difference between amp and sub clipping?

[keep_hope_alive Premium Member]

You can do it by ear if you don't have to ask how. Clipping is audible. Clipping pure tones is more audible.

 

[plantinseeds]

You can do it by ear if you don't have to ask how. Clipping is audible. Clipping pure tones is more audible.

So you think I will be better off turning up the gain until the sub sounds distorted? Just want to get as loud as possible without the possibility of destroying my amp/subs.

 

[IonRL205 10+ year member]

This is the original phrase


That made no sense at 3:30am and it doesn't make much more now, though the fact that some claim that everyone should know that RMS is synonymous with power really proves my point that there's just way too many unfinformed people slinging around too much horse ****.

Well this topic is about clipping and setting gains, and wouldn't you know, that's the formula to set the gain for your DMM. Seriously it's obvious he was talking about power. Being it 3:30 am is no excuse.

I wish you would explain how YOU set your gains step by step

Ok

1. Disconnect speaker wires from amp.

2. Turn gain and bass boost all the way down.

3. Now take the ohm load you are going to run the amp at and the RMS power it puts out at that load and multiply it together, and then square root this number. So if your amp does 1500 watts at 1 ohm, you would do 1500 x 1 which is 1500, then square root, which is roughly 38.7

4. Get a 50 hz test tone, either -3 db or 0 db. I use -3 db because i bass boost songs and thats where I record the bass at, but if you listen to alot of regular cds and non bass boosted music then use a 0 db tone.

5. Get your DMM and connect it to the positive and negative speaker terminals on the amp and set it to AC volts

6. Turn your head unit to 3/4 volume, or the loudest you'll play it at but not high enough for it clip. 3/4 the way is a good start.

7. Play the 50 hz tone and put it on repeat.

8. Turn up your gain until the DMM reads 38.6 volts.

9. I normally back off just a little bit. And that's it. Connect your speakers back up and start playing.

 

[quackhead 10+ year member]

Well this topic is about clipping and setting gains, and wouldn't you know, that's the formula to set the gain for your DMM. Seriously it's obvious he was talking about power. Being it 3:30 am is no excuse.


Ok

1. Disconnect speaker wires from amp.

2. Turn gain and bass boost all the way down.

3. Now take the ohm load you are going to run the amp at and the RMS power it puts out at that load and multiply it together, and then square root this number. So if your amp does 1500 watts at 1 ohm, you would do 1500 x 1 which is 1500, then square root, which is roughly 38.7

4. Get a 50 hz test tone, either -3 db or 0 db. I use -3 db because i bass boost songs and thats where I record the bass at, but if you listen to alot of regular cds and non bass boosted music then use a 0 db tone.

5. Get your DMM and connect it to the positive and negative speaker terminals on the amp and set it to AC volts

6. Turn your head unit to 3/4 volume, or the loudest you'll play it at but not high enough for it clip. 3/4 the way is a good start.

7. Play the 50 hz tone and put it on repeat.

8. Turn up your gain until the DMM reads 38.6 volts.

9. I normally back off just a little bit. And that's it. Connect your speakers back up and start playing.

1. why remove your resistance load from the amp?? you said you set the gain for 38.6v output...how are you compensating for ohm rise @ tuning frequency? How about power output just before tuning frequency? by this method based on what you did 1st tossed everything out the window. you set to 38.6 with no load, that brutus is rated for 2100 at 1 ohm (i assume d4 skars x2 @ 1 ohm?), that amp's output could possibly fluctuate 20 to 30v between 20 and 100hz, depending on xover point, subsonic filtering and tuning freq.(if any)..assuming flat eq, no bass boost...and how do you KNOW what you are doing, if you cannot hear it and detect any clipping before your "formula" tells you?...or worse, what if you cut 30% of clean usable power and toss it in the trash?

You are only getting 1500 watts out of that Brutus @ 1ohm?...that *****...did you clamp it at 1ohm resistance to know what's up???

2. why use 50 hz test tone? I agree with Hope, with test tones, it is ALOT easier to detect distortion by ear....but why did you single out 50hz for your system?

..ummkaayy..so, your 8300 puts out 4v max (according to the manual, but I don't know if you use an external eq/line driver/bass boost, so we'll go with that)....do you feel like your gain is set close to the 11 to 12 o'clock position on that Brutus?...did you eyeball it and confirm a reasonably close proximity, while listening for a hint of clipping/distortion/bottoming as you eased up to your suggested 3/4 volume?? did you take it to a steady clip blink and back it out? I use the cousin to your HU and have no problem going to my max 52/62...but that is my system and my music.

...one more question..what in the world possessed you to buy 2 of what has to be some of the most inefficient subs I have ever seen???....and then used a DMM as sole means of setting u gain??...WTF, who are u to flame me??...NO, I do not know all there is to know about sound, or anything else for that matter, I learn something every day...it is common sense, or in your case, a lack there of.

 

[keep_hope_alive Premium Member]

So you think I will be better off turning up the gain until the sub sounds distorted? Just want to get as loud as possible without the possibility of destroying my amp/subs.

simply setting gains once doesn't protect you forever. it requires constant attention to what your speakers are doing. this is easier when the sub cones are in the listening area. much more difficult with trunk subs.

trying to get as loud as possible will eventually result in you damaging your gear. just enjoy the music. it's as loud as it is.

when doing the calculations for DMM setting, you need to monitor supply voltage so you can extrapolate approximate power output at that voltage. the HiFonics amps (like most on the market) produce much less power at 12V than 14.4V - usually about half.

 

[quackhead 10+ year member]

What's crazy is I went out and visited my sister for a couple of weeks here awhile back. We were down at the local drug store and while I was waiting out by the truck, I kept hearing these farting noises from out across the parking lot...I remember I was laughing because this dude kept walking around his car all bent over trying to figure out where this terrible farting noise was coming from, I reckon....all I could hear from that distance was a bunch of rattling, figured due from being a plastic Saturn and all..anyhoo, I'll be back in a couple of weeks and i'll have to keep an eye out for that little Saturn Ion again...and maybe extend some of this good old Texas hospitality his way...kinda IonRonic, me thinks.

...peace out!

 

[wickedwitt 10+ year member]

RMS means "root mean squared" it's a handy way to find an average varience from 0 from a group of numbers (positive and negative mixed or the mean can be derived without the square and root). RMS does NOT mean power.
POWER = square root of (current * impedence), or current * voltage, or whatever other variation of the equasion

IMO unles you're playing one specific tone at a specific record level any form of "precision" gain setting is pointless. To match all potential unknown program material at unknown record levels cannot be done.

My method is head unit volume around 2/3 to 3/4 depending on the head unit, gain it up til it doesn't get any louder when you turn it up more, then turn it back a little bit. Except in cases of grossly over-powering speakers I've never blown stuff up with this method. The point is to have your max undistorted output somewhere before the top of the dial on your head unit so that you're not pushing that into a clipped signal when you need a little more gain to overcome low record levels. Anything you throw in for source material beyond your test track will require a little discression and knowing when to back off.

And I still have yet to fathom why everyone feels the need to use the term RMS in regards to an AC signal, considering 99% don't understand what it means, where it comes from and why it's not relevent.

Yes, for music applications hispls is correct. Doing it via ear is essentially good enough. You are going to be a bit into clipping on a tiny percentage of stuff played, and be under optimum on quite a bit of it.

The easiest thing to do is pick a 40hz or 50hz tone(40 if you use any bass boost, 50 if not), turn the deck up to the maximum volume you will listen to it at (should be no more than 3/4 because most decks send a distorted signal beyond this), turn the gain up until you hear the note change tones. This will be quite audible, and easy to detect. As soon as you hit that tone change, back it off a bit (until that tone change completely disappears), and voila; you're set for daily listening. Just remember that if you use a tone later to compete or show off recorded at -3 or -0, you will probably need to drop the volume on the deck a bit for it. A DMM or O-scope method is really only optimum for burp vehicles that are going to play the same note, on the same recording every time. If you O-scope a daily music system, you are missing quite a bit of output (of which isn't dangerous to your system's longevity). I've had the same setup for 7 years and never blown a sub or sent an amp into protect.

4. Get a 50 hz test tone, either -3 db or 0 db. I use -3 db because i bass boost songs and thats where I record the bass at, but if you listen to alot of regular cds and non bass boosted music then use a 0 db tone.

Ion, I love ya buddy, but this is backwards. Since you listen to music created at -3, you should set yours on a -0 track to be safe. People that listen to -6 CD recordings or non boosted music could get away with setting their gains via a -3 tone.

Also with the hz lvl tone. If anyone uses any bass boost whatsoever (I do), the test tone needs to be at the hz level the amp boosts. For 95% of the amps out there, that is 40hz. If you use 0 bass boost, a 50hz tone is easier to distinguish distortion by ear. If you are setting gains with a dmm, the tone should most often be the box tuning frequency, as that would be the note that your subs would see the least movement, and therefore benefit the least from cooling measures.

 

[quackhead 10+ year member]

Yes, for music applications hispls is correct. Doing it via ear is essentially good enough. You are going to be a bit into clipping on a tiny percentage of stuff played, and be under optimum on quite a bit of it.
The easiest thing to do is pick a 40hz or 50hz tone(40 if you use any bass boost, 50 if not), turn the deck up to the maximum volume you will listen to it at (should be no more than 3/4 because most decks send a distorted signal beyond this), turn the gain up until you hear the note change tones. This will be quite audible, and easy to detect. As soon as you hit that tone change, back it off a bit (until that tone change completely disappears), and voila; you're set for daily listening. Just remember that if you use a tone later to compete or show off recorded at -3 or -0, you will probably need to drop the volume on the deck a bit for it. A DMM or O-scope method is really only optimum for burp vehicles that are going to play the same note, on the same recording every time. If you O-scope a daily music system, you are missing quite a bit of output (of which isn't dangerous to your system's longevity). I've had the same setup for 7 years and never blown a sub or sent an amp into protect.

Ion, I love ya buddy, but this is backwards. Since you listen to music created at -3, you should set yours on a -0 track to be safe. People that listen to -6 CD recordings or non boosted music could get away with setting their gains via a -3 tone.

Also with the hz lvl tone. If anyone uses any bass boost whatsoever (I do), the test tone needs to be at the hz level the amp boosts. For 95% of the amps out there, that is 40hz. If you use 0 bass boost, a 50hz tone is easier to distinguish distortion by ear. If you are setting gains with a dmm, the tone should most often be the box tuning frequency, as that would be the note that your subs would see the least movement, and therefore benefit the least from cooling measures.

Me either..except protect once while DMM'ing a sub amp...it was all good though and taught me to be a wee bit more careful with the probes..amp still pumping fine to this day..

 

[IonRL205 10+ year member]

1. why remove your resistance load from the amp?? you said you set the gain for 38.6v output...how are you compensating for ohm rise @ tuning frequency? How about power output just before tuning frequency? by this method based on what you did 1st tossed everything out the window. you set to 38.6 with no load, that brutus is rated for 2100 at 1 ohm (i assume d4 skars x2 @ 1 ohm?), that amp's output could possibly fluctuate 20 to 30v between 20 and 100hz, depending on xover point, subsonic filtering and tuning freq.(if any)..assuming flat eq, no bass boost...and how do you KNOW what you are doing, if you cannot hear it and detect any clipping before your "formula" tells you?...or worse, what if you cut 30% of clean usable power and toss it in the trash?
You are only getting 1500 watts out of that Brutus @ 1ohm?...that *****...did you clamp it at 1ohm resistance to know what's up???

2. why use 50 hz test tone? I agree with Hope, with test tones, it is ALOT easier to detect distortion by ear....but why did you single out 50hz for your system?

..ummkaayy..so, your 8300 puts out 4v max (according to the manual, but I don't know if you use an external eq/line driver/bass boost, so we'll go with that)....do you feel like your gain is set close to the 11 to 12 o'clock position on that Brutus?...did you eyeball it and confirm a reasonably close proximity, while listening for a hint of clipping/distortion/bottoming as you eased up to your suggested 3/4 volume?? did you take it to a steady clip blink and back it out? I use the cousin to your HU and have no problem going to my max 52/62...but that is my system and my music.

...one more question..what in the world possessed you to buy 2 of what has to be some of the most inefficient subs I have ever seen???....and then used a DMM as sole means of setting u gain??...WTF, who are u to flame me??...NO, I do not know all there is to know about sound, or anything else for that matter, I learn something every day...it is common sense, or in your case, a lack there of.

Dude are you stupid or something? Where the fuck did I say I was using my amp for the example? I just picked the number 1500 for an example. And if I only wanted to run 1500 out of that amp (although I have it at 1700ish until electrical upgrades) it would still be the same.

1. Why take off the speakers? Do you want a 50 hz test tone blasting in your ears? Also when your ohms go up, the a/c volts will change too, so if you wire to 1 ohms and rise to say 2 ohms, your amp will see 2 ohms, and do whatever it's supposed to at 2 ohms, but the formula would still be the same as if you originally set it for 2 ohms. You still wouldn't be clipping.

This method is one of the most known methods to set your gain, just google or look it up on the site.

I don't use any bass boost, you're not supposed to anyway. And what do you mean Skar subs are inefficient? My skar subs sure as hell get loud for what they are, have you even heard a skar setup at all? Everybody has heard it has been impressed, have a buddy with Two 18" B2 audio on a DC 3.5k and he said he had never heard 10s get loud like that.

You're the stupid one that says to eyeball your gain and just guess. The DMM is highly effective method of setting your gain, dude do a bunch of reading cause apparently you don't know as much as you think. And if you don't know about things, then don't post and give people stupid info.

What's crazy is I went out and visited my sister for a couple of weeks here awhile back. We were down at the local drug store and while I was waiting out by the truck, I kept hearing these farting noises from out across the parking lot...I remember I was laughing because this dude kept walking around his car all bent over trying to figure out where this terrible farting noise was coming from, I reckon....all I could hear from that distance was a bunch of rattling, figured due from being a plastic Saturn and all..anyhoo, I'll be back in a couple of weeks and i'll have to keep an eye out for that little Saturn Ion again...and maybe extend some of this good old Texas hospitality his way...kinda IonRonic, me thinks.
...peace out!

Cool story bro? I don't know what this has to do with anything though. I think you are just butthurt.

 

[quackhead 10+ year member]

Dude are you stupid or something? Where the fuck did I say I was using my amp for the example? I just picked the number 1500 for an example. And if I only wanted to run 1500 out of that amp (although I have it at 1700ish until electrical upgrades) it would still be the same.
1. Why take off the speakers? Do you want a 50 hz test tone blasting in your ears? Also when your ohms go up, the a/c volts will change too, so if you wire to 1 ohms and rise to say 2 ohms, your amp will see 2 ohms, and do whatever it's supposed to at 2 ohms, but the formula would still be the same as if you originally set it for 2 ohms. You still wouldn't be clipping.

This method is one of the most known methods to set your gain, just google or look it up on the site.

I don't use any bass boost, you're not supposed to anyway. And what do you mean Skar subs are inefficient? My skar subs sure as hell get loud for what they are, have you even heard a skar setup at all? Everybody has heard it has been impressed, have a buddy with Two 18" B2 audio on a DC 3.5k and he said he had never heard 10s get loud like that.

You're the stupid one that says to eyeball your gain and just guess. The DMM is highly effective method of setting your gain, dude do a bunch of reading cause apparently you don't know as much as you think. And if you don't know about things, then don't post and give people stupid info.

Cool story bro? I don't know what this has to do with anything though. I think you are just butthurt.

lol...nah, u got me all wrong, bro... My little sis lives out off Buffalo Gap Rd, bro.

I asked you to explain step by step how YOU set YOUR gain..I am sure you misunderstood the request... If you like your setup and are fine with it, that is all that matters. It is your world, I'm just passing through...bro.

 

[psych0ticnemes1 5,000+ posts]

Yes, for music applications hispls is correct. Doing it via ear is essentially good enough. You are going to be a bit into clipping on a tiny percentage of stuff played, and be under optimum on quite a bit of it.
The easiest thing to do is pick a 40hz or 50hz tone(40 if you use any bass boost, 50 if not), turn the deck up to the maximum volume you will listen to it at (should be no more than 3/4 because most decks send a distorted signal beyond this), turn the gain up until you hear the note change tones. This will be quite audible, and easy to detect. As soon as you hit that tone change, back it off a bit (until that tone change completely disappears), and voila; you're set for daily listening. Just remember that if you use a tone later to compete or show off recorded at -3 or -0, you will probably need to drop the volume on the deck a bit for it. A DMM or O-scope method is really only optimum for burp vehicles that are going to play the same note, on the same recording every time. If you O-scope a daily music system, you are missing quite a bit of output (of which isn't dangerous to your system's longevity). I've had the same setup for 7 years and never blown a sub or sent an amp into protect.

Ion, I love ya buddy, but this is backwards. Since you listen to music created at -3, you should set yours on a -0 track to be safe. People that listen to -6 CD recordings or non boosted music could get away with setting their gains via a -3 tone.

Also with the hz lvl tone. If anyone uses any bass boost whatsoever (I do), the test tone needs to be at the hz level the amp boosts. For 95% of the amps out there, that is 40hz. If you use 0 bass boost, a 50hz tone is easier to distinguish distortion by ear. If you are setting gains with a dmm, the tone should most often be the box tuning frequency, as that would be the note that your subs would see the least movement, and therefore benefit the least from cooling measures.

I've never heard that before. Anyone else second that?

 

[quackhead 10+ year member]

I've never heard that before. Anyone else second that?

I have noticed impedance falls back down close to nominal right at port tune, so from this standpoint, it would make sense to DMM tune at tuning frequency.

 

[psych0ticnemes1 5,000+ posts]

I have noticed impedance falls back down close to nominal right at port tune, so from this standpoint, it would make sense to DMM tune at tuning frequency.

Would you do this with the sub connected or no?

 

[wickedwitt 10+ year member]

I have noticed impedance falls back down close to nominal right at port tune, so from this standpoint, it would make sense to DMM tune at tuning frequency.

I've never heard that before. Anyone else second that?

Would you do this with the sub connected or no?

At tuning, the subs should technically see the least actual power, as the port is doing all the work. That doesn't mean it's the least stressful on the sub, for reasons I stated previously. Could always clamp the amp, and DMM at the lowest resistance point, but you typically see quite a bit of driver cooling at this point because it is often 15-20hz below port tuning and therefore the fullest excursion point for the subs.

If you know your frequency, there's no need to have the subs connected when setting w/ DMM. If you have over-head in your amp (it is bigger than your subs will handle), it's always good to do a check for bottoming out, or thermal buildup on the subs due to being overpowered even by a clean signal.

 

[psych0ticnemes1 5,000+ posts]

At tuning, the subs should technically see the least actual power, as the port is doing all the work. That doesn't mean it's the least stressful on the sub, for reasons I stated previously. Could always clamp the amp, and DMM at the lowest resistance point, but you typically see quite a bit of driver cooling at this point because it is often 15-20hz below port tuning and therefore the fullest excursion point for the subs.
If you know your frequency, there's no need to have the subs connected when setting w/ DMM. If you have over-head in your amp (it is bigger than your subs will handle), it's always good to do a check for bottoming out, or thermal buildup on the subs due to being overpowered even by a clean signal.

Thanks for the info man. I didn't notice a huge difference between the voltage at 50 and the voltage at tuning (35 in this case).