Home› AMX User Forum› AMX General Discussion

Converting TP levels to AutoPatch db volumes

PyroGuyPyroGuy Posts: 121
in AMX General Discussion
Good day...

I need to determine the best way to translate a level value generated on an AMX touch panel (in this case AXT-CV12) which is tracking a volume level of 0% to 100% and convert it to the ABSOLUTE value that AP switcher is expecting. I need to be able to send that db volume (-70 to +10) to the switcher in an RS232 string.

I can only guess that there are other swithers that work in this fashion - my experience is limited to the previous AMX PLB-AS16 which let me send a level directly to it)

What is the best math to figure it out?

Hope I am not violating any protocols by posting here (as well as AP Forum) The AP forum doesn't get much traffic - yet) This one seems to have ALL of the answers.

Thanks!

Comments

  • NMarkRobertsNMarkRoberts Posts: 455
    If you type "volume conversion" into the handy dandy search tool just up there ^^^ the first hit (from just a few weeks ago) will tell you everything you need to know.

    I would guess that most folk here watch all of the fora so posting the same request in two places is redundant.
  • PyroGuyPyroGuy Posts: 121
    Thanks - I thought that most posts would be watched but wasn't sure. I'm fairly new to using the forum so still learning it's characteristics.

    The thread you noted is close (covers the AMX side of the problem) but not quite what I need.

    The problem is matching up the level value - be it 0 to 100 or 0 to 255 with a decibel range on an audio router that works in dB. It swings from -70 to +10. There must be a calculation formula for such a conversion, but my math head seems to be on holidays.

    Cheers!
  • DHawthorneDHawthorne Posts: 4,584
    Autopatch to level (where db = Autopatch volume, nVol = level value):

    (db + 70) * 1.25 = nVol for a level scale of 0-100.
    (db + 70) * 3.1875 = nVol for a level scale of 0-255.

    Level to Autopatch:

    (nVol / 1.25) - 70 = db for level scale 0-100
    (nVol / 3.1875) - 70 = db for level scale 0-255
  • PyroGuyPyroGuy Posts: 121
    Thanks Dave!

    I am on my way to the site so your timing is perfect. I'll give it a shot!

    Cheers!
  • yuriyuri Posts: 861
    actually, you send out '-100' and '700' so a multiply by ten is needed ;)
  • NMarkRobertsNMarkRoberts Posts: 455
    Try this thread for a range including negative values

    http://amxforums.com/showthread.php?t=3017
Sign In or Register to comment.