Laptop to detect clipping?

[riceboy319 10+ year member]

I have a factory HU to a LOC. i was wondering if it would be possible to play a test tone on the HU say 50Hz and record it from the RCAs using a 3.5mm jack converter and plugging it into the MIC of the laptop. if i the sine wave starts looking deformed ill be able to tell its clipping and stay a few lvls below that since this might not be so accurate. i tested a MP3 player and found when the recording starts to get deformed. tomorrow im going to test how close this method came out by using an oscilloscope.

if this method works, does it mean i could do the same off a 1000watt amplifiers speaker out + and -? could a 1Meg pot be used to scale the high voltage (30Vish) down to a lower one (like 2V) solder to a 3.5mm jack and do the same thing?

I think theres a flaw in this plan somewhere...

small update i guess... I just got back from testing the mp3 player (actually played a wav file test tone). 0dB 50Hz and detected the clipping right away on the Oscope and turned out to be the exact same volume that was found using the recorder. Now the only thing i have left is to test if a cheap sound card in my laptop can record it since my desktop has a fairly good one. Also spoonraker did make an interesting point so i tested scaling the signal as well. this mp3 player outputs about a .4V signal so with a 1Meg pot and scaling it down the signal could still be read and the clipped signal could be detected way down till the noise in the measurement was too much so i need to test this more i guess.

while searching around a bit i found that theres a lot of software for this sound card/oscope thing so i guess that ends my posts.

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[spoonraker 10+ year member]

It seems to me like amplifying a signal, and then doing the exact opposite process would potentially skew the results

 

[Kriszilla 10+ year member]

Simply playing it back won't tell you anything. You need to look at the electrical signal with an o-scope.

 

[newusername 10+ year member]

The general concept works. You play a sine wave of a given frequency, look at the signal output, and note the odd order harmonics. Do this a few times, decreasing the gain between each, and you should eventually be able to set your gain in the exact same way you would with a oscilloscope.

 

[spoonraker 10+ year member]

What kind of software are you using to accomplish this?

 

[Lakota 5,000+ posts]

Set your gain with a termlab

 

[riceboy319 10+ year member]

updated

Simply playing it back won't tell you anything. You need to look at the electrical signal with an o-scope.

i dunno what to say to this

What kind of software are you using to accomplish this?

nothing special just an old sound recording program called cool edit but i think they were bought out by adobe or something.

Set your gain with a termlab

i wish i had one :[