Amp Install

FreeWilly!

FreeWilly!

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Mar 27, 2012
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:banghead:

The fucking four channel goes into safe mode! Help me fix it!



I have 2 amps in my truck right now and the 4 channel amp is producing an annoying amp whine, I paid to have the amp installed but I was wondering if there is a how to that we could put together to help me re-wire and to help others out. :thumbsup:



My system specs:

Kenwood DDX512 HU
Infinity Kappa Perfect 6.5 Components
Infinity Kappa 2 way 6.5 Coaxials
Kicker 10s
Alpine PDX 4.100
Alpine MRPM1000


Sorry for the mess.
 
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I think I figured out my amp issue, the ground seemed like it worked itself loose.


But I do have another question, my 4 channel amp is an Alpine PDX 4.100 and if I have the stereo up past 3/4 volume the sound will stop ( I guess this is the amp going into safe mode?) why does it do this and what can I do to fix it? The subs will continue playing though even though the 4 channel cutout.
 
Amp probably just get too hot or the ohms are messed up on it causing it to go into "safemode".
 
sounds like gain which is causing clipping. You need to take your amp somewhere that knows what they are doing and have your levels set, or buy a smd dd-1 and do it yourself, but either way it needs to be done. and use a bolt with threadlock for a ground point not a self taping sheet metal screw...
 
Cheeny23 said:
sounds like gain which is causing clipping. You need to take your amp somewhere that knows what they are doing and have your levels set, or buy a smd dd-1 and do it yourself, but either way it needs to be done. and use a bolt with threadlock for a ground point not a self taping sheet metal screw...
Click to expand...

I have changed out the ground bolt put some thread lock on too. The amp gains are set right now at just above the halfway point. What's a good rule of thumb when it comes to setting the gains and other settings on the amp.
 
my quoting isnt working but what blome said is pretty correct. i usually use 3/4 as my fraction. you dont want to ever turn your hu up past the 3/4 volume mark ever.

there is a little math involved if you want to do it right. you need a digital multimeter and a cd with test tones on it. the equation for setting your gain is:

voltage = sqrt(rmspower* speaker impedance)

after you calculate this, write the number down as you will need it to set your gains.




what you want to do is set your hu the way you want it as far as the equalizer goes and all other settings(if you are using a different sound processor or an external eq, set those too)

put the test tone cd in your car, turn car on (obviously), and disconnect the speakers from the amp. put the hu to the 3/4 volume with all your settings as stated above. insert the multimeter leads in the amp outputs and play a 1kHz test tone. adjust the gain of the amp until the readout on your multimeter matches the number you calculated with the equation above. double check your math too.


i like using an o-scope (oscilloscope) over a multimeter since you can actually see where the amp clips and set it to its absolute maximum.


i'll do a how to write up on it later so more people can see it.
 
Cheeny23 said:
my quoting isnt working but what blome said is pretty correct. i usually use 3/4 as my fraction. you dont want to ever turn your hu up past the 3/4 volume mark ever.

there is a little math involved if you want to do it right. you need a digital multimeter and a cd with test tones on it. the equation for setting your gain is:

voltage = sqrt(rmspower* speaker impedance)

after you calculate this, write the number down as you will need it to set your gains.




what you want to do is set your hu the way you want it as far as the equalizer goes and all other settings(if you are using a different sound processor or an external eq, set those too)

put the test tone cd in your car, turn car on (obviously), and disconnect the speakers from the amp. put the hu to the 3/4 volume with all your settings as stated above. insert the multimeter leads in the amp outputs and play a 1kHz test tone. adjust the gain of the amp until the readout on your multimeter matches the number you calculated with the equation above. double check your math too.


i like using an o-scope (oscilloscope) over a multimeter since you can actually see where the amp clips and set it to its absolute maximum.


i'll do a how to write up on it later so more people can see it.
Click to expand...
For the rms do I multiply by 2 since I have 2 speakers per channel or just take the single rms. the rms for my components is 100 watts rms, does that mean my front channel can handle 200 watts? I'm willin to take the time to do this right so I appreciate your help.
 
take the 400 rms and that number divided by 4. you have 2 gain controls on the amp( 1 for 1&2 and 1 fr 3&4) so if you set one to say 20v, each channel controlled by that will get the amount of gain you specify.
 
Cheeny23 said:
take the 400 rms and that number divided by 4. you have 2 gain controls on the amp( 1 for 1&2 and 1 fr 3&4) so if you set one to say 20v, each channel controlled by that will get the amount of gain you specify.
Click to expand...

So to calculate my front channel I need to take the rms of the pair which would be 200 watts and then muliply that by The impedence of the front two which is 3 ohms, does that need to be 6 ohms since its 3 per speaker? Then on my multimeter do I measure the ohms or the voltage that I would get from multiplying the rms by the ohms? Am I making this way more complicated?
 
you want the rms power of the amp. do it per channel. whats the model number of your speakers, bc i found the kappa perfect 6.1 6.5" component set and it said 4 ohm not 3.
 
Cheeny23 said:
you want the rms power of the amp. do it per channel. whats the model number of your speakers, bc i found the kappa perfect 6.1 6.5" component set and it said 4 ohm not 3.
Click to expand...

The speakers are infinity kappa perfect 6.1 6.5 components and the rears are the infinity coaxials 62.9i. The amp is an Alpine pdx 4.100. I really appreciate the help man.
 
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