Setting Gain

[LazyFcuk 0]

Ok so My FI BL 12" just arrived, i had a 18" previous in my Ford explorer. Now since I have a 240sx i need something smaller. I have my amp (saz-1500D) all set-up and ready to go. I forgot i need to reset my gains because when I tested the sub I could hear it clipping, and for some reason my gain (min/max) control knob mounted at the front of my car did not change the output of the sub. I lost the original cord but i read a phone cord could work so i tried and the blue led works at least. I digress to my problem which is that i forgot how to set my gain. I remember sticking in a 60hz cd at 3/4 full volume and reading the voltage from the amp but i forget the calculation. I also have a stock alt ( i believe 85amps), and a new battery. I really do not want to harm any of my precious equipment so all advice would be greatly appreciated. Thanks, in advance. Greg

[LazyFcuk 0]

Update: Playing the sub out of the box sounds like complete shit. It sounds like its rattling underneath the cone somewhere in the magnets. When i mess around with the gain it does nothing. The sound is there at low levels of volume and gets louder when the volume is turned up. With the volume at 50% it is very noticeable, and changing the gain does change the output or the noise, not 1%. Ive tried disconnecting the gain knob extension and nothing happens. Please help, I just want to get this thing working properly.

[ricksi30 923]

It could be a loose dustcap. When you apply even pressure to the cone around the dustcap do you get any coil rub? Why are you playing the sub out of the box??

[Duran 387]

Put it in an enclosure and see if it goes away, there are mechanical noises when you play free air.

[LazyFcuk 0]

Put it in an enclosure and see if it goes away, there are mechanical noises when you play free air.

Thats what I am hoping the sound just sounded very strange to me, the reason i was playing it out of the box because i am thinking the is a problem with the gain. I remember in my old set-up when i turned the gain know to min the sub wouldn't move. Now at 60% volume the gain does nothing to alter the sounds of the woofer.

[CrownVic 15]

I just reglued a loose dust cap on my friends 12" Bl, took about 5 minutes.

[ricksi30 923]

Put it in an enclosure and see if it goes away, there are mechanical noises when you play free air.

Thats what I am hoping the sound just sounded very strange to me, the reason i was playing it out of the box because i am thinking the is a problem with the gain. I remember in my old set-up when i turned the gain know to min the sub wouldn't move. Now at 60% volume the gain does nothing to alter the sounds of the woofer.

Still don't understand why you would play it out of the box?

[LazyFcuk 0]

Put it in an enclosure and see if it goes away, there are mechanical noises when you play free air.

Thats what I am hoping the sound just sounded very strange to me, the reason i was playing it out of the box because i am thinking the is a problem with the gain. I remember in my old set-up when i turned the gain know to min the sub wouldn't move. Now at 60% volume the gain does nothing to alter the sounds of the woofer.

Still don't understand why you would play it out of the box?

Because I am just doing tests with the gain, the sound might just be mechanical, I am not sure. My worry is in the gain. Changing the gain at any volume does not affect the woofer at all, I find that strange compared to my last 18" BL. I am a student and cannot afford to purchase a new sub, because with shipping and brokerage fees this sub cost me over $550. I am trying to make sure I don't place it in the box and the sounds disappears only hiding a potential problem, and ending up with a blown subwoofer.

[ricksi30 923]

The sub is far more likely to be damaged free air than in the box.

[LazyFcuk 0]

The sub is far more likely to be damaged free air than in the box.

I understand, but my main concern is the gain. As far as mechanical noise, is it very noticeable Duran? I believe it is just that because it sounds like movement noise in the coils.

[Duran 387]

The suspension will pop, air wooshing through the gap, etc.

[LazyFcuk 0]

The suspension will pop, air wooshing through the gap, etc.

It sounds more like a rattle, ill have to take a video tomorrow as it is to dark tonight.

[jesseadkins187 5]

Put it in an enclosure and see if it goes away, there are mechanical noises when you play free air.

yeah duran is correct i believe its mech. noises stick it in a enclosure

[KennethColeman 16]

You sound like your more worried about the gain than the sub. If it's not a free air sub I wouldn't be playing it outside the box.You can hook it up to make sure it works but not play it loud hooked up to an amp. I'm pretty sure that once you put it in a box that sound will go away.So try that and then respond back.K

[LazyFcuk 0]

You sound like your more worried about the gain than the sub. If it's not a free air sub I wouldn't be playing it outside the box.You can hook it up to make sure it works but not play it loud hooked up to an amp. I'm pretty sure that once you put it in a box that sound will go away.So try that and then respond back.K

Yeah that was basically my point. It will be in the box by the end of this weekend because I am busy with school. Any ideas about the gain?

[pmureika 31]

You sound like your more worried about the gain than the sub. If it's not a free air sub I wouldn't be playing it outside the box.You can hook it up to make sure it works but not play it loud hooked up to an amp. I'm pretty sure that once you put it in a box that sound will go away.So try that and then respond back.K

Yeah that was basically my point. It will be in the box by the end of this weekend because I am busy with school. Any ideas about the gain?

Use a dmm to set it.

[LazyFcuk 0]

You sound like your more worried about the gain than the sub. If it's not a free air sub I wouldn't be playing it outside the box.You can hook it up to make sure it works but not play it loud hooked up to an amp. I'm pretty sure that once you put it in a box that sound will go away.So try that and then respond back.K

Yeah that was basically my point. It will be in the box by the end of this weekend because I am busy with school. Any ideas about the gain?

Use a dmm to set it.

What is the volatage im looking for though, from my OP I last used a 60hz CD and set the gain to around 30 something volts. Where can i calculate this voltage.

[pmureika 31]

You sound like your more worried about the gain than the sub. If it's not a free air sub I wouldn't be playing it outside the box.You can hook it up to make sure it works but not play it loud hooked up to an amp. I'm pretty sure that once you put it in a box that sound will go away.So try that and then respond back.K

Yeah that was basically my point. It will be in the box by the end of this weekend because I am busy with school. Any ideas about the gain?

Use a dmm to set it.

What is the volatage im looking for though, from my OP I last used a 60hz CD and set the gain to around 30 something volts. Where can i calculate this voltage.

do a search on the internet the have graphs already made up. 50 hz for a sub. plus what is the headunits output 4volts?

[S.DeYoung 967]

So you want 1500 @ 1 ohms? 1500wrms x 1ohms = 1500. Square root of 1500 = 38.73volts. Better to use your ears. But this gives you a good starting point at least.

[pmureika 31]

So you want 1500 @ 1 ohms? 1500wrms x 1ohms = 1500. Square root of 1500 = 38.73volts. Better to use your ears. But this gives you a good starting point at least.

He needs to know the voltage output of his head unit.

[S.DeYoung 967]

So you want 1500 @ 1 ohms? 1500wrms x 1ohms = 1500. Square root of 1500 = 38.73volts. Better to use your ears. But this gives you a good starting point at least.

He needs to know the voltage output of his head unit.

Not if he's using this method.

[pmureika 31]

So you want 1500 @ 1 ohms? 1500wrms x 1ohms = 1500. Square root of 1500 = 38.73volts. Better to use your ears. But this gives you a good starting point at least.

He needs to know the voltage output of his head unit.

Not if he's using this method.

Dont agree .

[S.DeYoung 967]

So you want 1500 @ 1 ohms? 1500wrms x 1ohms = 1500. Square root of 1500 = 38.73volts. Better to use your ears. But this gives you a good starting point at least.

He needs to know the voltage output of his head unit.

Not if he's using this method.

Dont agree .

And why not? If you play a 50/60hz tone on your headunit, turn the volume up to 3/4 volume, plug your dmm into the outputs of the amp, turn the amp to ac voltage, and set the gain to the given voltage(which is 38.73volts). Why would you need to know the voltage output of the headunit?

[pmureika 31]

So you want 1500 @ 1 ohms? 1500wrms x 1ohms = 1500. Square root of 1500 = 38.73volts. Better to use your ears. But this gives you a good starting point at least.

He needs to know the voltage output of his head unit.

Not if he's using this method.

Dont agree .

And why not? If you play a 50/60hz tone on your headunit, turn the volume up to 3/4 volume, plug your dmm into the outputs of the amp, turn the amp to ac voltage, and set the gain to the given voltage. Why would you need to know the voltage output of the amplifier?

[pmureika 31]

From what I have been reading its better to know the head unit voltage its more reliable.