Gain Setting Tutorial

[nitsuj 10+ year member]

I just noticed on the illustration that they only disconnect the positive wire for the speaker. I thought both, could this be a problem????

 

[sumone 10+ year member]

doesn't matter. disconnecting only one is so you only have to reconnect one wire, instead of both. with either or both disconnected, the circuit is open and there is no current flow across the sub(s). If you don't hear anything or see any movement coming from the sub, then the circuit is open.

nitsuj - try doing a voltage reading while playing music at a hefty volume...do you get any fluctuations in voltage?

 

[nitsuj 10+ year member]

It actually doesn't read a thing. Unless I have the gain up all the way, then it reads 2 to 3. I accidentally played the 50hz sine wave with the sub hooked up and it was a nice belch. So I know that the the signal is good.

My belief is that it is the volt meter, has a top of 750 volts, so I am wondering if I have a sensitivity issue with my meter.

 

[sumone 10+ year member]

yea cause if you're getting low readings with loud muisc playing, it's obviously something wrong with the way you're measuring whether it be physical or regarding settings on the meter, OR a problem within the meter itself.

Are you sure the meter supports and you have selected AC or RMS voltage readings?

 

[loudfivepoint0 10+ year member]

Great tutorial here. I had trouble at first getting a .1 reading no matter what i moved the gain to. Then i changed the multimeter from dc mode to ac mode and that was the problem all along. Anyway i also took the tutorial a step further. My amp OVERpowers my sub so what i did instead was take my subs power rating and ohms rating to figure out voltage. 750wrms wired @2ohm giving me 1500 watts. SQRT gave me 38.7 volts. Now i dont have to worry about overpowering my sub! (actually a little too loud and i may turn it down some)

 

[Shyne151 10+ year member]

Has anyone found a 1khz test tone? if so e-mail it to joel@project04.net and i can host it on my server, because i'm having a hell of a time finding one.

 

[ANeonRider 10+ year member]

just download a tone generator, I found a good one using a google search.

 

[btnhfan 5,000+ posts]

i finally set my gains, and during the 50hz tone, the volts fluctuate up and down. so i just set it to right below where it peaked at right below 44 volts. is that good enough? i used the 50hz from the bass mekanik cd. should i use the one on the treo website?

 

[nismboy6986 10+ year member]

yeah it did fluctate a lot when i tried a 50hz of it. sine waves demand much more from your amps than actual music right. because i had singifacntly less voltage when i did this playing music that just hit really hard than with a sine wave. Most people don't go around listening to sine waves so wouldn't you be limiting output capability if you regulate your amps by playing something that would demand much more than you would give it (do i make any sense)

 

[nismboy6986 10+ year member]

ok i get what you are saying. what i did is after i set my gain by this level and played the 50hz sine it was loud as hell just like it supposed to be but actual music wasn't as loud as it was so i turned it up a bit since it seemed rediculously low ( hifonics accepts up to 9v head unit puts out 6.5 volts i had it up 20/35 and i BARELY had the gain a twitch above bare minimum) kind of like when a electrican is figuring out the amp load of a stove he would derate the max amp draw since no one would have all four burners and the oven on all at the same time all wide open. and i would reset them by JL's method the few times i would go to a comp and this i why for street use i still think the best method is to turn up the gain until you hear distortion then promply turn it down a notch or two.

 

[nismboy6986 10+ year member]

i would agree that the method you listed was safer since clipping/distortion would never be introduced to the speaker in the first place but i would say your method would set a good basemark as to where the gain should be set if you do use the crank-it-up-till-distiortion method so you would know about where it should be

 

[-CT- 10+ year member]

great tutorial/posts....didnt have a clue what gains were before this but will now be ready when i do get my car and install a system. Although my amp also has a few more knobs so which ones do i turn down all the way?

its got:

level 5v-0.15v

bass boost 0db-18db

hpf 30hz-500hz (also lpf one but im guessing these got summin to do with the x-over switch inbetween which is set 2 hpf)

subsonic 10hz-100hz

 

[Nikuk 5,000+ posts]

great tutorial/posts....didnt have a clue what gains were before this but will now be ready when i do get my car and install a system. Although my amp also has a few more knobs so which ones do i turn down all the way?
its got:

level 5v-0.15v

bass boost 0db-18db

hpf 30hz-500hz (also lpf one but im guessing these got summin to do with the x-over switch inbetween which is set 2 hpf)

subsonic 10hz-100hz

is this amp for a subwoofer or for those mid speakers you were working with?

 

[-CT- 10+ year member]

is this amp for a subwoofer or for those mid speakers you were working with?

yea this is the amp for the 6x9's (im gonna get another one for the mids)

 

[Chris02NeonSXT 10+ year member]

When I hooked the dmm up the speaker terminals on the amp, I kept getting 55-60v regardless of where i put the gain. What gives? I was using the 200m Voltage setting on my dmm in the AC mode. I need 24.5 v for my amp.

Thanks,

Chris