Tell me if I am setting the gain correctly

[CrAiZ3 10+ year member]

Hello everyone,

I just wanted to explain how I set the gain on my amp with a multi-meter and have someone tell me if I'm missing something. I've done this a bunch of times but something unusual happened this time.

I did the normal:

• All speaker wires disconnected
  
• Amp gain all the way down
  
• Bass boost all the way down
  
• Subsonic all the way down
  
• LP all the way up
  
• Calculated my voltage to be 34v. Amp is 1150rms with a 1ohm load
  

When I was ready to go, I played a 50hz test tone @ 3/4 volume of my HU. For clarification my multi-meter is a Craftsman model #82141 and was set on Vac 200. Now, here is the weird thing that I've never encountered before when setting the gain on an amp. I turned the gain all the way up and only hit ~26v, when my target was 34v. I had to add bass boost to get a reading of 34v on my multi-meter. I hooked the subs back up and did a test run at 1/2 volume and didn't notice any distortion with the bass boost. Now I don't know if this makes any difference, but I have a brand new car so I wanted to keep my factory HU and am using a Lineout converter with the settings relatively low.

Any advice would be greatly appreciated.

Thanks!

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[CSCStang]

So you don't have a separate sub level control? Where's the loc set at?

 

[CrAiZ3 10+ year member]

So you don't have a separate sub level control? Where's the loc set at?

Nope, just the HU settings for bass which is at 0.

Honestly, I can't remember what the LOC is set at, and if I didn't have to rip my dash apart to get to it I'd tell you.

 

[AudiOn19s]

What was the output of the amp with everything set to low?

I've been trying to research this issue as well in a similar situation. Do you know what your max output is of the head unit, or the max input of the amp coming from the head unit? IF so I think you need to tweak the LOC until you have that level at the amp with gain all the way down before going through the gain setting process.

Please do not take this as the ultimate answer only a suggestion, this is what I gathered from several threads here trying to understand how to properly set gains when having levels on both the LOC and the amp. I too am still in the middle of this process trying to make sure I don't send too much or clipped signals to my new sub.