# Setting Gains - What's your method?



## Thunderplains (Sep 6, 2009)

I had a discussion last night regarding setting gains and most of the discussion revolved around using sine waves with / without speakers attached, use of pink noise in specified freq range both with the use of measuring voltage at terminals under load and plain old music and your ear.

I, personally, am using pink noise in specified range and measuring voltage at speaker terminals, speakers attached while running volume up to maximum unclipped (62 on P99)

So, I figured why not find out what everyone else is doing to get the most out of their amp.


----------



## ErinH (Feb 14, 2007)

i've done a lot of different ways of measuring gain: dmm, oscope, tones, etc...

the most beneficial to me was simply connecting the drivers, turning the gain up and listening to see when I heard white noise through the drivers (ie: floor noise). When I got to a point where it was just below audible from the driver's seat, I stopped and left them there. I then did level matching based on the highest output driver (ie: lower gains only, never raise them).
The potential issue with this is if you have a really low SNR vs. output, but I highly doubt anyone will run into that issue. 

my $.02.


----------



## matthewo (Jan 31, 2008)

i try to keep the gain as close to 0 as possible, i have my bitone set to put out a max signal (4 volts rms) at a 0 db recording at 48 volume on my pioneer f90bt. my gains are just around 0-1/4. personnaly i use the SD card slot and usb of the deck, and the output level is not as high as CD, i have had to use SLA a bit for that, on the deck.

i pretty much just do it by ear. like bikin said, keep the floor noise down, but still retain good enough output. if you have been in car audio for a while you can tell when you go to high and are sending a clipped signal.


----------



## diamondjoequimby (Jun 30, 2009)

Combination of both.

In a retail environment, O-scope / sine wave then adjust down from there to balance. It tends to be pretty conservative and also leads to longer life of equipment to an abusive consumer (as long as said consumer a: doesn't screw with gains, and b: listens to source material that is at least somewhat clean)

In my own car, use the Scope as a reference to get a base line, then go by ear from there.


----------



## nineball (Jan 17, 2008)

where is the choice for "using test tones and my ears"?


----------



## masswork (Feb 23, 2009)

bikinpunk said:


> i've done a lot of different ways of measuring gain: dmm, oscope, tones, etc...
> 
> the most beneficial to me was simply connecting the drivers, turning the gain up and listening to see when I heard white noise through the drivers (ie: floor noise). When I got to a point where it was just below audible from the driver's seat, I stopped and left them there. I then did level matching based on the highest output driver (ie: lower gains only, never raise them).
> The potential issue with this is if you have a really low SNR vs. output, but I highly doubt anyone will run into that issue.
> ...


+1 !!

I'm using 3 way+sub all active.
First i listen to white noise in the tweeter using above method.
Then i adjust the gain for midrange, midbass, sub by measuring the response - relative to the tweeter.


----------



## hottcakes (Jul 14, 2010)

masswork said:


> +1 !!
> 
> I'm using 3 way+sub all active.
> First i listen to white noise in the tweeter using above method.
> Then i adjust the gain for midrange, midbass, sub by measuring the response - relative to the tweeter.


i think bikinpunk means that he connects the drivers without anything playing, for example a cd with the volume at zero, and listens for an audible noise being played through the speakers. then lowers the gain from there to where the noise is no longer audible. 
at least that is how i read it being done elsewhere by the man.


----------



## masswork (Feb 23, 2009)

Ow, then it's slightly different with mine.
But the idea is same i guess... noise floor 

In contrast, i put the HU in aux mode so the zero bit detector doesn't kick in, and put the volume at least 75% then listen to the noise floor.


----------



## metanium (Feb 2, 2007)

Here's a method learned from Mark Eldridge at a get-2-gether. To use this method you'll need a radio shack mini-amp and a test disc. Also possibly a voltage divivder, which is pretty east to construct.

The first thing to do prior to setting gains is to set all pre-amp levels and EQ’s to flat (zero) on HU and processors. Secondly, any electronic crossover settings should be adjusted to include the frequency of the test tones that will be used to set gain. For example, my subwoofer output is usually set to low-pass at 63 or 80Hz. For setting gains on the sub channel, I will use a 100Hz test tone, so I will adjust the low-pass for my sub output to 200Hz.

Once the adjustments have been made, you’re ready to pop in a gain setting CD such as Autosound 2000 Disc 104. Gain settings should be adjusted from the beginning of the signal chain to the end. So, you’ll want to start at the HU(s) and work your way through processor(s), then to the amplifier(s). The gain for each channel (or channel pair) should be set using an appropriate test tone. By appropriate, I mean the test tone should be a sine wave at a frequency within the usable range of a particular channel (see note on crossover settings above).

I use a 3-way active HU, so I have High, Mid, and Sub outputs. I will set the gains of these outputs using 100 Hz, 1 kHz, and 4 kHz respectively. I will also be using a test tones recorded at -5dB. This will allow some minor clipping when driven to maximum levels, but any distortion should still be inaudible. The Autosound 2000 Disc 104 includes multiple tracks that will allow for overlap. Gain overlap will allow the user to extract every bit of undistorted power out of their system. The table below illustrates the pros/cons of using overlap when setting gains.

Note: The mini amp can’t play the 100Hz tone with much output at all, so it’s likely necessary to place the speaker of the mini amp closely to your ear before setting the gain. The change in pitch that occurs when the signal begins clipping should be audible.

0 dB Overlap	No-clipping, but good amount of power unused	+/- 0.1% THD
5 dB Overlap	Minor, inaudible clipping (Good compromise)	+/- 0.3% THD
10 dB Overlap	Clipping is audible (Max. overlap to set gain)	+/- 1.0% THD
15 dB Overlap	Noticeable clipping is present	+/- 10% THD

With all of the preliminary stuff out of the way, it’s time to determine at what volume level our HU starts to distort. The mini amp is connected to one of the mid channel(s). The min amp is to be powered on, but the volume should be kept to it’s minimum (turned all the way down) to avoid hearing the internal amp clip, as opposed to the incoming signal. With a 1kHz test tone playing, the volume of the HU is increased until the pitch of the tone from the mini amp changes. If the HU reaches full volume without this occurring, that HU doesn’t clip. If there’s a slight change in pitch of the tone from the mini amp, the volume of the HU should be reduced to the point just prior to the change in pitch of the test tone. This is the HU’s maximum, unclipped output (MUO) setting.

Note: The change in pitch heard from the mini-amp, indicates the point at which the signal begins to clip. The observed change in pitch comes from second, third, and fourth-order harmonics which occur with clipping. So instead of hearing a single-frequency tone, we hear multiple-frequency tones playing together.

This process is to be repeated, in order, down the signal chain. So any processors between the HU and amplifier(s) are to be tested with the mini-amp and test tones. Remember to use an appropriate test tone for each channel being used (i.e. 100Hz for sub, 1kHz for mid, and 4kHz for the high channel(s)). When setting gains on processors in the signal chain, the HU’s volume should be set to the MUO, as determined previously. The gain controls of the processor being set should be set for the MUO. If the output of the processor clips even when its gain is set to the minimum, the HU’s volume may need to be reduced below the MUO.

Once the gains have been set to MUO on the HU and any processors in the signal chain, the amplifier is ready to be adjusted. Since the output of the amplifier is much greater than the pre-amplified signal, its voltage must be reduced prior to feeding it into the mini amp. This is accomplished by using a voltage divider. I am using a 10:1 voltage divider to set gains for my amplifiers. Depending on the output of the amplifiers being adjusted, a larger voltage divider might be necessary.

The voltage divider is placed inline, prior to the mini-amp. The inputs of the voltage divider are connected directly to the speaker outputs of the amplifier. The HU is once again, set to its MUO. The amplifiers gains are adjusted using the same test tones as before. Once the gain pots on the amp have all been adjusted for MUO, you’re done.

NOW, you can go set you EQ, but remember that any boosts will cause the signal in that range to exceed MUO earlier. To avoid this scenario, only use “cuts” in EQ, as opposed “boosts”.


----------



## hottcakes (Jul 14, 2010)

ah yes, i forgot about some HUs zero bit mute function. t3sn4f2 made a track that supposedly gets by this by being just "loud" (used loosely) enough to not have that kick in. the link still works as i have just tested it, however i do no know if this truly works since there are no replies to confirm it working nor does my source have the muting function.


----------



## ErinH (Feb 14, 2007)

hottcakes said:


> i think bikinpunk means that he connects the drivers without anything playing, for example a cd with the volume at zero, and listens for an audible noise being played through the speakers. then lowers the gain from there to where the noise is no longer audible.
> at least that is how i read it being done elsewhere by the man.


Yep. That's exactly right.

to go further, I'll say that I've also done the entire gain structure discussed in the above post. What I've found is that you're left with a higher SNR, depending on the attenuated tone you use.
So, really, the weakest link isn't the actual signal, it's the noise floor. That requires you to back down the amp gain.
*Caveat: It also depends on the amp's power, too. The case above involved amps that were 100w for non-subbass drivers. But, really, I never gain up to that much power anyway...

So, I quit bothering with tones, etc. I just put the headunit volume to zero, and start raising the gain until I hear white noise (static, whatever you want to call it) come through the driver. I then listen to it from the driver's seat until I get it just below audibility (or just above... whatever you want). I stop.
I then move on to the next driver. 

Now my entire system's noise floor is completely acceptable and I'm still within "clean" (ie: no clipping on -5 or -10dB tones) signal range, providing me with good output and low noise floor.

Next would be the "tuning" portion:
If I listened to the system at the levels the gains were set at it would be unbearable due to the mismatch in output relative to my hearing.
So I just start backing gains down based off my sub or midbass (as these require more power typically, all things equal), which means I usually wind up turning my tweeters' level down and then midrange down. I then do L/R gain matching via the DSP and away I go.

Pretty simple, really.


----------



## hottcakes (Jul 14, 2010)

metanium said:


> The first thing to do prior to setting gains is to set all pre-amp levels and EQ’s to flat (zero) on HU and processors. Secondly, any electronic crossover settings should be adjusted to include the frequency of the test tones that will be used to set gain. For example, my subwoofer output is usually set to low-pass at 63 or 80Hz. For setting gains on the sub channel, I will use a 100Hz test tone, so I will adjust the low-pass for my sub output to 200Hz.


firstly, i've read that method here, perhaps you should've linked to it so others may read the thread if they choose. secondly, i don't get why you would set the LPF for the subs at 200hz, use a 100hz tone to test with, then cross it at 63 or 80 or whatever for musical listening. what am i missing?


----------



## Angrywhopper (Jan 20, 2010)

Ear.


----------



## Brian_smith06 (Jan 31, 2008)

the system I have now im actually leaving the gains down all the way and adjusting with xover levels. I have 650 watts on tap per mid and who really needs that much lol. I bought just to have the extreme headroom.


----------



## kvndoom (Nov 13, 2009)

I just set it by ear to a particular volume level on the HU... and I don't allow any kids to be in my car if I'm not in it too.


----------



## cvjoint (Mar 10, 2006)

The proper way to answer this is to pick: 2nd and 4th choices.

Here is why you need 2nd option:
You have 3 subwoofers getting amplified by separate monoblocks. The proper gain setting is somewhere in the middle. How much do you turn the knob? Do you do it by ear? The proper way is to play a 40hz tone and measure the V on the terminals with speakers connected. 

Here is why you need 4th option:
There is subjectivity involved. For example Bikinpunk hates background static. I do too, but I'm not willing to live with the compromises of low gain levels. For one, I have lots of test CDs recorded at very low average volume levels. Whenever I take them into other people's cars I need to max out their volume knob to get any acceptable output. In my car I'd rather live with high background noise but have the complete freedom to adjust the output level as high as I want on any material. I generally have the engine on and covering distance when I'm in my car so the static is almost never heard. 
Both options are fine here, but the ear dictates final SPL.


----------



## jrs1006 (Sep 19, 2010)

good stuff. I just usually use my ears and have never had a problem.


----------



## computerjlt (Nov 29, 2010)

i run the least amount of gain on the amp as possible; if you do the oscope method and have an active setup then you'll wind up with say your tweeters being VERY loud compared to everything else in the system; then you'll have to lower the level with your proc/crossover and that could result in hiss/noise.

the best way i've found when running active with different amps/speakers is set the gains about 1/4 (if you have a high voltage (5v+) source) then set the levels in the processor/crossover with pink noise and your ears or rta (phone rta works wonders). you'll wind up with some drivers needing more and some needing a lot less. i wound up with ZERO gain on my tweets on a ppi art a200, and about 1/8 gain on my mids on 2ch off a pg xs4600 and my mids need about 1/2 gain on the other two channels on my pg amp. All of this results in a -0 level for all channels on my rf 360.2. I could turn up the amp gains a little bit higher but right now i'm PASSED the limit of my weakest set of drivers (midbasses) so until they're upgraded they'll sit there. plus as it sits my system gets louder than i can stand for any long period


----------



## ErinH (Feb 14, 2007)

cvjoint said:


> Here is why you need 4th option:
> There is subjectivity involved. For example Bikinpunk hates background static. I do too, but I'm not willing to live with the compromises of low gain levels. For one, I have lots of test CDs recorded at very low average volume levels. Whenever I take them into other people's cars I need to max out their volume knob to get any acceptable output. In my car I'd rather live with high background noise but have the complete freedom to adjust the output level as high as I want on any material. I generally have the engine on and covering distance when I'm in my car so the static is almost never heard.
> Both options are fine here, but the ear dictates final SPL.


I wouldn't be so certain that my setup doesn't get plenty loud. 
My typical volume is maxed at 30/40 _when driving_. The extra 10 volume steps are there for what you mentioned. 

Stopped, ie: demoing or at a comp, the volume is typically at about 25/40 and for the louder 'linearity' portion of the testing it's probably about 33 or so. So far, I've not had anyone say that the volume is lacking. 
But, I do see where you might feel that it would be. The goal for me is ability to crank it without sacrificing via noise floor. Depending on what components are used, it shouldn't really be a big issue for others to do the same. 

Plus, one can tune a car to sound louder than another setup that is EXACTLY the same, minus EQ settings.


----------



## stereo_luver (Oct 30, 2007)

Basically the same as Erin. I use a zero data track and start with my gains down to lowest setting. I raise them until I 'think' I begin to hear some noise then stop. I run back down a slight twist then back up and back down to be sure I'm where I want to be. Bridged amps I do the same but one side at a time. Then use a MM to set the 2 channels the same using the lowest value. Then I gain match my drivers using pink noise doing one side (left / right) at a time. Then I set a close to center stage using the driver levels on my HU for each driver equally. Then I move onto TA....then EQ...then the sub in the final stages of my settings.

I went too far I know.


Chuck


----------



## cvjoint (Mar 10, 2006)

bikinpunk said:


> I wouldn't be so certain that my setup doesn't get plenty loud.
> My typical volume is maxed at 30/40 _when driving_. The extra 10 volume steps are there for what you mentioned.
> 
> Stopped, ie: demoing or at a comp, the volume is typically at about 25/40 and for the louder 'linearity' portion of the testing it's probably about 33 or so. So far, I've not had anyone say that the volume is lacking.
> ...


We can't prove one or the other, you are right. In my setups I've always had a bit of bknoise or sacrificed output. To add in my setups I also have loads of output compared to the average diyer. 

It seems to me that if the bknoise is not binding in your case you shouldn't be tuning the way you are. What stops you from turning the gains even lower? You may keep your amps. even cooler. You have the upper bound but what's your lower bound gain? 

I'm not sure what you mean by the last statement. EQ. taxes your resources all the same. In simulations you should look at amplifier apparent load - it should increase as you boost. Most guides tell you to enter half the power if you EQ. in 3db of output as a rule of thumb. Some are more comprehensive with a table of entries available.


----------



## Commissionmip (Jan 27, 2011)

matthewo said:


> i try to keep the gain as close to 0 as possible, i have my bitone set to put out a max signal (4 volts rms) at a 0 db recording at 48 volume on my pioneer f90bt. my gains are just around 0-1/4. personnaly i use the SD card slot and usb of the deck, and the output level is not as high as CD, i have had to use SLA a bit for that, on the deck.
> 
> i pretty much just do it by ear. like bikin said, keep the floor noise down, but still retain good enough output. if you have been in car audio for a while you can tell when you go to high and are sending a clipped signal.


Same here.... I usually try to keep them closer to "0"...


----------



## ErinH (Feb 14, 2007)

cvjoint said:


> What stops you from turning the gains even lower?


that's exactly what I posted above... my current settings are a good compromise between audible background noise vs. desired volume "headroom" for less dynamic/quiet tracks like you mentioned in your post. 
So, the answer to your question for me is simple: loudness. I'm pretty much right where I want to be with the gain setting... any louder and you start to hear background noise. Too much lower and I don't have the headroom at the headunit's volume I want. Realistically, I could go a bit either way on the gain itself and be fine. I'm sure you understand what I mean.



cvjoint said:


> You have the upper bound but what's your lower bound gain?


To me (and I'm speaking for myself here) I'm bound by the two things I mentioned above:

Noise Floor
Volume Level
I'm at the compromise as far as gain pot location goes. I turn it up until I get some background noise and stop. Then I start tuning. I could probably eek out a bit more, but I don't bother. It's just a method that has worked well for me so I've stuck with it. Plus, it's a helluva lot easier than breaking out the oscope and dummy load. 

Hope that answers your question.




cvjoint said:


> I'm not sure what you mean by the last statement. EQ. taxes your resources all the same.


I simply mean that the way a person sets his gains isn't really telling of how loud their system may sound, all things the same sans EQ. 
A couple EQ bumps (or dips) here or there really do affect _perceived _loudness.
That's all I really meant by that statement. 


Edit: A lot of over-explaining on my part. Not needed. Cut out all my yapping.


----------



## cvjoint (Mar 10, 2006)

bikinpunk said:


> that's exactly what I posted above... my current settings are a good compromise between audible background noise vs. desired volume "headroom" for less dynamic/quiet tracks like you mentioned in your post.


Aha, compromise! So we do agree. 

Here's an interesting test I ran. My car has a lid that hides the headunit. I have a nifty chip that adapts the P99 to use my oem dash mounted volume knob.
What that means is that I can adjust the volume without actually knowing what the the readout is out of 62 max. 

Average listening volume with the lid open:
52
Average listening volume with the lid closed:
40!

What does that mean? Beats me! But while both volume levels are picked by ear I seem to be much more of an output junkie when I can see how much more I have to go to max out. You can expect such lack of reliability from your ears because the eyes always meddle!


----------



## jimmy2345 (Jul 12, 2010)

Dynamic track....ears and eyes.


----------



## ErinH (Feb 14, 2007)

cvjoint said:


> What that means is that I can adjust the volume without actually knowing what the the readout is out of 62 max.
> 
> Average listening volume with the lid open:
> 52
> ...


I've noticed the same myself. My wife says I'm going deaf. I wonder why.


----------



## t3sn4f2 (Jan 3, 2007)

cvjoint said:


> Aha, compromise! So we do agree.
> 
> Here's an interesting test I ran. My car has a lid that hides the headunit. I have a nifty chip that adapts the P99 to use my oem dash mounted volume knob.
> What that means is that I can adjust the volume without actually knowing what the the readout is out of 62 max.
> ...


That's interesting, must have something to do with not having a point of reference as to how hard you are pushing your drivers.


----------



## cvjoint (Mar 10, 2006)

t3sn4f2 said:


> That's interesting, must have something to do with not having a point of reference as to how hard you are pushing your drivers.


I thought about this too. I'm reluctant to think this is the major reason. I can't actually see any of my driver cones moving so the volume readout is a poor proxy for system risk. 

Second I abuse all things I own, not for the sake of it but I don't feel like backing of the knob if I like where it's at. I broke down the mighty Seas W26 in a midbass application! I also rev the piss out of the S2000 everytime I drive it. If it breaks easily then it's not a good choice for me.


----------



## computerjlt (Nov 29, 2010)

when i start smelling hot voice coil i'll usually turn it down


----------



## cvjoint (Mar 10, 2006)

computerjlt said:


> when i start smelling hot voice coil i'll usually turn it down


Doesn't work so well for mechanical damage. It doesn't take a lot of power to destroy a speaker with subsonics.


----------



## Kenreau (Feb 10, 2011)

It's a balancing act between the output of the HU and amp gain for me. 

I currently have my amp gain turned down to about 50% gain. If it goes up any higher, I lose all reasonable granulation between volume steps on my HU volume controls. (ie - one step down its not loud enough, next volume step up and its too loud). I set the amp gain by running up the HU volume control to about 2/3 maximum and adjust the amp gain to a comfortable / typical listening level. I now have finer granulation between volume steps and have some head room for louder listening sessions.

Another issue to consider is the quality of the volume control / attenuation. Coming from the home audio side, from what I've read, the best SQ is achieved with minimal volume attenuation. Cheaper volume control pots when used with a heavy hand (say first 1/3 of volume range) can degrade the sound quality. With higher quality pots or digital attenuation this isn't as much of a concern. The closer the volume control is to wide open (least attenuation) the better the SQ should be (in theory). 

Is there a typical volume control assembly used in modern HUs (ie like an Alps pot or?).

Kenreau


----------



## 000zero (Mar 12, 2011)

I thought you were just supposed to match the your amp gain to your RCA inputs coming from the HU? For example, my pioneer is supposed to put out 4V and the max gain on my amp is 4V (Arc Audio XXD4080) so does that mean im just supposed to put the gain on my amp all the way up? Wont the amp be clipping if I do that?


----------



## subwoofery (Nov 9, 2008)

000zero said:


> I thought you were just supposed to match the your amp gain to your RCA inputs coming from the HU? For example, my pioneer is supposed to put out 4V and the max gain on my amp is _*4V (Arc Audio XXD4080)*_ so does that mean im just supposed to put the gain on my amp all the way up? Wont the amp be clipping if I do that?


The 4V setting on your amp is the max input. Therefore, you need to leave your gains all the way DOWN (theorically). 

Kelvin


----------



## 000zero (Mar 12, 2011)

subwoofery said:


> The 4V setting on your amp is the max input. Therefore, you need to leave your gains all the way DOWN (theorically).
> 
> Kelvin


I have done a bit more research and I'm not sure you are correct, can you explain a bit more?

I would post the link but I don't have the required 30 but I have posted part of the link (the article is on this website)

/forum/how-articles-provided-our-members/542-tutorial-gain-setting-amplifier-power-usage.html


----------



## subwoofery (Nov 9, 2008)

000zero said:


> I have done a bit more research and I'm not sure you are correct, can you explain a bit more?
> 
> I would post the link but I don't have the required 30 but I have posted part of the link (the article is on this website)
> 
> /forum/how-articles-provided-our-members/542-tutorial-gain-setting-amplifier-power-usage.html


I said "max INPUT" ; meaning if your Head-Unit puts out 4V, then you need to match your amp gains to the 4V HU's output. 4V is then going to be your max OUTPUT gain - going past that is going to increase distorsion. 
You have to remember that most HU don't put out what's written in the specs - you need to max everything (which is not a good thing to do) in order to have 4V output from the HU. 

Kelvin


----------



## ZAKOH (Nov 26, 2010)

I turn off the sub, and adjust the speaker gains with the aim that when the HU volume is close to max level my ears can't take it any more. Then I turn on the sub and set its gain to blend with the rest of music.


----------



## SoulFly (Mar 15, 2011)

I use my ears only cause its faster/easier. Basically good enough, nothing else about my car, system or my hearing is perfect so no reason my gain needs to be perfect either.


----------



## splaudiohz (Apr 1, 2011)

KISS method. Keep It Simple Stupid.


----------



## bass lover (May 2, 2011)

im new here and still trying to find out how this forum works but thanks for all the wisdom


----------



## splaudiohz (Apr 1, 2011)

Well at least we know your a "bass lover". Hit up the SPL area and get educated. Unless you want an all around approach, then WELCOME!!!! and ask as many questions as possible.


----------



## radarcontact (Oct 28, 2010)

ZAKOH said:


> I turn off the sub, and adjust the speaker gains with the aim that when the HU volume is close to max level my ears can't take it any more. Then I turn on the sub and set its gain to blend with the rest of music.


ADOPTED!!!


----------



## TxHouse (Nov 7, 2010)

I use my ears because I do not have the tools necessary to do a proper gain setting. But you are using your ears anyway to listen so that is what I feel should be used if you can't use the proper tools.


----------



## Fixxer (Jul 27, 2007)

Can anyone recommend a good True-RMS DMM/O-Scope? Love the Fluke offerings but they are so expensive. Anything $500 and under, though less expensive is appreciated.


----------



## cobb2819 (Jan 13, 2011)

Tpi440 is kinda the installer goto 


Sent from my iPhone


----------



## HondAudio (Oct 19, 2006)

Is there anything available that's less than $100?


----------



## subwoofery (Nov 9, 2008)

HondAudio said:


> Is there anything available that's less than $100?


Your ears are free  (sorry had to) 

What are you looking for? RTA or oscope? 

Kelvin


----------



## HondAudio (Oct 19, 2006)

subwoofery said:


> Your ears are free  (sorry had to)
> 
> What are you looking for? RTA or oscope?
> 
> Kelvin


Oscillocope. I have a rudimentary RTA on my Palm Centro that actually seems decent.


----------



## jalba (Dec 20, 2010)

HondAudio said:


> Is there anything available that's less than $100?


ARM DSO Nano can be had for $69 shipped on ebay (new). I'm happy with mine.


----------



## 11blueGTI (Apr 24, 2011)

Get a used Techtronics 465M. It is the military model, big and built like a tank.


----------



## Hertz5400LincolnLS (Mar 29, 2010)

I just picked up the SMD DD1 but haven't tried it yet...I will soon though and I'll report back with my findings.

Sent from my ADR6400L using Tapatalk


----------



## t3sn4f2 (Jan 3, 2007)

You guys are gonna have the bestest gain structure out there. No way are you going to hear clipping in those steady tones, sweet. But how does that translate to that thing called music. With its non 0dB peaks, HUGE crest factors, low level recordings, etc. And of course this only matter at that ONE signal head unit volume setting. Once you go over or under that, the precision calibration goes to poopoo.


----------



## Tantrim (Jun 2, 2010)

digital multimeter is the most accurate way.


----------



## subwoofery (Nov 9, 2008)

Tantrim said:


> digital multimeter is the most accurate way.


???  ??? 

Kelvin


----------



## bmxscion (Jan 31, 2011)

Hertz5400LincolnLS said:


> I just picked up the SMD DD1 but haven't tried it yet...I will soon though and I'll report back with my findings.


I have a DD-1 and it works awesome. I found my hu can be turned up all the way and not have any distortion in the output signal. But setting the gains is super easy, fast, and is now louder and cleaner than it was before using it to adjust gains.


----------



## minbari (Mar 3, 2011)

Tantrim said:


> digital multimeter is the most accurate way.


not its not. you might be able to set your amplifier gains to a calculated voltage based on the wattage the manufacturer claims the amplifier will put out, but you have no way to see if it is clipping or not. you will get close, but an o-scope is the only way to be "accurate"


as for the poll, you dont have the best method up there. 

sinewave, o-scope, speakers connected.

without a load on the amplifier, setting the gains is pointless.


----------



## chad (Jun 30, 2005)

Not to mention the differences in driver sensitivity... methinks that there are a LOT of people driving around with some pretty unbalanced sounding systems.

On top of that a WFO sinewave into a tweet... yeah... Kiss those tweets goodbye.

Common sense and ears go a long way.


----------



## minbari (Mar 3, 2011)

chad said:


> .........On top of that a WFO sinewave into a tweet... yeah... Kiss those tweets goodbye.


WFO?


----------



## chad (Jun 30, 2005)

Wide ****ing open.


My failed attempt at keeping things PG


----------



## redbaronace (Sep 27, 2011)

Can someone please list what the best method of setting the gains using just your ears.

I plan to install a system in the car and do not have any of the previously mentioned tools at my disposal.

Thanks,


----------



## redbaronace (Sep 27, 2011)

Another question.

How much $$$ and time (hours) does it typically take a professional with the best tools to tune a stereo system that has already been installed? Or put another way, how much would a really good installer charge to tweek the settings to optomize what is already in place, using all the best tools.

I may go that route depending on the results of my install. The person assisting in the install is more experienced with SQL than SQ and I want to be sure that he does not set my stereo up in a manner that threatens the longevity of the components.

Thanks,


----------



## minbari (Mar 3, 2011)

chad said:


> Wide ****ing open.
> 
> 
> My failed attempt at keeping things PG


lol, ok. just hadnt seen that acronym yet, so had to ask 

and I agree. setting the gains to max output is not always the best goal anyway.


----------



## chad (Jun 30, 2005)

Common acronym in the music industry.


----------



## minbari (Mar 3, 2011)

redbaronace said:


> Can someone please list what the best method of setting the gains using just your ears.
> 
> I plan to install a system in the car and do not have any of the previously mentioned tools at my disposal.
> 
> Thanks,


1) turn your HU up to about 3/4 volume 
2) turn all the gains down to minimum.
3) slowely turn up gains one at a time until you just start to hear distortion.
4) turn down a touch to give a bit safety.

and remeber you can always turn gains down, it wont hurt a thing, just dont turn them up too far



> Another question.
> 
> How much $$$ and time (hours) does it typically take a professional with the best tools to tune a stereo system that has already been installed? Or put another way, how much would a really good installer charge to tweek the settings to optomize what is already in place, using all the best tools.
> 
> ...


really depends. that is like asking "how much will it cost to tune my car engine?" what level of tune do you want? just basic level setting? RTA in car with EQ adjustments? speaker re-location? time alignment? most of the time, the level expertise will dictate the cost. most high end installers charge by the hour. the longer it takes, the more it will cost 

if your friend is a competant installer, then he should be able to tune it to your specifications. if he is just a basshead, look elsewhere.


----------



## chad (Jun 30, 2005)

minbari said:


> 1) turn your HU up to about 3/4 volume
> 2) turn all the gains down to minimum.
> 3) slowely turn up gains one at a time until you just start to hear distortion.
> 4) turn down a touch to give a bit safety.
> ...


Yep, I like to think about the passband that will crap out first... so by using common sense and remembering that max output is 10LogP one can find out which passband is going to distort first (hopefully) Listen there.... Generally the subwoofers or midbass.


----------



## redbaronace (Sep 27, 2011)

minbari said:


> 1) turn your HU up to about 3/4 volume
> 2) turn all the gains down to minimum.
> 3) slowely turn up gains one at a time until you just start to hear distortion.
> 4) turn down a touch to give a bit safety.
> ...


Thanks.


----------



## hari-bhari (Nov 1, 2006)

dmm with 50hz tone for the sub, by ears for the speakers


----------



## cvjoint (Mar 10, 2006)

t3sn4f2 said:


> You guys are gonna have the bestest gain structure out there. No way are you going to hear clipping in those steady tones, sweet. But how does that translate to that thing called music. With its non 0dB peaks, HUGE crest factors, low level recordings, etc. And of course this only matter at that ONE signal head unit volume setting. Once you go over or under that, the precision calibration goes to poopoo.


I like all these hard rules about gain setting. I think if I used any of them I wouldn't even hear my phone calls through the speakers.


----------



## 14642 (May 19, 2008)

The O-Scope method used to be a good way whent he head unit was followed in the signal chain by and EQ (with a gain screw), crossovers (also with gain screws) and then an amplifier. Now, much of that stuff is built into the amp so it's less important to match everything to elimnate noise. 

If your system is a head and an amplifier, then none of this matters. set the mid/high to the loudest setting that doesn't cause system hiss and then adjust the bass. Done.


----------



## cvjoint (Mar 10, 2006)

Andy Wehmeyer said:


> The O-Scope method used to be a good way whent he head unit was followed in the signal chain by and EQ (with a gain screw), crossovers (also with gain screws) and then an amplifier. Now, much of that stuff is built into the amp so it's less important to match everything to elimnate noise.
> 
> If your system is a head and an amplifier, then none of this matters. set the mid/high to the loudest setting that doesn't cause system hiss and then adjust the bass. Done.


That's where having enough power comes into play imo. The best way to gain set is to get a healthy amount of juice on the speakers. That keeps the hiss down since you don't have to flip that switch for low voltage to get the most out of the amp. It also keeps you from clipping at high output. 

I was reading a JBL power recommendation webpage, General Audio FAQ. Feeding twice the IEC rating worked for me so far. This I can relate to.


----------



## tonesmith (Sep 8, 2011)

jalba said:


> ARM DSO Nano can be had for $69 shipped on ebay (new). I'm happy with mine.


X2 , great little product!


----------



## xMplar (Feb 18, 2009)

hmm my new way for setting gains is using the SMD DD1 i used to put the deck up to three quarter volume and turn till a pop the qurter tun back now its a machine and its perfect everytime
Ren
xMplar


----------



## Kenreau (Feb 10, 2011)

WFO



chad said:


> Common acronym in the music industry.


Wow, that brings back memories. We used that all the time in my old glory days of MotoCross racing. Usually "endo" was also used shortly there after.

Kenreau


----------



## chad (Jun 30, 2005)

Kenreau said:


> Usually "endo" was also used shortly there after.
> 
> Kenreau


Nicely done!

Got a good chuckle out of me there.


----------



## adrenalinejunkie (Oct 17, 2010)

minbari said:


> not its not. you might be able to set your amplifier gains to a calculated voltage based on the wattage the manufacturer claims the amplifier will put out, but you have no way to see if it is clipping or not. you will get close, but an o-scope is the only way to be "accurate"
> 
> 
> as for the poll, you dont have the best method up there.
> ...



I used a "DD-1 on my equipment, but had the speakers/subwoofer disconnected. So it's safe to leave the speakers/subwoofer connected on the ampps while using the "DD-1" assuming the speakers/subwoofer can handle the power the amps can deliver? Will the speakers/subwoofer volume decrease once adjusted with a "load?" Thanks


----------



## dietDrThunder (Nov 4, 2010)

minbari said:


> not its not. you might be able to set your amplifier gains to a calculated voltage based on the wattage the manufacturer claims the amplifier will put out, but you have no way to see if it is clipping or not. you will get close, but an o-scope is the only way to be "accurate"
> 
> 
> as for the poll, you dont have the best method up there.
> ...


Sorry to be so late to the thread...just saw it.

I didn't realize that there would be such a difference with or without load. I set my gains on my current system by using the Archer/Radio Shack method w/ all drivers disconnected. Then when I got to the amps, I used a DMM to adjust the voltage as you described above. Once that was done I had to turn the tweeters down a bunch of course, but apart from that it seemed to work ok but "seemed to work ok" is a long ways from "definitely is optimum." 

How does the difference between doing this with a load and without manifest? Thanks!


----------



## slipchuck (Dec 19, 2011)

just a quick question... how far do you put your ears away to listen for the noise floor?
(no intentions of high jacking this thread  )
thanks

randy


----------



## D-Bass (Apr 27, 2012)

buy an amp with 6times the power you need, turn the gain all the way down and hope for the best.

just kidding. 90% of the installs we do are basic systems adjusted by ear. When we're getting a processor involved, we break out the AC3055 RTA, pink noise, and an oscope. figure out maximum unclipped levels, and things can be turned down from there.


----------



## ChaunB3400 (Dec 12, 2009)

I have been using my ears for over 15 years to set gains, never failed me yet


----------



## adrenalinejunkie (Oct 17, 2010)

slipchuck said:


> just a quick question... how far do you put your ears away to listen for the noise floor?
> (no intentions of high jacking this thread  )
> thanks
> 
> randy






No need to move your ears closer unless that's the position you'll be when you drive.


----------



## xtremevette (Apr 14, 2011)

Yeh for me, I just turn up the volume to max then slowly bring the amp(s) up until I hear the first little bit of distortion. I then back it off about 1/8 to 1/4. Close enough for me. I don't compete.


----------



## Thunderplains (Sep 6, 2009)

D-Bass said:


> buy an amp with 6times the power you need, turn the gain all the way down and hope for the best.


So, two Soundstream XXX amps for the mids is what I should get?


----------



## dietDrThunder (Nov 4, 2010)

xtremevette said:


> Yeh for me, I just turn up the volume to max then slowly bring the amp(s) up until I hear the first little bit of distortion. I then back it off about 1/8 to 1/4. Close enough for me. I don't compete.


There isn't anything terrible about this, except that you want to limit the head unit volume to about 75% of max, then proceed. Many (most, even) head units will clip the signal well before 100% volume.


----------



## dietDrThunder (Nov 4, 2010)

D-Bass said:


> buy an amp with 6times the power you need, turn the gain all the way down and hope for the best.
> 
> just kidding. 90% of the installs we do are basic systems adjusted by ear. When we're getting a processor involved, we break out the AC3055 RTA, pink noise, and an oscope. figure out maximum unclipped levels, and things can be turned down from there.


Even on a basic system it takes about 2 minutes to do it with a multi-meter...why not do that v. doing it by ear?


----------



## quality_sound (Dec 25, 2005)

Doesn't always work well that way. I'm running a 900/5 and 600/4. 900/5 bridged to the tweeters at 150/ch and the 600/4 bridged to the midbasses at 300/ch sub gets 500-ish. Drivers are Quart QTD-25s, QWD-160s, Ox 300L sealed in 1.5cf. All drivers are 91-92dB efficient. Levels set with a DMM using JLs method. To keep it balanced the mids are down about 18dB and the tweeters about 20dB.


----------



## t3sn4f2 (Jan 3, 2007)

dietDrThunder said:


> There isn't anything terrible about this, except that you want to limit the head unit volume to about 75% of max, then proceed. Many (most, even) head units will clip the signal well before 100% volume.


Not really, not anymore. Nowadays even affordable head units don't clip at all or at the very least anywhere that low in the volume range. The main reason to do that is to have extra head unit gain for low recording level tracks, high crest factor tracks, and to leave EQ/tone boost headroom available.


----------



## MarkZ (Dec 5, 2005)

dietDrThunder said:


> Even on a basic system it takes about 2 minutes to do it with a multi-meter...why not do that v. doing it by ear?


Because there's absolutely zero benefit in using a meter to do this. And there are literally dozens of threads in this forum where people DID use a meter and now their gain structure is all f'd up, because they're trying to adhere to some arbitrary standard. "Arbitrary standard", by the way, is an oxymoron, so that should make it clear why the meter method doesn't make any sense.


----------



## hpilot2004 (Dec 13, 2011)

MarkZ said:


> Because there's absolutely zero benefit in using a meter to do this. And there are literally dozens of threads in this forum where people DID use a meter and now their gain structure is all f'd up, because they're trying to adhere to some arbitrary standard. "Arbitrary standard", by the way, is an oxymoron, so that should make it clear why the meter method doesn't make any sense.


I do agree with this statement. Only because I did set my gains with a m/m at one time, and later went back and set by ear (much happier). I was able to have a more dynamic, full sounding system.


----------



## dietDrThunder (Nov 4, 2010)

t3sn4f2 said:


> Not really, not anymore. Nowadays even affordable head units don't clip at all or at the very least anywhere that low in the volume range. The main reason to do that is to have extra head unit gain for low recording level tracks, high crest factor tracks, and to leave EQ/tone boost headroom available.


My Pioneer DEH-80PRS clips the output at roughly 85%. That model came out less than a year ago. So how recently are you referring to when you say "not any more?"


----------



## dietDrThunder (Nov 4, 2010)

MarkZ said:


> Because there's absolutely zero benefit in using a meter to do this. And there are literally dozens of threads in this forum where people DID use a meter and now their gain structure is all f'd up, because they're trying to adhere to some arbitrary standard. "Arbitrary standard", by the way, is an oxymoron, so that should make it clear why the meter method doesn't make any sense.


EDIT: never mind...there is no point.

I will say this. If you really think that it "makes no sense" and there is "absolutely zero benefit" to baselining w. a meter, you owe it to your customers to learn more about this, from a technical, objective perspective.


----------



## The Performer (Aug 12, 2012)

dietDrThunder said:


> My Pioneer DEH-80PRS clips the output at roughly 85%. That model came out less than a year ago. So how recently are you referring to when you say "not any more?"


I don't think that is correct, I haven't seen that headunit clip at all up to 60.

Sent from my DROIDX using Tapatalk 2


----------



## dietDrThunder (Nov 4, 2010)

The Performer said:


> I don't think that is correct, I haven't seen that headunit clip at all up to 60.
> 
> Sent from my DROIDX using Tapatalk 2


I just grabbed my notes...you are correct in that I had the % wrong. Mine clipped at 58. The point is that one should not assume that the hu will output a clean signal at 100%.


----------



## chad (Jun 30, 2005)

dietDrThunder said:


> EDIT: never mind...there is no point.
> 
> I will say this. If you really think that it "makes no sense" and there is "absolutely zero benefit" to baselining w. a meter, you owe it to your customers to learn more about this, from a technical, objective perspective.


Many of us run active, so please do tell how you baseline this with a meter, on each passband, using drivers with radically different sensitivities.

A meter will not tell you a clipping point either.... Ever.


----------



## dietDrThunder (Nov 4, 2010)

chad said:


> Many of us run active, so please do tell how you baseline this with a meter, on each passband, using drivers with radically different sensitivities.
> 
> A meter will not tell you a clipping point either.... Ever.


Did I say anything about clipping?

I run active myself. I don't use a meter for tweeters, as they never get anywhere near rated power handling. In my car now, I baselined the HAT mids at 85w at the instruction of a tech guy at HAT, and the tweeters are roughly 15% of that, after tuning by ear and with an RTA.

Look, I'm not starting a holy war here...all I said was that it is silly to say that using a meter for level setting has "absolutely no value" and that's what the guy said. Give it a rest already.


----------



## chad (Jun 30, 2005)

dietDrThunder said:


> Did I say anything about clipping?
> 
> I run active myself. I don't use a meter for tweeters, as they never get anywhere near rated power handling. In my car now, I baselined the HAT mids at 85w at the instruction of a tech guy at HAT, and the tweeters are roughly 15% of that, after tuning by ear and with an RTA.
> 
> Look, I'm not starting a holy war here...all I said was that it is silly to say that using a meter for level setting has "absolutely no value" and that's what the guy said. Give it a rest already.




Did not mention starting a war, you answered my question perfectly. I have absolutely no issue with using a meter to set a baseline with either the least efficient passband or the amp that will **** the bed first. Then going from there. I DO in my profession set for different sensitivities, but I work in an industry that utilizes predictable standards.

HOWEVER some think that the meter sets gains across the board then get pissed off because their system attempts to break their eyeballs and has no low endl


----------



## dietDrThunder (Nov 4, 2010)

chad said:


> Did not mention starting a war, you answered my question perfectly. I have absolutely no issue with using a meter to set a baseline with either the least efficient passband or the amp that will **** the bed first. Then going from there. I DO in my profession set for different sensitivities, but I work in an industry that utilizes predictable standards.
> 
> HOWEVER some think that the meter sets gains across the board then get pissed off because their system attempts to break their eyeballs and has no low endl


I apologize...I really wasn't directing the 'give it a rest' at you in particular...I was just a little frustrated.

Also, I think using a meter can be important to show a customer (I'm out of the biz now) what the max is on input gain on amps, so that when they jack around with it they know that no matter what _here_ is your limit. This is mostly an issue w sub amps when kids try to go get max blast out of their subs in sad and terrible ways


----------



## chad (Jun 30, 2005)

dietDrThunder said:


> I apologize...I really wasn't directing the 'give it a rest' at you in particular...I was just a little frustrated.
> 
> Also, I think using a meter can be important to show a customer (I'm out of the biz now) what the max is on input gain on amps, so that when they jack around with it they know that no matter what _here_ is your limit. This is mostly an issue w sub amps when kids try to go get max blast out of their subs in sad and terrible ways


LOL I had a great sign above my bench that said "Never underestimate the diligence of an idiot with a screwdriver"


----------



## subwoofery (Nov 9, 2008)

chad said:


> LOL I had a great sign above my bench that said "Never underestimate the diligence of an idiot with a screwdriver"


Where did you get that sign? I want one  

Kelvin


----------



## chad (Jun 30, 2005)

subwoofery said:


> Where did you get that sign? I want one
> 
> Kelvin


It was passed down from a mentor and I passed it on when I moved over to the Uni.

Made in a sign stamping shop and well worn... I'll try to get a pic of it.


----------



## The Performer (Aug 12, 2012)

I must not be on the same track with everyone in this thread, so I don't know what were discussing but all this talk of using a meter to set amplifier gains?... really?

In my opinion the only reason there is a technique for doing so is to prove a law of physics that you CAN if need be calculate at where an electronic component will efficiently operate. When dealing with a car stereo I that there is no perfectly set in stone "your gain should be set here" rule.

Point being the only way to see a clipped signal is with an oscilloscope. Period. If you're using a meter you'd do better to just use your ears and listen for the clip. 

You wouldn't buy a painting from just reading a description of how many of what colors were used to make it would you? No, you would want to see the painting with your own eyes.

Sent from my DROIDX using Tapatalk 2


----------



## subwoofery (Nov 9, 2008)

The Performer said:


> I must not be on the same track with everyone in this thread, so I don't know what were discussing but all this talk of using a meter to set amplifier gains?... really?
> 
> In my opinion the only reason there is a technique for doing so is to prove a law of physics that you CAN if need be calculate at where an electronic component will efficiently operate. When dealing with a car stereo I that there is no perfectly set in stone "your gain should be set here" rule.
> 
> ...


:snacks: 

Kelvin


----------



## MarkZ (Dec 5, 2005)

dietDrThunder said:


> EDIT: never mind...there is no point.
> 
> I will say this. If you really think that it "makes no sense" and there is "absolutely zero benefit" to baselining w. a meter, you owe it to your customers to learn more about this, from a technical, objective perspective.


Nice snipe job.


----------



## MUGWUMP (Jan 29, 2012)

I've been using my ears and some -5db tones for the last few years to set gains. I'm not suggesting I've got any real experience. I know just enough to make me dangerous.

I just got the SMD distortion detector in a drunken purchase and while it is a really cool product, it turns out my ears are pretty ****ing spot on. I actually had my gains set a fraction below where the signal starts to clip.


----------



## quality_sound (Dec 25, 2005)

MUGWUMP said:


> I've been using my ears and some -5db tones for the last few years to set gains. I'm not suggesting I've got any real experience. I know just enough to make me dangerous.
> 
> I just got the SMD distortion detector in a drunken purchase and while it is a really cool product, it turns out my ears are pretty ****ing spot on. I actually had my gains set a fraction below where the signal starts to clip.


If you get really drunk again and wanna sell it cheap I'd like to try it out and see how it works.


----------



## MUGWUMP (Jan 29, 2012)

quality_sound said:


> If you get really drunk again and wanna sell it cheap I'd like to try it out and see how it works.


Not likely, but I'll remember the offer if I change my mind 

At the rate I've been "testing" equipment I'll have a closet full of stuff in a few years so it should get plenty of use. 

Next up are 2 more Idmax12s to go from one ported to 3 IB. I'm sure I'll need a little more power for them at some point.


----------



## (s)AINT (Aug 5, 2010)

dietDrThunder said:


> I just grabbed my notes...you are correct in that I had the % wrong. Mine clipped at 58. The point is that one should not assume that the hu will output a clean signal at 100%.


I must be a total puss. I have a 600/4 on the C5s active (150w per tweeter/woofer) with gains all the way down and Ive never been over 52 ,unless it's something really old with zero compression, then I might go to 55


----------

