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How to hook a car amp up to your PC

Discussion in 'Cases, Modding & Electronics' started by hellrazor, Feb 25, 2010.

  1. hellrazor

    hellrazor

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    Do you have a car amp laying around? Are your gaming experiences too.... quiet? Do you have crappy-ass Durabrand PC speakers that snap, crackle, AND pop? Do you get the itch to wake up your neighbors?

    If you answered yes to any 2 of these questions, this guide may be for you!

    Ok, enough of the cheesy advertising. I've had this one done for a while, so I can guarantee if you do it right (and every part works), that it should all be fine and dandy.

    Things you'll need:

    1 x Car Amp
    2 x Box Speakers
    1 x Minijack-to-RCA cable
    Some x Various other wires and cables
    Various x Tools
    A x PC

    Knowledge You'll need:
    A 200 watt car amp DOES NOT pull 200 watts (that would mean my entire PC is running off 50 watts) - I'm not sure what it does pull though, so don't ask.

    A car battery gives 12 volts, so does your PSU.

    If your doing this with an independent PSU (AKA, not the one in your PC), you'll need to connect wires 15 & 16 (green and the black right next to it) to get your PSU to turn on. I'd also recommend getting one with a rocker switch in the back, so you don't have to rig one in between 15 & 16.

    If your amp uses more than around 500 watts you'll want to use multiple molex connectors, because a single 14-gauge wire might not be able to hold all the charge needed for the entire amp, causing it to heat up and possibly melt. There is a method to the madness; if you unplug all your drives and your video card, you should be able trace all the wires back to 2 or 3 bunches (unless you have a modular PSU, in which I'm not sure how this would work), you'll want to connect the amp to as many bunches as you can. This way you're effectively dividing the charge on each wire (and sometimes making it easier on your PSU), if it works correctly. If you do two (or more) connectors on a particular bunch, your not gaining much because the charge will still have to go through the single wires that come out of the PSU, which is what you're trying to avoid in the first place.

    Step 1: Prep your PC
    Turn down the volume on the taskbar, and I mean DOWN to like 2-10%. Remove your side panel (unless your using an independent PSU)

    Step 2: Wiring up The Amp
    Connect the red wire (Positive) to the orange wire (Remote). Make sure that there's just bare wire at the end of all of the wires coming from your amp.

    Grab a Molex connector, you want the male end. Cut the Yellow (+12v DC) and the Black (-12v DC) right next to it, you'll want them as long as you can get (you can also remove the red and black if you want, but when I did it the Yellow and Black got a little shaky/loose).

    Connect the Molex's Yellow to The Amp's Red & Orange, connect the Molex's Black to the Amp's Black. Twist, tie, tape.

    Step 3: Connecting the Amp and Speakers
    You want box speakers (the ones that just have the - and + wires hanging out the back), if you don't have any you could try Goodwill (you can usually get them for like $20 over there). Connect them to The Amp. I'm not sure whether the - on the speakers really needs to be connected to the - on The Amp, but do it just to be safe (my speakers just have 2 nondescript wires, and they work fine). You may need to make them longer too.

    Step 4: Connecting it to your PC
    Plug the male Molex into your PSU, grab the minijack-to-RCA and plug the minijack into your sound card with the RCA connected to The Amp. If you have an amp that has more than 2 channels, you may need to move the speakers and RCA cables around to get the right ones.

    Step 5: Fine tuning
    Make sure all the wires are insulated good. Check them again. The last thing you want is your house up in flames, so check them once more.

    If your using an independent PSU, make sure it's plugged in.

    Turn on your PC. Adjust volume as needed (I did this with a 200 watt amp, and mines at 4% volume).

    Step 6: Make sure it's all up to par
    Play a game, more specifically, a really power-hungry one *cough* Bioshock 2 *cough*. Make sure your PSU is fine and running good.

    Other remarks:
    You could also hook up a car radio to your PC if you'd like, but I haven't done it yet so I don't have a guide.

    If your case is a tank (really heavy-like) you could rig up The Amp to your right-side panel, but mine's a lightweight, so again, no guide.

    If your using an independant PSU, you might want to remove unnecessary wires. I cannot recommend this as your PSU could deep-fry your pasty-white nerdy ass any day of the week. PSU vs. You = Dead You (and possibly cops). I have done this though (rigging it up for a friend ;)), so I won't say it's impossible.

    YOU MAY NEED TO ADJUST YOUR BASE. It'll probably be overwhelming. Try adjusting the gain on The Amp first, then adjust the equalizer in your drivers/programs next.

    IF YOUR AMP NEEDS A CAPACITOR don't ask me, I don't know what to do with it or how to rig it or charge it or do anything with it. Mine doesn't need one, so no guide.
     
    Last edited: Mar 1, 2010
    erixx, burtram, ex-dohctor and 2 others say thanks.
  2. MKmods Case Mod Guru

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    this would be a fun mod to do, making a case with a quality amp , head unit, separates with sub. (maybe even throw in a headphone amp)

    Be careful when using a car amp and a comp PS, very few comp PSs are able to supply as much current as a good amp needs. So make sure to do your homework (my car amp can use up to 100A) So its important to know how many amps your stereo amp pulls (dont pay as much attention to the amount of advertised watts as on most car stereo amps thats misleading)

    and most likely you will need to run several yellow wires(grounds too) off your PS together to supply the current.
     
    Last edited: Feb 25, 2010
  3. Zebeon New Member

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    that is awsome!!

    but like MK said.. BE CAREFUL or you will burn something up.
    My amp pulls LOTS of power
     
  4. TVman

    TVman New Member

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    no pics:(
     
  5. theonedub

    theonedub habe fidem

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    You need thicker gauge wire to prevent burning or melting, the min I run even for a 200 watt amp is 8ga from the battery to the amp. This really has bad idea written all over it in terms of safety.
     
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  6. cdawall where the hell are my stars

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    this will only work with low watt amps my car amps will smoke any current PSU...
     
  7. Papahyooie

    Papahyooie

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    I thought this was going to be a thread asking how to hook up a car amp to household speakers. A big no-no of course. I was pleasently surprised to see a nicely put together guide for something that is useful and actually works the way it is meant to, and by someone who's done his homework no less. Something that could be mentioned is gauge of wires needed. Too thin wires could be bad for business. Other than that, Kudos!

    D'oh dub beat me to it. And as CDawall says, only very low wattage amps. 2000w kickers will NOT work for this lol.
     
  8. selway89

    selway89

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    I would NOT recommend using the PSU to power BOTH the amp and pc. You could take the whole lot with it! A separate PSU with a large current rating on the 12V rail.

    I have a home made sub-woofer using a car amp to power it with my hifi speakers. I measured the current that my amp drew at the volume I would be listening at and checked the PSU could deliver. I should ideally change the fuse on the amp to the rating of the 12v rail or less but haven't got round to it.
    And as others have mentioned fatter wire is needed to ensure no wires burn up! I removed all the un-used cables from the PSU and combined all +12v and GND to build up the thickness to take the current.

    On a side note I personally don't like the sound of car speakers. I have always and will prefer proper HiFi equipment, I am only using a car amp for the sub as it has the functions I need and was dirt cheap. :)

    I may have pics for guidance somewhere.
     
  9. cdawall where the hell are my stars

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    my pair of 600w rockford fosgate class A/B's wont do it either...
     
  10. theonedub

    theonedub habe fidem

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    Selway89 has a much more sound attack plan. The way the OP explains it he has one 14ga (if that) wire supplying power to the amp- bad idea.

    My A/B Fosgate is strong but is the poster child of inefficiency, if I pushed my stereo often in my car it would be replaced my a class D in a heartbeat (powers my Premier sub only) /OT
     
    Crunching for Team TPU
  11. hellrazor

    hellrazor

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    No camera.

    Mine works fine with normal Molex wire (and whatever gauge is on the amp). I haven't done any real tests with it yet though (I live in an apartment complex, and I DON'T want to wake the neighbors). It's probably a good idea, but the only way to get the full benefits from doing that is to replace the wire inside the PSU, which is NOT a good idea.

    Same as above. I've rigged this with an indie-PSU for a friend and the PSU in my PC for me (I don't have PSUs laying around like he does). Mine hasn't ever gotten really loud, so unless you're throwing a party or so, it should be fine.

    I did, however, plug an old kitchen-counter style radio into his, and saw how loud it could go. I was pleasantly surprised, it started fluttering before it the radio maxed out. No fires, no sparks, it might have gotten warm though (I used liquid tape on his, and that stuff never seals right the first time, so I wasn't in a hurry to go check it out - and yes he did retape it after I was done and left).

    Also, the comment about the "crappy-ass Durabrand PC speakers that snap, crackle, AND pop" at the top was my reason for doing the whole thing in the first place - and believe me, it was very well justified. They sounded like a 50 year old record player, and only got worse when I moved the mouse (or did anything else, for that matter).
     
  12. cdawall where the hell are my stars

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    i have my fosgates powering a alpine type E 10" each in a slot port box i have peaked both the subs but not the amps hehe. great amps IMO who needs class D's these hit harder than any other similar class D setup i have heard
     
  13. theonedub

    theonedub habe fidem

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    little more OT :D

    Fosgate amps are indeed very nice. I had bought a Hifonics 1206D that I used for a short time, but was more satisfied with my P5002. My situation is reversed though, I have mine powering a Premier TS-W3002SPL slot ported to ~36hz- peaked the amp not the sub.
     
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  14. Lazzer408

    Lazzer408

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    Will this help? Note the green ps-on terminal for both 20 and 24pin ATX connectors. Green wire on either.

    As far as the math. If a 12v rail can supply 20a then 12*20=240w. Amplifiers are about 65%(Class-AB) to 90%(Class-D) efficient.

    Derated Class-AB 240w*65%=156watts/2ch=78w per channel
    -or-
    Derated Class-D 240w*90%=216watts/2ch=108w per channel.

    [​IMG]
    [​IMG]
     

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    Last edited: Mar 1, 2010
  15. hellrazor

    hellrazor

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    Yeah, that's really good. Thanks!
     
  16. theonedub

    theonedub habe fidem

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    I hate to bump this, but it is relevant. That's not how efficiency works for a car amplifier. If you have an amp rated for 240w that has an efficiency of 50% its going to draw 480w to produce the 240w and waste the other 240w in heat. Its just like efficiency in a computer PSU- a 700w PSU that is 80% efficient will supply the 700w, but it will consume over 700w in order to do so. The rest is thrown away in heat.

    It changes your numbers around by a substantial margin.
     
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  17. assaulter_99

    assaulter_99

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    Ah so you posted it here! rofl! I commented bout that in another thread earlier. Thats cool man, I might give it a run this week end. I have a couple of car stuff lying around.
     
  18. dr emulator (madmax)

    dr emulator (madmax)

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    ha ha i did this years ago when someone bought a car tape player around, so i wired it up to my snes and had it in my shed /workshop/room ahh the joys of not having anyone near enough to moan about the noise :D

    @Lazzer408 where's the diode on that relay man :wtf::shadedshu

    also another consideration is that unless you have an ultra stable psu your likely to have the the psu cut out because of big variations in the amount of current drawn :p
     
  19. Lazzer408

    Lazzer408

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    It's in the other schematic I posted weeks ago when the last guy asked how to do this. :D
     
  20. dr emulator (madmax)

    dr emulator (madmax)

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    just pullin your leg :laugh::D
     
  21. Lazzer408

    Lazzer408

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    I figure but I did update the schematic and slapped in a diode. :toast:
     
    dr emulator (madmax) says thanks.
  22. SabreWulf69

    SabreWulf69 New Member

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    Lol, I've done this before, completely impractical though. Had an old Dell server board with dual independent 750Watt PSU's connected to it, with a lot of Amperage and it still distorted more than when I simply had a car battery hooked up to it. Dangerous, need thick cabling, and a lot of power, DO NOT put car battery in your room if you were thinking about it either, as the amount of amperage in them is enough to weld a spanner across the terminals. The only safe way to do this I found is to get an expensive adjustable DC power supply with at least 120+ Amps of power, or buy proper home theater gear, that isn't designed in any means for weather durability, just quality with the higher end stuff. PSU's are simply NOT designed to supply enormous amounts of current draw on and off all the time, that any decent car amplifier will require.
     
  23. Lazzer408

    Lazzer408

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    Post #14 I explained that.
     
  24. Lazzer408

    Lazzer408

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    Read it again. You basically just repeated what I said but I based my amps 'rating' off available power and when the efficiency of the amp is taken into consideration that power becomes alot less.
     
  25. LDorn920 New Member

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    Hello!:) What about Just having the amp Hooked to a Car(or Large MotorCycle)Battery, but have the Mini-Plug from the PC to the amp! That would sove the Power consumtion Problem, with out putting a strain on your PC!
    This is a Very Good Idea! Minds Are at Work out there! Thanks for the tips!
     

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