Setting HU to Max Pre Out?

[bgowdy 5,000+ posts]

I dont have a oscope so dont say use a scope lol.... So this may be a noob question. I have been looking but get inconsistent info. Im trying to figure out how to set HU to give the full preout volts(or close to).

I know to keep the "loud" setting turned off, and bass boost flat on HU, mine technically doesnt have a Bass Boost setting but has low/mid/hi settings with a seperate setting for Sub-output so i just keep the "low" setting flat.

So my Sony HU has a 2V pre out, and idk how i should set my subwoofer output setting. I read some people say max out the subwoofer output and but dont go over 3\4 of the max volume and some say other wise.

So can anyone shed some on light on the correct way.

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[gimling]

Do you have a multimeter?? you can get one for 5.99 at harbor freight, that is your best bet, that way you can measure if its truly 2v and go from there, if you can give me the brand and model and u dont want to get a multimeter i can help you from there.

 

[93_Az_TransAm 10+ year member]

Test it with a Scope... Lol jp im curious about this as well because i dont see why you set everything up with a meter or scope with the head unit flat then trun the head unit up wouldnt you need to have the head unit set how you will have it first?

And Op like Gimling said a DMM (Digital Multi Meter) is a simple way to test everything in your audio system

 

[bgowdy 5,000+ posts]

Do you have a multimeter?? you can get one for 5.99 at harbor freight, that is your best bet, that way you can measure if its truly 2v and go from there, if you can give me the brand and model and u dont want to get a multimeter i can help you from there.

yes i have one, but how would that tell what my preouts are on my player. Im not looking to set my amp if thats what you mean by using a multimeter

 

[gimling]

No you can put a 1khz tone through your headunit and measure the DC voltace on the rca line. on an aftermarket headunit you dont want to go all the way up, depending on the quality there is a clipping point, thats what the oscope is for, if you only have a meter its not quite as accurate of a measurement so you want to go say 3-5 notches below max then take your reading on the rca line

 

[93_Az_TransAm 10+ year member]

Im pretty sure you could set it to volts then with your head unit on test your rca jacks

 

[bgowdy 5,000+ posts]

Im pretty sure you could set it to volts then with your head unit on test your rca jacks

hm i guess, i just didnt see anyone sat they used one from what ive read

 

[gimling]

what amp and speakers are you wanting to set??

 

[93_Az_TransAm 10+ year member]

hm i guess, i just didnt see anyone sat they used one from what ive read

Im not completely sure since ive never tested one before but im guessing yours should read 2v or around there

 

[fly_marlin]

The pre-out voltage you see (2V in your case) is a max rating. The actual voltage that comes out from the pre-outs is dynamic and dependent on the frequency and volume. You should be able to set your amp to 2V input. If it sounds like too much, you can turn it down from there. You can also turn up/down the subwoofer level on your HU as desired.

 

[gimling]

Yes it is max rating its why you dont want to set wrong on the amp to keep it from clipping, here is the easiest way to set your gain, record a 60hz tone. disconnect the speakers, turn amp gain all the way down, subsonic all the way down, bass boost all the way down, LPF all the way up. turn your headunit to withing 4-5 of max. play the tone, put the multimeter to AC put it on the output of the amp where u disconnected the speakers, USE OHMS law to find out what voltage you need, IE if your Amp is rated at 1000watts rms at 1ohm use this formula, Voltage = square root of watts X's Resistance. so square root of 1000 X's 1 = 31.622 Volts. so push play on your cd player at that level within 4-5 of max turn up the gain till the meter reads 31.622 VAC.

 

[bgowdy 5,000+ posts]

Im not completely sure since ive never tested one before but im guessing yours should read 2v or around there

me either i have alsways set mine with the sub output flat and stay under 3/4 volume

 

---------- Post added at 08:33 PM ---------- Previous post was at 08:32 PM ----------

 

what amp and speakers are you wanting to set??

not setting amp, just trying to set HU correct. i know how to set the amp, well as good i as know with out a scope

 

[93_Az_TransAm 10+ year member]

me either i have alsways set mine with the sub output flat and stay under 3/4 volume

Ive read online a couple places that some headunits with the sub eq settings if its not turnd up to the highest lets say +15db then the pre outs wont be supplying the full rated voltage

 

[gimling]

The pre-out voltage you see (2V in your case) is a max rating. The actual voltage that comes out from the pre-outs is dynamic and dependent on the frequency and volume. You should be able to set your amp to 2V input. If it sounds like too much, you can turn it down from there. You can also turn up/down the subwoofer level on your HU as desired.

then what he said ^^^^^

 

[93_Az_TransAm 10+ year member]

Dang i completely missed that post lol that gives me a little more useful info lol