My Direct to PA challenge/issue - HELP!

racman

I have a particular problem with live sound that is just getting way too much for me and was wondering if anyone can help.

I run a “direct to PA” setup and have constant issues with setting up the gain structure for the OD’s as the stage and monitor mix varies all the time for a variety of reasons e.g. different musicians playing at different volumes etc. but mostly as a result of hugely different stage volume for each session. Not an unusual problem for any musician I guess. However, for some reason I having constant issues with setting up a relatively good, consistent sound. (Running a mic’ed Amp is not an option.)

I set up my OD’s with Guitar volume at 8 for decent crunch, smooth OD etc. and in theory I thought would be perfect and relatively stable. Is it odd that this gain structure seems to change when the “sound guy” increases/decreases my monitor volume to the point that the signal either cleans up or has too much overdrive? I would have thought that this would not happen.

I was wondering if I needed a buffer of some kind before the signal goes to DI and PA?

At the same time I am convinced that the problem or solution is very simple and I will feel like an idiot for not figuring it out.

So my signal chain if it helps is: Strat=>Tuner=>OD1=>OD2=>Delay1=>Delay2=> Ethos PreAmp/OD=>Reverb=> DI=> PA

Our stage sound can get LOUD at times as drummer, Bass and Keyboard sometimes seem to battle for dominance. A few weekends ago my stage monitor volume was increase to such an extent that it was breaking up… and I could still barely hear myself. To try and remedy this I now have a dedicate monitor channel with only my guitar sound or whatever I want.

Looking forward to a solution….

I have no idea if this is in the correct section so if not could one of the mods moved it to the appropriate one please

mtmattan

Howzit man,

I think your problem is likely caused by an impedance mismatch at one (or multiple) places in your circuit.
I'd highly recommend a quick google search on "impedance mismatch" to narrow down your exact symptoms.
Here's a link as an example: http://www.ovnilab.com/articles/active.shtml

Essentially, when connecting two devices, an ideal situation is for the sending device to have a LOW output impedance and the receiving device to have a HIGH input impedance - it results in the minimum signal loss.

Passive pickups = high impedance output, active pickups = low impedance output. For that reason, connecting say a Telecaster vs EMG pickups, the EMG's signal will be stronger simply based on less signal loss.

So if you have different instruments as well as different mixers to send the signal, I assume DI's and buffer's would solve the volume problems. A "buffer" (vs a "boost") takes a high impedance signal and converts it to line-level low-impedance. A DI box does that as well as making the signals "balanced".

For your specific situation, it sounds like a buffer/DI BEFORE the OD pedals would change the instrument signal to a low-impedance and serve to give the OD a uniform response. The output from an OD is low-impedance anyway, so a buffer/DI AFTER would serve mainly to preserve signal from long cables.

I'm no expert but hope that helps! ?
Regards,
Matt.

racman

Thx Matt, I was thinking the same ie buffer in front of the OD's. I run the board into a DI before going to PA and may try and remove that as well.

AlanRatcliffe

No the buffer after pedalboard will stabilise your sound before it goes to desk - the pedals will see the same impedance regardless of what happens on the desk side.

I think the key to your problem is this:

the stage and monitor mix varies all the time for a variety of reasons e.g. different musicians playing at different volumes etc. but mostly as a result of hugely different stage volume for each session.

From that, I'd guess that you have monitors that change response at different volumes (or you're using different monitors in different shows). Plus of course, those old b'tards, Fletcher and Munson mean that we hear frequency response differently at different volume levels, which can screw with our perception of even the most carefully crafted tones. I'm also guessing you don't have a system where you have any control over your sound in the monitor mix without affecting the house mix? The engineer is EQing the guitar to sit in the house mix and that affects your tone in the monitor mix (which usually has a completely different balance).

BTW, if you are given a monitor with 15" bass driver, see if they can rather give you a 12" - 15s typically have a dip right in the vocal/guitar crucial midrange and are only really suitable IMO for monitoring bass and kick.

The solution is a dedicated powered monitor for your guitar. Something that you know and something that keeps the same (perceived) frequency response at varying levels and you can tweak quickly when needed. Feed the desk a signal that the engineer can do with what he wants and mirror/mult the same signal to your dedicated monitor. This keeps the guitar out of your normal monitor mix and gives you complete and reliable control over your stage sound. Many modern powered monitor speakers have simple mixers in them so you can also use it for the monitor mix but still have control over the balance between the guitar and the other instruments and the EQ.

racman

Thx Alan - I think you are correct.

Ok, so let me explain in a little detail how we work. The monitors are not fantastic quality and at best probably merely average or below that. This morning was a little better as I asked the "Sound Guy" to remove all instruments from my monitor and so had it dedicated to just my guitar. Our stage is set back (I call it the "Grotto") and the house speakers are not too far from where I stand - about 3m on my right. What I was noticing was that the Bass guitar and drums were booming from where I stand which had the effect you mentioned.

So this morning, with no instruments in my monitor except my guitar I suddenly had so much volume available and no monitor breakup. Of course if that's the way I am going to keep it I will have to set up all the gains again but hopefully it will stay a little consistent.

My confusion is that logically I thught if I set all my gains and levels as well as the input gain of the mixer and that remained relatively static, then surely adjusting my monitor level should not effect the levels of the OD's?

I may look at the additional monitor or even a smallish amp on stage for that extra guitar fill as my concern is not hearing how the guitar sits with the rest of the band or musicians all the time. Anyhow went relatively well this morning, better but not perfect...

TomCat

PM'd......

matta

RoyC wrote: My confusion is that logically I thught if I set all my gains and levels as well as the input gain of the mixer and that remained relatively static, then surely adjusting my monitor level should not effect the levels of the OD's?

It's not effecting them, only your perception of them! Alan hit it with the Fletcher and Munson curves, out ears responds differently to sounds at different volumes. The optimal range for equal attenuation across the human hearing range is 80- 85 Db SP A weighted, though today I think 78 Db is the accepted practice, but a loud drummer and full band will put out well over 100Db or more, that will inherently screw up your perception of the tone/sound.

It sounds like when the full band is playing there isn't enough headroom in your current monitor system to give you the volume you need without break up, which further complicates things. You need a good clean amp/speaker to replicate your tones at high volumes that you can match to the level of the band behind you, it's the only way to have dependable results, again, what Alan suggested.

The DI should NOT be removed from the chain, there is nothing wrong with the chain itself and the DI is needed to run that balanced line to the mixer and match impedance accordingly.

I hope that helps!

Cheers

Matt

TomCat

RoyC wrote: Thx Alan - I think you are correct.

Ok, so let me explain in a little detail how we work. The monitors are not fantastic quality and at best probably merely average or below that. This morning was a little better as I asked the "Sound Guy" to remove all instruments from my monitor and so had it dedicated to just my guitar. Our stage is set back (I call it the "Grotto") and the house speakers are not too far from where I stand - about 3m on my right. What I was noticing was that the Bass guitar and drums were booming from where I stand which had the effect you mentioned.

If you are referring to the "Grotto" i think you are referring to then there will also be many acoustic issues on the stage that will not help.

Part of the solution may require treating the stage area acoustically to reduce reflected (Uncontrollable) sound and booming on the stage.
I think part of the problem is the uncontrolled energy on stage between the drums, bass guitar and keyboards. Volume without clarity is just noise.......
All of this energy also then mixes with the house sound and any change of clarity usually then goes out the window.....and you find yourself struggling to monitor yourself....

AlanRatcliffe

Monitor mixes are odd - the best ones give you no idea what is going on FOH but give you exactly what you need to hear yourself and get the cues you need to play your parts in time - but from only a few of the other instruments (the less the better - as with any mixing, if you try and get more than four instruments to have focus, they all lose out).

To some degree you have to ignore what the mix sounds like onstage and trust that the FOH engineer is doing his job (I know, scary prospect with many of them!). As long as you can hear what you need to lock in your timing and follow your cues, you have everything you really need.

racman

So it's all in my ears? ?

While I understand the percieved effect etc, there is no denying that I have to alter my Level and Drive controls to restore the desired effect as the volume deviates in the monitors ???

Thx guys - great advice.

Tom, you know the setup so you have have an understanding of the situation as well.

Rather than operate in complete isolation with just guitar in my monitor I will try with a little drums (they are top of range Roland electronic so are more controllable. Of course I hate electronic drums but that is besides the point ?)and maybe Keyboard. Bass guitar is lud enough on it's own.

racman

An update for all on where I am at the moment which seems to be working thanks to the great suggestions on this thread - thank you all.

I now run the board (Ethos - HOF) into a DI which then goes direct to PA. I purchased a DI with a "Link" output (I don't know if all DI's have it but it is essentially a direct link from the Input signal) to a dedicated powered monitor. I have also positioned myself a little better so I can hear the house sound and have also slightly turned the drummer members monitors so I can hear the rest of the band playing so I get great "context" as well. It is working very well with just one little modification that I still need to do and that is to install a unity gain buffer with a volume control to the powered monitor so I can adjust the monitor volume from where I stand.

At present I am using a small volume pedal for this (AMT Loudmouth) but a large volume control knob on a buffer would be best. Anyone know where I can purchase something like this?

Mr-M

RoyC wrote: At present I am using a small volume pedal for this (AMT Loudmouth) but a large volume control knob on a buffer would be best. Anyone know where I can purchase something like this?

Get Benj from Craigamps to make you one. I'm sure he could and his prices are very reasonable. http://www.craigamps.net/

BTW, how is the AMT Little Loudmouth? Some guys on TGP say that it has a bad/ abrupt sweep (for volume swells) and that it doesn't completely mute the volume when rocked all the way back. You found any of these issues? I do understand you're not really using it as a traditional volume pedal in guitar setup, but I am very interested i getting one so any help would be appreciated.

racman

@MrT - Thanks, I am already in discussion with Benj about this (and a few other things as well).

I have only just received the Loudmouth and the Japanese Girl (the pedal of course) Wah and will hopefully start testing them live this week sometime and post a review or send a pm.

Mr-M

RoyC wrote: @MrT - Thanks, I am already in discussion with Benj about this (and a few other things as well).

I have only just received the Loudmouth and the Japanese Girl (the pedal of course) Wah and will hopefully start testing them live this week sometime and post a review or send a pm.

Cool. Benj has done some great custom work for me and other forum members, so I'm sure you'll get exactly what you're looking for.

Thanks. Would appreciate your thoughts on it. ?