# Subwoofers pulsating



## DtotheG

alright well i have been having some minor problems with my sterio. first my acc from my head unit stoped turnong on and off my amps so i put a switch in. that worked good for a lil while but recently they started just shuting off or i would change songs or pause the music and my subs would just pulsate. so i got another switch thinking it may solve my problem so i successfuly put it in and turned up my radio changed the song and it was pulsating. i read about someone haveing probs with the same thing slightly and it was their amp. i would like to kno if it is just my amp. i have two amps one for subwoofers and one for mids and highs. only my subwoofer amp does this. plz help.


----------



## jaggerwild

We need more info then that (amp specs,speaker watts) Make sure you have good ground. I assume the amp is just turned up too high and is making feedback or the head unit is, as most units once they go past 3/4 or so. they will put out distortion, what head unit do you have? You may try an in line filter for the RCA'S see if that helps, but it may cut done the final boom coming through.


----------



## lcurle

is your sub amp set up correctly to filter out the HP? also, how is the power wire connected? to the battery or through your fuse box?


----------



## DtotheG

ok well i have and 1100 watt amp powering two audiobahn 15's and i have it bridged and the lvl is turned all the way up the bass boost is about 3/4 the way up. and i have a power acoustic cap 3 farids to help power it all. its to a distributer distributng to another amp. i dont think its the power because vrything is louder now that i have the cap instead of straight to the batterie. soo i turned down the amp and stil it does it. also iv had a couple diff head units and it has done the same thing with them.and sorry im not sure the wattage of the subwoofers.i know its 500+ rms.


----------



## DtotheG

o yea and i have a power wire with a fuse on it.conneected to the battery.wich goes from batterie to my cap then to the fuse block and to the amps.


----------



## jaggerwild

Turn down yer gains, only pushing distortion after so high...........


----------



## DtotheG

but there is NO distortion at all when it is all the way up. its amazing lol is it just too much for it to handle? do u suggest a new bigger amplifier?


----------



## lcurle

is your sub amp tuned for filter out anything above 80hz? and is it a constant steady pulsing? like a heart rate?


----------



## DtotheG

yea it has all the crossovers and wht not. it has one for hi frequencies and low. and yea like a heart beat but fast.


----------



## lcurle

amp is bad, replace


----------



## jaggerwild

You may try using a relay on the turn on lead to the amps, if that does not fix it then...............


----------



## DtotheG

thanx alot.


----------



## lcurle

it is a voltage thing internally


----------



## DtotheG

could i justtake it appart and fix it?


----------



## lcurle

ummm......yeah if your really good at electronics, find out what is wrong wne then find the proper replacement part for it.


----------



## lcurle

the main problem is your signal wire, check the voltage that is going to your amp, if it is lower then 10 volts, then you might want to check your alternator. Check the voltage at the battery, then at the alternator. Even though a car is 12volts, it should run about 14.4. Again, start your car and plop a voltmeter on the amp to see the voltage on the remote wire, thats where we will start.


----------



## DtotheG

ok... i have a volt meeter in my car and as soon as i start my car it jumps to 14. and i dnt c how that would be a problem because i have a capacitor.?and i have the remot wire running throu a switch thats being powered from the amplifier.


----------



## lcurle

ugggghh....the remote wire should be attached to your head unit, not through the amp.
And by volt meter in your car that means your capacitor has a multimeter on it. 
Click here for Diagrams


----------



## DtotheG

yea i kno it should be throu my head unit but through my head unit it wasnt powering it so i threw a switch in directly to the amp. and i have a volt meter for the battery. and my cap is at like 13 or somwhere around there.


----------



## lcurle

quick fix, run the remote from your head unit to amp 1, run a remote wire from amp 1 to amp 2, 2 to 3, 3 to 4 so on and so forth. Check your signal converter as well.


----------



## DtotheG

thats how i had it all in the firstplace. it was all set up rly nice then it all went to shyt. the amps stoped turning on thats y i hadda wire it with a switch like i said earlyer. lol. iv tried evrything. its rly a bother.


----------



## DtotheG

i had it like that before and the amos just shut off outa no where.thats y i hadda runa switch and do it like i mentioned above.


----------



## lcurle

I am guessing that the wire was clamped down to hard and it severed the wire and couldnt make a connection.


----------



## DtotheG

no i think its because the signal from my headunit was too weak that is y the pulsating stoped when i aded a switch and ran it all off the amplifier. but thanks for your help anyways


----------



## lcurle

switch should hinder the signal not increase it, theoretically speaking. If the output voltage for the signal is 11.8 volts and you add a switch you are adding a variable that could eat 1/4-1/2 volt, odd that it made the signal better.


----------



## Biohazardewz

i got a idea if u think ur having voltage troubles buy a computer backup battery with 18 amp hours, charge it up and then wire it to ur amp. then turn the amp up and if theres any pulse its probably ur amp. 
http://www.batterymart.com/p-12v-18ah-sealed-lead-acid-battery-1.html

those are the most stable 12 volt batteries ull find


----------



## lcurle

He doesnt need one for the tiny system he has. The alternator should be able to keep up.


----------

