setting gain with ddm subwoofer setting h/u

[Xjeff]

ok so my friend was telling me the other day i should set my gain for my subwoofer with the subwoofer setting at the middle i.e 04/08 on my head unit and i've always set my gain with it at 08 or all the way max because i figured i wouldn't be clipping my sub even at my max volume so who's right? lol should i be setting my gain wit the subwoofer setting at the middle or the max setting? thanks in advance you guys always end up helping me

[BNolan12]

ok so my friend was telling me the other day i should set my gain for my subwoofer with the subwoofer setting at the middle i.e 04/08 on my head unit and i've always set my gain with it at 08 or all the way max because i figured i wouldn't be clipping my sub even at my max volume so who's right? lol should i be setting my gain wit the subwoofer setting at the middle or the max setting? thanks in advance you guys always end up helping me

I'm not sure if this answers your question but if you're talking about bass, EQ, treble, etc on the head unit. Those should be zeroed out or turned off when you tune with a DMM

[Xjeff]

its a subwoofer setting, 0 means its sending 0 voltage to my rcas and the higher i turn it up the more voltage it sends, up to 2v since thats all my headuntil says it will put out. its not a bass eq.

[itsblown]

It doesn't matter what your pre out voltage is set at on your head unit as long as the gain on your amplifier is matched to the RCA voltage its receiving. Bassically if you set the gain right it doesnt matter at what level you set it at. However some amplifiers are set up to handle higher voltage inputs and when you use a lower voltage head unit, like 2 volts and down, even with the gain set correctly there can be a white noise sound, even though the amp isnt clipping. So with your 2 volt head unit you probably want to set the gain with the pre out voltage turned as high as it can possibly go. The only problem is you dont know when your head unit starts clipping, so with the subwoofer pre out voltage at 8/8 you may already have a clipped signal.

I would play it safe and set your gain at 6/8 enless you have access to an o scope and can test where your head units max volume/ max subwoofer pre out level is before clipping.

[thorshammer1]

I wish people would quite suggesting setting gains with a dmm. Pointless, Stupid, and just dont fawking work.

[plugger]

I wish people would quite suggesting setting gains with a dmm. Pointless, Stupid, and just dont fawking work.

what???

how should I be doing it then? and no i dont have an o-scope or any other 100 dollar tools laying around

[thorshammer1]

In theory you can use a dmm to set output. i.e. acv x aca = watts. What people arent stating is that by doing this and using the manafacturers rating you are most definately putting it in full clip.

Just do it old skool. Set hu volume to 3/4 and slowly bring gain up on amp. Set lowpass to 80ish and ssf 5hz below your box tuning. I never and I repeat never run my sub output above half. Hell most of the time I barely touch it i.e. +1 or 2. Let the amp do the work.

[plugger]

slowly bring gain up on amp until what? thats how i did it at first and my gain was well over half now that i set it with a dmm its at like a quarter

[jungstah]

slowly bring gain up on amp until what? thats how i did it at first and my gain was well over half now that i set it with a dmm its at like a quarter

slowly bring it up til it sounds like azzz n back it down

[Xjeff]

ok, i've tired the by ear and i don't like it at all because you have no sense at how much power your sub is seeing and like the guy above said he did it by ear and the amp was over half way up but by ddm it was at a quarter. i can turn my amp to full gain by ear and it sounds fine to me but i know its clipping like a mofo and my only turn my hu to 3/4 max volume never higher which is 35/50. i've tired the voltage coming from my rca's on the back at 50/50 volume head unit and sub 8/8 it reads 2v so if i only ever play at 3/4 volume with the sub set to 8/8 its probably only seeing 1.5v but that's on a sine wave and not music. figured the bashing will continue but in this case using a ddm subwoofer lvl on hu middle or max? and i don't have the need to get a o scope (more bashing on how i'm going to kill my eqiupment ) but not everyone has the access to every tool ever made.

Edit: also wouldn't tuning by ear find the clipping point of the amp? and not the max power the sub can take? Because my amp says i does 1500rms but im sure its only reall 1200rms clean and only want to give my sa12 1000rms clean so i would be overpowering my sub before i reach clipping on my amp? or the speaker distorts with too much power?

[Humansville]

ok, i've tired the by ear and i don't like it at all because you have no sense at how much power your sub is seeing and like the guy above said he did it by ear and the amp was over half way up but by ddm it was at a quarter. i can turn my amp to full gain by ear and it sounds fine to me but i know its clipping like a mofo and my only turn my hu to 3/4 max volume never higher which is 35/50. i've tired the voltage coming from my rca's on the back at 50/50 volume head unit and sub 8/8 it reads 2v so if i only ever play at 3/4 volume with the sub set to 8/8 its probably only seeing 1.5v but that's on a sine wave and not music. figured the bashing will continue but in this case using a ddm subwoofer lvl on hu middle or max? and i don't have the need to get a o scope (more bashing on how i'm going to kill my eqiupment ) but not everyone has the access to every tool ever made.

Edit: also wouldn't tuning by ear find the clipping point of the amp? and not the max power the sub can take? Because my amp says i does 1500rms but im sure its only reall 1200rms clean and only want to give my sa12 1000rms clean so i would be overpowering my sub before i reach clipping on my amp? or the speaker distorts with too much power?

You are correct that you should set the amp gains with the HU's sub out turned all the way up. Not bass boost, EQ settings, or anything else, just the sub output level. For someone who knows stereos it's not such a big deal because you can hear when your equipment is being pushed too hard. But to the average guy it's a good idea to set it where they can't push it to clipping easily.

You can't really know how much power your sub is getting without an A/C clamp and volt meter. Both of these are available at Harbor Freight for cheap. You can have both for under 50.00. And it's not like you won't use them if you're really into car electronics. The cheap meters won't give an exact reading but it's enough to give you a good idea on what your gains need to be set at. Hook the amp meter (set on AC current) and the multimeter (AC volts) up to the amps output and let it play at full tilt. Multiply the two readings and you will have watts. Adjust the gains until you get the desired power level.

[plugger]

i dont have an amp meter or volt meter but i do have a digital multimeter but it dosent matter because i still dont understand what was just said... "hook it up and let it play at full tilt" ??? can you be more specific does that mean turn the gain all the way up or the head unit volume all the way up or what

[darron016]

Funny some people say don't turn the SUB setting up.. But my dmm wouldn't give me a straight forward reading, until i turned my HU SUB to 10. Than I was able to correctly tune my amp. I just figured this out yesterday,

[TaylorFade]

I wish people would quite suggesting setting gains with a dmm. Pointless, Stupid, and just dont fawking work.

In theory you can use a dmm to set output. i.e. acv x aca = watts. What people arent stating is that by doing this and using the manafacturers rating you are most definately putting it in full clip.

Just do it old skool. Set hu volume to 3/4 and slowly bring gain up on amp. Set lowpass to 80ish and ssf 5hz below your box tuning. I never and I repeat never run my sub output above half. Hell most of the time I barely touch it i.e. +1 or 2. Let the amp do the work.

Dude, people at your level can do this. Not very many are at your level though. Less experienced people need SOMETHING to go by. Is it perfect? No? Is it all most people have to go by? Yes.

By the time you hear distortion in a sub, you're probably at 10% THD. Or worse. That's a lot of f'n clipping. Your ears (and nose) are a great tool, but less than ideal instruments.

In a perfect world, we'd all have scopes and know how to use them. This isn't a perfect world. But with that said, every "good" amp I have is pretty dead on balls with the DMM method when done side by side with a scope.

Funny some people say don't turn the SUB setting up.. But my dmm wouldn't give me a straight forward reading, until i turned my HU SUB to 10. Than I was able to correctly tune my amp. I just figured this out yesterday,

That's because most sub levels are just attentuation. As in... it only backs the voltage down from whatever your HU can put out. Even so, I don't set mine at max level because not all recordings and tracks are a perfect -3db or whatever and I like to have some headroom.

[Humansville]

i dont have an amp meter or volt meter but i do have a digital multimeter but it dosent matter because i still dont understand what was just said... "hook it up and let it play at full tilt" ??? can you be more specific does that mean turn the gain all the way up or the head unit volume all the way up or what

A multimeter is a volt meter. Hook it up and turn the headunit up to the highest volume you can. The amp meter is only like 15.00 from harbor freight. That is the only way you will get a semi-accurate reading of how many watts you are putting out.

Funny some people say don't turn the SUB setting up.. But my dmm wouldn't give me a straight forward reading, until i turned my HU SUB to 10. Than I was able to correctly tune my amp. I just figured this out yesterday,

I said to turn the sub setting up. Don't turn up the EQ, bass boost, or anything else. Leave it all flat until you get the gain set.