assistance please

[jco1385 5,000+ posts]

im setting my gain w/ DMM. i set all HU settings to 0 and all knobs on the amp down. i'm looking for 46.9v, but even with the gain all the way up i only get ~10v. wtf is the deal?

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[luvinthebass 5,000+ posts]

does ur head unit have a sub level adjustment?

 

[jco1385 5,000+ posts]

yeah, -14 to 14 i think. it's at 0

 

[WulfComp 10+ year member]

Volume on the HU should be about 3/4 up

 

[luvinthebass 5,000+ posts]

put it to 14 then set ur gain again, you'll hit ur target voltage

 

[jco1385 5,000+ posts]

ok, volume was 30/40. so turn the sub setting all the way up? thought it had to be 0...

trying that now.

 

[WulfComp 10+ year member]

what do you have the LP filter set to on the amp and HU? do you have it set to full on the HU or using it to limit freq?

what freq are you using to test with?

 

[jco1385 5,000+ posts]

done. thanks. but why does the voltage jump around so much? i had a 36hz tone at 30/40 vol. and i wasn't getting a constant number. it would jump around a lot. i just set it to where the max was closest to my target. any advice, or is this normal?

 

[tsenfw 10+ year member]

What's your HU sub gain set to now dude? Also, how far up is your gain turned?

 

[jco1385 5,000+ posts]

it goes from +7 to -7. when i turned it up to +7 i got the volts i was looking for, but not a constant number. maybe the 15sec track was too short? i dunno, but there was a lot of jumping around. i'm gonna re-do this tomorrow when it's not freezing outside. i figured that my box is tuned to 38hz, so 36hz was the closest i saw.

 

[jco1385 5,000+ posts]

also, i have the EQ and FREQ knobs on my amp all the way down. even with that, my gain is ~95% up.

 

[jblayz1 10+ year member]

set you HU volume to 30/40. turn your sub volume up all the way 14/14. if you're setting gains for your sub amp use a 45hz-50hz test tone. remember to disconnect your sub wires off the amp. leave the rca's on. EQ off. if you have a defeat on/off use that and set it to on. if your amp has bast boost turn that all the way down. play test tone and set the gain to the voltage desired.

 

[luvinthebass 5,000+ posts]

use a 50 or 60 hz test tone, i'm guessin with that 36 hz tone ur dmm is prollynot as accurate and that's why ur gain is near the end, most dmm's if ya got one for like $15 is most accurate at 60 hz with a 50 or 60 hz it will prolly be half way on ur gain

 

[jco1385 5,000+ posts]

i got this DMM: ~$60

http://www.greenlee.com/product/DM-60.html

i'll use the 50hz tomorrow when i redo it.

 

[DejaWiz 5,000+ posts]

Few things to look out for.

Keep the Install Setting sheet for your amp handy.

1. You might want to see if changing to the 10x setting for input sensitivity helps (your HU has a 2vrms, 5v peak RCO output rating).
   
2. Set the gain to MIN.
   
3. Amp EQ boost to 0dB (completely counterclockwise is -12dB... you don't want that).
   
4. Amp LP XO set to around 75-80Hz (or a little lower, if you need).
   
5. Having the SSF on probably wouldn't be a bad idea.
   
6. Disconnect the sub from the amp.
   
7. Start your car and let it run so the electrical gets full voltage.
   
8. Play a 50Hz, 0dB test tone at 3/4 HU volume.
   
9. Your target output voltage is 44.7V

Hopefully this does the trick!