Channel EQ raising level on Master Channel when rolling off

Hi There

 

I have noticed a problem on my master channel when loading logic's factory default channel EQ.

 

If I pull in a mastered track and play it back, the levels don't go above 0db which is correct as the file has been limited. I then load channel EQ onto the master channel and all is fine and remains at 0db BUT as soon as I start to roll-off the bottom end at about 50hz onwards, the master channel level suddenly shoots up above 0db.

 

Why is the level increasing when simply rolling off the low end?

 

There are no boosts on the graph and the channel EQ overall gain has remained untouched - at 0db. Am I missing something?

 

Thank you

How do you roll it off - with the shelving band or the high pass?

If it's the shelving band: even a minimally raised Q will result in a boost.

No I am rolling off using the high pass filter. Making sure the Q is below 1.00. By default the high pass Q is set to 0.71. Even after lowering the Q to its lowest value of 0.10 we still have the same problem with level exceeding 0db on the master channel.

Although it goes against intuition, it is quite common to get gain boosts sometimes when cutting EQ.

 

For instance, if you have two signals which are to some degree phase cancelling, the rolling off those frequencies from one part means it no longer cancels out the previous frequencies, and so the result parts reinforce and get louder.

Thank you for the information. We were testing this using some library music which seems to show quite an increase in level. We then compared that to some of our own mixes and there is still an increase but not as drastic.

 

The information you have given us makes sense and we now understand what is going on.

 

Thanks again