when you want to record them to audio it's just a button press away.
Disadvantages:
Mixers with ALT busses cost more,
but are worth it in my opinion.
Note:
The same setup applies to large 8 bus mixers like the Behringer mx9000
and Mackie 24-8, except with these you have 8 alt outputs instead of 2.
Here's nmodi's famous pic (my eternal thanks for his graphic wizardry)
Two Way Communication Mixer to Soundcard AND Soundcard to Mixer with Direct Outs or Inserts
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Simply connect the direct out on the channel you want to record to the soundcard's line input.
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Note: When a cable is connected to the direct out jack, the signal from that channel goes down it and is removed from the rest of the mixer. That is, it goes out, but does not go through. So the signal travels to the soundcard, get recorded, and if software monitoring is ON in the sequencer, it comes back with the soundcard output.
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You can sometimes use inserts to function as direct outs by inserting the plug in "halfway" (to the first click). Not all mixers have these. The cheaper mixers do not

This pic, from
a Soundcraft M12
(which has no conventional busses) shows the direct outputs and inserts at
the top of the mixer.
Workaround with a mixer without an ALT bus, direct outs or inserts
If you already bought a cheap mixer without alt/subgroups out here is the workaround.
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Connect two of the
send outs (hopefully you have 2) directly to the soundcard. Bring the soundcard output back to
any 2 available line in channels. Yes you may need adapters to take the 1/8th inch stereo out of the soundcard to two
separate line in jacks. You need an stereo mini jack to dual mono cable.
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On your mic channel, when you want to record, turn up the send on that channel so the signal goes to the soundcard.
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In some situations you may have to turn off "software monitoring" in your sequencer software while you record.
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NOTE: If you still have feedback you might use the TAPE inputs on the mixer. This works sometimes but often will not allow you to monitor your hardware synths playing back MIDI. Its hard to give an absolute answer as every mixer is slightly different. Experiment before you ask a question about this, OK? Try the Tape, try the line ins, try the aux returns, try turning software monitoring off. One of these 6
possibilities usually works.

In the
Behringer 1002 you only have one FX send, so that means you will have to record track at a
time in mono. Note that you can send both channels back to the mixer.
You could also route the cables from the soundcard to the tape in jacks.
Mixers with ALT 3-4 outs
Course there are others.
This is not a comprehensive list, but those that list this feature. Always
check the manufacturers website and read online product manuals to see if the
mixer features you need are listed.
Go to the
Next Class

Go back to
page 3 on Mixers
Check out my
article on choosing a mixer
Go to the studio
central forum on
Mixers
• Choose a Mixer • • How to set up a Mixer • • Picking the Right Monitors • • Making the Perfect Mix • • Using Pan Controls • • Using EQ • • Mixing in Software vs Hardware • • Guide to Control Surfaces • • Mastering at Home • • 16 vs 24 bit Demystified • • Basics of Surround sound • • Catalog: Studio Monitors • • Catalog: Mixers • • Using Waves Plugins • • Mixer Calibration • • Review: Mackie 1402 VLZ Pro • • Review: Mackie HR 824 • • Review: Behringer MX9000 • • Setting Up Surround on an 8 Bus Mixer • • Configuring a Recording Rig-Page 3 •
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