Why do we need to have the gains bottomed out?

[museav]

TS or TRS depends on whether the output and input is TS or TRS, A lot of 1/4 inch devices are unbalanced.

And specific to this application, there are even some wireless mic receivers with unbalanced outputs on XLR, certainly not normal but not actually wrong in any specific way. That's why you should always check the product specs to verify the level and format of the output(s) regardless of the connector type used.

 

[SHARYNF]

I guess putting things a bit more bluntly, before changing ANYTHING you first need to research what you have and how it all interfaces. I have seen many posts about your school and there seems to be one problem after another, stolen speakers by contractor, destroyed main drape, improperly set up systems

I also see a tendency to take a ready fire aim sort of approach

Changing the levels on the wireless transmitter, or the output level on the mono on the Mackie etc, all should never have been done without first looking at what you have. Several of us all pointed out that the probably error was using line out into mic in on the mixer. It was only when it was guessed what wireless units you had that it was clear that these are line out only and that was the basic problem.

Since this is an educational orientated site, I think it is important to realize that it is RESEARCH FIRST before ACTING. the old RTFM (read the .... Manual) really is important especially now a days when a google search can typically find the missing manual or specs

Gain structure is important, but understanding what you have and the levels of the inputs and outputs that are expected is important FIRST It comes down to: is it line of mic, is it pro level or consumer, is it balanced or unbalanced in most cases, this information really is IMPORTANT to make decisions before action. Otherwise you wind up with a difficult situation trying to resolve problems some of which you may have introduced by changing things.


It is easy (relatively speaking) to operate when everything works, where this site, and the people on it are trying to help is teaching HOW to diagnose problems and resolve them.

Sharyn

 

[MillburyAuditorium]

Yeah, I was looking at the mics today. The old ones are EW 100 G1s and the new ones are EW 100 G3s
Now that we lowered the main gain and turned up the channel gains the older mics are able to be much louder without any squealing. I will have to take the new belt packs up to -30 though since they are now not as loud as the old ones at -30. SO that should solve this problem. I will also try the Line In suggestion as well.

I have read most of the manual.


Other questions-

I do not know if it is the age of the board or what, but I have two things. One, I was playing a recording of the orchestra for practice one day from the CD player, and it was pretty loud, so I put on the headset to listen to the actors to EQ them, so I am listening to them on solo. And the CD channel is not on solo, but I realized I was still getting some of the CD being played through the headset, I hit the solo button for that channel and it came in louder and clearer through the headset, turned it off, and it was still there just a little muffled and quit.
Also, I was recording clips of the rehearsal today for a commercial we do plus we need them to make something for the opening, So I was running out of one of headphone jacks to the mic in on my laptop, I played music through the 'Line' channel form my iPod, had the channel on solo, and my laptop was picking it up fine, but it was also coming out the speakers very faintly. I was confused, the slider was all the way down, yet still coming out a bit.

Why is this?

 

[SHARYNF]

The gain on the belt pack is for control of the signal in the belt pack, so that you do not overload it and cause distortion. It is set so that you still have a hot enough signal so that you have good SNR ration but don't overload. it is important to get it correct since there are electronics in both the belt pack and the receiver that need to have the proper gain structure for them

Making sure that since you only have line out on your receivers you have the input pad and trim set properly on the Mackie is important so that you don't overload the input stage on the MIXER

The control on the mono output on the mixer is so that you don't overload the input stage on what is down stream from the MIXER... Your amps probably have a level control on them which adjusts the LEVEL OF THE INPUT since the amps them selves run at a fixed setting it is just the level of the input signal that is varied.

You seem to keep attempting to correct the wrong end of the problem.


Your fader will not be able to completely shut off a signal that is too hot coming in to and thru the preamp. So if you are putting a line level signal from a CD player into a mic input and don't have the pad and trim set correctly the fader will not completely cut off the signal. You can check this by simply muting the input, the low level you are hearing should go away.(assuming a reasonable level of channel isolation on the Mackie)

Taking headphone out and putting it in to MIC in is another Level mismatch. Typically you should use LINE out, and LINE in. Just because the jacks fit does not mean the signal will work properly. Are you going to get something, sure but is it the correct way to do it ??? At a minimum take the Headphone out and put it into a LINE level input.

As mentioned before Gain structure is important and should not be ignored

At each stage you are trying to get the best match of signal level above noise and before clipping.

If you run your belt packs too low, you will get too much noise, if they are too high you will get distorted overload. If you run line levels into mic level settings on a mixer you will get an overload input and as you have seen an inability to totally shut off the signal via the fader.

As I said you need to take some time and think about all this, it is not just that the plug fits, but that you have the correct level to match the signal thru the system, There really is a reason for the adjustment controls that are placed on the ins and outs of most pro gear. It is not like consumer stuff where they are all designed to pretty much just plug in and the compromises are made by the manufacturer

Sharyn

 

[Morpheus]

This is where your wireless mics should be coming in.

 

[SHARYNF]

Morpheus is correct, on the Mackie you have there is NO input pad, and it is not possible to connect a line level signal to the xlr inputs without a real danger of overloading the pre's So you need to get some cable adaptors that convert from xlr to trs.

Sharyn

 

[MillburyAuditorium]

Alright, Well it's been running like this for years. Good thing nothing has happened. I'll get those adapters soon.

And about the not being able to cut off the sound. It isn't really that, we can cut off all sound via the faders, so say I have the headphones on and nothing on solo. I hear nothing, good. I press solo on channel 11 (wireless 1), and I can faintly hear the CD track through the headset.

And I dont understand what you meen plug the headphones into a Line in? DO I not conect it to 0one of the two Headphone Outs?

And the CD player is using a line in, not mic.

It's fine that our floor and hanging mics are using MIC inputs right?

 

[SHARYNF]

I am just responding to what you wrote

Also, I was recording clips of the rehearsal today for a commercial we do plus we need them to make something for the opening, So I was running out of one of headphone jacks to the mic in on my laptop


Connecting a headphone out jack to the mic in on a laptop is going to cause problems.


Sharyn

 

[MillburyAuditorium]

Oh about the laptop one. Well it worked out alright. And I really wasn't sure where to connect it. I tried the Aux. Stereo Outs but that wasn't working and I didn't have much time to try things.

 

[Morpheus]

stuff like line level out into mic level in (like your laptop thing, or even the hanging mics you mentioned vs the wireless) is all about matching the correct levels....

Basically, your "line level" signal is up here: ↱

while your "mic level" is down here: ↳

So, when you put the connector into the device, it's dumb and doesn't know what you want it to do, it only does what is expected, which is get the signal here: →
So.... that means it boosts what it thinks is "mic" level, and cuts what it thinks is "line level"...
And if it boosts too much, it clips and sounds bad.
If it cuts too much, you don't hear anything.

 

[museav]

stuff like line level out into mic level in (like your laptop thing, or even the hanging mics you mentioned vs the wireless) is all about matching the correct levels....

Basically, your "line level" signal is up here: ↱

while your "mic level" is down here: ↳

So, when you put the connector into the device, it's dumb and doesn't know what you want it to do, it only does what is expected, which is get the signal here: →
So.... that means it boosts what it thinks is "mic" level, and cuts what it thinks is "line level"...
And if it boosts too much, it clips and sounds bad.
If it cuts too much, you don't hear anything.

Good points but the last couple may be misunderstood. Mixers are not trying to get a signal level between mic and line level, they are essentially trying to get everything internally at a nominal line level. Being of much lower level, mic level signals coming in to a mixer typically need significant gain or boost their signal to get to that nominal level while line level signals may require either some lesser gain or some attenuation.

Clipping does not result from the gain (boost) or attenuation (cut) applied, it results from the signal level being greater than the electronics can handle. Every electronic circuit will have maximum signal levels it can properly handle and any signal level above that is 'clipped', which is undesired electronically and audibly. In general, a signal of higher or lower level than optimum can be undesired in terms of how it affects the signal, the resulting noise or the operating headroom (the room between the average signal level and the peak level when clipping occurs). That is where gain structure comes into play in optimizing the signal levels.

 

[Morpheus]

Good points but the last couple may be misunderstood. Mixers are not trying to get a signal level between mic and line level, they are essentially trying to get everything internally at a nominal line level. Being of much lower level, mic level signals coming in to a mixer typically need significant gain or boost their signal to get to that nominal level while line level signals may require either some lesser gain or some attenuation.

Clipping does not result from the gain (boost) or attenuation (cut) applied, it results from the signal level being greater than the electronics can handle. Every electronic circuit will have maximum signal levels it can properly handle and any signal level above that is 'clipped', which is undesired electronically and audibly. In general, a signal of higher or lower level than optimum can be undesired in terms of how it affects the signal, the resulting noise or the operating headroom (the room between the average signal level and the peak level when clipping occurs). That is where gain structure comes into play in optimizing the signal levels.

Well, yea.
I was trying to make it simpler to understand... Sometimes i get really into the tech and make it way more complicated than it needs to be

 

[MillburyAuditorium]

Well as I said, it sounds fine now, was just the Amp master was down and the EQ gain was up to much. I will see about those 1/4" converters.

Maybe this is why we keep the beltpack gains at -40?

 

[SHARYNF]

Somehow I get the impression that you really have not read carefully the recommendations and the discussion on gain structure

Sharyn

 

[MillburyAuditorium]

What makes you say that? If you are because I said the amp was down..Obviously if an 800 watt amp is turned down to only give out 50 watts, I was being forced to increase the gains and levels. But now that I turned the amp up to were it should be I can do things normally now.

And I people are saying using a Line out to Mic In is bad so either way I would want to get the Mic-Line converters.

 

[museav]

What makes you say that? If you are because I said the amp was down..Obviously if an 800 watt amp is turned down to only give out 50 watts, I was being forced to increase the gains and levels. But now that I turned the amp up to were it should be I can do things normally now.

An 800W amp is an 800W amp and a set signal level to the amplifier crcuit in the amp will generate that, all turning down the levels does is attenuate the signal level before the amplifier circuit itself, it does not reduce the potential amp output or prevent getting the full rated output.

The most common and recommended approach is to properly set gain structure then adjust the amp levels to get the desired output levels.

 

[Morpheus]

Somehow I get the impression that you really have not read carefully the recommendations and the discussion on gain structure

Sharyn

Reading and comprehending are two different things....

What makes you say that? If you are because I said the amp was down..Obviously if an 800 watt amp is turned down to only give out 50 watts, I was being forced to increase the gains and levels. But now that I turned the amp up to were it should be I can do things normally now.

And I people are saying using a Line out to Mic In is bad so either way I would want to get the Mic-Line converters.

wait, when did we start discussing amps and signal post-mixer? (while we're there, if you need to clamp your amp down that much, time to look at getting a different amp)
It's good that you're starting to think about the gain structure, but start from the right end - start at the top of the signal chain, not the bottom

 

[Eboy87]

What makes you say that? If you are because I said the amp was down..Obviously if an 800 watt amp is turned down to only give out 50 watts, I was being forced to increase the gains and levels. But now that I turned the amp up to were it should be I can do things normally now.

And I people are saying using a Line out to Mic In is bad so either way I would want to get the Mic-Line converters.

The gain controls on amps don't work that way. They attenuate (turn down) the incoming signal. They don't control the output wattage. You still need to read the article on gain structure. There's more going on here than you're willing to admit, much of it probably over your head at this point. This isn't about getting the maximum output from everything, there are impedance mismatch issues as well as level mismatches in your system. Spend some time here. It's the study hall over at ProSoundWeb. Read some articles and understand the principles of what's going on with how the gain structure relates to each piece of gear. You need a foundation before you can accurately diagnose your problem, and the people in this thread have been trying to help.

Now, for your mic/line level situation. I look at it this way; I would rather have line level coming into my board (via the Line level jacks on the back of your Mackie) than mic level. I would find 1/4" balanced (TRS) to 1/4" balanced cables, and connect your mic receivers that way. Sending line level signals to an input expecting a mic level will overload the circuit, leaving you with garbage for a signal. The garbage in/garbage out ratio applies here.

I also suggest you go back and re-read this thread carefully, paying attention to what is being suggested. It will actually benefit you in the long run. I would also suggest you bring in someone more knowledgeable in audio to help you with this, and also to tech you and any other techs at your school just what is going on with your system.

Good luck!

 

[SHARYNF]

My Mistake, reading and comprehension are not one and the same

several of us tried to explain the difference with the setting on the belt pack and the line out on the receiver

The reason why you need to convert the line out on the receiver with an XLR connector to 1/4 TRS

Why connecting a Speaker level signal to a Mic level input is not a good idea

Why Understanding gain structure is important, and the in and out levels on devices and how the input control on an amp works.


Sharyn

 

[MillburyAuditorium]

Guys, I dont know why your yelling at me 0_0. I have said that I am going to be doing what you have suggested.

And you are not understanding what I am saying.

I DO NOT need to turn the amp down.

And my problem is resolved by the way. The reason why I couldn't get hardly any sound out without turning the gains up so much was because someone had turned the amp nearly all the way down. I have turned it back up and we are all good.

I do not know if our amps are different then others? Because our single 800 watt amp has a physical knob that read VOLUME. And if the VOLUME knob is all the way down, it doesnt mater if the gains are set perfectly on the board nothing is going to come out..