Cranking red VUs.... Is This REALLY Bad?

[hollyrockets]

So...

I've been cranking things up... (Afraid to use my tape deck, even though it works SO GREAT! Which is not related to my Q...)

My VUs are running into the red consistently: I like the Foo Fighters; What can I do?

I don't want to turn the bass down or the loudness off!
So should I do it anyway? I know this is taxing on the amp, but... I LOVE IT!!!!

HELP ME!

 

[sony_apm_fan]

Hmmm, I hear you on this.

I too like to run my boxes quite hard, not ever into distortion but, especially with the M70, thumpin' loud.

So, I risk amp IC's and speaker surrounds and voice coils.....sure.

Is It REALLY bad? Probably not but it may shorten the life of some components.

But, the pleasure I get from jammin' FAR outweighs the risk of potential damage.

And, to date my M70 is still in excellent shape. I have blown one APM woofer, and had to refoam my robo but thats it.

It's like this, if I had an exotic car would I redline every shift...no. But, I'd sure drive it like I stole it occasionally.

And my boxes are the same

 

[mmcodomino]

Hmmm, I hear you on this.

I too like to run my boxes quite hard, not ever into distortion but, especially with the M70, thumpin' loud.

So, I risk amp IC's and speaker surrounds and voice coils.....sure.

Is It REALLY bad? Probably not but it may shorten the life of some components.

But, the pleasure I get from jammin' FAR outweighs the risk of potential damage.

And, to date my M70 is still in excellent shape. I have blown one APM woofer, and had to refoam my robo but thats it.

It's like this, if I had an exotic car would I redline every shift...no. But, I'd sure drive it like I stole it occasionally.

And my boxes are the same

 

[Fatdog]

I can't remember if the M70 VUs are tied to the volume or line level. Holly, turn down your M70 all the way. If the VUs are still dancing then they are measuring line level and not actual output. That would be okay.

 

[Superduper]

The M70 meters measures power level unless you are recording, so to get into the red, she's working her pretty hard.

I say pump it until it dies. M70's are plentiful so when it pumps no more -- GET ANOTHER ONE.

 

[Reli]

So how did JVC determine where to put the "red" mark? Is it based on a certain level of distortion? Or percentage of total wattage potential used?

 

[hollyrockets]

So how did JVC determine where to put the "red" mark? Is it based on a certain level of distortion? Or percentage of total wattage potential used?

Just for the record I hear ABSOLUTELY NO distortion or clipping; even in the lowest boomy bass in this scenario... It only dances into red... while I do this:

, ,

:ymca: ,



and

 

[Superduper]

So how did JVC determine where to put the "red" mark? Is it based on a certain level of distortion? Or percentage of total wattage potential used?

Most likely, 0db in this case represents the power level at max volume with a steady standard input signal level. Since audio music signals are dynamic, the signal level to the amp will fluctuate. Remember that an amplifier's main function is.... yup, you guessed it -- to amplify an audio signal. So feed it a lower signal level and it spits out a certain higher audio signal. Feed it a higher signal level and it will once again, spit out a higher signal level at at the tail end. So depending upon how strong the signal is that gets fed to the main amp, that resulting output can be higher or lower than the 0db mark. Anything above 0db is usually represented in red with a +db scale. Feed it the standard (as chosen by JVC engineers) steady signal level and the meter needle should hover at exactly 0db.

 

[uns69]

Hmmm, I hear you on this.

I too like to run my boxes quite hard, not ever into distortion but, especially with the M70, thumpin' loud.

So, I risk amp IC's and speaker surrounds and voice coils.....sure.

Is It REALLY bad? Probably not but it may shorten the life of some components.

But, the pleasure I get from jammin' FAR outweighs the risk of potential damage.

And, to date my M70 is still in excellent shape. I have blown one APM woofer, and had to refoam my robo but thats it.

It's like this, if I had an exotic car would I redline every shift...no. But, I'd sure drive it like I stole it occasionally.

And my boxes are the same

+2. I don't think its a biggie

 

[Ken]

... and the meter needle should hover at exactly 0db.

That's where I try to keep mine for both playback and record...I know a little bump up into the red doesn't hurt on the recording side but the M-70 will hover and not bounce at all on playback. It's perfect for in the house.

Take this bad mama jamma outside, though, and all bets are off.

 

[hollyrockets]

OK, I know many of you said this is ok, but can you look at this and make sure?
[youtube]bCwb5E8wCeU[/youtube]

 

[baddboybill]

OK, I know many of you said this is ok, but can you look at this and make sure?
https://www.youtube.com/watch?v=bCwb5E8wCeU

Holly seems all fine, don't look or sound like it's being overloaded. To me an amp is being overloaded when you go beyond distortion levels when the speakers have a crackling that's not good and can overheat amp and damage speakers

 

[Superduper]

I would not worry about it. The needles are not pegging. Your volume control is not at max, is it?

 

[hollyrockets]

I would not worry about it. The needles are not pegging. Your volume control is not at max, is it?

No, but it's at max in the computer and the player on the computer which was playing a CD. The sliders are at 3.5 on the box....

That just makes me giggle.... he he he he he!!!!

That box is SO LOUD!!!
(I just don't want to blow the amp or the speakers... )

 

[Jwrok707]

I don't see that being a problem, my M70 plays like that, and my M90's are similar, as well as my 838. Keep PUMPIN, these things were meant to play, go ahead use your tape deck, I rarely use anything else than my tapes with these boxes!

 

[Superduper]

I see. Ok, perhaps what's happening is that your input signal is too high. Rememer, the amplifier is exactly that -- an amplifier. Feed it more power in, and it will produce more power out. Presumably, at the red mark, it is expecting probably .7 volts at the input. Obviously, if you pump more than .7 volts into the amp, it will probably produce more than the rated output at the speakers. (BTW, I don't know what input signal voltage JVC used to calibrate their meters so I'm arbitrarily saying .7 here). Probably better to tone down the ouput on your source devices a bit so you don't oversaturate the preamps and also to give your preamp volume controls a greater adjust range. Right now -- you are going from zero to max with just the first 3.5 range of your vol control. Better to go from zero to max using the 1-10 range of your volume dial range.

All of this is presuming that your meters are properly calibrated and they frequently are not.

I would say forget the meters and just allow your ears to be the judge. Unless the meters are pegging and physically striking the high end, don't worry too much. When it's too loud, your ears will tell you since you'll know it by the quality of the sound. Once it starts to sound shitti -- turn it down a bit until the audio quality is good again. Your amps and speakers WILL distort once they are at the straining point.

 

[hollyrockets]

I see. Ok, perhaps what's happening is that your input signal is too high. Rememer, the amplifier is exactly that -- an amplifier. Feed it more power in, and it will produce more power out. Presumably, at the red mark, it is expecting probably .7 volts at the input. Obviously, if you pump more than .7 volts into the amp, it will probably produce more than the rated output at the speakers. (BTW, I don't know what input signal voltage JVC used to calibrate their meters so I'm arbitrarily saying .7 here). Probably better to tone down the ouput on your source devices a bit so you don't oversaturate the preamps and also to give your preamp volume controls a greater adjust range. Right now -- you are going from zero to max with just the first 3.5 range of your vol control. Better to go from zero to max using the 1-10 range of your volume dial range.

All of this is presuming that your meters are properly calibrated and they frequently are not.

I would say forget the meters and just allow your ears to be the judge. Unless the meters are pegging and physically striking the high end, don't worry too much. When it's too loud, your ears will tell you since you'll know it by the quality of the sound. Once it starts to sound shitti -- turn it down a bit until the audio quality is good again. Your amps and speakers WILL distort once they are at the straining point.

Thank you, Superduper.

I know from my audio classes, there are several points in the chain where things are amplified and it can put a load on components, especially when considering you amplify before you even get to the unit.

 

[saxonman]

I never run the computer output volume more than 60% on my m70 and full volume is more like full volume on the sliders!!!