keyboards, any use to run them in stereo on a live pa?

[earworm]

ok, so the band i started working with has keyboards in their setup,
they got the headphone output connected to a mono channel in their cheap mixing desk... thats something i never do in my homestudio,
but now i wonder,
whats the difference between headphone outputs and L+R outs?
are headphones unbalanced, but stereo,
any difference in volume, impedance, quality or whatever?

and i'll rather use the L(mono) out, run that to the mixer, only cause its a habit to use MAIN outputs instead of headphones-outs,

but do i need to run it in stereo, and pan hard L+R,
will that be of any use in a cheap/small live pa setup
(only vocal mics, keys, bass and guitar direct outs go trough PA, no drums)

or can i just save a channel and keep it in mono...?

[boingoman]

Go for mono, for the most part. It's just easier to deal with. As always, the best is to try it, and see. But here are a few thoughts.


Running keys stereo can be fun. A stereo keyboard with a good organ sound just sounds cool, for instance. A lot of times the stereo/mono choice comes down to room and PA. If a lot of people are going to be outside the stereo field (which is shockingly small) they will not hear the opposite side. This can be offset sort of if the keyboard player is using an amp, and the room is small. It does have the advantage of leaving a nice hole for the vocals in the middle of the listening area, which can get overwhelmed by stage volume there. That's great until you get too far off axis, as the vocals can get overwhelmed by that side of the stereo feed.

The actual stereo field in a 15x30 meter room, speakers in the corners angled 45 degrees in, is about the size of a sofa, about 5-8 meters back. It gets narrower the closer together the speakers are. It gets a bit deeper as well, but the basic area size stays the same. Everyone else hears mono, pretty much. Think about monitoring stereo music on your home studio monitors. The place where you get good stereo is about the size of your head.

In fact, in just about any space, with any size PA, the size of the stereo field never gets much bigger than a sofa.

More than 3db difference in volume between the two speakers from the listener's perspective, and the ability to localize sounds accurately in the stereo field starts to be lost. (Stereo starts to disappear) More than 6db, the listener starts to strain to hear the other side, which can be fatiguing, as we do it unconsciously. At 10db difference, the other side is inaudible.

Also, at some distance, your head starts to treat the PA as one source. Stereo depends on things reaching your ears at different levels. Far enough away, and your brain can't seperate the two signals into left and right. They seem to come from the same point in space. Stereo becomes worthless.

Stereo can definitely make the keys seem bigger, and that leads to the other limiting factor- PA. You need to have enough PA to make it worth it. If all the "space" in the PA is taken up by keys so you can hear all those nice stereo subtleties, vocals can suffer. Sometimes thinner mono keys are the ticket to better sound. They still cut through without being overwhelming.

ps-headphone outs are powered outputs, just like speaker outs. A lot of line-level inputs can handle some signal from a headphone out, and for sure if you use a DI. Just be very careful. The signal will likely be pretty noisy, as the headphone volume must be very low so you don't damage the input of whatever you are going into.

[fraserhutch]

If your keyboard has stereo effects and you want to take advantage of them, then you need to go stereo. Essentially, you are doing a sub-mix in the box.

[stanjanssen]

I own a yamaha P80 digital piano, and it simply sucks if you only connect one side, because the samples are stereo, it just sounds very boxy when not connected in stereo. With my keyboards this is less of a problem, as the samples aren't so dependant on stereo. Just see if it sounds better when you connect it in stereo.

Stan.

[seismetr0n]

stereo stereo stereo.... if you got an extra channel use it, it will beef up and widen your sound, there a high probability that your keyboard has stereo outs for a reason

[Rennikcks]

Use balanced connection......you loose 6db gain using unbalanced connection. You will notice a difference.