Jump to content


Michael Poole

Wiring 2 alternators to completely separate batteries

Recommended Posts

Hey guys I'm brand new to this forum and need a little help. I apologize up front if this question has already been answered. If so please shoot me a link. I've scoped the internet far and wide and can't find a good answer. Anyway, let's get to the point. I'm in the works of new audio build and I want to run a high output alternator straight to a battery bank that will power all of my subs (8 in total totaling 2700 watts rms) then I want to run a step above stock alternator to the start battery and high/mid range speakers. So here's the problem (or at least I think so). The alternator grounds to the engine directly through the mounting bolts so unless I make an insane alternator mount I can't avoid having 2 power sources sharing the same ground. 

Is this even a problem? Can you share the same ground or will you ultimately be connecting the batteries together? I want the systems to be completely separate but the more I think about it the more I think I'm not going to be able to do it. 

Any help would be appreciated. Sorry if the question is layed out poorly hard to think of the right words and terminology.

As a side note in case anyone is curious, the build I'm on is 2 15" JLW0v3's, 2 12" JLW0v3, 2 10" JLW0v3's, 2 8" JLW3v3, 2 6.5" JL C7 speakers, 2 1" JL C7 tweeters, 2 5.5" JL C5 speakers, and 2 .75" JL C5 tweeters. 8 subs 8 speakers as many different sizes as possible all on a pioneer p99 in a chevy astro. All JL amps as well except for the highs and mids only because I love pioneer for multi channel applications. 

Share this post


Link to post
Share on other sites

Oh god......2 15s, 2 12s, 2 10s, 2 8s, 2 6.5s.  Terrible idea.

 

 

BTW 2000 watts is not even close to needing two alternators. My single DC power 270xp runs my 5 batteries and 6 amps just fine.


2016 Focus ST3 - Rockford DSR1 / PPI 900.4 / Silverflute 6.5" mids / Massive CT2 tweeters /Sundown Xv2 15"/ Taramps DSP3k / Stinger Roadkill / KNU wiring / Northstar SMSAGM80 /

2010 Focus coupe 157@46hz

Pioneer 80prs /(8) FU Audio 750 12"s / (4) FSD 2600s / (1) FSD 125.4 / (1) FSD 85.4 / (4) Crescendo UN-10" mids / (4) Crescendo FT1 tweeters / Stinger Roadkill / 2/0 EB flex wire / (5) Powerware 90AH batteries / DC 270XP Alt /

https://www.youtube.com/popwarhomie

too many freq at once, burn the coil, we all know, over 40-50hz, its all coilburning material.

Share this post


Link to post
Share on other sites

I'm all ears on why this is a bad idea, please explain. I want as many sizes as possible to focus specific hz levels to the speakers who play it best. best example is 8" subs vs 15" subs. 8s just don't play low frequencies as well as 15s and vice versa. Also the reason I want 2 alternators is because the hot idle amperage of the best alternator I can find (which is the 270xp from dc power inc.) is not enough to handle the max amps needed to power all of the subs, that mixed with the power needed to run the car, lights, spark plugs, heater, A/C, etc. not to mention the high end speakers. Total wattage is 3500 by the way. Another side note, this build is focused on sound quality not shake. Hence the p99, multiple speaker sizes, and crossovers.

Edited by Michael Poole
Wanted to add more information

Share this post


Link to post
Share on other sites
1 minute ago, Michael Poole said:

I'm all ears on why this is a bad idea, please explain. I want as many sizes as possible to focus specific hz levels to the speakers who play it best. best example is 8" subs vs 15" subs. 8s just don't play low frequencies as well as 15s and vice versa. Also the reason I want 2 alternators is because the hot idle amperage of the best alternator I can find is not enough to handle the max amps needed to power all of the subs, that mixed with the power needed to run the car, lights, spark plugs, heater, A/C, etc. not to mention the high end speakers. Total wattage is 3500 by the way. Another side note, this build is focused on sound quality not shake. Hence the p99, multiple speaker sizes, and crossovers.

That is incorrect. Ive had 8" subwoofers all the way to 21" subwoofers.  An 8" subwoofer will play just as high and low as a 21". Its all in building the proper enclosure. Mixing subwoofer sizes causes cancellation.  Nothing sound quality about running 8 different sized subwoofers in 4 different boxes.   You must not be looking at the correct alternator companies. Excessive amperage will build a 400 amp large case alt for many different vehicles.    3500rms is nothing for a single alternator. 


2016 Focus ST3 - Rockford DSR1 / PPI 900.4 / Silverflute 6.5" mids / Massive CT2 tweeters /Sundown Xv2 15"/ Taramps DSP3k / Stinger Roadkill / KNU wiring / Northstar SMSAGM80 /

2010 Focus coupe 157@46hz

Pioneer 80prs /(8) FU Audio 750 12"s / (4) FSD 2600s / (1) FSD 125.4 / (1) FSD 85.4 / (4) Crescendo UN-10" mids / (4) Crescendo FT1 tweeters / Stinger Roadkill / 2/0 EB flex wire / (5) Powerware 90AH batteries / DC 270XP Alt /

https://www.youtube.com/popwarhomie

too many freq at once, burn the coil, we all know, over 40-50hz, its all coilburning material.

Share this post


Link to post
Share on other sites

All of the enclosures are built to exact specifications.

I know where you're coming from.  enclosures, amps, and audio processors must be perfect to produce the right sound, but I have personal experience with 2 JL W0v3 10's and 2 JLW0v3 12's both in the bass wedge box from JL (so perfect enclosures) both have the same exact driver on the same exact power supply. The 12s did much better with low frequencies than the 10's this was in the same car at the same time. Saying that an 8" sub can do the same thing a 21"  sub can is like saying you can get bass from a tweeter if the enclosure is right (in my opinion) 

Share this post


Link to post
Share on other sites
1 hour ago, Michael Poole said:

All of the enclosures are built to exact specifications.

I know where you're coming from.  enclosures, amps, and audio processors must be perfect to produce the right sound, but I have personal experience with 2 JL W0v3 10's and 2 JLW0v3 12's both in the bass wedge box from JL (so perfect enclosures) both have the same exact driver on the same exact power supply. The 12s did much better with low frequencies than the 10's this was in the same car at the same time. Saying that an 8" sub can do the same thing a 21"  sub can is like saying you can get bass from a tweeter if the enclosure is right (in my opinion) 

What do I know about car audio. You clearly know more than I do.  Good luck with your build then. 


2016 Focus ST3 - Rockford DSR1 / PPI 900.4 / Silverflute 6.5" mids / Massive CT2 tweeters /Sundown Xv2 15"/ Taramps DSP3k / Stinger Roadkill / KNU wiring / Northstar SMSAGM80 /

2010 Focus coupe 157@46hz

Pioneer 80prs /(8) FU Audio 750 12"s / (4) FSD 2600s / (1) FSD 125.4 / (1) FSD 85.4 / (4) Crescendo UN-10" mids / (4) Crescendo FT1 tweeters / Stinger Roadkill / 2/0 EB flex wire / (5) Powerware 90AH batteries / DC 270XP Alt /

https://www.youtube.com/popwarhomie

too many freq at once, burn the coil, we all know, over 40-50hz, its all coilburning material.

Share this post


Link to post
Share on other sites
1 hour ago, Michael Poole said:

"perfect enclosures"

That above is quite an assumption... especially in a mobile environment.

Every enclosure I've ever designed has been a collection of compromises... some minor some large... some goal orientation,  others install specific but never mixing driver sizes... well... ever since the mid-80's  (high school).

Calling a basswedge "perfect" ... lol

Welcome to the forum, looks like you need some solid advice.

You debated solid advice with "personal experience"?.. this forum IS entertaining... good luck


JVC KD-X350BTS, Sundown Sa-15 5.7ft3 net ported @ 43hz, Synergy 3K@ 2 ohm, RF 500s, Polk DB comps, Cache Preamp/EQ

Share this post


Link to post
Share on other sites

I believe you know a lot about car audio but you still haven't answered my original question. We can bicker all day and all night but it sounds like I'm going to have to learn the hard way. Maybe I'll catch you at a car audio competition and you can hear my system. Until then let's keep the thread to the original question. Thanks for the advice, I will be looking into the subject in depth before moving forward. A link to some information on mixing drivers and why it is bad would be highly appreciated 

Share this post


Link to post
Share on other sites
26 minutes ago, Michael Poole said:

I believe you know a lot about car audio but you still haven't answered my original question. We can bicker all day and all night but it sounds like I'm going to have to learn the hard way. Maybe I'll catch you at a car audio competition and you can hear my system. Until then let's keep the thread to the original question. Thanks for the advice, I will be looking into the subject in depth before moving forward. A link to some information on mixing drivers and why it is bad would be highly appreciated 

Have you even been to a show and seen someone compete with mixed subwoofer sizes? Ive been going for 10 years now and have never seen anyone. Thats for a reason. Use the search feature here or even google "mixing subwoofer sizes" I also answered your alternator question. EA can make a 400 amp alt that will be more than enough to supply a 3500rms amp.


2016 Focus ST3 - Rockford DSR1 / PPI 900.4 / Silverflute 6.5" mids / Massive CT2 tweeters /Sundown Xv2 15"/ Taramps DSP3k / Stinger Roadkill / KNU wiring / Northstar SMSAGM80 /

2010 Focus coupe 157@46hz

Pioneer 80prs /(8) FU Audio 750 12"s / (4) FSD 2600s / (1) FSD 125.4 / (1) FSD 85.4 / (4) Crescendo UN-10" mids / (4) Crescendo FT1 tweeters / Stinger Roadkill / 2/0 EB flex wire / (5) Powerware 90AH batteries / DC 270XP Alt /

https://www.youtube.com/popwarhomie

too many freq at once, burn the coil, we all know, over 40-50hz, its all coilburning material.

Share this post


Link to post
Share on other sites

Popwar is right mixing subs is stupid.

 

To your original point no reason to make separate systems make a joined system.

Share this post


Link to post
Share on other sites

It is ok to share the same ground. Beneficial though? Debatable. I do not really understand your concern...If you think otherwise, try it and see. 

Same for mixing Sub-woofer sizes.  Advice is advice, you take it or leave it, if you doubt or have a better idea try and see for your self. 

The depth of how sound, resonance, acoustics, etc. and all this stuff works is vast.  Folks all over the world learning better ways to build and achieve stuff that has never been thought of. I was remembering back in the 90s when I was even just scratching the car stereo scene's surface from my perspective seemed like I had seen it all.  Then I was reading a post from a 90's car audio veteran (I guess you could call them that...) who would build enclosures that would compliment or take into consideration the air space in the cabin of the vehicle.  Supplementing and using the vehicles resonance to achieve SQ, efficiency and loudness with what seemed like hardly any power...Calculating that stuff back then had to be done with out little gadgets that you can simply connect to your phone nowadays...

 It is very likely they gave a few pointers like above for a reason ;).

Share this post


Link to post
Share on other sites

"What is cancellation, for $500 Alex."

I have no idea how you plan to run 16 speakers off of one headunit and no processing. You're going to need a 16ch dsp and 4 4ch amps unless you butcher the shit out of everything

Edited by wew lad

I AM The Future of personal transportation, NOW!!
Pretty sure everyone on this site hates you (@JohnKuthe) more then me and that's very hard to accomplish.

Share this post


Link to post
Share on other sites

Create a free account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's free & easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Recently Browsing   0 members

    No registered users viewing this page.


  • Similar Content

    • By Deluxe_Fox
      I have tried so many things but none worked so far. I have a JVC KW-DB93BT and a McHammer Mystic 5.1 amp. When i connect 1 RCA cable to my amp from my head unit there is no whine, but as soon as i put in the other RCA cable into the head unit alternator noise starts coming from the speakers that are connected to the amp.
      I also tried a few fixes from this pinned topic (>>>Engine whine and ground loop fixes... take two) but none have worked so far.
    • By Owen prce
      Helloooooo
      Just to be clear i literally know nothing about car audio installations and i need help so i came here.
      I have a renault clio hatchback 2007 and i am wishing to install the skar audio spx-65c component system to the vehicle
      i dont want it to be runnning very loud, so i would like to stick to the stock amplifier if that is possible with the components i have brought (but only if it would work). Also how would i go about wiring up the external crossovers to the items that come stock in the car?
      and finally...
      what will i have to change / buy (besides from the mountings in the door) to make all the of this work?
      any help is greatly appreciated 
    • By JWD
      I ordered the head unit, wiring harness from crutchfield as well as a little controller module thing and another harness so the steering wheel controls will work. However, looking at the instructions provided by crutchfield, it says that both of the wiring harnesses need to connect to the factory 20-pin connector. I'm pretty sure you can't stack them/connect more than one in this way. 
      The whole reason i ordered through crutchfield was so i wouldnt have to splice into my factory wiring, which makes me uncomfortable (i dont want to create a problem). 
      I thought maybe i could splice the two harnesses together, but they dont have leads in the correct pin positions. Is there a way to splice a wire into one of these multi-connectors without cutting into my factory wiring? 
       
      Basically i have this:
      [steering wheel] --> [factory 20pin connector] <-- [crutchfield steering adapter harness] <--[control module] --> [head unit]
      but at the same time i have [factory 20pin connector] <--[crutch. receiver harness] <--[head unit]
       
      Either of these are easy enough by themselves, but i'm trying to do both at once, and as far as i can tell i can't snap both harnesses onto the factory connector at the same time. 
       
    • By Loganc720
      If anyone can lend some knowledge please help out .
      i have an aftermarket stereo with recently upgraded door speakers , now I am trying to install a 5 channel amp and subwoofer so I could boost all the door speakers and also power my subwoofer.
       I’m pretty confused on which wires have to run to which place , I wanted to just connect  the from the amp to the head unit to power all of the speakers from one place instead of running all new speaker wires. I’m trying to install this weekend just need more guidance
      Thanks Guys 🤙
    • By Christina Tipton
      Hi,
      I’m hoping someone can help me find the right adaptor for my car stereo.
      It’s my first car, a Volkswagen Beetle 2001, and the stereo is a Sony one (see photos). The previous stereo was taken out of the car so I’m not sure if I have all the right wires to get this one set up.
      I’ve attached photos of the stereo and the wires that I’ve currently got in my car.
      I did originally take this to Halford’s but they said they didn’t sell the correct adaptor and that I’d have to find this on Sony’s website.
      Does anyone know the correct adaptor, and the best/cheapest way of getting this?
      Thanks in advance for any help! :)




×