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Florida_Audio

How to tell if my subwoofer is clipping and/or going to overheat?

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18 minutes ago, ///M5 said:

Stop guessing.  You have no faith in NVX but I have one and it is fine at 100% gain.  Absolutely no big deal to it and it won't go poof.  Amusingly it is actually designed to do that.  Bit of thermal noise at 100%, but no ill effect otherwise.

If you have no thermal noise at a gain level there is no reason to run the amp at a lower level.  There can surely be reasons why it makes more sense to run it at a lower level, but as long as the input level is matched to the actual input so that the amplifier stays within its specification and doesn't add noise you are golden.  

Your perfect scenario isn't relevant either, but if you slightly modify what you said it would be fine.  A perfect scenario is having enough power to make your subs do what you need without distorting and/or creating thermal noise.

Uhh that's what I said already. I love how you always say I'm wrong then go and say the exact thing I said just in different wording. 

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1 minute ago, Billy Jack said:

Uhh that's what I said already. I love how you always say I'm wrong then go and say the exact thing I said just in different wording. 

Not even close, you said this which is COMPLETELY different and untrue:

21 hours ago, Billy Jack said:

If you turned the gain all the way up your definetly clipping the amp, and sending the sub a distorted signal, which will burn it up. A distorted signal will burn a voice coil faster then over powering a sub with clean power. 

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The gain level on an amp on its own has ZERO bearing on clipping.  It is related to the input voltage as well.

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21 minutes ago, ///M5 said:

You should be worried about how it sounds and understanding how to set it up.  Your amp has a gain knob for a reason.  The manufacturer expects input voltages to be able to vary from it's lowest setting to it's highest.  Whichever one is right for your car is fine to use.  This could be at the minimum or the maximum.  Normally it is somewhere in the middle and that can be preferable depending on the equipment, but you can also sure be just fine at either extremes.

All this being said, it sounds to us like the way your gains are set right now have no basis in performance or correctness.   You should surely start listening more closely and make sure they aren't set in a way that adds distortion and/or noise.  If that is the case then you are fine.

Wait a minute just 2 seconds ago you said the amp was fine at 100% gain and distortion can't hurt anything. So which is it, it can't be both ways it either is or it ain't. 

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8 minutes ago, ///M5 said:

The gain level on an amp on its own has ZERO bearing on clipping.  It is related to the input voltage as well.

But it's not on its own is it. He already said he had 4volts of input which is plenty and just like I said before I have never ever seen a amp need to have the gain and bass boost set to 100% at that input voltage. Maybe your junk NVX or PPI or Polk may need it but I haven't used or seen those in use except the 3000 watt NVX in which it took a entire suv loaded to the b-pillars to do a 151. Pathetic!!!! 

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And are we wrong M5 by telling him to turn his gain up until it distorts then back it off a little until it sounds good or should he go buy $2500 worth of high end equipment to adjust a $200 amp? 

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45 minutes ago, ///M5 said:

Wow.  Rofl.

Only two things kill subs.  Average power or Instantaneous power.  It is completely irrelevant whether the signal is "clipped' or not.  Absolutely no bearing whatsoever except of course that by the nature of clipping the power is increased.  

Plenty of modern music sounds like clipping anyway...boo :(

Yes I understand having a tiny little NVX amp want blow anything but if you have a real amp that has enough power to push your sub past its mechanical or thermal limit then a clipped signal will in fact burn it up if your not careful. You know exactly what I mean but want to act silly and make it out like I'm suggesting something I'm not. 

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Stop intermixing emotion, desire and fact together.  You are only confusing yourself.  

Let's start VERY simple and look at your premise:

10 minutes ago, Billy Jack said:

....a clipped signal will in fact burn it up if your not careful.

  Answer one simple question and the rest will be clear.   Why does it matter if the signal is clipped or not?  ie, what about the clipped signal will cause it to "burn up"?

Since you hate to answer questions I'll help.  It absolutely won't unless the clipping causes you to go over the max power of the driver.  Is that clear enough?  

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1 hour ago, ///M5 said:

You should be worried about how it sounds and understanding how to set it up.  Your amp has a gain knob for a reason.  The manufacturer expects input voltages to be able to vary from it's lowest setting to it's highest.  Whichever one is right for your car is fine to use.  This could be at the minimum or the maximum.  Normally it is somewhere in the middle and that can be preferable depending on the equipment, but you can also sure be just fine at either extremes.

All this being said, it sounds to us like the way your gains are set right now have no basis in performance or correctness.   You should surely start listening more closely and make sure they aren't set in a way that adds distortion and/or noise.  If that is the case then you are fine.

ok thank you for the response, and for clarifying that is can be safe for the amplifier to be turned all the way up. although it depends. and thanks for explaining how most often its around the middle thats best.

but i would like to ask, how should i really be listening for distortion? by opening the rear seats and placing my head near the subwoofer to listen to music for several minutes? because im not really paying too close attention for distortion from the subwoofer specifically when driving and listening to music. i feel like hearing distortion from the subwoofer may be more difficult to notice when sitting in the front seat?

ill take a look and see, but also its a bit difficult, because in order to get my subwoofer really bumping, i need to turn the volume up to around 20 out of 30 notches for the volume.

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1 hour ago, Billy Jack said:

And are we wrong M5 by telling him to turn his gain up until it distorts then back it off a little until it sounds good or should he go buy $2500 worth of high end equipment to adjust a $200 amp? 

he alrdy said the answer to this.

he said this "You should surely start listening more closely and make sure they aren't set in a way that adds distortion and/or noise.  If that is the case then you are fine. "

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1 minute ago, Florida_Audio said:

ok thank you for the response, and for clarifying that is can be safe for the amplifier to be turned all the way up. although it depends. and thanks for explaining how most often its around the middle thats best.

but i would like to ask, how should i really be listening for distortion? by opening the rear seats and placing my head near the subwoofer to listen to music for several minutes? because im not really paying too close attention for distortion from the subwoofer specifically when driving and listening to music. i feel like hearing distortion from the subwoofer may be more difficult to notice when sitting in the front seat?

ill take a look and see, but also its a bit difficult, because in order to get my subwoofer really bumping, i need to turn the volume up to around 20 out of 30 notches for the volume.

You need to train your ear.  Regrettably in general human ears are not sensitive to low frequencies.  Of course the good news means that you have a hard time hearing distortion at low frequencies.  Of course along with this it means most people crank their gains way into distortion on subs and have no idea.  

As for how to train your ear you can either impart distortion into a song via software or do so by overgaining some section of the amplification chain.  No matter where you impart the distortion you can't remove it so that is irrelevant, but getting used to hearing it will help you listen for it and adjust appropriately.

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1 hour ago, ///M5 said:

You need to train your ear.  Regrettably in general human ears are not sensitive to low frequencies.  Of course the good news means that you have a hard time hearing distortion at low frequencies.  Of course along with this it means most people crank their gains way into distortion on subs and have no idea.  

As for how to train your ear you can either impart distortion into a song via software or do so by overgaining some section of the amplification chain.  No matter where you impart the distortion you can't remove it so that is irrelevant, but getting used to hearing it will help you listen for it and adjust appropriately.

yea cause all low end frequencies sound very similar lol. almost the same

i saw a video on youtube with a 40 hz test tone, and they slowly rose the gains, till the tone changed in its sound to a slightly different tone. barely noticeable in the youtube video they recorded, but still very slightly noticeable. and thats at one single frequency... i cant really imagine when playing a song. but as you or someone else said, that the test tone will limit alot, by possibly setting the gain much lower than needed? right? but then i guess the same might be said if i can even notice distortion in a song. because the distortion would be occurring at a specific frequency? maybe i can use the 40hz test tone, then right when i hear a slight distortion, keep the gain at that setting? or it might cause be to keep the gains too low still?

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6 minutes ago, Florida_Audio said:

maybe i can use the 40hz test tone, then right when i hear a slight distortion, keep the gain at that setting? or it might cause be to keep the gains too low still?

Doesn't work.  Music won't be recorded at the same level as the test tone.  Perhaps one random song or a few, but a bunch will be lower and some higher.  Then your setting is wrong.  Exactly the reason using an Oscope or other measurement device is completely pointless.  Won't tell you anything about what the driver will receive with music.  You NEED to train your ear and listen EVERY day.  Once you do, you can surely turn the gain up high enough to compensate for any situation and never have a risk to your equipment.  Any time high power is involved you can destroy anything.  The only real cure is to listen all the time.

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1 hour ago, ///M5 said:

Doesn't work.  Music won't be recorded at the same level as the test tone.  Perhaps one random song or a few, but a bunch will be lower and some higher.  Then your setting is wrong.  Exactly the reason using an Oscope or other measurement device is completely pointless.  Won't tell you anything about what the driver will receive with music.  You NEED to train your ear and listen EVERY day.  Once you do, you can surely turn the gain up high enough to compensate for any situation and never have a risk to your equipment.  Any time high power is involved you can destroy anything.  The only real cure is to listen all the time.

so simple yet so complicated lol....

ok thanks. i guess all i can do is try and pay very close attention. its difficult with music in the front. maybe ill take like 30 minutes to just sit in back with seats down, listening to the subwoofer.

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just shut off everything else, no reason to sit in the back.  Then vary the level and distortion amount.  Teach yourself to hear :)

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1 hour ago, ///M5 said:

just shut off everything else, no reason to sit in the back.  Then vary the level and distortion amount.  Teach yourself to hear :)

how do i shut off everything else? would just unplugging the RCA cables from the amplifier do it? and be safe to do? also if thats the safest and easiest way, id be somewhat afraid to just lay the ends of the RCAs cables anywhere, what precaution should i take to make sure the RCA ends dont touch anything that would cause damage to my system?

thanks again!

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Honestly that amp isn't strong enough to blow those subs at any setting but running it wide open can over heat it and mess it up. Most small amps like that I have ever set up at that input voltage where always set at half or 3/4 the way up on gain. Now some of my higher end stuff where i was running more then the rms of the sub with 2-4volt pre-out I always ended up using 1/4-1/2 of the gain. Obviously this is just a rough estimate but I'm just giving you a idea of where it might end up. But the best way is to pick the loudest hardest hitting song you will ever play on your system, yes we all have that one song and use it to adjust your gain like me and a couple of other guys already said "by ear". You will be perfectly fine doing it that way. 

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1 hour ago, Billy Jack said:

Honestly that amp isn't strong enough to blow those subs at any setting but running it wide open can over heat it and mess it up. Most small amps like that I have ever set up at that input voltage where always set at half or 3/4 the way up on gain. Now some of my higher end stuff where i was running more then the rms of the sub with 2-4volt pre-out I always ended up using 1/4-1/2 of the gain. Obviously this is just a rough estimate but I'm just giving you a idea of where it might end up. But the best way is to pick the loudest hardest hitting song you will ever play on your system, yes we all have that one song and use it to adjust your gain like me and a couple of other guys already said "by ear". You will be perfectly fine doing it that way. 

Have you ever measured signal voltage coming out of a head unit?

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2 hours ago, ///M5 said:

Stop guessing.  You have no faith in NVX but I have one and it is fine at 100% gain.  Absolutely no big deal to it and it won't go poof.  Amusingly it is actually designed to do that.  Bit of thermal noise at 100%, but no ill effect otherwise.

If you have no thermal noise at a gain level there is no reason to run the amp at a lower level.  There can surely be reasons why it makes more sense to run it at a lower level, but as long as the input level is matched to the actual input so that the amplifier stays within its specification and doesn't add noise you are golden.  

Your perfect scenario isn't relevant either, but if you slightly modify what you said it would be fine.  A perfect scenario is having enough power to make your subs do what you need without distorting and/or creating thermal noise.

That last sentence sounds exactly like what I said. If a sub is rated at a 1k watts RMS and you run a 1200 watt amp with the gain turned down slightly then your subs will get all the clean power to reach there limit without clipping or distortion which will help both components. See you always suggest I'm saying or implying something I'm not then word what I'm saying differently to come out to mean the same damn thing. Let me take a guess here your a 40 something year old man who has no wife no kids no life and still lives with his mother. You where probably fired from your last job for arguing with the boss that even though he was in charge you where smarter and there for he should respect your authority. So you set back watching guys like Tony D'Amore get filthy rich and bang hot women while you come on SSA to insult and demean noobs so you can stroke your ego and feed your need to feal superior cause you got a degree in which thousands of others have also. It also sounds like your compensating for something like a little tiny short coming. Have I pretty much hit the nail on the head? Go ahead and tell us all how wise and great you are it's been almost 5 minutes since you told someone. 

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ROFL.  Go reread the thread.  You change your comments to try to not sound stupid left and right...and again you choose to just thread dump.

Since you are so emotionally disturbed by what I typed, focus on your discussion with Lithium.  Obviously some audio 101 would be helpful as you are stuck repeating every nonsensical fact that car audio shops have been propagating incorrectly for the past 30 years.

As for your guess on my life, you are way off...I won't stoop to your level and return the favor

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11 hours ago, Florida_Audio said:

how do i shut off everything else? would just unplugging the RCA cables from the amplifier do it? and be safe to do? also if thats the safest and easiest way, id be somewhat afraid to just lay the ends of the RCAs cables anywhere, what precaution should i take to make sure the RCA ends dont touch anything that would cause damage to my system?

thanks again!

 

4 hours ago, ///M5 said:

ROFL.  Go reread the thread.  You change your comments to try to not sound stupid left and right...and again you choose to just thread dump.

Since you are so emotionally disturbed by what I typed, focus on your discussion with Lithium.  Obviously some audio 101 would be helpful as you are stuck repeating every nonsensical fact that car audio shops have been propagating incorrectly for the past 30 years.

As for your guess on my life, you are way off...I won't stoop to your level and return the favor

is just unplugging the RCAs fine? to stop the sound from playing from speakers?

and if so where should i place the RCA cable ends. id assume if they touch something like metal it can damage the speaker?

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10 hours ago, hdrox88 said:

Have you ever measured signal voltage coming out of a head unit?

Nope but I can read and I'm gonna assume if it says it has 4volts of pre out and it's a decent brand it's probably close. I know when I changed from 2 volts to 4 volts I had to turn my gains down a quarter of a turn so seems to me there real close anyways.

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3 hours ago, ///M5 said:

ROFL.  Go reread the thread.  You change your comments to try to not sound stupid left and right...and again you choose to just thread dump.

Since you are so emotionally disturbed by what I typed, focus on your discussion with Lithium.  Obviously some audio 101 would be helpful as you are stuck repeating every nonsensical fact that car audio shops have been propagating incorrectly for the past 30 years.

As for your guess on my life, you are way off...I won't stoop to your level and return the favor

I didn't change nothing you just have a problem understanding simple English so I cleared some things up for you. And you have no room to be talking about how other people sound have you read some of your old comments to other posters your rude as shit and very disrespectful and not just to moods your rude to other  engineer's like Tony who is actually successful and doesn't drive a busted ol Chevy with some used JL in it. Ow wait you replaced those with some tiwan amps right my bad. I can spot a hater when I hear one. 

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1 hour ago, Billy Jack said:

Nope but I can read and I'm gonna assume if it says it has 4volts of pre out and it's a decent brand it's probably close. I know when I changed from 2 volts to 4 volts I had to turn my gains down a quarter of a turn so seems to me there real close anyways.

So the headunit always outputs around 4v?

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1 hour ago, kirill007 said:

So the headunit always outputs around 4v?

No, the voltage isn't constant. It goes up and down with the volume and the audio signal that's being played. The 2v, 4v or whatever rated signal is the maximum rated output of the circuit. 

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