I was reading some old threads and saw a post you made.
"i run 2-3250.1 strapped at .5 and never dip below 12.8v. 300a alt and a yellow top"
is that with just one g34 yellow top in the back? anything under the hood?
that seems insane to be pushing ~4000 rms out of each amp at .25 ohm each.
hell even at 2 ohms strapped running 6k that seems like a pretty solid electrical for just one batt.
Im curious because i have a 200 amp alt, a stock batt and 2 spv70s and I drop to 12.6 running one atomic 3k @ .5ohm, i hope its not time for new batteries.
300 amp alt. multiple runs of 1/0 front to back. probably a optima gr31 in the front and back. if i was assuming. and upgraded big 3 im sure as well. best way i found was to run the power and ground from just bat to bat. (alternator is the same way) and then do as many runs as you can of wire front to back. if your serious about your voltage lol. with 2 xs power d3100s and a mechman 270 amp alty on 1 D9 at .35 full tilt my voltage never dropped below 14.0
glass, yea its a 300 amp but with one battery im pretty skeptical. hes drawing at least 450 amps and thats being pretty conservative.
Hunter, that is a quote from scott. He says "a" yellow top which implies to me one.
but i guess the alt makes a huge difference then. I was thinking about getting an mla module but forget that i just need a larger alt. my 200 amp isint cutting it.
Im about to be running 6k rms too, its never gonna hold up even after i put in my third spv70. I have wiring but my rocker panel is already completely full of wire so im going to need to find an alternate route. looks like a got a lot of work and money to spend this summer.
in competition, the car engine has to be shut off, so current is supplied solely by batteries. The lifespan will depend on amp-hours available from those batteries.
when the car is running, current is supplied by the alternator. batteries act to stabilize voltage rails, since they should be in a charge state above idle RPM.
if an amplifier is rated at 1000 watts RMS, that is rated with white noise (20Hz-20KHz test tione) sustained, on a resistive dummy load at full volume/output. Usually if it's a loosely regulated, or unregulated power supply, this is done at a jacked up voltage, like 14.4 to 16 volts.
That said, remember that when listening too music in your car, speakers present an inductive or reactive load, which is furthermore affected by the enclosure housing the subs, which can also have an affect on impedance and thus power output and current draw. On top of this, the input source is dynamic (music) causing the input signal to fluctuate greatly, and usually well below the reference "peak" reached with a test tone. Now figure that the volume level of a system during music playback is usually well below "full volume" and every audible halving of the volume from "full" is a drop in power of tenfold. If you're at one quarter volume, that's about one one hundredth of the full power of the amplifier being used.
All of these things factored together, means a system rated at "5000 watts" is really only going to draw maybe a few hundred watts continuous while being used to play music with people sitting in the car.
Suddenly, a 300A alternator doesn;t seem so unreasonable.
well then why the hell does my voltage drop so much?
I agree with everything you said but you cant assume he is testing his voltage drop on anything other than full or near full volume. what is the point of saying i have no voltage drop but only at 25% of full volume, to me this makes no sense.
I know that most of the music i listen to is hip hop, metal, and rock. rock music i can blast all the way up indefinitely and not even touch my electrical since there is almost no bass. metal/hardcore drops me into the low 13's easy with double bass and bass booms and hip hop puts me into the 12's sometimes, with the long loud bass notes and extended lengths of bass throughout the songs.
to assume he is not drawing 450 continuously is valid for some songs but at some point throughout a song he is drawing at least 450 amps and on hip hop songs with long extended bass lines he quite possibly could be pulling 450 continuously amps considering i did the calculation for 6000rms 14 volt and 100% efficiency.
realistically its more like 650 amps of draw at peak output (7000 rms, 14 volt, 77% efficiency) on music he is never averaging this but he very easily could be averaging 450 with some of these hip hop songs.
Most people don't listen to a stereo system at full blast all the time. That's all. Also, if the amplifiers are well made, they will have pretty massive toroids and capacitors, and they will have the capacity to supply the current demanded for those sudden spikes in demand. That aside however, I've always said see how the system does. If you have a problem, fix it. You apparently have a problem with the voltage rails, so sure, you'll need a larger alternator, or, have you considered runnign two or more alternators, with at least one deditaced solely to the audio system? This is a solution I've used, in addition to a bank of deep cycles in the trunk, to manage high current competition systems in the past.
I'm not arguing with you here, mon ami. I'm trying to help solve whatever problem you're having, without costing you any more than required. That's all. I also want to make sure people understand why they need to do whatever is required, so I tend to explain a lot of the complexities to be sure they know what's going on in their cars. Keep in mind I don't know what you do or don't know, so I have to start with assuming you don't know this stuff, till I know better.
hunter i correct it was alot of wire runs and i ran iasca st the time so the vehicle was allowed to run so yeah the alt helped alot. it was .5 each so a 1ohm strap also.
o alright so only a 30 second run. that makes more sense then.
I guess ill see where im at once i add another set of runs from the hood to the trunk and the third stinger but im almost positive im going to need something more.