• ### Is there something wrong with the construction of this patch?

Hi I just started yesterday night late to investigate in Pure Data, but Im not sure if the audio signal sumatory is adding or just passing only one signal?

I hear 2 signals but as the right inlet is dominant?

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• @an123 It's fine..... nearly.
The [+~ ] is summing its 2 inlets.
All audio inlets sum signals from audio cords..... so technically you don't need the [+~]...... you could send both the signals straight into the left inlet of [* ~]
However 0.011Hz is nearly a DC (direct current) signal so you cannot really hear it.
You will be hearing the 240Hz signal modulated very slowly, and mixing 2 sine waves can create beating, but also changes of perception........ try this...... perception.zip
There is no difference between the left and right inlets of [+~] unless you give it an argument e.g.[+~ 5] (see the help file for what happens when you do that).

When I say "fine.... nearly" it is because I have seen [6( as a number into the right inlet of [*~].
All audio at the final output from Pd should be in the range 0-1... so it is a bad idea to send a value of plus or minus 6 into [dac~].
Distortion is usually the result when you do that, but with that 0.011Hz signal you could overload the soundcard so that you hear nothing at all for most of its cycle..
David.

• OK, thanks, I understand now.

• @an123 Just thought I would add a little....
Because you are adding 2 sources, 0.5 would be a good value for [*~ 0]....
Each oscillator will output a waveform from +1 to -1 so the maximum summed values when their phases are aligned will be +2 and -2.
Multiplying by 0.5 brings the signal back in range.
Of course that will produce maximum volume..... so 0.1 or 0.25 might be preferable.
Maybe put a slider with a range of 0 to 0.5 connected to the right inlet of [*~ 0] as a volume control?

Also, DC is bad for speakers..... pushing the speaker to the front or back and holding it there means that there is maximum current but no movement of cooling air around the coil..... and you can burn out the coil very quickly (in seconds).
Some amplifiers have DC protection built-in...... some not.... I don't take the risk as it is expensive and can put an unscheduled end to a show.
So adding a high pass filter before [dac~] is always a good idea.
You cannot hear very low frequencies anyway, only feel them, so with headphones they are pointless.
A [hip~ 5] before [dac~] will protect your speakers without affecting what you hear.
David.

Posts 4 | Views 1113
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