What order?

[iancollett6]

 So, I have an Ipod plugged into a usb powered interface that has some powered speakers plugged into that.
 The thing is that the Ipod has a volume control, the interface has an input volume control and a speakers output volume control and the speakers have a volume control.
 Thats 4 ways of turning the music up or down!  Is there any order in which this is done?
 Is it best to have the source (Ipod) turned right up and control it from the one of the other controls? Maybe it doesnt matter at all?..

[lazyfingers]

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[lazyfingers]

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[Bob]

Everything has some machine noise.  Sounds like white noise when it's amplified.

So if you want the purest sound, crank the volume up to 100% at the source.  That way the original sound (what you want) is as loud as it can get, and then there's the machine noise that goes along with that.

At the next step, the signal you want and that noise will get a boost.  Plus whatever noise gets added at the second step, if there is one.  So crank that up as high as it will go too.

At the last step, the speaker, that's where you would turn it down.   Along the way, the original sound is kept as high as it can be, up until the very end.

Might look like this...
source -- Signal=100%, noise=10%
second step - Signal=100%, noise=10%from source, 5% from second step
speakers -- Signal=100%, noise=10%from source, 5% from 2nd step, 5% speakers.


The opposite/wrong way would be to adjust at the source..... Machine noise at the source would stay the same, but you would have less of the sound signal you want.  Say 50% signal  and still 10% noise.   At the second step you crank all that up a bit, say 60% signal now and now 20% noise.  Then again at the end, 70% signal, 30% noise.  You end up emphasizing the noise in the system that way.


So if it's an iPod plugged into a computer... Max out the volume on the iPod.  If the speakers have volume, crank up the volume on the computer and adjust from the speakers.  Otherwise, adjust the speaker volume at the computer.


Everything has some kind of noise.  Once you start amplifying things, you'll be able to hear it.  Each step of a system adds some noise.  So it's good to have everything on the same level of quality -- If you've got high end for every except one step, that one step of lower quality determines the overall quality.  It will lower the quality of what gets spit out of it, at whatever step in the process that is.  In that case, high end in other places really doesn't matter.  Garbage in, garbage out.  Money wasted.


Watch out for unplugging things if you set it up for the best sound.  Haha.  If the source is cranked up to 100% and then it gets unplugged it can damage its own little speakers.


All that is if you want the purest sound possible, to get the best signal and least amount of noise.  Realistically if you set it up for other people, they might not want to adjust the volume at the last step -- adjust at the speaker across the room if they have volume controls on the source right in front of them?  Or they might not get the whole concept... until they hear the noise amplified for themselves.

[iancollett6]

Thanks for that Bob! Very informative.