Gain setting problems

[transamfan 10+ year member]

I have Pioneer DEH-P980BT head unit with 5V preouts, Boston Pro 60 components, and a Kicker SX700.4 amp.

I used a 1khz test tone at 0dB for my measurements. Turned eq to flat, volume to 45/62...etc.

The components are rated for 125 RMS and they are a 3 ohm load.

The amp puts out 82 watts per channel at 4 ohm and 163 per channel at 2 ohm, so I was shooting for 120 watts at 3 ohm, or a target voltage of 18.9V.

What I was able to measure was:

1) voltage of RCAs at the amp was only .5V

2) I was only able to get about 14V per channel with gain maxed out, not anywhere close to my target voltage of 18.9.

3) The amp was seeing 14.3V

What's the problem with my numbers? This is my first time trying to correctly set my gains, so I know I have probably done something wrong. My guess is some setting either on the amp or head unit (both are new to me and pretty technical). I am supposed to unhook speakers and measure with no impedence load on the amp, correct? At first I thought I would be able to set the impedence with my multimeter (a high dollar simpson 260) to simulate the 3 ohm load the amp would be seeing but this is not possible. Someone set me straight please.

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[endofdays89 5,000+ posts]

I have Pioneer DEH-P980BT head unit with 5V preouts, Boston Pro 60 components, and a Kicker SX700.4 amp.
I used a 1khz test tone at 0dB for my measurements. Turned eq to flat, volume to 45/62...etc.

The components are rated for 125 RMS and they are a 3 ohm load.

The amp puts out 82 watts per channel at 4 ohm and 163 per channel at 2 ohm, so I was shooting for 120 watts at 3 ohm, or a target voltage of 18.9V.

What I was able to measure was:

1) voltage of RCAs at the amp was only .5V

2) I was only able to get about 14V per channel with gain maxed out, not anywhere close to my target voltage of 18.9.

3) The amp was seeing 14.3V

What's the problem with my numbers? This is my first time trying to correctly set my gains, so I know I have probably done something wrong. My guess is some setting either on the amp or head unit (both are new to me and pretty technical). I am supposed to unhook speakers and measure with no impedence load on the amp, correct? At first I thought I would be able to set the impedence with my multimeter (a high dollar simpson 260) to simulate the 3 ohm load the amp would be seeing but this is not possible. Someone set me straight please.

yes, unhook the speakers and measure only 1 channel at a time. You did unhook them right?

make sure your AC voltage is at 200

 

[FurbiesAndBeans 10+ year member]

try setting it with ur volume at 50 instead of 45. In my pioneer HU, the jump from 45 to 50 is a lot...

 

[endofdays89 5,000+ posts]

try setting it with ur volume at 50 instead of 45. In my pioneer HU, the jump from 45 to 50 is a lot...

Pioneers piss me off, do they clip at 50 or 46? Or something else?

 

[gunz4me 10+ year member]

oops, wrong thread... dang multiple tabs open

 

[transamfan 10+ year member]

Yes, I did unhook the speakers when I tested it. I will try turning up the volume, that was one thing that I thought about late last night that I could try. Isn't .5V on the RCAs low? I had the meter set right, and I read it right, so I am sure that it was .5V.

 

[transamfan 10+ year member]

I fixed the problem. The sx700.4 amp has a digital screen through which you make all of your adjustments. I didn't know that within the main menu there was a setting for input votage range of the RCAs. I had to adjust this down to the voltage input of my RCAs which was around 2V with the volume turned up to 85% or so.