setting gains
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=104033
Printed Date: April 29, 2024 at 1:02 AM
Topic: setting gains
Posted By: chaos420
Subject: setting gains
Date Posted: April 16, 2008 at 11:26 AM
I'm trying to set my gains on an alpine pdx 4.100 amp. I used a test tone at a couple of different frequencies, 1000 and 600 for my front speakers. The speakers are all 4 ohm, rms of the amp is 100x4. So if i'm reading this forum right using my meter, the proper reading should be at 20V AC out of the amp. sq. root of (watts x ohms)= 20. Problem is the highest reading I get about 12V. Am I doing this wrong?
Replies:
Posted By: sedate
Date Posted: April 16, 2008 at 12:16 PM
With your head unit turned all the way up and your gain turned all the way up you can only get 12v AC out of your amp? That sounds - uhh - odd. I dunno PDX amps - but maybe you tripped a "high voltage" switch on the input of the amp?
Posted By: chaos420
Date Posted: April 19, 2008 at 1:05 PM
The problem is, i'm using a computer as my source, and after thing about it for a while it became obvious that my onboard sound is just not powerful enough.
Posted By: DYohn
Date Posted: April 19, 2008 at 4:12 PM
Try a line driver like a PIE LD-1 between your computer sound card and the amp. That particular model will get you up to +18db gain.
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Posted By: haemphyst
Date Posted: April 19, 2008 at 9:25 PM
Ahhh... but if your meter ISN'T a true RMS meter you could be perfectly within range!
Even most true RMS meters cannot accurately read 600Hz, that's 10 times higher than the meter might have been designed for! Check with the manual of your meter, and see if it has any suggestions for reading higher frequencies like that.
Either that, or see if you can lay hands on an o-scope. I bet you're OK, or at least pretty close to it!
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: chaos420
Date Posted: April 21, 2008 at 12:26 AM
I think the meter is fine. I used it with another system and it read as high as 80v ac.
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