I used a PC oscilloscope and mic to set the gains on my amp yesterday.



My wave form looked like that, so I ran a sweep and made sure it wasn't doing that at any frequencies.

Is that clipping though? Or just a problem with the way I'm doing it? I had it set up to the sqrt(RMS*ohms) voltage before, and this SHOULD be the RMS, but it is a lot quieter. (Mind you, it sounds better)

Yes, your wave should be clean top and bottom.

While thats not a tradition form of clipping, it is doing something to the signal. was the pc oscope operated from a mic?

They arent very accurate, because the mic will distort at low volumes.



Elemental Designs
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alexl@edesignaudio.com
Warehouse Manager

Yeah, it was just some unidirectional mic. Rated at 60hz +, but I managed to see the sines at about 15. (With a fair amount of background noise, the car was running)

Oh, it's coming from a mic, my bad, I thought it had leads.

i'd try it again when the outside noise is quiet and the car is off


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Do you have a capacitor? Try disconnecting it and doing this test again. The shape of the that wave looks almost exactly like a discharge wave from a charged capacitor.

Nope, no capacitor, straight from the battery to the amp.

And sndsgood, I would do it with the car off, but then I would be setting the gain at 12V instead of 14.4V

I'm going to try and get my hands on a plug-in battery charger so I can get a constant 14.4 with no noise.

duhhh your right lol


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I also had waveforms like this



That I assumed were clipping, even though they didn't have the typical "flat" head. Was I right there?

its clipping....you need to figure, a mic creates voltage by moving a tiny speaker back and fourth. much like a speaker takes power and moved back and fourth.

If the mic you are using, cant sustain high sound pressure levels, it will distort the signal, and give you the appearance of clipping, even when it isnt there.

just a thought.



Elemental Designs
Performance.Mobile.Audio.
alexl@edesignaudio.com
Warehouse Manager

Then would the solution just be to move the mic farther away?......

not really sure... im guessing the sound pressure levels a car can produce is going to be more than a stardard computer mic can handle...the solution is getting access to a real o scope...you can usually get them on ebay for around 75$



Elemental Designs
Performance.Mobile.Audio.
alexl@edesignaudio.com
Warehouse Manager