YACAudioT: Amplifier gains

[Aharami]

I have created a detailed thread over in the vwvortex car audio forums. Please take a look there to get a full understanding of whats going on

http://forums.vwvortex.com/zerothread?id=2570014

Basically I spent a lot of money and time to redo my car's audio and while Im happy with it, I think the SQ from my gf's Scion tC is better (all she has is an alpine HU feeding stock speakers).

So while having a discussion about this over in that forum, I mentioned that my amp gains are set to 0.2V and my HU's preouts are 4V. To that someone said

you have so fried your tweeters. if not all your speakers. you need to set the gain on your amp to match the output voltage on your HU. going from 1 to 2 to 4 is actually turning down your gain, not up. the number gets bigger, but its the other way around. yeah its louder but its all distortion. a square wave is three times more powerful than a sine wave, and youve been running a square wave the whole time. i think you fried your voice coils.

is the bolded part really true?? If so, I need to go out there and change it asap.

Also for those who read thru the other thread, if you have any input/thoughts on what others are saying in that thread...id appreciate it. thanks

 

[Aharami]

all the audio people must be sleeping still...

 

[Accipiter22]

******...wrong thread

 

[Aharami]

Originally posted by: Accipiter22
I....I got nothing

hah. thanks for trying

 

[Heisenberg]

Well I'm not sure the terminology is quite right, but I think what the guy's saying is that by turning up the output voltage of the HU you're overdriving the amplifier and causing clipping, which is reasonable. What exactly is the 'amp gain' that you're setting to 0.2V?

 

[Aharami]

the amp has input level settings. goes from 0.2 V to 4V. the HU puts out 4V via each of the pre amp outputs - front, rear, and sub. Thats 4V value isnt changeable.

 

[Specop 007]

You should match your amp gain to your headunit, however what they guy said is complete hogwash. Your speakers only know 1 thing. Power, Theres either too much or there isnt. Distortion has nothing to do with it. You could play the most distorted signal in the world, as long as the speakers arent being driven with too much power they'll happily play that distorted signal all day long.

 

[Aharami]

Originally posted by: Specop 007
You should match your amp gain to your headunit, however what they guy said is complete hogwash. Your speakers only know 1 thing. Power, Theres either too much or there isnt. Distortion has nothing to do with it. You could play the most distorted signal in the world, as long as the speakers arent being driven with too much power they'll happily play that distorted signal all day long.

so i should set the amp gains to 4V? and is it true what he said about lowering the gain actually means increasing the actual voltage?

 

[Golgatha]

The whole point of a gain is to match sound output levels from multiple amplifiers. If you have a single amp, my best advise would be (with protection for your ears) to turn up the head unit at about 80% volume, then adjust the gain knob about 25% under the point at which the amp begins to clip or you hear any audible distortion.

If you're not a SPL freak, then just set the head unit nearly all the way up and adjust the gain to the maximum level you'd ever consider listening to your music at. If you have something to measure SPL, I'd leave the maxiumum SPL at 131dB (an "ears ringing afterwards" rock concert is 125dB and 131dB is four levels of magnitude greater) or less where your head is going to be situated.

 

[Golgatha]

Originally posted by: Aharami

Originally posted by: Specop 007
You should match your amp gain to your headunit, however what they guy said is complete hogwash. Your speakers only know 1 thing. Power, Theres either too much or there isnt. Distortion has nothing to do with it. You could play the most distorted signal in the world, as long as the speakers arent being driven with too much power they'll happily play that distorted signal all day long.

so i should set the amp gains to 4V? and is it true what he said about lowering the gain actually means increasing the actual voltage?

http://en.wikipedia.org/wiki/Potentiometer

A gain is just a variable resistor, meaning the maximum signal your head unit could ever feed the amp is 4V.

 

[dmcowen674]

Originally posted by: Specop 007
You should match your amp gain to your headunit, however what they guy said is complete hogwash. Your speakers only know 1 thing. Power, Theres either too much or there isnt. Distortion has nothing to do with it. You could play the most distorted signal in the world, as long as the speakers arent being driven with too much power they'll happily play that distorted signal all day long.

Originally posted by: Golgatha
The whole point of a gain is to match sound output levels from multiple amplifiers. If you have a single amp, my best advise would be (with protection for your ears) to turn up the head unit at about 80% volume, then adjust the gain knob about 25% under the point at which the amp begins to clip or you hear any audible distortion.

If you're not a SPL freak, then just set the head unit nearly all the way up and adjust the gain to the maximum level you'd ever consider listening to your music at. If you have something to measure SPL, I'd leave the maxiumum SPL at 131dB (an "ears ringing afterwards" rock concert is 125dB and 131dB is four levels of magnitude greater) or less where your head is going to be situated.

Both guys gave "sound" advice. :thumbsup:

/thread

 

[Specop 007]

Originally posted by: Golgatha
The whole point of a gain is to match sound output levels from multiple amplifiers. If you have a single amp, my best advise would be (with protection for your ears) to turn up the head unit at about 80% volume, then adjust the gain knob about 25% under the point at which the amp begins to clip or you hear any audible distortion.

If you're not a SPL freak, then just set the head unit nearly all the way up and adjust the gain to the maximum level you'd ever consider listening to your music at. If you have something to measure SPL, I'd leave the maxiumum SPL at 131dB (an "ears ringing afterwards" rock concert is 125dB and 131dB is four levels of magnitude greater) or less where your head is going to be situated.

Wrong!
GAIN IS NOT A VOLUME KNOB!
GAIN IS NOT A VOLUME KNOB!

 

[Golgatha]

Originally posted by: Specop 007
You should match your amp gain to your headunit, however what they guy said is complete hogwash. Your speakers only know 1 thing. Power, Theres either too much or there isnt. Distortion has nothing to do with it. You could play the most distorted signal in the world, as long as the speakers arent being driven with too much power they'll happily play that distorted signal all day long.

Yeap, hogwash. However, if you drive the amp to clipping (square wave) or drive the speakers to the point of overextension, then the voice coil is essentially going to go outside the magnetic field of the speaker's magnet, thus making overheating and failure of the speaker much more likely. Any good tweeter crossover is going to have circuitry to prevent clipping, but they can't do much about being overdriven.

 

[Golgatha]

Originally posted by: Specop 007

Originally posted by: Golgatha
The whole point of a gain is to match sound output levels from multiple amplifiers. If you have a single amp, my best advise would be (with protection for your ears) to turn up the head unit at about 80% volume, then adjust the gain knob about 25% under the point at which the amp begins to clip or you hear any audible distortion.

If you're not a SPL freak, then just set the head unit nearly all the way up and adjust the gain to the maximum level you'd ever consider listening to your music at. If you have something to measure SPL, I'd leave the maxiumum SPL at 131dB (an "ears ringing afterwards" rock concert is 125dB and 131dB is four levels of magnitude greater) or less where your head is going to be situated.

Wrong!
GAIN IS NOT A VOLUME KNOB!
GAIN IS NOT A VOLUME KNOB!

I agree. I said to turn the head unit volume up before adjusting the gain. Changing the gain will certainly inc/dec the SPL at a fixed volume level coming from the head unit. Personally, I'm 28 and already have some hearing loss due to lifestyle and an unfortunate laboratory accident, so I keep the maxiumum volume I could ever listen to in check by adjusting the gains as outlined above.

System (in case anyone is interested)

Boston Acoustics 6.4 Pros in front. (6.5in Woofer, 1in tweeter component set)
Boston Acoustics 6.5 Rally series in rear (6.5in Woofer, 1in tweeter component set)
Boston Acoustics G5124 subwoofer
Punch 240x4 (4-channel) for mids, and bridged Punch 100x2 for sub.
Phoenix Gold 215ix eq, 1Farad cap, 4ga/8ga throughout for distribution.

This is my third large scale system and I've been an enthusiast ever since I could drive at 16 . I love my car audio!

 

[davestar]

Originally posted by: Aharami
I have created a detailed thread over in the vwvortex car audio forums. Please take a look there to get a full understanding of whats going on

http://forums.vwvortex.com/zerothread?id=2570014

Basically I spent a lot of money and time to redo my car's audio and while Im happy with it, I think the SQ from my gf's Scion tC is better (all she has is an alpine HU feeding stock speakers).

So while having a discussion about this over in that forum, I mentioned that my amp gains are set to 0.2V and my HU's preouts are 4V. To that someone said

you have so fried your tweeters. if not all your speakers. you need to set the gain on your amp to match the output voltage on your HU. going from 1 to 2 to 4 is actually turning down your gain, not up. the number gets bigger, but its the other way around. yeah its louder but its all distortion. a square wave is three times more powerful than a sine wave, and youve been running a square wave the whole time. i think you fried your voice coils.

is the bolded part really true?? If so, I need to go out there and change it asap.

Also for those who read thru the other thread, if you have any input/thoughts on what others are saying in that thread...id appreciate it. thanks

the bolded part isn't exactly accurate, but the advice is correct. your headunit's preouts are 4V, so your amp should be set to accept inputs of that level.

 

[Specop 007]

Originally posted by: Golgatha

Originally posted by: Specop 007

Originally posted by: Golgatha
The whole point of a gain is to match sound output levels from multiple amplifiers. If you have a single amp, my best advise would be (with protection for your ears) to turn up the head unit at about 80% volume, then adjust the gain knob about 25% under the point at which the amp begins to clip or you hear any audible distortion.

If you're not a SPL freak, then just set the head unit nearly all the way up and adjust the gain to the maximum level you'd ever consider listening to your music at. If you have something to measure SPL, I'd leave the maxiumum SPL at 131dB (an "ears ringing afterwards" rock concert is 125dB and 131dB is four levels of magnitude greater) or less where your head is going to be situated.

Wrong!
GAIN IS NOT A VOLUME KNOB!
GAIN IS NOT A VOLUME KNOB!

I agree. I said to turn the head unit volume up before adjusting the gain. Changing the gain will certainly inc/dec the SPL at a fixed volume level coming from the head unit. Personally, I'm 28 and already have some hearing loss due to lifestyle and an unfortunate laboratory accident, so I keep the maxiumum volume I could ever listen to in check by adjusting the gains as outlined above.

System (in case anyone is interested)

Boston Acoustics 6.4 Pros in front. (6.5in Woofer, 1in tweeter component set)
Boston Acoustics 6.5 Rally series in rear (6.5in Woofer, 1in tweeter component set)
Boston Acoustics G5124 subwoofer
Punch 240x4 (4-channel) for mids, and bridged Punch 100x2 for sub.
Phoenix Gold 215ix eq, 1Farad cap, 4ga/8ga throughout for distribution.

This is my third large scale system and I've been an enthusiast ever since I could drive at 16 . I love my car audio!

I read your first statement wrong.

Off to find some coffee.

I set my gain with a multimeter so.....

 

[Golgatha]

the bolded part isn't exactly accurate, but the advice is correct. your headunit's preouts are 4V, so your amp should be set to accept inputs of that level.

If and only if there is one amplifier, no distortion at maxiumum head unit volume, no clipping occuring,....etc.

Almost all systems need gain adjustments even if you're just wiring up a single sub with a set of stereo speakers. Even when using the built-in crossover of the amp, you still need to set gains for the sub and mids to get as flat of a frequency response as possible if you're going for SQ.

 

[Aharami]

Originally posted by: Golgatha

the bolded part isn't exactly accurate, but the advice is correct. your headunit's preouts are 4V, so your amp should be set to accept inputs of that level.

If and only if there is one amplifier, no distortion at maxiumum head unit volume, no clipping occuring,....etc.

Almost all systems need gain adjustments even if you're just wiring up a single sub with a set of stereo speakers. Even when using the built-in crossover of the amp, you still need to set gains for the sub and mids to get as flat of a frequency response as possible if you're going for SQ.

i have 2 amps. one mono amp driving the sub and a 4 channel amp driving the speakers/tweeters

 

[Golgatha]

Originally posted by: Specop 007

Originally posted by: Golgatha

Originally posted by: Specop 007

Originally posted by: Golgatha
The whole point of a gain is to match sound output levels from multiple amplifiers. If you have a single amp, my best advise would be (with protection for your ears) to turn up the head unit at about 80% volume, then adjust the gain knob about 25% under the point at which the amp begins to clip or you hear any audible distortion.

If you're not a SPL freak, then just set the head unit nearly all the way up and adjust the gain to the maximum level you'd ever consider listening to your music at. If you have something to measure SPL, I'd leave the maxiumum SPL at 131dB (an "ears ringing afterwards" rock concert is 125dB and 131dB is four levels of magnitude greater) or less where your head is going to be situated.

Wrong!
GAIN IS NOT A VOLUME KNOB!
GAIN IS NOT A VOLUME KNOB!

I agree. I said to turn the head unit volume up before adjusting the gain. Changing the gain will certainly inc/dec the SPL at a fixed volume level coming from the head unit. Personally, I'm 28 and already have some hearing loss due to lifestyle and an unfortunate laboratory accident, so I keep the maxiumum volume I could ever listen to in check by adjusting the gains as outlined above.

System (in case anyone is interested)

Boston Acoustics 6.4 Pros in front. (6.5in Woofer, 1in tweeter component set)
Boston Acoustics 6.5 Rally series in rear (6.5in Woofer, 1in tweeter component set)
Boston Acoustics G5124 subwoofer
Punch 240x4 (4-channel) for mids, and bridged Punch 100x2 for sub.
Phoenix Gold 215ix eq, 1Farad cap, 4ga/8ga throughout for distribution.

This is my third large scale system and I've been an enthusiast ever since I could drive at 16 . I love my car audio!

I read your first statement wrong.

Off to find some coffee.

I set my gain with a multimeter so.....

QFT. Even if you do the install yourself, it's worth an hour of labor at a reputable shop to get the whole thing fine tweaked by a professional using a multimeter. That said, after the fine tweaking, I have no problem writting down where everything is set and then adjusting for personal preferrence. e.g. I tend to slightly accentuate the very high frequencies because my hearing in that range demands it for my personal listening enjoyment. At the end of the day, as a daily driver my car is tweaked to my ears and no one else's. However, no one has complained about the SQ in my car yet .

 

[Golgatha]

Originally posted by: Aharami

Originally posted by: Golgatha

the bolded part isn't exactly accurate, but the advice is correct. your headunit's preouts are 4V, so your amp should be set to accept inputs of that level.

If and only if there is one amplifier, no distortion at maxiumum head unit volume, no clipping occuring,....etc.

Almost all systems need gain adjustments even if you're just wiring up a single sub with a set of stereo speakers. Even when using the built-in crossover of the amp, you still need to set gains for the sub and mids to get as flat of a frequency response as possible if you're going for SQ.

i have 2 amps. one mono amp driving the sub and a 4 channel amp driving the speakers/tweeters

Then both of your amps will need gain adjustments for the best possible SQ. Pay someone who knows what they're doing if you're not comfortable doing it yourself. An easy way to get a descent setting (provided your crossovers don't have any frequency overlap) is to get a SPL meter, unplug one amp's RCAs so it gets no signal, run some pink/white noise, and set each accordingly as previously mentioned.

http://hyperphysics.phy-astr.gsu.edu/HBASE/audio/equal.html

I am very convinced a properly tweaked and installed $1,000 system can sound better than a $10,000 bass cannon any day of the week.

 

[Aharami]

Originally posted by: davestar

Originally posted by: Aharami
I have created a detailed thread over in the vwvortex car audio forums. Please take a look there to get a full understanding of whats going on

http://forums.vwvortex.com/zerothread?id=2570014

Basically I spent a lot of money and time to redo my car's audio and while Im happy with it, I think the SQ from my gf's Scion tC is better (all she has is an alpine HU feeding stock speakers).

So while having a discussion about this over in that forum, I mentioned that my amp gains are set to 0.2V and my HU's preouts are 4V. To that someone said

you have so fried your tweeters. if not all your speakers. you need to set the gain on your amp to match the output voltage on your HU. going from 1 to 2 to 4 is actually turning down your gain, not up. the number gets bigger, but its the other way around. yeah its louder but its all distortion. a square wave is three times more powerful than a sine wave, and youve been running a square wave the whole time. i think you fried your voice coils.

is the bolded part really true?? If so, I need to go out there and change it asap.

Also for those who read thru the other thread, if you have any input/thoughts on what others are saying in that thread...id appreciate it. thanks

the bolded part isn't exactly accurate, but the advice is correct. your headunit's preouts are 4V, so your amp should be set to accept inputs of that level.

my mono sub amp has gain settings from 0.2V to 4V. goes .2, .3, .4, .5, .6, .8, 1.0, 1.5, 2.0, 2.5, 4.0
my 4 channel amp has 2 separate gain settings - one for channel 1&2 (fronts) and one for channel 3&4 (rears). those go in the same increments as mentioned above.

Should I set all 3 gain settings to 4V?

 

[Aharami]

Originally posted by: Golgatha

Originally posted by: Aharami

Originally posted by: Golgatha

the bolded part isn't exactly accurate, but the advice is correct. your headunit's preouts are 4V, so your amp should be set to accept inputs of that level.

If and only if there is one amplifier, no distortion at maxiumum head unit volume, no clipping occuring,....etc.

Almost all systems need gain adjustments even if you're just wiring up a single sub with a set of stereo speakers. Even when using the built-in crossover of the amp, you still need to set gains for the sub and mids to get as flat of a frequency response as possible if you're going for SQ.

i have 2 amps. one mono amp driving the sub and a 4 channel amp driving the speakers/tweeters

Then both of your amps will need gain adjustments for the best possible SQ. Pay someone who knows what they're doing if you're not comfortable doing it yourself. An easy way to get a descent setting (provided your crossovers don't have any frequency overlap) is to get a SPL meter, unplug one amp's RCAs so it gets no signal, run some pink/white noise, and set each accordingly as previously mentioned.

http://hyperphysics.phy-astr.gsu.edu/HBASE/audio/equal.html

I am very convinced a properly tweaked and installed $1,000 system can sound better than a $10,000 bass cannon any day of the week.

Im going to meet up with a professional installer this wed. But until then, I want to make sure I dont damage anything

 

[Golgatha]

Originally posted by: Aharami

Originally posted by: davestar

Originally posted by: Aharami
I have created a detailed thread over in the vwvortex car audio forums. Please take a look there to get a full understanding of whats going on

http://forums.vwvortex.com/zerothread?id=2570014

Basically I spent a lot of money and time to redo my car's audio and while Im happy with it, I think the SQ from my gf's Scion tC is better (all she has is an alpine HU feeding stock speakers).

So while having a discussion about this over in that forum, I mentioned that my amp gains are set to 0.2V and my HU's preouts are 4V. To that someone said

you have so fried your tweeters. if not all your speakers. you need to set the gain on your amp to match the output voltage on your HU. going from 1 to 2 to 4 is actually turning down your gain, not up. the number gets bigger, but its the other way around. yeah its louder but its all distortion. a square wave is three times more powerful than a sine wave, and youve been running a square wave the whole time. i think you fried your voice coils.

is the bolded part really true?? If so, I need to go out there and change it asap.

Also for those who read thru the other thread, if you have any input/thoughts on what others are saying in that thread...id appreciate it. thanks

the bolded part isn't exactly accurate, but the advice is correct. your headunit's preouts are 4V, so your amp should be set to accept inputs of that level.

my mono sub amp has gain settings from 0.2V to 4V. goes .2, .3, .4, .5, .6, .8, 1.0, 1.5, 2.0, 2.5, 4.0
my 4 channel amp has 2 separate gain settings - one for channel 1&2 (fronts) and one for channel 3&4 (rears). those go in the same increments as mentioned above.

Should I set all 3 gain settings to 4V?

I honestly wouldn't set any of the gains more than halfway up (2V marking) until you have that meeting with a professional. If your sub amp is at least twice the RMS wattage of the mid amp, then I would set the gains approximately equal to each other. It's impossible for me to tell you approximately where to set anything since I'm not there to hear it in person.

 

[davestar]

Originally posted by: Aharami

Originally posted by: davestar

Originally posted by: Aharami
I have created a detailed thread over in the vwvortex car audio forums. Please take a look there to get a full understanding of whats going on

http://forums.vwvortex.com/zerothread?id=2570014

Basically I spent a lot of money and time to redo my car's audio and while Im happy with it, I think the SQ from my gf's Scion tC is better (all she has is an alpine HU feeding stock speakers).

So while having a discussion about this over in that forum, I mentioned that my amp gains are set to 0.2V and my HU's preouts are 4V. To that someone said

you have so fried your tweeters. if not all your speakers. you need to set the gain on your amp to match the output voltage on your HU. going from 1 to 2 to 4 is actually turning down your gain, not up. the number gets bigger, but its the other way around. yeah its louder but its all distortion. a square wave is three times more powerful than a sine wave, and youve been running a square wave the whole time. i think you fried your voice coils.

is the bolded part really true?? If so, I need to go out there and change it asap.

Also for those who read thru the other thread, if you have any input/thoughts on what others are saying in that thread...id appreciate it. thanks

the bolded part isn't exactly accurate, but the advice is correct. your headunit's preouts are 4V, so your amp should be set to accept inputs of that level.

my mono sub amp has gain settings from 0.2V to 4V. goes .2, .3, .4, .5, .6, .8, 1.0, 1.5, 2.0, 2.5, 4.0
my 4 channel amp has 2 separate gain settings - one for channel 1&2 (fronts) and one for channel 3&4 (rears). those go in the same increments as mentioned above.

Should I set all 3 gain settings to 4V?

I don't have any first-hand experience with your amp, but from my interpretation from the owner's manual is that 0.2V doesn't mean low gain and 4.0V doesn't mean high gain. Assumably, it's the opposite. why don't you just set it in the middle and increase/decrease the "gain" to see what effect it has on volume? then, just to be safe, set it on the low volume end of things.

 

[Aharami]

Originally posted by: davestar

Originally posted by: Aharami

Originally posted by: davestar

Originally posted by: Aharami
I have created a detailed thread over in the vwvortex car audio forums. Please take a look there to get a full understanding of whats going on

http://forums.vwvortex.com/zerothread?id=2570014

Basically I spent a lot of money and time to redo my car's audio and while Im happy with it, I think the SQ from my gf's Scion tC is better (all she has is an alpine HU feeding stock speakers).

So while having a discussion about this over in that forum, I mentioned that my amp gains are set to 0.2V and my HU's preouts are 4V. To that someone said

you have so fried your tweeters. if not all your speakers. you need to set the gain on your amp to match the output voltage on your HU. going from 1 to 2 to 4 is actually turning down your gain, not up. the number gets bigger, but its the other way around. yeah its louder but its all distortion. a square wave is three times more powerful than a sine wave, and youve been running a square wave the whole time. i think you fried your voice coils.

is the bolded part really true?? If so, I need to go out there and change it asap.

Also for those who read thru the other thread, if you have any input/thoughts on what others are saying in that thread...id appreciate it. thanks

the bolded part isn't exactly accurate, but the advice is correct. your headunit's preouts are 4V, so your amp should be set to accept inputs of that level.

my mono sub amp has gain settings from 0.2V to 4V. goes .2, .3, .4, .5, .6, .8, 1.0, 1.5, 2.0, 2.5, 4.0
my 4 channel amp has 2 separate gain settings - one for channel 1&2 (fronts) and one for channel 3&4 (rears). those go in the same increments as mentioned above.

Should I set all 3 gain settings to 4V?

I don't have any first-hand experience with your amp, but from my interpretation from the owner's manual is that 0.2V doesn't mean low gain and 4.0V doesn't mean high gain. Assumably, it's the opposite. why don't you just set it in the middle and increase/decrease the "gain" to see what effect it has on volume? then, just to be safe, set it on the low volume end of things.

vol is loudest with it set at 0.2V and gets quieter as you increase the voltage setting.