Question/problem with mixer output?

[slap-a-da-bass]

Hi All,

First off I've posted this on another forum, but have had very few views & zero posts, so I though I'd try here. Here's what I posted...

I'm fairly new to the band thing, but have been playing guitar for six years, & picked up some bass in the last year or so. I'm the guy with the PA system, & I've been really struggling with vocal volume or I should say lack of.

Here's my set up...

Peavey 16FX mixer
Peavey PR15's - mains 8ohms
Crown XLS2000 (mains - 375w per side - 8 ohms)
Subs - 2 Fender 118's w/eminence drivers, though I'm not sure what model they are)
Sub amps - 2 Crown XLS1500 each bridged mono - 8ohms - 1050w each
31 band EQ for main mix
2 - 31 band EQ's for 2 monitor mixes
Crown XLS202d for 2 monitor mixes - 200w each 8 ohms

That's mostly it, we rung AKG D5's for our mics, and the lead singer has a wireless D5

The bass player & drummer are the only two in the band that have giging experience. The lead singer has never gig'd, the lead guitar player (while playing 14 years, has only played 2 gigs), and myself maybe 6 gigs, but with a different band & I didn't run sound or have the gear.

On to the problem. During our practice, I have settings on the mixer & what I would consider near gig levels, and the vocals just aren't enough. This makes me really nervous playing our 1st gig as a band, thinking My system is lacking or something is wrong with my usage or set up. To keep it simple, I've experimented with just 1 mic, set pre gain to bring the channel to -3/0, then the slider to -6 on the channel, and mains sliders to 0. For this test subs & monitors are off, no vocal effects, & the signal went right too the power amp. With our practice, vocals are very hard to hear and there isn't much room to boost vocals or feedback will start. If this were a gig situation, the room would likely be 5 to 10 times larger than our practice space.

I'm questioning the true output of the mixer, because my input LED's on my power amp aren't even close to 0, it's more like -20, and at very loud vocal tests, only flashes the -10 light on my amp. Also testing my EQ in the chain, the LED's are also reading an input of -24/-18, though I can boost the EQ with the output level knob. To me something just seems off with my mixer output, I would think 375w per side should be more than enough for practice & small clubs. I'm almost ready to call Peavey tech support, but thought I'd check here first.

Any advise or what I should look at next?

Thanks,

 

[steveksux]

with the pre set the way you have it, -3/0, what exactly does that mean? You have a clip light on each channel that's lighting up some of the time? Or are you referring to numbers on the input gains?

You should be lighting the clip light once in a while at your loudest vocals on each channel. Sounds like you may have that right depending on what you meant.

You have output level meters on the mixer? what do they say?

Try 0 on the channels and 0 on the masters, that should give you about full output if the input levels right. See what that does. That should be able to drive the power amps fully.

Sounds odd that the eq meters are down so far.

Feedback is a seperate issue, small practice space makes it hard to get loud without feeding back. Instrument amps probably just too loud.

On the gig you should be able to get the mains louder without the feedback. IF you have room on the volume knobs to get louder.

Monitors may be another issue on the gig.

Most likely culprit is the input attenuation is set too low, so you aren't getting enough signal to the individual mixer channels to drive the output to full blast. Sounds like you have the channel volumes high enough, as well as the mixer master out.

Randy

 

[slap-a-da-bass]

Ok,

Each of my channel strips has a PFL button by each channel slider. I engage this button when setting gain input on a mic, then my output meter shows -3/0db on the leds. I assume this is for the one channel. I don't know how to get the mixer output to show in the leds. I assume there should be a AFL, which there is, on the aux sends, & the two FX blocks. I'll check that out, maybe I have a level low that needs to be turned up in the FX controls.

Because I was only using the one mic, I assumed the -3/0 channel output would have been the total output. I'm hoping the output is restricted somewhere.

edited...

I just looked at it...another piece of the puzzle,There are AFL switches at each sub group, so I can get AFL output which should be going out the board at the main L/R sliders. It's quiet time at the house now, so I won't be able to try it out until tomorrow, but I think I did get more output, because as I pushed the group output a little more, I can get the AFL to 0. I suppose now I'll have a whole new problem of feedback in the practice space.

 

[MuzikMan]

Your small practice space will feed back faster than a larger gigging space so you should be able to get more volume at gig time. It sounds like you know how to set the gains on the mic channels. You are correct about your sub groups. Keep them up if you can. My bet is that you will be just fine at the gig but I know how nerve racking that can be when there are unknowns involved. Maybe you should hire a consultant to help you get set up for your first gig?

 

[slap-a-da-bass]

I couldn't agree more, about hiring someone for our first gig. If I can set things up, do a sound check using my wireless, that's fine, but if there are feedback or monitor problems, I can't be screwing around with the EQ while I'm trying to play.

A question I have about feedback in a practice space...If I build some treatments (broadband & bass traps) will that dramaticly reduce feedback in the practice space? Our practice space is 12x24 - 8' ceilings, and all drywall & brick...I assume the sound us just bouncing around and recycling, thus the low feedback threshold, correct?

 

[Keithwah]

"I couldn't agree more, about hiring someone for our first gig. If I can set things up, do a sound check using my wireless, that's fine, but if there are feedback or monitor problems, I can't be screwing around with the EQ while I'm trying to play.

A question I have about feedback in a practice space...If I build some treatments (broadband & bass traps) will that dramaticly reduce feedback in the practice space? Our practice space is 12x24 - 8' ceilings, and all drywall & brick...I assume the sound us just bouncing around and recycling, thus the low feedback threshold, correct?"

The room absorption will help make it a better sounding and more tame space. Mostly in the lower frequencies as far as traps go, but overall it will help to minimize the reflections which are an issue with the drywall and brick. Some Blankets or tapestries on the walls will help too, anything soft is a plus.

The low ceilings are helping actually, since it minimizes the distance sound can bounce from floor to ceiling. If its a "drop-in-tile" type ceiling, all the better too acoustically.

I agree that it seems as if you are setting things up correctly, tho like Steve I'm not exactly sure of all of your meter readings. You certainly do have enough power, I assume the subs have some sort of "full range crossover built in them.

A big secret to getting vocals up in level in to reduce the bass you put on it on the channel strip and at the EQ. Sometimes you have to sacrifice a little boom for the good of the rehearsal mix. A mixer like you have, has a little "speed bump" at the 12:00 position. This is where the channel is set to a "flat" setting. Anything you do in a live situation like when you turn that treble,bass, mid cut/boost knob past that 12:00 mark, is synthetically attempting to create something that isn't really there in the first place. To a certain extent anyway. Anything you do by lowering the knob below 12:00 is cutting or attempting to remove a known problem. Therefore, cut as much as possible, and only boost when necessary.

Let's get started a bit here. Start by putting a CD on or your iPod, to a song that it is recorded very cleanly and that you know how it should sound through a good system, alot of us pro audio guys use Lyle Lovett, or Steely Dan to listen to systems because its mixed sweet and clean not because we like it. But metal is not a good source of preview music due to the over done low end. Nor would hip hop be good. Seal, sure. Jack Johnson, oh yeah clean, very clean stuff. Dial your outboard EQ to Flat across the front. Then light cut the frequencies you think are overbearing on the song. Just because you can make GWAR like bottom end doesn't mean its proportional to the mids and highs in level. This is creating a flatter response. If you need to boost a few freqs, no big deal but you should not need to boost anything more than about 3-6db, you may need to cut more low end as you go as well. Oh yeah, when you plug in your music source, make sure the channel EQ is set to flat (12:00) before messing with the outboard EQ.

A very valuable tool you have to fight feedback is the parametric midrange you have on your vocal channel. Here's how it works. Start by putting your mic's channel's bass and treble (I know HF and LF but get real people) at 10:30 to 11:00 on "the dial". Hopefully you understand how I am referencing your knobs as clock dials ok? Bring your mic up to the level where it starts to feed back and then mute the channel. Now reach up to that mic's parametric mid EQ controls, roll the cut/boost (-?db to +?db) knob all the way counterclockwise to its fullest "cut" setting and do the same for the Freq. control knob as well. Unmute the mike and let it ring again, while its lightly ringing (but not getting out of control) start slowly turning the Freq knob back up towards the center and past 12:00 if needed until you find the Freq. spot where your feedback problem is. Now bring the cut/boost level knob back up towards 12:00 until the ringing comes back. Then back turn the cut/boost knob back down till the ringing goes away again, which is usually not all the way down but maybe at -6db to -9db or so. Now you should be able to bring the gain on the channel strip up a few more db to get the most optimized you will get without a real time analyzer to dial your rig in.

If you still have some problem with lower freq feedback, roll the bass (LF) back down some more. If its treble (HF) dial it down a little more. If you are not having any high freq. feed back and your mic sounds a bit dull, no harm in boosting the HF a tad, but a little EQ can go a long way.

Your PR15's while not bad sounding cabinets are not really the most efficient boxes. They should sound better facing away from you in a club setting than they do in your room. They aren't bad speaker, just not great. Might look at some newer JBL stuff, or some EV stuff in the plastic box department if you are looking for good lightweight to haul sound.

Hope this helps, its the way I set up 100's of sound systems, minus I have an IVIE IE45 RTA rig worth about $2K to make it all happen.

 

[modulusman]

The biggest problem i see with your PA is your speakers are low budget. The PR15s suck big time. Here is a recent thread over at Harmony central. Link Removed I have used The fx mixers before and had plenty of gain. Are your 31 band EQs set flat or are you cutting alot of frequencies? EDIT are you using the built in feedback ferret in the mixer?

 

[steveksux]

The biggest problem i see with your PA is your speakers are low budget. The PR15s suck big time. Here is a recent thread over at Harmony central. Link Removed I have used The fx mixers before and had plenty of gain. Are your 31 band EQs set flat or are you cutting alot of frequencies? EDIT are you using the built in feedback ferret in the mixer?

They aren't the best speakers, no doubt, and I wouldn't try to argue that they don't suck, but they are pretty loud, should not be a problem hearing the vocals with them.

I'm assuming the OPs getting high freq feedback from the vocal mics, not low freq feedback, so I'm more into the treatments like ceiling tiles, fabrics, carpet rather than bass traps for his situation. If he is getting lows feeding back, I'm wrong.

Randy

 

[slap-a-da-bass]

I'm going to run down the ringing out process today, I have gotten more output by using the sub groups & pusing a little with that slider, also moved the channel slider to 0 instead or -6.

I have the next couple days off from work, & I'm going to work on ringing out the system & the new levels, & see what I can get out of it. I suspect it will be much better. Thanks Keithwah for take the time to post some very good details.

I should also add my 31 band eq is fairly flat, & the feedback ferret is on, but the ferret is catching quite a few freqs, & then is sounds pretty bad. Thus making me think I need to work more with the 31 band so the ferret doesn't have so much to do. Besides, I need to work with the EQ anyway for the added gain from the board.

Two other points to address, one my feed back problems are no low end, high mids, & highs. And I've been thinking about my PR15's for quite some time now, and have thought they sounded thin and don't fill the gap very well between the subs & the tops. If I'm looking at something else in the $400/ea range for tops, what's better than what I have? I was thinking 12's instead of 15's, and maybe some mackie c300z's or the new EV live 12's? How are those speakers or could you suggest sometning else?

Thanks

 

[modulusman]

Yamaha club series are generally considered the best speaker at that price point. The EV may be good but is too new to have any reviews.

 

[StuartV]

Leave your PFL and AFL off.

Turn your Master all the way down.

Set your input gain on your vocal channel by singing at whatever volume is going to be your loudest and set your gain so your clip light flashes occasionally (or gets to 0 in the input meter occasionally).

You should be good from there. It sounds like you're using the PFL incorrectly.

Oh, and your power amp situation sounds way lopsided. Way more power for the subs than you need compared to what you're feeding the mains.

I run all Yamaha Club V series speakers and P series amps. My setup is:

P5000S (500W/ch) -> 1x15 x 2
P7000S (750W/ch) -> 1x18 x 2

That gives plenty of volume and a good, flat response.

You could probably just drop one sub amp and use the other to run both your subs.

Also, what somebody else already said. If your current limit on vocal volume is really because of feedback - well, that's the nature of trying to turn up really loud in a small practice space.

 

[slap-a-da-bass]

had a pretty interesting day today. A buddy came over with his Behringer auto EQ processor. I was able to do pretty well with my 31 band EQ to remove feedback. There were a few freqs that I had trouble with, though. We routed his Auto EQ in my system, and ran the process, I had some spikes in the room, that it took care of, but I noticed it brought a lot of high end into the mix. It got me thinking, this isn't hifi, so a question I have is is there a freq range I should focus on for mains in a gig situation? Mabye 60-8000? Another thought is if there is too much high end to my ear, listners will not like that as well. I'm thinking the sound from the mains should be balanced, smooth, & not harsh on the high end.

What do you think?

 

[StuartV]

Dunno about your last post, but there was one more thing I wanted to mention about your first post.

I don't know anything about your specific board, but check to make sure it doesn't have an output level on the back or somewhere that is separate from your Master Volume fader.

I got a Presonus StudioLive recently. First time I used it, I ran from the Main L out to my EQ. Worked fine. Then I changed it to run from the Main Mono out instead and it wouldn't get as loud as I thought it should. Eventually figured out there's a trim pot on the back, next to the Mono Out that I just needed to turn up to make it the same level as when I had been using the Main L output. I had never seen such a thing on a board before.

 

[uhdinator]

as far as your practice space goes speaker placement and the room are your problem. Hang some comforters, moving pads, or heavy blankets along the cinderblock walls and staple some across the overhead joists if its not a dropped ceiling to tame the room.

Gain stage your system like this:

1. Unplug your PA speakers first. Leave amps on and turned down, EQ and crossover on too. Make sure that all components are set to +4 db if they have a setting for -10/+4. Most all gear now is +4 db standard for line level.

2. plug in an Ipod, or cd player/tape deck to a channel or pair of channels and pan them L/R if using 2 channels or use a mono to stereo cable and use 1 channel. play music into mixer. pick a song that is similar to the style you are playing in your band or better yet search for a pink noise wav file on the web that you can burn to a cd and use that.

3. push the PFL or solo for the channel(s) one at a time and set the pre amp/trim so its a hair below zero on the mixer meters (set EQ flat or off for the channels) then turn off PFL or solo and do the 2nd channel the same if using 2.

4. route the channel(s) to main out only not sub groups and set fader(s) on main/master a zero unity. If your EQ is inserted on the main outs set it flat or bypass but leave it on.
if the main outs go to the EQ that fine too but leave it on.

5. set the one or two channel faders you just PFL'd to zero also and look at your main meters with all PFL/solo and AFL switches off.

6. if your EQ is patched with insert cables on the main outs unplug the inserts as the EQ input/output settings even when bypassed will effect the master meters if set wrong. IF your EQ is patched to the outs of the mixer we'll set that later.

7. your main meter should read about zero. IF using 2 channels to do this it will be a little higher as you are summing 2 channels. if using 2 channels turn the pre's/trim down a little (equally on both channels to get zero on the meters) make sure all PFL/AFL buttons are off.

8. Now you got the master meters going at zero plug the EQ inserts in. If the level changes your EQ should be adjusted so the meters read zero with the EQ on bypass or set flat. If you have meters on the EQ you can use them to see whats going in and out and they should be reading close to zero also. Not all meters are calibrated exactly the same so there could be a slight difference.

9. If the EQ is patched to the outputs of the mixer instead of inserts then use the meters on the EQ and set so they are at zero.

10. set crossover input and HF/LF outs at zero

11. With speakers unplugged and amps turned down, turn up amp volumes to zero on the amp meters NOT zero on the dials. If you dont have amp meters turn the dials up till you see a slight flicker of the clip light and note where the dial is and turn is back about -12 db. Most mixers have about that much headroom above zero/unity without distortion. (this is why amps with detented knobs are nice so you can get exact settings. after you have noted the optimal position for the amp settings turn them back down and plug in your speakers.

12. turn down your master fader on the mixer and turn your amps back up to your noted volumes and play some music thru the system. Bring the master up where you think your ideal playing volume will be and listen.

13. If your subs are too much turn the LF out on the crossover down to get it balanced. If the subs are too weak turn the HF out on the crossover down to balance. As you adjust overall master volume you will have to adjust slightly. Always turn down one or the other to balance. dont boost as you loose head room.

14. now use EQ to taste after getting the high and low balanced. Always better to cut out offending freqs then boosting the good freqs as your gain staging you just did goes out the window. The PR15s are a bit boxy sounding but you can find those freqs and cut them a bit.

15. Now when adjusting channel EQ's say for a vocalist use PFL to read the level before you EQ, note what the level is first. Say the vocal channel is to much bass or muddy so you cut some 80hz or better yet use the HPF if the channel has one to roll off low end. With the PFL in you can see how much it drops the level. If it drops 3 db then after eq'ing trim the pre back up 3 db. If boosting something then trim it down so it was where it was at before adjusting EQ then turn off the PFL when done.

16. Note where your meters are when adjusting the mains EQ also and if it drops or raises after EQ is set adjust master level as needed also.

When you have say 8 channels going on the board the PFL/trim for each channel should be set lower than zero as summing that many channels will go over zero on the master.
if you need a little more punch then run them right near zero but the master will need to come down a little.

Thats why a sound guy that knows this stuff is always good to have at the board.

Hope this makes sense.......this is so everything you see on the meters on the board is doing the same thing thru every component. Headroom is close to the same all the way thru.
IF your master fader on the mixer hits +6 you know you are safe as you set up so you have the headroom so you are not clipping amps or getting distortion


Any other volume issues are probably because your stage/amps/drums volume is too loud.

 

[Zooberwerx]

Gain stage your system like this:...

This is a nice variation on the clipping-based procedure I snagged from dbx. It embraces gain structure but falls short of addressing EQ measures.

Copied and saved...thank you!

Riis

 

[uhdinator]

Thanks!

Its kinda general but works. The only thing it does not take into account is the headroom variations in each component. If you want to get really perfect and squeeze every bit of volume you can out of a system you gotta account for that by using the clipping method so all your components clip at the same point. Hard to get it dead on unless all your components have clip indicators and requires knowing the headroom specs and more research of your gear. Slight variations in clip indicators makes it more complicated too. Some gear may audibly clip when the indicator comes on, some gear clips a few db after the light comes on as a safety margin. Using limiters and compression of course will squeeze more volume out of the system too, but tried to keep it simple. The zero method will get you close enough for the average layman to keep you out of danger of damaging your gear.

If you were running a simple mixer to an amp and you know the mixer has 18 db of headroom above unity on the main outs before distortion then I crank up the master to clipping and the dials on the amp to clipping and back them off -18db.

likewise if an EQ is in between that has only 10 db headroom I would back the EQ input down 8 db so if I did slam the mixer master up that high the EQ would not cause distortion in the system.

Then you have the slight differences in gear where some pre amps may have a sweet spot that sounds better if ran higher or lower, the same with each component.
I know most good mixers sound better with faders up within +or- 6 db or more from unity too. In a Studio/recording environment you can hear it, but in a sloppy gymnasium playing a prom its hard to dial in unless you have really dialed it in first playing an acoustically pleasant room which never happens playing bar gigs.

Think of improper gain staging as trying to put out a fire with a big hose running into a small hose then back to a big hose........you would not have the volume needed at the other end as you would if the hose was the same size from one end to the other.

 

[Zooberwerx]

Its kinda general but works....

We're on the same page. The dbx protocol has you bouncing back 'n forth with the amp attenuators (clipping vs. non-clipping) then rolling in the limiters to preserve headroom. There's room for error based on the factors you mentioned but, overall, the results have been consistent & reproducible with each change in our rack configuration. FTR, I use a pink noise CD.

Either way, the set-up process is a learning experience and I strongly recommend it for any wannabe / novice soundguy who wants to get a handle on how components truly interact. The first time I tried it, I said "...oh, now I get it!".

Riis