first off, sorry to post in subs but we all know the subs section is the everything section including drugs cars and other things lol.
when you tune your amp you turn all procressing off correct? like 0 treble 0 bass 0 mid. sub level to 0. loudness off. now you would play a 50hz tune at 0db for tuneing a sub amp.... you turn it up 3/4 the way.... now go back to ur amp (which is not hooked up to the sub) and read the AC volts from the amp with a true rms dmm. okay now say im tuning to 500w appx. the subs load is 2 ohms. so say 32V we'll ttune too. 32x32 =1024/ 2 = 512w oh and i almost forgot. prior to that make sure the bass boost is at 0 or off. now, jonathan or anyone else who knows about this well, do you just hook up the sub now and call it quits (besides making ur treble mid and bass the way you like it) and make note that the bass on my HU doesnt make my sub louder really... now the subwoofer level. am i suposed to keep it on 0? will my amp clip when i put it up some? i aready know that when you turn bass boost up it will definetly clip your amp. but im not sure about the subwoofer level. you want to be able to adjust ur subwoofer level right? so why would it always have to be on 0?
All processing off, yes. No bass boost, no EQ, all crossovers are flat. You will use a 0db reference tone in the frequency range, 50hz is good for a sub amp. The one thing you've left out is a dummy load. You need a resistive dummy load that matches the nominal impedance of the driver you're using. You could get away with it with the subwoofer hooked up, but you have to make sure that the subwoofer is within it's flat part of the impedance curve (not at resonance, not at inductive rolloff). This is more difficult with a subwoofer.
"now the subwoofer level. am i suposed to keep it on 0? will my amp clip when i put it up some?"
That depends on the head unit. For example, the Alpine units are actually designed to cut, not boost. So you'd want it on 12 or 13 before setting the gain. But anyway, just keep in mind what you want to use sub level for. If you want it to cut only, you should set the gains with the sub level up higher. If you want to do both, you should leave it on 0 and set the gains there. I'd only use sub level to cut, but some people configure it where they can boost bass at lower volume levels. It's your choice, you just need to remember what maximum output is and don't exceed it.
"You need a resistive dummy load that matches the nominal impedance of the driver you're using. You could get away with it with the subwoofer hooked up, but you have to make sure that the subwoofer is within it's flat part of the impedance curve (not at resonance, not at inductive rolloff). This is more difficult with a subwoofer. "
i follow you in everything except this part. arent you suposed to make sure the driver is not hooked up? according to JLs tutorial you dont hook anything up to it....
"but you have to make sure that the subwoofer is within it's flat part of the impedance curve (not at resonance, not at inductive rolloff). "
and that... i dont have a clue what you mean, sorry ... thank you for the response though i know what you mean by using the sub level to cut. thanks.
"i follow you in everything except this part. arent you suposed to make sure the driver is not hooked up? according to JLs tutorial you dont hook anything up to it...."
Didn't know you had a JL amp, sorry. Their amps differ because they change voltage rails according to the impedance of the driver. In their case you don't use a resistor. In other cases with a fixed rail, you should. In your case, just do it as the JL tutorial states.
"and that... i dont have a clue what you mean, sorry ... thank you for the response though i know what you mean by using the sub level to cut. thanks."
In your case, don't worry about it since you won't be using the sub.
well i currently have a JL amp. but i will be installing my brother rockford bd1001p and in the future i will be running eDnine.1s so just leave the sub hooked up as i read the voltage?
oh and i almost forgot. how do i know if the sub is in the flat part of the impedence curve?
and just a relating question. when i hook my ddm up the the wires to the sub. it should tell me the resistance in ohms correct? but it jumps around. its not steady....
"well i currently have a JL amp. but i will be installing my brother rockford bd1001p and in the future i will be running eDnine.1s so just leave the sub hooked up as i read the voltage?"
Ideally you'll have a dummy load. Just a single resistor that matches nominal impedance of the sub, it won't cost much at all.
"oh and i almost forgot. how do i know if the sub is in the flat part of the impedence curve?"
Something that's specific to the subwoofer. Resonance will occur specific to the sub enclosure in relation to the sub, so you have to know the exact configuration it's in. Impedance will typically roll off well above 100hz assuming it's not a huge excursion SPL sub.
"and just a relating question. when i hook my ddm up the the wires to the sub. it should tell me the resistance in ohms correct? but it jumps around. its not steady...."
You can NOT use an ohmmeter on a live circuit, big no-no. What you need to do is measure voltage and current, and calculate impedance from there. Ohms law, Voltage/current = resistance.
"i didnt mean i did it as the sub was playing. i did it with the sub not hooked up to the amp. isnt current measured in volts?"
As long as the amplifier wasn't on, that's fine. If it was on, it's still a no-no. Current is measured in amps.
"so should i just go buy a 2 ohm and 4 ohm resistor?and where to get them? but dont they blow with very little power?"
Yup, you just go buy a resistor. Different wattages are available, but it's like a fuse. With too much power it doesn't instantly blow, it will heat up until it's destroyed. It can take a burst of power for a short period of time.