11 Rack Direct to PA - LOUD Hiss!

[FreeBlues]

I'm using my 11R as my live rig: guitar(s) into 11R, 11R connected via line out (XLR) to PA. On stage we are using IEMs, so from the PA there is a connection to a headphone amp into which I plug my IEMs. There are no other devices in my chain.

Both in the house and to a MUCH greater extent in my IEMs there is a loud, very loud hiss whenever the 11Rack is on. The hiss is mostly lost when we start playing, but between songs this is quite annoying (since I play in church, we really, really want the hiss to go away when we aren't playing and someone is talking!).

I should add the hiss is in all band members' IEM's not just mine. Our sound guy is not very knowledgeable, but he is trying. So far, his solution is to have me turn the 11Rack volume up high, say around 7.5, then to pad my signal on the PA, -20 dB I think he said. This helps cut down the hiss, but sends a super hot signal to my headphone amp, meaning my own personal stage mix is almost impossible to control - I go from zero to near deafening with just the slightest twitch on my headphone amp volume knob. If I lower the volume on my 11R to something around 2.0, my headphone volume control works well, but the hiss comes back in full.

My sound guy says all the hiss is a result of the line level signal I am sending from the 11Rack - none of the other instruments cause this problem since they are all sending mic level signals. Really? I don't believe this, but I can't argue the hiss.

So, any ideas? Can I run another device like a DI (or something) between the 11Rack and PA to lower the signal level? Settings on the 11Rack to help? Loads of people use the 11Rack live, so I know it works, just not - yet - for me. What say you?

[junkgear]

The main XLR outputs are line level and should not be plugged directly into a mic input on a PA.

You have two options:
1.) Plug the main outputs into a line level input on the PA.
2.) Plug the main outputs into a direct box, then plug the direct box into the mic input of the PA.

Either method should get rid of the hiss.

[therealmf]

Originally Posted by junkgear

The main XLR outputs are line level and should not be plugged directly into a mic input on a PA.

You have two options:
1.) Plug the main outputs into a line level input on the PA.
2.) Plug the main outputs into a direct box, then plug the direct box into the mic input of the PA.

Either method should get rid of the hiss.

That post deserves some clarifications.
Modern boards usually have XLR mic inputs and sometimes additional jack line inputs. And usually the XLR goes with a pad switch to reduce the gain level.
The common way of using such boards is to plug the signals in via the XLR jack and in case of line level signals activate the pad to adapt to the higher output on these channels.
So basically: using an XLR in with the pad leads to the same effect as using a line input. Sometimes with the added advantage of maintaining the symetrical signal path (line inputs aren't always symetrical).
As for the second recommendation: there is no need to use a di box with the 11R since that's already built in. The XLR outs on the back even have a ground lift like most DI boxes.

Simply plug an XLR cable into each out, run the cables into the XLR ins of the board and control the signal level. If it is too hot, use the pad and/or lower the gain control of the board. That should do it.

I think the hiss is coming from somewhere else. If it is a constant high frequency signal it is most likely light. Check if it changes when you turn down the stage lighting (or switch it off completely). Other causes could be radio interference from wireless transmitters etc.

[FreeBlues]

Thanks for the replies! I'm working with our sound guy to see if I can get this sorted. It's hard for me to believe our soundboard does not have both line and mic level inputs, even harder to believe that he would plug me into a mic spot if there was a choice, but I'll admit I've never checked.

Just to be certain, I only use one main output, not both. Is there any reason I would want both left and right to go to the board? I am sending a mono (guitar) signal, so I just use one (usually the right).

I know the power on stage is pretty dirty, nothing I can do about that, but would that manifest as a hiss and not a hum?

[junkgear]

Originally Posted by FreeBlues

Thanks for the replies! I'm working with our sound guy to see if I can get this sorted. It's hard for me to believe our soundboard does not have both line and mic level inputs, even harder to believe that he would plug me into a mic spot if there was a choice, but I'll admit I've never checked.

Just to be certain, I only use one main output, not both. Is there any reason I would want both left and right to go to the board? I am sending a mono (guitar) signal, so I just use one (usually the right).

I know the power on stage is pretty dirty, nothing I can do about that, but would that manifest as a hiss and not a hum?

Well, checking that you aren't connected to a mic input is a good place to start.
Here are some links to other posts where people have reported hiss. There are a couple of reasons this can happen, so read through them and see if anything helps.

Hiss Thread 1

Hiss Thread 2

Hiss Thread 3

[FreeBlues]

Originally Posted by junkgear

...read through them and see if anything helps.

Ah, the search function is your friend! I did not search far enough back. EXACTLY what I was looking for, can't wait to try the suggestions out.

My sound guy has just purchased an XLR to TRS cable, one solution, I will try cranking the volume on the 11R then let the sound guy reduce my signal, will check all my internal settings. One "issue" I am not sure of is the volume sensitivity on my IEMs, but that is likely a different problem.

Many thanks!

[albee1952]

Let's dig a bit deeper. As a pro/touring engineer for far too long, I can tell you that there are several audio consoles that are quite happy to take line level signals into the xlr inputs. The most important question(at first glance anyway) that has not been asked is; how high is the console's GAIN knob on your guitar channels? If its way high, that means the 11rack is sending a very low signal(requiring a lot of preamp gain, which can add noise and hiss). If the gain is way low, how much signal level is showing on the meters if the channel is solo'd?

Proper gain staging is what I am steering you towards. When you play your loudest patch(and hardest strum) the channel on the console should not hit clip lights(or bury the meter). Assuming a proper level, revert to my initial question. If gain on the console is right(telling us what console you have might help) according to the meter, AND the console gain knob is not maxed, then is it the patch(es) in the 11rack? Does the 11rack offer any noise gating?(don't own one so I don't know). Do you have cabinet emulation turned off?(which would likely put lots of extra top end into the signal)

There's a bit more to think about in solving this, but it SHOULD be solveable

[Deansy]

The sound man is not far from the solution. If Eleven Volume knob is at 2, you will have hiss ! I have mine at ten for best signal to noise ratio! The fix is by adjusting your patch volume using the internal amp block level (not amp volume) and leaving the Unit volume knob cranked. If you're using the software editor you will see amp volume and another knob "Level"/Output, that's your fix. I had the exact problem and that was my fix.