How do you install speakers, do I need new wire?

[trumpet 5,000+ posts]

To estimate the maximum current your amps might draw take the RMS watts, add it up for all the channels, and divide that number by 14.4(standard operating voltage with the engine running). A 1,000W RMS system would then draw 69.4 amps. In reality it will use much less than that on average, so this is why a stock alternator can usually handle that much power. This depends on the wiring under the hood, so the Big 3 upgrade is a must.

 

[keep_hope_alive Premium Member]

a few hundred watts shouldn't cause dimming issues if the main battery is in good shape, the alternator is working properly, and the big 3 is done, and you don't have everything in the car on while sitting at idle. you can get your battery and alt tested for free at autoparts stores. you can do teh big 3 with 4 awg and be fine (for your plans).

pretty much ignore max wattage ratings. RMS matters but you won't attain rated output anyway (unless you start clipping).

an alt produces about half it's rated output at idle. turn on your A/C and lights adn you are probably using 1/3 of it's output right there.

 

[zorphon 10+ year member]

a few hundred watts shouldn't cause dimming issues if the main battery is in good shape, the alternator is working properly, and the big 3 is done, and you don't have everything in the car on while sitting at idle. you can get your battery and alt tested for free at autoparts stores. you can do teh big 3 with 4 awg and be fine (for your plans).
pretty much ignore max wattage ratings. RMS matters but you won't attain rated output anyway (unless you start clipping).

an alt produces about half it's rated output at idle. turn on your A/C and lights adn you are probably using 1/3 of it's output right there.

Ok sure thing. I'll get it tested at an autopart story and do a 4 awg Big 3 upgrade. I looked at the wires that are grounding my alternator and battery and what-not under the hood and they're very small wires. That might be what was causing the problem, and Big 3 would fix that.

My new amp will take 340 watts RMS and my headunit 88watts (all channels added) RMS.

That's a total of 61 amps being used taking (340*2) + (88*2)= 856. I multiplied by two assuming it's not very effective being an A/B amp. 856/14 (assuming my battery isn't doing full voltage) = 61.14 amps. Granted it would probably only use half of that during normal use, if that.

Considering my stock alt is stated at 95 amps I'm assuming it has about 80% efficiency so that would be 76 amps. Assuming normal functions like lights, AC, etc. take half of that it leaves me with 38 amps in reserve. All my stuff would take about that many amps. It's basically going to be using the entirety of the reserves on my alternator. But that's considering I haven't done the Big 3 yet. Taking that into consideration I would say the alternator/battery become 90% (10% more) effective because of the way better current and ground.

That would leave me with 42-44amps instead of 38 amps in reserve, and my equipment would probably use 30amps on average in normal play, going up to 35-40 while peaking. So I'm still going to be using almost all my reserves of alternator amperage when playing music, but at least it should be able to do it. Would you guys suggest investing in a capacitor since after everything my alternator will only have a couple amps in reserve, and a capacitor would keep the voltage more stable?

Thanks in advance.

 

[Flex68 10+ year member]

Would you guys suggest investing in a capacitor since after everything my alternator will only have a couple amps in reserve, and a capacitor would keep the voltage more stable?

Nopey

 

[Pborcich 10+ year member]

Sure thing thanks for the info. I'm upgrading from a stock deck to a headunit and from stock speakers to new ones, but the existing wire should be fine? I'll look into a spool of 14ga or so, just in case.

I would consider this dependant....

most cars nowadays have some sort of "premium sound" and as such have an amplifier with their own unique connection at the speaker.... which can be quite annoying but what you can do is cutoff the speaker connections and use the wire

theres very few super easy swapout options in cars IMO

 

[goingdef 10+ year member]

Nopey

^^^this^^^

In a system so close to the edge of maxed out the cap will hinder your ability to bring voltage back up quickly after a current spike as now the cap has to charge before your amp will see stable voltage again, so if the voltage dips it will be for a longer period of time then if the cap wasn't in the system. I'm also not guessing or assuming on this, I played around with these years ago and there really useless, just invest in a good battery under the hood and save yourself the headache that most of us have been thru trying to make a cap work.

 

[zorphon 10+ year member]

^^^this^^^
In a system so close to the edge of maxed out the cap will hinder your ability to bring voltage back up quickly after a current spike as now the cap has to charge before your amp will see stable voltage again, so if the voltage dips it will be for a longer period of time then if the cap wasn't in the system. I'm also not guessing or assuming on this, I played around with these years ago and there really useless, just invest in a good battery under the hood and save yourself the headache that most of us have been thru trying to make a cap work.

So would something like this http://www.sonicelectronix.com/item_17907_SHURiKEN-SK-BT20.html help, to replace my current (way worse) battery? Would be alt be able to function with that battery without straining too hard?

Thanks guys for the help.

 

[SuperSaeYoung]

What you can do is run new wires for the back speakers, and use the back speakers wire and connect to the the front speakers at the headunit wiring.

 

[zorphon 10+ year member]

What you can do is run new wires for the back speakers, and use the back speakers wire and connect to the the front speakers at the headunit wiring.

Sorry, slightly confused with what your saying. So just replace rear speaker wiring?

 

[goingdef 10+ year member]

So would something like this SHURiKEN SK-BT20 (SKBT20) 850 Amp 12 Volt AGM Power Cell Battery help, to replace my current (way worse) battery? Would be alt be able to function with that battery without straining too hard?
Thanks guys for the help.

It looks like it should, I just go with the biggest yellow top I can fit in my car and it has served me well just be sure to never charge it with a normal battery charger,but if it's in there right it should never need charging I leave my stereo and highbeams on for hours at a time when working on friends cars and it runs into the night and never once needed a jump or even have it sound like it was struggling to start up.

 

[SuperSaeYoung]

Sorry, slightly confused with what your saying. So just replace rear speaker wiring?

What I was trying to say was if you're lazy and don't want to rerun wires, and you're using an amp, you can use the rear speakers wires for the front speakers and use new wires from amp to back speakers.

Does your car have it's own speaker harness?

 

[goingdef 10+ year member]

So would something like this SHURiKEN SK-BT20 (SKBT20) 850 Amp 12 Volt AGM Power Cell Battery help, to replace my current (way worse) battery? Would be alt be able to function with that battery without straining too hard?
Thanks guys for the help.

It looks like it should, I just go with the biggest yellow top I can fit in my car and it has served me well just be sure to never charge it with a normal battery charger,but if it's in there right it should never need charging I leave my stereo and highbeams on for hours at a time when working on friends cars and it runs into the night and never once needed a jump or even have it sound like it was struggling to start up.

 

[SuperSaeYoung]

Sorry, slightly confused with what your saying. So just replace rear speaker wiring?

What I was trying to say was if you're lazy and don't want to rerun wires, and you're using an amp, you can use the rear speakers wires for the front speakers and use new wires from amp to back speakers.

Does your car have it's own speaker harness?

 

[goingdef 10+ year member]

What I was trying to say was if you're lazy and don't want to rerun wires, and you're using an amp, you can use the rear speakers wires for the front speakers and use new wires from amp to back speakers.
Does your car have it's own speaker harness?

I see what your saying but it's going to be a wiring nightmare and very hard to keep it straight and leaves a ton of spots for shorts so the time you save will be spent trying to fix the half@ss wiring job you started just trying to save time.

 

[goingdef 10+ year member]

What I was trying to say was if you're lazy and don't want to rerun wires, and you're using an amp, you can use the rear speakers wires for the front speakers and use new wires from amp to back speakers.
Does your car have it's own speaker harness?

I see what your saying but it's going to be a wiring nightmare and very hard to keep it straight and leaves a ton of spots for shorts so the time you save will be spent trying to fix the half@ss wiring job you started just trying to save time.