Need help choosing alternator

[ayoparky]

Hi everyone, im new to this forum and also new to the upper levels of car audio. Like others i kinda wallowed in the middle area of car audio for years sort of operating under the notion that rockford fosgate and others were the best to be had in car audio. It wasnt until recently that I discovered this level of car audio, and so now im trying to build my first system with high level components. Based on my research, building a system at this level all starts with an alternator upgrade. I will try and be as detailed as possible, but if I leave out anything important, please let me know and i will try and provide more info. So, as it stands right now, my plan is to run a pair of cdt component speakers in my front doors the rms per door there is 190 so thats 380 watts rms total for the fronts. Im gonna do a set of cdt rear fill speakers in my back doors, 100 watts rms per door. so 200 watts total rms for the back doors. Im gonna power hose speakers with an nvx 4 channel amp JAD-800.4, which seems to have great specs at that price...i do have some reservations about that amp though cause nvx hasnt been around that long and any info or critiques or suggestions in that area would be appreciated. Anyways, for my sub im gonna run a single 18, with an rms of 2500...currently im undecided on which one, but im considering a platform 3 psi 18 at 2500 watts, an incriminator audio judge 18 at 2500 watts, the crescendo audio contralto 18 at 2500 watts...any input here also appreciated. Then im gonna have an amp to power it...which im also undecided on, gonna kinda scope the amp lab for the amps they have available when im ready to purchase and try and swing a good deal there. So officially, im looking at an rms of a little over 3000 watts. So, now comes the alternator. I have a 2003 subaru forester, what alternators should i be looking at....its also very confusing, cause i know subs at this level usually dyno out at a wattage far exceeding what they are officially specced at, and i know amps usually do as well. Im very confused by all of this in terms of alternators so any input would be appreciated. Also, I currently have an xs power 1200d battery under the hood and I realize i will probably need another supplementary battery to put in the back so any help there also appreciated. I have also already done the big 4 upgrade with 0 gauge wire that i plan on upgrading with bigger wire.

[DLHgn]

So, saying you have 380 on front, 200 in back and 2500 for sub, you have a total of 3080W RMS running in equipment. Now figure about 80% efficiency (could be more or less depending on your equipment). That puts you at 3850W. Then throw in about 1000W for engine and other electronics in car just to be safe so you're at 4850W RMS. Round up to a even 6000W just to give you some head room just in case you feel like upgrading a bit later on or what not. Those D1200 from XS say they put out 3000W. So get another one of those batteries. Those are rated at 44aH a piece so a total of 88aH. Now you need to have an alt to recharge those. Lets figure a 20% loss due to heat and what not. So you need to be able to supply ~106A. You could get a 150A alt and have plenty of power or even a 200A alt if you think you'll upgrade later (to something somewhat similar to this setup) and be fine. With a 150A alt you could play full tilt for a minute and be fully recharged after about 42 seconds of full output of alt. With a 200A alt you could play full tilt for a minute and be fully recharged after about 32 seconds of full ouput of alt. Now keep in mind that having this much electrical would be overkill but on the plus side you would know for sure that you electrical could keep up to whatever you threw at it with this setup. You would probably see very little voltage drop. Now some of my math maybe a bit scewed or have an error so someone please feel free to correct me if i'm wrong. Make sure that whatever alt you go with it is from a reputable company. I for sure found your car's alt on DC's website (assuming it is a 2003 Subaru Forester 2.5L H4) but you can also put in a inquiry to US and singer to see if they have one for your car. From what I could see, Mechman and Iraggi did not support your car but you could always try to contact them and see if they do. Also, another thing to look at with the alts is their different outputs. They will have different outputs based on the RPMs and if they're hot and cold. If you know that your alt doesn't output very much at idle, you will know that if you're playing it real hard that you may want to rev the engine for a bit. Things to consider.

[DLHgn]

Again, i'm no expert and I could be wrong but this is what i've read and practiced doing.

[ayoparky]

Speechless. Been looking for a well thought out, no b.s. easy to understand explanation to this question for quite sometime. Thank you so much.

[Ron36]

Finding an alt could be alittle tough for a a Subaru, Also Ohio Generator great company , Don't buy an amp for the good price make sure u do your homework , good amps make good clean power and they are more money but it's all worth it.

[ayoparky]

Dont get me wrong i fully realize that you can take two amps, put them side by side, say they both do 3000 watts rms yet one amp drastically outperforms the other. I always attributed this to circuit board design, and the quality and configuration of the internal components. What sucks, is that it is very difficult to get access to that type of info with out actually owning the amp and opening it up. Regardless of access to that information about circuit boards and components. Its obvious that trends emerge over time and that certain manufacturers start to stand out above the rest. I guess my next question who are those manufacturers. The ones that have continually put out consistently good amps year after year? Sundown Audio and DC Audio are the two that i know that I think fit that category, can you guys offer up some recommendations in regards to who these quality amp makers are. Also, it seems like now more than ever that there are alot of upstarts that are making huge waves that make everything all the more confusing...Crescendo comes to mind, are there any other makers out there like crescendo that are worth looking at...or is crescendo not worth looking at?

Sorry if all these questions seem dumb or uneducated, but im really really new at this level and have very little knowledge of all these makers.

[DLHgn]

Dont get me wrong i fully realize that you can take two amps, put them side by side, say they both do 3000 watts rms yet one amp drastically outperforms the other. I always attributed this to circuit board design, and the quality and configuration of the internal components. What sucks, is that it is very difficult to get access to that type of info with out actually owning the amp and opening it up. Regardless of access to that information about circuit boards and components. Its obvious that trends emerge over time and that certain manufacturers start to stand out above the rest. I guess my next question who are those manufacturers. The ones that have continually put out consistently good amps year after year? Sundown Audio and DC Audio are the two that i know that I think fit that category, can you guys offer up some recommendations in regards to who these quality amp makers are. Also, it seems like now more than ever that there are alot of upstarts that are making huge waves that make everything all the more confusing...Crescendo comes to mind, are there any other makers out there like crescendo that are worth looking at...or is crescendo not worth looking at?

Sorry if all these questions seem dumb or uneducated, but im really really new at this level and have very little knowledge of all these makers.

I would be careful with what you say in regards to this. Can be taken as VS thread which is a big no no. As for recommendations, I would have to say B2 audio. They make great high quality equipment. I've never heard someone who didn't like their stuff.

The website link: b2audio.com

Store link: b2audiostore.net

They're not super popular but still do great things. On top of that the owner is a very nice person (I should know, just spent 2 days with him at Heatwave in Austin this past weekend) and really knows his stuff. Their amps put out a lot of good clean power.

Bench testing of one of their discountiued amps:

Just goes to show you that they perform very well past ratings.

[DLHgn]

Speechless. Been looking for a well thought out, no b.s. easy to understand explanation to this question for quite sometime. Thank you so much.

No problem. I actually learned this from a post another much more knowledgeable guy made but I can't seem to find it.

[DLHgn]

Finding an alt could be alittle tough for a a Subaru, Also Ohio Generator great company , Don't buy an amp for the good price make sure u do your homework , good amps make good clean power and they are more money but it's all worth it.

Exactly. Most likely, if the amp is cheaper than it should be, it is making lots of dirty power that will probably fry your drivers.

[Wehan]

I'm going to be totally honest with you, I don't know jack shit about what the hell DLHgn just said but it doesnt sound 100% correct based on the recommendation I got from this site and then the real world implementation of said advice for a 2500w system. I was recommended as close to 200a at idle as I could get and as high of a peak as I could, I ended up with a Singer hairpin 190/270 model and I'll tell you what, at idle at full tilt I dip ever so briefly into mid 11v. so for DLHgn to say that a 200a model will be good and even overkill for 3000w rms is just plain screwy to me. Email Mike at singer alternators and he will help you out.

http://singeralternators.com/