Topic: How to interprete this display?
Hey everyone!
Please assist me interpreting the following readout. It's a byeffect of using Logic Pro 8's "Gain" Utility (it does not happen with Ableton Live's "Gain" Utility).
What I wonder about is: Is this DC? And if it is how can I identify it as such when DigiCheck makes no difference in its display? Maybe it would help if DigiCheck would color the 25 Hz bar in another color or lid an extra LED when DC is identified!?
Here is a screenshot demonstrating how a seemingly *empty* frequency spectrum produces ongoing +5.5 dB overs. I don't know what this would do to speakers or amplifiers, but I know that this setting shots down the OS X Realtek driver which needs a reboot to be repaired.
RME's DigiCheck is able to identify the signal in its 25 Hz spectrum, likely because DigiCheck includes DC in its 25 Hz bar (routed the Fireface's output back to its inputs in order to get a reading on OS X).
By the way, this example shows a 200 dB gain-boost of a supposely *not existing* signal, namely the cancellation/inversion of two tracks. Why does it not cancel to 0 then? Because at *one* point of the signal chain there were +1 dB -1 dB gain applied!
Off course no one would hear the remaining artefacts anyway, but what about the crazy low frequency noise (DC?) there? Does it matter to you when you pump it out of a live PA system without any filter in between? Frankly, I lack experience with these matters.