Help me understand solo ducking - 1640i

[Basturma]

I must be misunderstanding something - why would soloing a channel automatically cut out all other sound in the mixer if soloing is the only way to actually meter the input gain on a channel? For example, I'm tracking a song and the singer suddenly sings way louder than when we initially set the input gain on her mic pre. To actually meter the gain, I have to solo her channel, but this cuts out what she's hearing in her headphones and what we're monitoring from the main outs.

How do people do live sound with these, then?

[RoadRanger]

Are you using the mixer's headphone jack for her headphones? Are you using the control room outs instead of the main outs? Both the headphone jack and control room outs follow the solo buttons. You would use pre-fader aux outputs for the monitor amps/powered-monitors/IEM's and the main outs for the PA.

[Greg C.]

Are you using the mixer's headphone jack for her headphones? Are you using the control room outs instead of the main outs? Both the headphone jack and control room outs follow the solo buttons. You would use pre-fader aux outputs for the monitor amps/powered-monitors/IEM's and the main outs for the PA.

+1

Pre-fader auxes for monitor mixes only. The purpose of the "solo" (known in the pro world as a "pre-fader listen" or PFL) button is so the person doing the mixing can cue up individual channels in headphones or monitors on purpose and listen to individual microphones/sources.

[Basturma]

Gotcha, that makes more sense. Yeah, I just use the headphone out, I don't use an aux send feeding a headphone distributor or anything like that. I guess that would be the more common implementation.

Still don't get why solo ducks the MAIN outputs (not control room).

[Greg C.]

Gotcha, that makes more sense. Yeah, I just use the headphone out, I don't use an aux send feeding a headphone distributor or anything like that. I guess that would be the more common implementation.

Still don't get why solo ducks the MAIN outputs (not control room).

If the Main Outs are muting when you solo a channel, the mixer is broken. It's not supposed to do that. There are mixers that have the ability switch to a solo mode that will send solo'd channels out of the main mix. That feature is usually called "solo in place" and can be very dangerous in a live sound setting. It's something one might use during sound check but would want disabled for a show. In any case, the Mackie mixers don't do that. From the Mackie 1640i user guide:

41. SOLO
Whenever a solo switch is engaged, you will only hear the soloed channel(s) in the headphones and control room. This gives you the opportunity to audition the channels before they are added to the main mix. You can still hear, even when the level is down. Solo is also used to set the gain of each channel correctly. When a channel is soloed, you can adjust the channel gain [26] until your input source reaches the level of the 0 dB LED of the right meter.

Solo signals reaching the headphones and control room are not affected by the channel level or main level; therefore, turn down the
phones level [48] and control room level [47] first, as soloed channels may be loud. The rude solo light [50] will turn on as a reminder that what you are listening to in the headphones and control room is just the soloed channel(s). Soloed channels are sent to the source mix, which ultimately feeds your control room, phones, and meters. Whenever solo is engaged, all source selections (main mix, tape, and FireWire) are defeated, to allow the soloed signal to do just that—solo!