keep blowing amp
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=127080
Printed Date: May 14, 2024 at 9:46 PM
Topic: keep blowing amp
Posted By: cbringe1
Subject: keep blowing amp
Date Posted: April 23, 2011 at 5:44 PM
so i keep blowing my amp and keep haveing to send it in to get fixed and i dont understand why? this is my set up if any one can help me or give me some ideas i would greatly apprecate it i have a yellow top up front with the big 3 upgrade runing o gauge wire to a 200 amp fuse then all the way back to my stinger 30 fard cap i grounded the cap to the chassis with 0 gauge then i ran 0 gauge to my power base 3000d amp witch i have ground with 0 gauge as well to the chassis i have 2 10s digital designs ran to 1.7 ohms on a dmm i dont get why i keep blowing it i was told to get a second battery but i dont know i am confused i have a pioneer avic n4 dvd head unit all good rcas if any one has any sugestions please let me know thanks chris
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chris bringe
Replies:
Posted By: i am an idiot
Date Posted: April 23, 2011 at 11:00 PM
do we have any idea of the ohm load presented to the amp?
Posted By: cbringe1
Date Posted: April 24, 2011 at 1:12 AM
yes its 1.7 ohms i have it going in to the amp at is that too low??
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chris bringe
Posted By: blanx218
Date Posted: April 24, 2011 at 1:42 AM
it looks like all the power bass d-class amps are 1 ohm stable so you should be fine there. have they given you any details on what was wrong or what part of the amp was repaired? was it the power supply, inputs, outputs, etc.? if the power bass stuff is like some older concept amps you may need a higher input voltage, blew a few 2400d's a few years back and they told me the amp needed between 6-8v inputs. threw in a line driver to get upto 8v and everything was fine
Posted By: i am an idiot
Date Posted: April 24, 2011 at 8:34 AM
How many woofers? Single or Dual voice coil? What is the impedance of each voice coil?
Posted By: cbringe1
Date Posted: April 24, 2011 at 10:17 AM
2 woffers dual voice at 4ohms each
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chris bringe
Posted By: i am an idiot
Date Posted: April 24, 2011 at 1:26 PM
Your choices with that configuration are 4 ohms or 1 ohm.
A DMM reads DC resistance. Impedance is an AC measurement. How do you have the woofers wired?
Posted By: cbringe1
Date Posted: April 24, 2011 at 4:18 PM
i have them wired up as the diagram on hear has them shown 2 woffers dual 4 ohm is negitive to niegitive on coils then negitive to both subs to amp then same with the positive i put my dmm on the positive wire that gose to amp and the negitive wire witch i get a reading of 1.7 ohms thats what i hooked up to the amp i was bumping and didnt have the car running and i only have one batt do u think that could of been problem ?? its a yellow top optima but i didnt kill the batt i was just bumping for a few min then amp went to protection
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chris bringe
Posted By: oldspark
Date Posted: April 24, 2011 at 7:59 PM
The Optima yellow will not blow your amp - no 12V battery can.
Being Optima might explain a battery failure though....
(Yes, I'm having a dig...)
(At Optima!)
Posted By: lspker
Date Posted: April 24, 2011 at 8:31 PM
Seems like that is under 1 ohm load, what does the meter read when you short the thest leads together. Probably .6 to .8 ohms.
Posted By: i am an idiot
Date Posted: April 24, 2011 at 9:48 PM
Four 4 ohm voice coils paralleled = 1 ohm.
Posted By: cbringe1
Date Posted: April 25, 2011 at 7:45 AM
it reads .01 when i touch leads to geather
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chris bringe
Posted By: DYohn
Date Posted: April 25, 2011 at 3:34 PM
You cannot read voice coil impedance with an ohm meter. ------------- Support the12volt.com
Posted By: cbringe1
Date Posted: April 25, 2011 at 9:55 PM
then how you read it ?? i got a dmm
------------- chris bringe
Posted By: i am an idiot
Date Posted: April 25, 2011 at 10:47 PM
Posted By: jmelton86
Date Posted: April 26, 2011 at 8:30 PM
Now THAT is cool!
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2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
Posted By: ac0j
Date Posted: May 01, 2011 at 1:44 AM
If you are drawing more amps than your alternator is putting out, chances are you are running the system below 12 volts after extened listening. IF your battery voltage drops below 12 volts, the amp will draw more current to compensate for the low voltage. This causes power supply components to overheat. Thus kiling the amplifier. You have plenty big wire, and a good battery, but I bet you altenator is not keeping up. Adding another battery will only make the problem worse. It will play longer before the voltage drops, but then the chargeing system will have to run double duty to recharge the batteries. You should put a bigger alternator in FIRST.
As a rule of thumb, Take the maximum watts output of your amp, divde by 13.5 volts, and that is how many amps your altenator needs to produce JUST FOR THE AMP, add to that the original size of your altenator. Some big amps might require more than one altenator.
Posted By: oldspark
Date Posted: May 01, 2011 at 2:47 AM
ac0j has a good point that none of us have mentioned (LOL, other than OP cbringe1 in his OP about "too big a battery".)
(Onya ac0j - keep it real! (That's an AC joke - not meaning to be out of sequence...).)
But amps should protect their own PSUs with their own fusing, and it has been assumed it is the output that is blowing - not the PSU (input); maybe that needs confirming?
Also we and most tend to use the "divide by 10" rule - ie, output Watts RMS divided by 10 = input Amps. EG - if 3000d is 3kW Music Power output, then it's 1500W RMS => 1500W/10V = 150 Amps in.
That's based on amp voltage ranges down to ~12V (ie, battery discharging) combined with amp efficiency (say 80%), but it is for initial dimensioning purposed only, ie, it's an easy estimate. And it tends to underestimate.
If 1500W => 150A, then its distribution (+12V & ground) would probably be 200A or higher, with fusing to suit (either the cable capability else the (lower) amp's maximum RMS current; where the fuse should be rated to carry 70% to 80% or normal or max long-term current).
Using 13.5V and the output power leads to undersizing. It omits voltage drops below 13.5V (eg, when on the battery which will probably never exceed 12.5V) and the extra current for the amp's inefficiency.
Furthermore, the alternator (and distribution) has to supply the additional battery recharge current. And of course the other vehicle loads.
Nevertheless, an excellent point. Is it the amp's PSU that is blowing?
Posted By: i am an idiot
Date Posted: May 01, 2011 at 6:52 AM
What is the magic number? How many speakers can I connect to a single amplifier?
Posted By: DYohn
Date Posted: May 01, 2011 at 8:40 AM
Silly boy, the answer of course is 42.
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Posted By: i am an idiot
Date Posted: May 01, 2011 at 9:58 AM
I am such an Idiot, I posted the previous question in the wrong topic.
Posted By: DYohn
Date Posted: May 01, 2011 at 10:08 AM
i am an idiot wrote:
I am such an Idiot, I posted the previous question in the wrong topic.
Ha ha! I wondered... ------------- Support the12volt.com
Posted By: cbringe1
Date Posted: May 02, 2011 at 9:03 PM
it was a output mosfit that blew 15 dollor part and a130 to fix and ship not to happy but they told me it was due to vibration so i relocated amp to behind the subs and bolted down really good with pading underlay any way thats that thanks guys for all the info but i have couple more ?s about seting up the amp its got a phase setting gain base eq LPF and sub sonic i have my box built ported and tuned to 40hz i know how to set my gains and base eq just dont know what to put lpf too phase and sub sonic can any one help me out or sugest what to do i have 2 10s dd 3500s power base 3000d subs at 1 ohm any help is much apprecated thanks chris
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chris bringe
Posted By: ac0j
Date Posted: May 02, 2011 at 9:28 PM
cbringe1 wrote:
it was a output mosfit that blew 15 dollor part and a130 to fix and ship not to happy but they told me it was due to vibration so i relocated amp to behind the subs and bolted down really good with pading underlay any way thats that thanks guys for all the info but i have couple more ?s about seting up the amp its got a phase setting gain base eq LPF and sub sonic i have my box built ported and tuned to 40hz i know how to set my gains and base eq just dont know what to put lpf too phase and sub sonic can any one help me out or sugest what to do i have 2 10s dd 3500s power base 3000d subs at 1 ohm any help is much apprecated thanks chris
LPF= If you are using a deck with the sub controls biult in, and you can change them from the radio, I would set the LPF to its highest on the amp. If your deck does not have the controls, it is A matter of opinion, but I would set it around 125hz.
Bass eq, set it to what you think sounds best, if you compete, set it to your best SPL tone freq.
Posted By: ac0j
Date Posted: May 02, 2011 at 9:30 PM
OOOPS ! posted to quick! The phase is a matter of opinion as well, set it to whatever sounds best to you, but again,with the sub controls in the radio, most will switch phase as well.
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