- Nov 12, 2014
You can(and should) leave the volume up around 80% on your Mac Book Pro and use the Magni's volume control to reach your listening level. This will assure that you get maximum dynamic range. However, it will drain your battery faster.
For sources like portable players, car stereos, mixing boards, and anything else that has gain greater than 1.0, setting the output level to 75% is normal advice, and it's a good place to start. It will normally keep your source from clipping which makes nasty noises when it happens.
But for computers, this advice is incorrect. Computers generally do not have gain built in to their drivers. So setting system volume controls to 100% normally just results in a passthrough of the sound. No gain is applied and the signal is not reduced. It just goes through as is.
I've tested this on my Macbook Pro by producing a full scale sine wave at 220Hz and playing it back from Audacity and JRiver. Both played back a pure unaltered tone. To test further, I amplified this full scale signal by a litle more than 1 dB, which produced clipping that I could see in the waveform. Then I played it and it sounded "funny". like two tones. Because it was relatively severely clipped.
Note that the system volume and volumes of the media players were set to full for this entire test.
So, for the MBP, and every other computer I've experimented with, you can set the system volume to 100% and get a full signal with no clipping and no alteration or digital reduction. Digital reduction *can* introduce sonic problems in some operating systems. I like to have it at 100% as much as possible to eliminate any potential problems.