Karaoke Forums

Hi all,

I have my first outdoor DJ gig this weekend and I have some questions for those of you that own JBL Eon G2's:

I am using these with an American Audio mixer and I am wondering the best way to get the most out of them.


I usually run the output of my DJ mixer through my Mackie CFX12 and I run the Eons wide open. But I have never pushed them all that hard, as I have been doing smallish indoor gigs. This gig is a car show and I am hoping to have enough juice with only the Eons. It is a decent sized parking lot, but not huge.

If I set the master volume on my American Audio mixer at say 75%, how high can I turn my channels 1 & 2 faders up before I risk doing damage to my speakers?

Any help would be appreciated!!

Patrick

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Patrick
Twinbrook Sound
Waltham, MA

I have run both first gen and g2's outside and sound factors I usually run gain on g2's all the way up then down just a bit (why i dont know they are almost impossible to destruct) I started one show by turning every thing above unity and flying a 747 over (neat effects) it rattled glasses on picnic tables then all i got was do that again...and agin..
However I wouldnt run very long at this level.
Believe me you are not going to have to run full volume unless every body has ear plugs. Any thing above -6 db gives a rapid increase in volume. I run unity (or slightly less) into a dfx 12, channel faders about -5 to -10 and if you are running g2's at full bore you wont run mains at unity depending how close the neighbors are. I wouldnt hesitate to run unity (1 volt) into g2's but I might feel them periodically to see how hot they are (the heat sink is directly above the 15" speaker grill ) The high volume with sound quality out of 2 g2's are going to amaze you.
From past experience although it might not apply here i carefully monitor bass levels when running high levels. Rock'em Patrick

I've used G2s many times and never felt they were being driven hard at all. I normally use the earlier Eons (with a G2 sub) and crank them all the way, backing off on the mixer - however, I've never felt the need to set the G2s much past 60% or so. They also have better inherent bass to me, but if you have a sub use it, especially being outdoors. My EONs and the sub were fine at a parking lot car show I did (Walmart - fairly large lot).

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Sounds Great! Entertainment
Bartlett, Illinois

Yea Marty you are right on the G2 level I too hesitate to crank them up I was thinking of the older ones when I said wide open. Have you ever paired a G2 with an older one? I have done that and turned the base up a little on the G2. The first time was just to compare the sound on both. In fact one time in a small club I had to use my monitor Eon10 G2 as a main Now that is the speaker that amazes me..... I have to watch it some want to take it home..

Thanks for the relies guys!

I can't tell me how much you 2 are putting me at ease!

I don't have a sub, yet. Do you think I should see if I could rent a G2 sub?

I do have 1 G2 10 that I use as a monitor. When I went to the venue to see where I would set up, the best place seemed to be close to one end of a long parking lot. Most of the cars would be parked in the big part. But the woman told me some cars would be on the other end.

What I was thinking of doing was to set up my speakers so they point at an angle down to the end of the lot with most of the cars, hoping the sound would radiate so the small end as well. Then I would take my G2 10 and point it to the small end.

Does this soulnd like a plan?

A big worry of mine is that I have never used the speakers with only the DJ mixer; I have always run the output of the DJ mixer to a stereo channel on my CFX 12. This Saturday I will be using only the DJ mixer (mainly because I want to keep my load down). Now, when I set the G2 amps wide open, which is how I alway run them, and I have my master on the mixer at half way, it doesn't take much of the channel slider to make the light on the back of the G2 stay solid green.

Is there something I am doing wrong? Is there a way I can get more without overdriving the amps? Is there something wrong with my gain structure.

As you might guess I am fairly new at this!

I AM learning, though!

Thanks for the help, guys!!

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Patrick
Twinbrook Sound
Waltham, MA

Run them wide open. Your volume comtrol is coming from your mixer, if you blow them it will be because the speakers are turned down too low & trying to compensate at the mixer by turning them up. Listen, if they sound distorted at all, turn the mixer down.

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LIKE Lonman on Facebook - Lonman Productions Karaoke & my main site via my profile!

Personally, I can't imagine running the G2's wide open for any typical mobile gig...I've never been able to. They are hot. and I've used them for weddings with over 300 people - large, in my book.

The G2 sub is definitely worth looking into. And for that, you can run it all the way up, assuming you have a separate zone/sub out on your mixer (never cared for the daisy chain dealie off the mains).

The G2 EONs can be a bit "buzzy" to me when cranked. Maybe it's the mixer or something I use with them (another DJ companys) - dunno. The G2s are much hotter than their predecesor.

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Sounds Great! Entertainment
Bartlett, Illinois

I still prefer the first generation eons over the gen 2's. Either way JBL is the choice for sure.

So maybe I'll run the G2's wide open, the mixer master at half way, and the channel sliders up as far as they'll go without distorting.

How does that sound?

Should I keep an eye on the green light on the back? Should I worry if it is solid? Or do you think I will be fine considering that I will only be running them for 2 hours?

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Patrick
Twinbrook Sound
Waltham, MA

Set your master sliders at unity..........Set your speaker amps at max input gain.

Trim each channel to where you are peaking just slightly above 0...+2 or + 4 max.

Then if you ain't got nuff stuff, don't crank anything into clipping!

Your speakers can handle anything that ain't clipped. Their amps will hit full power whenever the mixer outs hit their input voltage sensitivity ratings. After that, if you crank anything, the speaker amps will clip, or will amp the clipped mixer signal and then the magic smoke will escape.

Bottom line is use your boards metering. Meter each mic at the input and trim it's input gain properly, then meter the strip out and trim it with it's slider....After you meter each input to the master, them sum all and meter it again. If the sum is too hot, lower all strip sliders, but leave the inputs for the strips hot.

Get all your gain possible at each mixer channel input gain twisty. Then slide that strip up till the master amp is seeing a unity signal from that strip, then nothing will be clipping and your inputs are hot, and your speaker amps won't see a clipped signal....after that, if she ain't loud enuff, you need more speakers and amps.

What you should see then is your masters at unity....Your input gains near unity....and your strip sliders somewhere up off the bottom....At no time should any strip slider be higher than your master sliders. If they are, you need to increase the input gain for that channel and lower the strip slider.

After all is set, use masters to control volume up to unity....

Let me add this:

Your system consists or several amps....There is one for each mixer input, one for each mixer bus and one for the mixer master. Your speakers also have amps. All of those amps have gain controls. They control the signal coming INTO each amp.

Each amp will amplify the signal it gets thru those input gains.

The idea is to structure each amp so that it is not limited at it's input. If you limit the input of any of those amps, you will narrow the dynamic range of that strip or the whole system.

Several of those amps have OUTPUT gains....One such example is a channel slider. If you crank an output too high, it will sound distorted cause it is overdriving the next amp's input.

At the top of each strip is your channel input gain....that gain controls the signal entering the strip pre-amp. It needs to be set at or near unity if you expect that mic to sounds as good as it should. If the mic is then too loud, lower that strip slider.

If your mixer has proper metering, set each strip starting at the input gain. Select pre for that strip meter and adjust the input while talking or singing loudly into that mic. Set the input gain to where you see it peak at or slightly above unity.

Then select post and adjust the slider till you see unity. You can do this with the masters down. The meter is all you need to watch.

When it is set to pre, you are metering the input to that channel. When it is set to post, you are metering the output of that channel. Unity at both means the channel is not undriven or clipping at either it's input or output.

After you set each channel this way, then meter the input to your master. That will indicate a sum of all channels. At this point, you may have to lower all channel slider a little so as not to overdrive the input of the master bus.

Now set the masters at unity and the speaker amps at max.

If during the show, any one mic is too loud, reduce it at the slider. If the CDG is too loud, reduce it's slider too. If the mics or music is too low, then DO NOT increase any slider above unity. If you do, you can overdrive the master bus and destroy your speakers fast.

Now you know what is called "gain structure"...at least enuff to host a good sounding show with out smoking anything.

Keith,

Thanks a lot for your reply! I appreciate the effort it took to write out all that information.

My problem right now is not my karaoke show, it is a car show that I am doing tomorrow. All I will be doing is playing music. I supposedly will not even be required to make announcements.

I am new at this, but I think I understand the concept of unity gain; as least as it applies to my Mackie CFX 12. My DJ mixer -- which is all I was planning to use -- has me set the master slider and the channel slider to 8, and then set the channel gain. Does this sound right?

If I did this, and brought my Mackie into the mix (whch I actually decided I would do so I could have some reverb on the mic if I was to need it) would I then just set the gain structure on the Mackie as outlined in the manual, and run the JBL Eons wide open?

Also, I am trying to set the gain on a stereo channel and they don't have the trim LED like the first 8 channels of my mixer do. Is there any trick to setting this up?

I SWEAR I am going to learn about gain structure, inside and out, after this gig!! Right now I am just trying to get through without the client noticing that I may not have enough juice for the event.

The bottom line is that all my worrying is probably for nothing. It is a car show and all they want is some background music for 2 hours. This isn't a rock concert!

Thanks for all the help! I'll let you all know how I make out.

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Patrick
Twinbrook Sound
Waltham, MA

For CD music playback on the CFX, jack in to a stereo strip. If you have no input gain meter for that strip, but you do for the output slider, then just bottom out the master sliders, set stereo strip slider to unity and meter the input to your master bus with CD playing.

You might discover that the signal is really hot with slider at unity. That's because most consumer CD players tend to overdrive the inputs of Pro Audio mixers. Even if you reduce the slider, you will still be overdriving the input and it will sound distorted, or not as good as it should.

To get around that problem, just plug your left input in to one mic channel, and the right in to another. Use the 1/4" line in jacks at the top of the strip. Then you can trim the gain for each so you don't overdrive the pre amps. All you do then is finger both sliders up and down at the same time. You will have great sounding stereo.

For the DJ mixer, they ask you to set at 8 because they don't provide any means of attenuating(reducing) the input gains. They know most CD players are too hot, so they have you do it that way to preserve headroom and gain structure. That's fine, just remember the golden rule...don't allow the strip slider to get higher than the master.

Set you Cabs high on sticks so they are over the heads of the crowd. Remember that being outside and not against a wall, you will have very little bass. Take care not to blow a driver trying to get bass. Crank cab input gains to max. Then if you have clip indicators on the cab amps, watch them at first....If they flicker, you are ok. They are only telling you that you are near max. Most lite several DB before clipping. A steady lited clip led is announcing the approaching death of you cabs.

Yeah, I know what they told you, but trust me, someone will want to grab the mic and make announcements, or have you do it.

Thanks again, Keith!

I am going to print this whole thread for future reference, as I think you have provided me a great explanation.

I am no longer under the gun here because my car show has been postponed until Agu. 7 due to rain.

This will give me a chance to digest all this info and try it out.

Thanks!

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Patrick
Twinbrook Sound
Waltham, MA

Yer welcome.

Please describe DJ mixer or provide link to it....I'm courious.

Keith,

Here is the link to my mixer.

http://www.americanaudio.us/product.asp ... cat=Mixers

Thanks again!

Patrick

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Patrick
Twinbrook Sound
Waltham, MA

Great!

I downloaded your mixer instruction manual.

Trim your inputs to each channel just like it explains in the instructions. They ARE metered, so will be easy. Then set their outputs also like explained in the instructions. (All on page 5)

On page 5 it shows what each control is for.

Use the twistys numberd 5 to adjust inputs to the mixer.

And then use the knobs numbered 6 to adjust the output from that channel.

For volume control, use the Master twisty knob. Use it like an on/off switch, tho.

If you are using a phono on one channel and a CD on another, they might not agree and one will sound louder than the other when shifting to it. That's when you use knob 6 to match levels, not knob 5.....knob 5 is a one time set and forget thang...Overall loudness is always controlled by the master thru the channel outs.

Set your speaker input gains to max, always. That allows them max headroom.

If you have trimmed the inputs and outputs like the instructions tell you to, then you cannot hurt your speakers. That's because your speaker amps are perfectly matched to your speakers powerwise. You can only hurt them if you clip at the mixer ahead of the speaker amps. So take care to trim your inputs properly. They are the most important stage. They have to be hot fersure, but not so hot that they overdrive the mixer pre amps. That is why you meter them like described. Make the lite flicker and then stop turning, If it don't lite start twisting till it does flicker. Now your mics or CD or phono input is hot and will sound full and brite.

It is at the mixer inputs that you establish all system initial gain. Initial gain is very critical. Get as much there as you can and your whole system will have all the dynamic range it can handle. It will sound bright and crisp. No flat spots....Really brite and full. Your mics will finally sound expensive.

Now here is the other important part...........Lets say the room you set up in doesn't require you run wide open at max volume....the first thing you think you need to do is crank down on the master, right?...Or turn down the speaker amps.....Wrong!

Instead reduce the number 6 knobs that controls the output of the channel that is playing. Leave the master and speaker amps at full and unity. You do this to preserve mixer headroom, just like in the speaker amps. You leave all amp inputs wide open and instead attenuate the output that is feeding it.

So, you being a not-stupid kinda guy.....You ask, "Why are there input gains on my speaker amps if this guy says I need to leave them always at max?"

Those input gains are on all power amps used in pro audio. All that makes your amps different is that the amps are built into your speakers....but the reason they are there is to match each amp to others in the stack. In your case to match powered speakers to other powered speakers or perhaps outboard amps for unpowered speakers.

Let's say you have matching Eon 2x15" cabs to use as mains and a Peavey 10" powered 2x10" for monitor. The Peavey will have a different input sensitivity rating than the Eons. What that means is they will respond at different input levels than the Eons. You want all cabs to respond together, right?...So you attenuate(turn down) the most sensitive of the powered speakers at their amp inputs....That way they all hit full power at the same time........They all have the same responce to the mixer output. This is important if you use monitors....Monitors cause most feedback, so set them up so they don't get ahead of your mains in volume.

All you do when you reduce the input gain knob to a power amp is change at what level of input it will go to full power...Let's say the amp will hit full power when it sees 1.54 volts at the input if the input gain is all the way up....When you turn that knob down, the amp requires a higher input voltage before it will go to full power. The amp can still hit full power no matter where the knob is set if it gets a high nuff input voltage. But setting too low will shave it's headroom.

The amps in your mixer will put out varying levels of voltage. If you leave your mixer masters at unity, then their voltage out is controlled by each or the total of the channel sliders....Unity means IN equals OUT....If a channel is producing 1 volt, then the master will only send 1 volt to the speaker power amp if set at unity....in that way, the channel sliders are actually controlling "volume", not the masters.....And that's good. The masters, when at unity, can then flow all voltage that the channels send...And the amps will react to the inputs up to their full power limits.

Only trim power amp inputs to match the other power amps in your stack. Use it only to match amps to each other. Read up on your amps and powered speaker amps to discover what their input sensitivity is. It will be stated in Voltage DC. If one of your amps has an input sensitivity rating of I volt and the other is 2 volts, then you need to attenuate the 1 volt amp input gains so that it doesn't hit full power before the other amp. Turn that amps input gains down till it matches the other, less sensitive amp, ok?

If you only have one amp, or matched pairs of powered speakers, then all amps inputs should be at max.

WOW!

Keith, I can't thank you enough for all this help!

I just printed this thread and I am going to keep it with all my other manuals.

I am in study-mode and I am going to learn all this stuff if it kills me!

A thousand thank yous!

Patrick

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Patrick
Twinbrook Sound
Waltham, MA

Yer welcome.........

, there really is one more thing..........The last, I swear!

The the two things that can hurt your speakers even after you do all the above is:

A: Feedback
B: Over excursion

You know all about feedback I'm sure, so nuff said about that.

But, over-excursion of the woofer cone must be addressed. Over excursion occurs when the speaker cone travels too far. Bass freqs are the blame for this. Even tho you ddn't over drive them with too much power and didn't clip them, they can still be fried real quick by over excursion.

Over-excursion happens when you send too low of frequencies to them when at hight power. It happens most often when you set up with out subs, or you don't cross over into the subs properly.

If you are using your Eons only, then you want to protect them from too low of bass freqs at high power. Perhaps the Eons have filters already installed for this, perhaps not. Read your product manuals or contact JBL to find out.

Basically, you never want to send anything below 40-50 Hz to your mains at high power. The most thump from bass is usually heard and felt at 65-85 Hz anyway.