# A little help...What level should I set my Amp at, all the way, 3/4?



## tcarcio (Jun 27, 2007)

I just hooked up a Crown cts-600 to run my mains and I was wondering what is the best way to run the gain and volume controls. Should I turn the amp up all the way and then adjust with the master volume or just run the amp at a lower gain. I will say that going from 120w to 300w makes a huge difference in the way things sound. I have full range mains and have never put more than 120w into them. Now I have to turn the amp way down to match the output of my Pioneer Elite. I have another one of these amps to hook up and I might have to pick up another for the center channel. Thanks for any help.....:wave:


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## salvasol (Oct 31, 2006)

tcarcio said:


> ... Should I turn the amp up all the way and then adjust with the master volume or just run the amp at a lower gain. I will say that going from 120w to 300w makes a huge difference in the way things sound. ... Now I have to turn the amp way down to match the output of my Pioneer Elite.
> ....:wave:


This will be interesting :yes:

I thought that you have to use the master volume at reference level and then adjust the gain on the external amp to get the 75db on the fronts (like a new calibration) ... and if necesary adjust the rest of the speakers :scratch:


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## tcarcio (Jun 27, 2007)

You may be right but couldn't I just turn the amp up with the master all the way down and then set levels. I just wasn't sure if that is the right thing to do. I know it is mostly trial and error to see what works best but I thought if someone else has a similar set up they might have found what works best. I will be doing alot of adjusting when the other amp gets here tommorrow so I should just wait till I have everything hooked up so I can re-cal and go from there.


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## eugovector (Sep 4, 2006)

I'm going to take a chance at showing my ignorance, but I'd always been told to run the amps full open, and it makes sense, at least with a clean, noise free signal. The last thing you want is the amps gain control introducing some resistance that alters the tone, and you don't want to overload the inputs of the amp by cranking your pre to high, that will result in speaker damaging distortion.


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## tcarcio (Jun 27, 2007)

eugovector said:


> I'm going to take a chance at showing my ignorance, but I'd always been told to run the amps full open, and it makes sense, at least with a clean, noise free signal. The last thing you want is the amps gain control introducing some resistance that alters the tone, and you don't want to overload the inputs of the amp by cranking your pre to high, that will result in speaker damaging distortion.


Thanks, I have been bouncing around and it seems that you might be right. I actually talked to a DJ and he said the same thing. I guess I will run it that way until I hear different. I am going to call Crown CS and see what they have to say about it. I ran it for awhile yesterday at about 3/4 and it really is a bigger difference in the way my speakers sound then I thought it would be. They have much more presence and punch then they did before. I cant wait to get the other one hooked up today and watch a movie. Thanks guy's.......:clap:


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## thxgoon (Feb 23, 2007)

Run it wide open if you can. In my particular case I can't trim the channel levels low enough to get 75db, so had to turn the gain down on the amp to about 70%. If it has an impact on SQ I can't hear it but that may differ depending on the situation.


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## salvasol (Oct 31, 2006)

thxgoon said:


> Run it wide open if you can. .... had to turn the gain down on the amp to about 70%...


You learn something new everyday :yes:

I have a Gemini P-07 that I use sometimes for music ... I always put the gain/volume to just half because I have the famous "hum" (I haven't look for what is causing that) :whistling:

So, it is recommended to use the Channel A and B (in my case) to the max??? ... and adjust the volume with the other equipment (mixer, EQ, etc) :dontknow:

For HT speakers ... I read that is not good to go above the recommended power (let's say 200 watts); and if you use a 350-400 watts amp, you don't have to play it loud because it can damage the speaker :huh: 

Can you damage the speaker having the amp to max (or 75%)??? ... or just if you set the AVR/pre pro volume to high ...:dontknow:


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## tonyvdb (Sep 5, 2007)

There is alot of debate over this as it depends on the noise in the incoming signal as well, Running the amp full open may actually introduce or amplify noise that otherwise wold not be heard. Anywhere between 3/4 and full is considered normal. I have my Samson at about 85%. Remember it is also possible to clip the input of the amp if the incoming signal is to hot coming from the receiver.

An over sized amp can of course damage speakers if the output is higher than the max rating of the speaker but so can an underpowered amp as it will distort and clip (this can do far more damage)


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## salvasol (Oct 31, 2006)

tonyvdb said:


> An over sized amp can of course damage speakers if the output is higher than the max rating of the speaker but so can an underpowered amp as it will distort and clip (this can do far more damage)


So if a speaker is rated 225 watts (110/440 peak) is okay to use a 350 watts amp??? or What will be max recommended??? :huh:

Sorry tcarcio for using your thread ... but I'm planning in case that I get an amp to run my fronts too :bigsmile:


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## avaserfi (Jul 5, 2007)

Typically speakers are rated using a constant amount of power via pink noise. This method is far more demanding than that found in music, even with extreme dynamics which are no longer common. So, if a speaker is rated at 100 watts during music playback it is very possible for the driver to successfully continue playback during a transient peak that requires 200 watts and higher before being damaged and in some cases distorting audibly.


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## tonyvdb (Sep 5, 2007)

salvasol said:


> So if a speaker is rated 225 watts (110/440 peak) is okay to use a 350 watts amp??? or What will be max recommended??? :huh:


I should also add that this depends on the speaker manufacturer, inexpensive speakers wont have the tolerance for the huge peaks that can occur in movies at reference. So you should be careful with watts ratings as they are very misleading.


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## salvasol (Oct 31, 2006)

tonyvdb said:


> I should also add that this depends on the speaker manufacturer, inexpensive speakers wont have the tolerance for the huge peaks that can occur in movies at reference. So you should be careful with watts ratings as they are very misleading.


The speakers are  JBL Stadium


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## tonyvdb (Sep 5, 2007)

salvasol said:


> The speakers are  JBL Stadium


although they are good middle of the road speakers and I see nothing wrong with them I would not push them too far past the 240watts they are rated for.


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## tcarcio (Jun 27, 2007)

Great info guy's. I am glad you guy's are bringing these things up because I was worried about the same thing with my mains. i have a pair of Cambridge soundworks towers that I have had for 10 years and I really love their sound and even more so now. I asked the store manager when I bought them how many watts they handle and he said we really don't feel that power is the problem it is distortion. The manual doesn't even list the max wattage for these speakers. He did say that he would not run more than 500w into them but I wouldn't think I would go that high. At 300w now I think I am at the limit. Now one question, if an amp is rated for 300w per and you have the gain at half would that mean you are putting 150w into the speakers or is there 300w going to the speakers at all times. Hope that is not a stupid question but if it is it wouldn't be my first and won't be my last.....:scratch:


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## salvasol (Oct 31, 2006)

tonyvdb said:


> although they are good middle of the road speakers and I see nothing wrong with them I would not push them too far past the 240watts they are rated for.


:T


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## tonyvdb (Sep 5, 2007)

tcarcio said:


> Now one question, if an amp is rated for 300w per and you have the gain at half would that mean you are putting 150w into the speakers or is there 300w going to the speakers at all times. Hope that is not a stupid question but if it is it wouldn't be my first and won't be my last.....:scratch:


It fully depends on the input level. If your running a very hot level you could theoretically be running the output of the amp close to max even at half gain. There should be a level indicator on the amp or at least a clip LED that will indicate this.


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## thxgoon (Feb 23, 2007)

tonyvdb said:


> It fully depends on the input level. If your running a very hot level you could theoretically be running the output of the amp close to max even at half gain. There should be a level indicator on the amp or at least a clip LED that will indicate this.


Exactly, it also depends on the load the amp is driving.


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## tcarcio (Jun 27, 2007)

Thanks guy's, There is a meter or lights on the front of the amp and with the gain wide open the light just starts to flash to the -20 unless I really play it very loud and then it might flash at -10 but that is much louder then I would play it anyway.The meter is 5 steps, power,signal,-20,-10, and clip.


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## salvasol (Oct 31, 2006)

tcarcio said:


> ... The manual doesn't even list the max wattage for these speakers. He did say that he would not run more than 500w into them but I wouldn't think I would go that high...


Don't you love when you can't find that information??? ... I'll go :wits-end:



> ... if an amp is rated for 300w per and you have the gain at half would that mean you are putting 150w into the speakers or is there 300w going to the speakers at all times. Hope that is not a stupid question but if it is it wouldn't be my first and won't be my last.....:scratch:


I had the same question (I think I asked before in anothe thread) but don't remember if it was answered, but I'm glad you asked... and I think is not a stupid question if you're not clear or don't know what you're asking :yes:


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## thxgoon (Feb 23, 2007)

tcarcio said:


> Now one question, if an amp is rated for 300w per and you have the gain at half would that mean you are putting 150w into the speakers or is there 300w going to the speakers at all times. Hope that is not a stupid question but if it is it wouldn't be my first and won't be my last.....:scratch:


Not a stupid question at all. The answer is unfortunately not all that cut and dry, hence a lot of the confusion.

An amp rated at 150 watts, is only 'rated' at that power. In actuallity it has the capability to put out much more than this depending on how much distortion you are willing to live with. The output level (watts) from an amp is entirely dependent on the input level as Tony said before. IOW, even if the gains are set to the max, if there is no input, there is no output. 0 watts. The amp will then operate anywhere between 0 and say 100 watts depending on how loud the particular scene or song you are listening to is recorded. So you can safely put a 1.21 gigawatt (bolt of lightning anyone??:dumbcrazy) amplifier on a set of speakers rated for 50 watts, and you would be perfectly safe as long as you didn't turn up the volume to the point where the speakers couldn't handle the additional power.


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## salvasol (Oct 31, 2006)

thxgoon said:


> ... So you can safely put a 1.21 gigawatt (bolt of lightning anyone??:dumbcrazy) amplifier on a set of speakers rated for 50 watts, and you would be perfectly safe *as long as you didn't turn up the volume *to the point where the speakers couldn't handle the additional power.


But the question is ... How can we be sure that the speaker won't get anything that can't handle??? :scratchhead:



> ... The amp will then operate anywhere between 0 and say 100 watts depending on how loud the particular scene or song you are listening to is recorded ...


That's true, most movies have some scenes where is quiet ... and suddenly a big explosion, or crash, airplane, etc. can produce a loud sound :yes: ... Is there any way to safely set up the amp to avoid damage to the speaker???



> ... *There is a meter or lights on the front of the amp and with the gain wide open the light just starts to flash to the -20 unless I really play it very loud and then it might flash at -10 *


Is this setting enough to be safe with those sound changes??? ... I mean, put the amp gain to the max or 3/4... then turn the AVR volume to the level we will use to watch the movie (eg: -20db, meter or light will flash slightly) but with a loud sound probably will go all the way up ... but as long as the clip light doesn't turn on, We'll be okay, Right??? :dontknow:


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## tonyvdb (Sep 5, 2007)

salvasol said:


> That's true, most movies have some scenes where is quiet ... and suddenly a big explosion, or crash, airplane, etc. can produce a loud sound :yes: ... Is there any way to safely set up the amp to avoid damage to the speaker???


Yes there is but its usualy done in the DVD player audio setup, by turning on the dynamic compression (usually called Dynamic range control) It will do just that. The softer parts will be far more even with the loud parts.




> Is this setting enough to be safe with those sound changes??? ... I mean, put the amp gain to the max or 3/4... then turn the AVR volume to the level we will use to watch the movie (eg: -20db, meter or light will flash slightly) but with a loud sound probably will go all the way up ... but as long as the clip light doesn't turn on, We'll be okay, Right??? :dontknow:


You will be ok as long as your speakers can handle that peak level.
I have done some pro audio setup for concerts on a road system and the general rule of thumb is to run the amp at no more than 50% of its power output during normal volume so you have some headroom for the peaks.

My samson amp has 5 segment level meters and I rarely see the second one light up even with the peaks at reference level.


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## salvasol (Oct 31, 2006)

All this (usage of external amp) seem overwelming :sad: ... at least, after I read some posts I'm affraid to take that route. :yes: ... I don't want to blow my speakers.




tonyvdb said:


> ... the general rule of thumb is to run the amp at no more than 50% of its power output during normal volume so you have some headroom for the peaks....


How do you acomplish that??? ... using the amp gain at 1/2 way??? ... Gain fully open, but volume on AVR not to high??? :dontknow:

Sorry for all newbie questions, but like I said before ... I want to learn for when the time comes :yes:


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## tonyvdb (Sep 5, 2007)

salvasol said:


> How do you acomplish that??? ... using the amp gain at 1/2 way??? ... Gain fully open, but volume on AVR not to high??? :dontknow:


Dont drive yourself nuts, if you do get an amp just set it to around 3/4 and run the avr's setup test tone to set the proper level and dont worry about it. Reference level is fairly loud and most of us dont run it that high.


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## eugovector (Sep 4, 2006)

tonyvdb said:


> Yes there is but its usualy done in the DVD player audio setup, by turning on the dynamic compression (usually called Dynamic range control) It will do just that. The softer parts will be far more even with the loud parts.
> 
> You will be ok as long as your speakers can handle that peak level.
> I have done some pro audio setup for concerts on a road system and the general rule of thumb is to run the amp at no more than 50% of its power output during normal volume so you have some headroom for the peaks.


Once again, wouldn't this be argument for running the amp full open? Let's see if I can get this out in a way that makes sense...

Let's assume that the most destructive thing you can do for your speakers is to overload the input of your amplifier causing distortion. Let's say the amp has gain settings 1-10, the pre-amp has output 1-10, and the overall level coming out of the speakers is define by the gain structure (amp gain) + (pre-amp output) = (Overall level). Let's say the minimum overall level you want for listening is 11. Let's also say that the amp distorts when fed an input above 8.

Okay, so you set your amp to 5, which means that for quiet scenes, you have your preamp outputting a 6 (under the 8 threshold of distortion), giving you the 11 for overall level. Everything is good, then all of a sudden, a +3 peak comes along in the movie soundtrack. Now all of a sudden your amp is receiving an input of +9 (above the 8 threshold) and distortion occurs. Bad.

Now, same scenario with the amp set to 10. For quiet scenes, you now have your preamp outputting a 1 (well under the 8 threshold of distortion), giving you the 11 for overall level. Everything is good, then all of a sudden, a +3 peak comes along in the movie soundtrack. This time, your preamp is only outputting a 4, still under the 8 threshold of distortion, and everything is good. You get all the dynamics, and none of the speaker distortion.

Hopefully, that super simplistic version of gain structure made sense.

Now, using the above numbers, if your amp goes to 20, you could set is for half power and still be okay. But, why would you if you are feeding it a noise-free signal? Wouldn't you want the extra headroom? In a live sound situation, sure, so fool drops his vocal mic on the stage monitor, you get crazy feedback, and you've fried some speakers. But, in the home situation, levels are much easier to control. Unless you sit on the volume control and max everything out, no one is likely to crank levels to the point of killing a speaker with pure power without blowing their eardrums first. And if you do, good! Life lesson: don't abuse your ears like that, and you won't blow speakers.


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## tcarcio (Jun 27, 2007)

Great explanation guy's. I think this just proves to me that I really need to run my whole system with these amps. What I mean is that if I am listening to music just having one amp to run your mains is fine but when watching a movie in 5.1,6.1,7.1 and you set levels with the test tones in the recievers auto EQ only 2 channels will have that extra power and your reciever is going to lower the output to the level that the reciever see's as correct. Which just brings you back to the limitations of your reciever because your center and surrounds are still running on the reciever. I have 2 amps and it looks like I will need at least 1 more to run a 5.1 soundtrack and 2 more to run a 7.1. I got these 2 Crowns for 500 so I would have a 1000 dollar investment in these amps which is very reasonable considering the dollar to wattage comparison in going with a HT amp as I could not get a good HT amp that does 300w a channel at that price unless I ran into a great deal.


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## tonyvdb (Sep 5, 2007)

tcarcio said:


> I have 2 amps and it looks like I will need at least 1 more to run a 5.1 soundtrack and 2 more to run a 7.1. I got these 2 Crowns for 500 so I would have a 1000 dollar investment in these amps which is very reasonable considering the dollar to wattage comparison in going with a HT amp as I could not get a good HT amp that does 300w a channel at that price unless I ran into a great deal.


dont get carried away, you need to remember that you also need to meet the AC power requirement for that many amps. You would need at least one dedicated circuit if not two.
Your receiver is more than capable to drive the other 3 or 5 channels its rare that your receiver would need to run all of them at even near full power during movies at the same time.


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## salvasol (Oct 31, 2006)

tcarcio said:


> ... and you set levels with the test tones in the recievers auto EQ only 2 channels will have that extra power and your reciever is going to lower the output to the level that the reciever see's as correct. Which just brings you back to the limitations of your reciever because your center and surrounds are still running on the reciever. ...


What is the best way to calibrate the speakers when adding an external amp??? ... the autoEQ or manually adjuted with test tones and SPL???

I think is better manually (but I could be wrong :yes ... in my case, the C+SL+SR+SBL+SBR gains on the AVR are set between -3.5db and 0db so there's no problem to adjust them.



> ... I have 2 amps and it looks like I will need at least 1 more to run a 5.1 soundtrack and 2 more to run a 7.1. ...


As Tony mentioned ... I read that is okay to use one amp for the fronts and the rest of the speakers can be powered by the AVR, or even better to use an external amp for L+R+C :yes:


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## thxgoon (Feb 23, 2007)

salvasol said:


> What is the best way to calibrate the speakers when adding an external amp??? ... the autoEQ or manually adjuted with test tones and SPL???
> 
> As Tony mentioned ... I read that is okay to use one amp for the fronts and the rest of the speakers can be powered by the AVR, or even better to use an external amp for L+R+C :yes:


Either way is fine. It's really up to you as the end user and your preferences.

Decent receivers these days have more than enough power to run every speaker in the system, so running just the center and surrounds would be a virtual cakewalk for it.

Don't get too carried away with the what if's and how do I's, it's a really simple addition to your system which should be completely transparent in the chain. There is no extra care that needs to be taken other than turning it down when things begin to distort. 

If you want numbers to confirm that your system can handle the power (or has enough power) you can look at the sensitivity of your speakers and calculate the power required to run them to reference level (taking any trim settings into account for your room).


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## tcarcio (Jun 27, 2007)

You guy's are right, I am getting a bit ahead of myself, thanks for pulling the riegns back.:duh: I calibrated this morning useing the pink noise in the reciever and I had to turn the amp down to a little less than 3/4 because when I turned the main speaker levels down all the way they were still giving me 85db's. I already have 2 of these amps so I should be fine letting the reciever handle the rest. Once I get both amps hooked up I will run the auto EQ and go from there with a little manual tweek. I don't know if any of you guy's have ever used the CSt 600 but the dual fan set up is really much quieter than I thought they would be. My wife asked me this morning how long will I be happy with this set up before I have to add something else.addle: I am just lucky she knows I really enjoy haveing this little hobby and really doesn't give me trouble about it. I told her I probably will be happy for awhile.:innocent: :rofl:


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## salvasol (Oct 31, 2006)

tcarcio said:


> .... My wife asked me this morning how long will I be happy with this set up .... I told her I probably will be happy for awhile.:innocent: :rofl:


Yeah, Right!!! :bigsmile:


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## salvasol (Oct 31, 2006)

salvasol said:


> ... like I said before ... I want to learn for when the time comes :yes:


That time is here ... I pulled the trigger and ordered a  Samson Servo 600  today :yes:


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## salvasol (Oct 31, 2006)

tonyvdb said:


> My samson amp has 5 segment level meters and *I rarely see the second one light up even with the peaks at reference level*.


I knew that I read this somewhere ... finally I did find it :bigsmile:

Last night I hooked my Samson Servo 600 (I haven't done a lot of calibration yet, I just hooked everything and set the gain level on the amp to get 75db at reference and is around 3/4) ... I watched TV for a little while (it was late); I know that probably is nothing to worry about, but just in case I will ask ...

Is this normal??? ... most of the time all segment were not lighted, and when the sound got a little louder during the program I was watching (Number on CBS) I can see the first segment and sometimes the first two; but suddenly when there was a really loud signal (before the commercials) "all segment got lighted (I think they're green, yellow and red)" but for a short period of time ...:yes: ... I think is a normal situation, but I just have to ask to keep a piece of mind :bigsmile:

By the way, the master volume was not even close to reference level (I think it was -30db, reference is @ -5db).

EDIT: I think is a good thing that we have the segments in the front of the amp to watch for the signal ... and because I'm not used to see any llights on the AVR, I just want to be sure that is normal for the lights to go to the top (red/peak) ...I haven't really checked for what it will show when the amp is clipping (I'm sure peak and clipping is different, RIght???)


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## tcarcio (Jun 27, 2007)

Well I have the same type of lights on my Crowns and they do the same thing except it should not get to the red. If it gets to the red that indicates clipping. You might not hurt anything if it only lights for a second but it really shouldn't. I have only seen my clip light come on once and that is when I was overdriving my sub, once I decreased the gain it didn't happen again. The lights on mine are labeled in this order, ready,signal,-20,-10, then clip. Even at high volume it only rarely gets to -20. The gains on my amp are set to a little more than half so you might just have to play with the adjustments till you get it right.


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## salvasol (Oct 31, 2006)

tcarcio said:


> ... If it gets to the red that indicates clipping. You might not hurt anything if it only lights for a second but it really shouldn't. I have only seen my clip light come on once and that is when I was overdriving my sub, once I decreased the gain it didn't happen again. The lights on mine are labeled in this order, ready,signal,-20,-10, then clip. Even at high volume it only rarely gets to -20. The gains on my amp are set to a little more than half so you might just have to play with the adjustments till you get it right.


Thank you ... I have a lot to do tomorrow (I haven't adjusted anything yet, I was inpatient last night so I hooked up the amp :bigsmile ...

This is what the manual said ...



> 3: LED meters - These ten-segment LED meters continuously monitor the power output level for the corresponding channel.
> For convenience, the segments are labeled, from left to right, -24 dB, -20 dB, -16 dB, -12 dB, -8 dB, -4 dB, -2 dB. O, +2 dB
> and +4 dB (PEAK). *The right (PEAK) segment lights whenever the channel is outputting signal at full strength.* For the best
> signal-to-noise ratio, *the right (PEAK) segment should light occasionally during peak levels*; if it lights frequently, you may
> ...


So I think is normal ... if the red segment light from time to time; I'll see after I calibrate eveything right raying:


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