Two quick MSP questions


    Jun 22 2011 | 5:33 am
    1. What is the best way to convert stereo into mono? I just drag them both into a "*~ 1." which seems to do the trick but I feel like thats not how it should work and I'm just sorta forcing the two together incorrectly. (See example below)
    2. What is the best way to turn a signal into the float/decimal of its volume. Currently I have it go into a "meter~" then taking connecting to the output of that. But if the meter won't be seen, isn't it just wasted CPU displaying it?
    Here is an example showing my two questions:

    • Jun 22 2011 | 5:42 am
      1. is perfectly OK-- it's the same as using a [+~] object
      2. depends on what you want to do, but a more efficient way would be to use [snapshot~], where you can change the polling interval and not have a UI display. You might want to also look at [average~] also
      T
    • Jun 22 2011 | 5:45 am
      Thanks so much for the help!
    • Jun 22 2011 | 6:29 am
      Hmmm after doing some testing, using the meter~ seems to work better results-wise. I'm having trouble getting snapshot~ to match it. If I set snapshot to 50 ms just as meter, it tends to be a lot shakier, I'm not sure if this has to do with not converting snapshot over the decibel system or what.
    • Jun 22 2011 | 7:42 am
      Ok so I've found that peakamp~ is the best replacement for meter~. It seems to put out the exact same results.
    • Jun 22 2011 | 4:58 pm
      The best envelope follower I know of in Max/MSP is also one of the most expensive, from a CPU cycle POV: Miller Puckette's fiddle~
    • Jun 23 2011 | 12:35 am
      To calculate the envelope I use the standard RMS definition and it just works fine:
      . square root of the signal (use *~ with the same signal at both inlets) . first-order low-pass filter with a time constant between 20ms and 200ms the latter roughly corresponds to the VU-meter standard) . snapshot~ with a period equal to a third or a half of the time constant . atodb to output the result in dB . / 2. to do the square root in the dB domain
      Alexis
    • Jul 15 2011 | 7:55 am
      @ codysherman
      how can I download the patches written like yours in this forum?
      (sorry but I m new in this forum)
    • Jul 15 2011 | 3:18 pm
      [meter~] indeed needs CPU even if not seen, but [snapshot~] is also not cost-free.
      i always use a meter~ object and downsample it using [poly~ mymeterpatch~ down 8]
      and 50 ms is just fine for a GUI.
      about "to mono" ... you add signals in msp by just running them in the same input - whereever. so +~ is a waste. try with dac~.
    • Jul 16 2011 | 9:00 am
      halflifebe Copy everything inc' the footer and the header like the example above and in max in the toolbar > file > copy from clipboard.