Jump to content
Please note: You can easily log in to MPN using your Facebook account!

Programming synths or mixes in dB's


Theo Verelst

Recommended Posts

Strange thing when adding signals you've characterized the volume of in dBs: the result is hard to express in decibels. Well, it's a Maxima (or Mathematica TM) formula of one line, but it's not very intuitive.

If we take the same signal coming to trough 2 amplifications doing 0 dB and -6dB in parallel and then added together gives after summing about +3.6 dB.

 

8 channels added (linearly mixed) in parallel, each uncorrelated noise of -80 dB gives -71dB (IIRC),

 

whereas the same with exactly the same signals (noise or other) gives a total summed signal of -80+18=-62 dB.

 

Sometimes it can be inportant in a feedback circuit for instance to consider changing one of two signals of almost the same amplitudeby a small amount. Say we subtract two signals of +10dB, on a mixer that can happen if you send the same signals to two strips, but you exchange the the phase and counter phase wires of the balanced inputs. The result would clearly be no signal in the mix. However if we have a 10% error in the gain settings of the strips, one signal is off by roughly 1dB, and the mix buss meter will say that the resulting addition is a signal of about -20+10= -10 dB.

 

I've worked on compensating synthesis signal paths, fot instance as a side chain effect, so there's the relevance. Gets even more "fun" when considering normalization and the dB accuracy in the various signal paths...

 

T

Link to comment
Share on other sites

  • Replies 0
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...