Trying to understand field mixers

Slash6airhead

Slash6airhead

Member
I have been hearing a lot about field mixers. I just don’t get why Sound devices recorders excel if used along with their mixers.
Exactly why would one need a SD-442 with a SD-744T?
Also if I were to buy a 442 and couple it with my 702T would that give me more channels to record on?
Or would it only allow me to use two channels on the mixer due to my recorder having only two channels.
Please explain the science and draw of mixing with a two to four channel recorder that I thought already would mix the two. I am new to this. If I seem naive you are probably right on the dot.
 
A mixer is only giving you more inputs to mix to stereo.

An alternative may be the Nagra VI (which I am getting) or the Sound Devices 788 - as these have more inputs and can mix down as well, you may not need a seperate mixer as well.
 
Slash6airhead said:
I have been hearing a lot about field mixers. I just don’t get why Sound devices recorders excel if used along with their mixers.
Exactly why would one need a SD-442 with a SD-744T?
Also if I were to buy a 442 and couple it with my 702T would that give me more channels to record on?
Or would it only allow me to use two channels on the mixer due to my recorder having only two channels.
Please explain the science and draw of mixing with a two to four channel recorder that I thought already would mix the two. I am new to this. If I seem naive you are probably right on the dot.
Click to expand...

Mixers add flexibility and make it easier to 'ride gain' - ie, adjust levels on the fly - during the recording process. A 442 has severall sets of outputs so you could, for example, send a stereo pair to the 744t recorder as the primary production recording while simultaneously sending a 'scratch track' to the camera's audio inputs. As already mentioned, they also let you mixdown multiple mics into your 2 stereo recording channels. The 744 has only two mic inputs (the other 2 are line level), the 442 has 4 mic inputs with a line-level 'direct out' on input channel - if you wanted to mic 4 performers each having their own lavs and record each performer on his own track on the 744, using the mixer in conjunction with the 744 gives you that ability while the 'naked' 744 would not.
 
Its not really a question of "need", but rather one of bringing more options and features to the job. Ergonomics are also an issue, since the tiny gain controls on the 702 can be frustrating for those of us with stubby fingers, and the 442 allows you to access all your mix controls without spending all day scrolling through menus. Additionally, the 442 will allow you to pan individual tracks.
 
wait so you can only link two proformers to a 744t? then how many mics/proformers can you link to a 702t? one? How many performers could be linked to a 702t if linked with a 422? *I use my 702t for recording sound effects for music. i've not gotten to any film production uses yet.* I'd like to know what it's capable of though in case i do decide to film.
 
Slash6airhead said:
wait so you can only link two proformers to a 744t? then how many mics/proformers can you link to a 702t? one? How many performers could be linked to a 702t if linked with a 422? *I use my 702t for recording sound effects for music. i've not gotten to any film production uses yet.* I'd like to know what it's capable of though in case i do decide to film.
Click to expand...

The 702 can record either 1 or 2 tracks at once. You can use those tracks for a variety of purposes, depending on the needs of the moment. For example, with proper stereo micing, you can use both of them to record in stereo with one track being Left and the other Right. Or if you prefer you can put a lav on the talent and record it on one channel while putting a boom mic on the other, letting you decide in post which sounds better, If you have two performers, say an interviewer and an interviewee, you can instead decide to use those same two channels to record a separate mic for each performer, so-called "iso (for "isolated") micing" Then during post you have good, strong sound for both actors to work with individually and balance them out in the final mix. Or you might choose to send the SAME mic to both channels but set one to a lower level than the other - then if there's a sudden loud sound that overloads or clips the channel with normal levels, the other lower level channel is there unclipped to fall back to. The idea is you can make decisions about how to best use the sounds you have captured in the edit room at your leisure rather than during the heat of the moment as you shoot.

You can only put two MICS directly into a 744. The other two channel inputs are line level only. But you can put 4 LINE level inputs into a 744 at once. Since the 442 can accept 4 mic inputs and send them to 4 line level outputs, the combination lets you record 4 mics at once, each on its own track. This is important because on many features each character is on his own mic and recorded his own independent channel in order to provide the best material for the post production team to work with.

Put aside the idea that on-set recording is in stereo. It's not, at least most of the time. Even if the final production is in stereo, most dialog is recorded in mono. Music is stereo, as is some of the sound effects and ambience. But the final stereo track is assembled piece by piece, sound by sound, from recordings that start out in mono.
 
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Steve house- Very good post thanks. Can you explain to me what line levels are exactly and how they differ from mic imputs. the two mic imputs on my 702t are marked mic 1 and mic 2 they also say line 1 and line 2. then there is a line out L(1) and line out R(1). I am totally confused. Might ask for another crash course via customer service at sound devices.
 
Slash6airhead said:
Steve house- Very good post thanks. Can you explain to me what line levels are exactly and how they differ from mic imputs. the two mic imputs on my 702t are marked mic 1 and mic 2 they also say line 1 and line 2. then there is a line out L(1) and line out R(1). I am totally confused. Might ask for another crash course via customer service at sound devices.
Click to expand...

Mic level is the stength of signals produced by microphoneand is usually very low. Line level is signal strength output devices like mixers, preamps, etc. Line level voltages are many time larger than mic level voltages so plugging a mic into a line input will result in hearing nothing at all while plugging a line out from a preamp into a mic level input will result in severe distortion and overload.

Levels are measured in decibels, abbreviated dB. This is a relative term so there can be +dB and -dB depending how strong a certain signal is when compared to a standard signal.

Mic level signals vary depending on the type of mic but generally fall between -55dB and -35dB. To keep things challenging, there are two standards for line level, consumer level and a stronger pro level. The consumer line is found most often in gear intended for the consumer market and is -10dBv. RCA jacks are usally consumer line level though other connectors can be used as well. Consumer level line outs are sometimes labelled "tape out." Pro gear is designed to work best with a higher level signal and its line level is +4dBu. It usually is found on 1/4 'phone' connectors or XLR connectors.

SD mixers provide different outputs or have outputs that can be adjusted for mic level, tape level, or pro line level, so you can set it up depending on the needs of the gear you're going to use it with.

In volts, pro line is about 1.6 volts, consumer line is about 0.316 volt and mic levels are a few millivolts.
 
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