About those Stereo PA Inputs

[Mandobart]

I'm still a novice on running sound systems, but I help out with a few open mics around town with a variety of sound systems. I usually have no problem with the input channels featuring a single 1/4" and a single XLR input, unless there is something wrong with the mixer like a bad connection for that channel.

However, on many systems, when I try to use one of the "further right" channels featuring two 1/4" inputs I often find the output level is much lower for the same gain setting used on the standard input channels (with just a single 1/4" in). Is there a reason for this? Should I even try to use the stereo channels for an instrument input? Thanks

[mandroid]

XLR inputs typically run through a Microphone Preamp stage to start.. the other paired 2
are likely expecting a Line level input ,

like coming off a Stage Piano or a CD player for set break fill music*, that is already
at a Higher output . so needs less preamp gain in the Mixer.

*often an RCA pair on that channel too for that purpose.

You can also use a small sub mixer with its own preamp-line level output . into that sort of channel

like say you had a multi instrument collection , all plugged in to their own Sub mix channel. raising and cutting their levels as needed ..

[almeriastrings]

Should I even try to use the stereo channels for an instrument input?

As Mandroid says - these are intended for keyboards or other electronic instruments, such as a drum machine, primarily. Usually at 'consumer' line level. They will have insufficient gain (and too low an impedance) for typical instrument pickups .

[briankeen]

you have two main options here, you can either buy a D.I box which will take your instrument jack as an input and convert it to a a balanced XLR output at the correct level for a mixer. The second option would be to buy a guitar pre-amp pedal and that will give you some gain and EQ control from the stage. both options are low cost and can be found in any music dealers

[Mandobart]

In every case the acoustic instrument being plugged in has an onboard or external preamp. I did find that when using my Red Eye (with an XLR out) and mando plugged into the XLR in on the stereo channel I had much better output than when my friend's guitar (with onboard preamp) was plugged into the upper 1/4" jack on the same channel.

[foldedpath]

In every case the acoustic instrument being plugged in has an onboard or external preamp.

Some onboard guitar preamps and compact external preamps are stronger than others. Many don't send an actual (nominal) consumer line level at the 1/4" output, due to trade-offs with battery life. It can still work reasonably well on a mixer's 1/4" input, as long as there is some additional fader gain available.

With AC-powered gear like a keyboard, or many AC-powered preamps, there is always a healthy line level signal on the 1/4" output. So it just depends on the specific external preamp being used.

I did find that when using my Red Eye (with an XLR out) and mando plugged into the XLR in on the stereo channel I had much better output than when my friend's guitar (with onboard preamp) was plugged into the upper 1/4" jack on the same channel.

Right, because when you plug anything into an XLR channel input on a mixer, the mixer thinks you're plugging in a microphone. So it runs the signal through a preamp with lots of gain available, which makes it easy to bring the signal up to internal line level before feeding it on down through the EQ and fader controls. The mixer thinks anything you're plugging into a 1/4" line input is already at that level of gain, so it doesn't apply any added preamp gain on that channel.

[mandroid]

When using my Red Eye (with an XLR out)

Labeled DI perchance?

and mando plugged into the XLR in on the stereo channel I had much better output than when my friend's guitar (with onboard preamp) was plugged into the upper 1/4" jack on the same channel.

So you 2 gleaners are out of channels and it's whats left, so have to share that last channel?

Maybe time to get a small sub mixer so each can have a channel on It,
then run its Pre amp/line level into the 2 stereo 1/4" inputs
and via the sub mix able to separate the gain required for each of You.

[Charlieshafer]

Yeah, like others say, a D.I. box will do the trick. You can sum the channels if you want and put them into one input usually, but that only works well if it's a mono send to the mains. Most of the time, mono is all you want into the mains as in a small venue, separating the channels usually means one side of the room gets too much of one instrument and too little of another.

[mandroid]

Who Gets 1st Priority to use the other channels, Bart ? why do you 2 have to share whats left?

[Jim]

Have you turned the pan all the way to the side you are plugging into? Such as and 8 ch mixer where 5&6 and 7&8 are stereo. To use 5 you may need to turn the pan all the way left to get full signal. This is OK if your output is Mono.

[Mandobart]

Thanks for the helpful replies, especially about the different gain supplied on an XLR vs a1/4" input and the tip about using the pan. As I might have not been clear enough in the OP; I don't own a PA. I'm active in a few local music organizations and help host a few open mics. The sound systems are already there; I don't pick them out or even set them up (usually).

So at a recent open mic at my friends tap room we are honoring a recently deceased friend and fellow musician. There are two mics, an acoustic guitar and my mandolin (via my XLR output Redeye) plugged into channels 1 thru 4. This leaves the last two channels, the ones labeled 5-6 and 7-8. Other guy wants to come up and join us on one of our dead buddies tunes. So I plug his internal pre-amped Taylor into channel "5" using a regular guitar cord and it's real quiet. I swap my Redeye from ch 4 to 5 and plug new Taylor into 4, and everyone sounds good now. I was wondering why, having noted similar results in the past using the "far right" inputs. Now I have more info why it works like that.

[mandroid]

pretty small a board for a Jam. maybe Open Mic , Individuals in a Queue Of solo Performances ,
a 6 channel (2 stereo, 4 Mic is OK..


Maybe the House need to invest in a 12 channel PA?

[Tim2723]

What 'Droid said. The important facts usually show up after about a dozen posts. Bart, you need a bigger mixer. All this band-aid business is great in a pinch, but you need more channels.

BTW, Hi guys. Long time no see.

[foldedpath]

BTW, Hi guys. Long time no see.

You're back! Welcome, and have you broken any new mandolins lately?

Still using the Bose? My guitarist partner bought one for his solo gigs recently, but I haven't had a chance to hear it yet. We'll probably stick with my K10's for most gigs, but the Bose might get some action, if we get booked into one of those wedding gigs where we need to set up in two different areas.

[Tim2723]

Hi FP, good you see your voice. Actually, I'm retired from music now. I don't want to break any rules about posting in the wrong places, but watch the classifieds.

[TonyP]

Retired

What could possibly make a warhorse like you hang it up? Did you win the lottery? I certainly hope so and you've been busy setting up your Bose dealership

Anyway we're glad you're back.