6G Celicas Forums

Hey everyone!

Just got my sound setup all put in (nothing huge)

Whats the best way to secure a 12" Sub box in the boot? So its easy to access the spare tyre etc.

Also, when i have my sub cranking at night (headlights on full beam) they tend to have a slight flicker with the beat. Could this be from a bad earth? Or do i need to upgrade my battery? Or even my alternator?

It could be a bad ground but its more likely to be the amp drawing too much current from the battery. This puts a lot of extra stress on the battery and alternator. What size amp do you have? A capacitor is supposed to be a fix for this issue. It acts as a second, small battery so that it takes the hit instead of your battery. However, I've heard several times that capacitors are a huge waste of money.

Ive never needed one but a capacitor is designed for delivering large amounts of current very quickly. Using a large capacitor would even out the spikes in the current.

As for securing the box, what I did was drill holes through the bottom of the box into the underside of the car. I felt that 3 bolts in a triangular layout were sufficient, since it was hard to reach two corners of the box from under the car. You will want bolts about 3"- 4" long, and what I did was cut up the sole of an old pair of running shoes for the mounts. You want a chunk of rubber between the chassis and the sub box, but you also need a chunk of rubber between the box and bolt head and between the chassis and nut. If you dont add these two extra rubber pieces then vibrations will travel through the bolt.

So here is the order I did starting from inside the box to the underside of the car.
Bolt head
washer
rubber chunk
washer
Sub-woofer box
Washer
rubberchunk
washer
Floorboard/chassis
Washer
rubber chunk
washer
Nylon lock nut

a capacitor does not do anything. many say it helps giving extra boost blablabla, but at the best, it MAY remove some noise from dynamo and reduce ripples.

it is only good for:
Jewelry in the trunk to impress chicks with a cylindrical shiny thing,
Extra weight
A very poor and expensive connection point
A projectile in event of a crash
A expensive rolling pin if you gotta cook something in your trunk on a trip.
Something you can brag about: Hey maan check this, ive got a condensator to fix all my battery problems.

A Capacitor only delivers around like 100W over almost 1 sec... well worth the bucks!! cheaper to go buy a scrapped battery at the junkyard and connect it up in your trunk, and it works way better because a battery delivers the power of 200++ capacitors.

It is funny how many that think capacitors work... I myself belive it triggers a "placebo effect"...


The easyest, and best way to improve it is better battery with lower inner ressistance (E) so it can deliver bigger discharges, and improve connections...

Edit: Soo, Bigger dynamo and battery is the way to go if you want to stop the flickering because when the lights flicker it is because your voltage dropps when the sub "suck the most" and the alternator cant keep the voltage up so it draws from the battery as well.

This post has been edited by tto010: Jan 19, 2013 - 11:52 AM

Haha, I guess electronics work by magic. All those capacitors inside everything from your TV to your cell phone must be TOTALLY useless.

I had to put decoupling capacitors on my sequential turn signal to make it work right. The cmos chips were too sensitive for the jitter caused by the 555 timer, adding a capacitor to the power supply fixed this. But Im sure it was because of magic and not because a capacitor is perhaps the most useful electronic component ever manufactured.(google RC, resistor-capacitor circuit)

A capacitor doesnt need to supply power for longer than even a few microseconds. When the amplitude of the music goes high, the capacitor drains, when the amplitude goes low or the wave crosses zero, the capacitor recharges. It does this hundreds to thousands of times a second, it is a decoupling capacitor and it smooths out the ripple from the power supply.

Adding a battery to the trunk is a stupid idea. Youve added 40lbs of unnecessary weight, you need a sophisticated electronic relay to keep it from supplying power back to the main battery or else you need to run a 0 or 2 gauge wire all the way to the trunk. Because when you hit the starter, its going to try to draw amperage from both batteries, and the 6-10 gauge wire running to the trunk isnt large enough and will get toasted.
The sulfur fumes from the battery are toxic, and youve now placed a battery inside the passenger compartment. The hydrogen fumes are explosive, and the trunk is not as well ventilated as the engine compartment. Youve also got a half gallon of battery acid in your trunk that can possibly spill.
A battery also cost money
If you use a bad battery it will kill the alternator and main battery in the engine compartment.



Need I go on?

This post has been edited by Special_Edy: Jan 19, 2013 - 1:58 PM

Acually, i know that the condensator is a very neat component, i was talking about the ones for stereo... its a beast when we talk about mA. But when it comes to delivering high amounts of burst, a battery with a low inner ressistance is the thing but they are expensive... so how to svolve it cheap?? another battery...

Yes i know that adding a battery costs more money, there is acid in it (Gel battery = no spill and no gases) And you gotta get a battery that is compatable with your existing battery. 6-10 gauge is enough... i bet you dont have anything bigger then 50gauge al cable to your house... and the starter does not draw more power than your house... the cable to the original battery is 10 gauge, why is not that fried? and when you have 2 batteries, it will draw half from each battery, or more from the one in front since its less ressistance to get to it... and 10 gauge is nothing for a power cable to the stereo...


and, Math to prove condensator does not do anything worth the money.

If we calculate how much Joule it delivers (Watts in secounds-ish... 10 joule = 1watt for 1 sec or 5watt for 2 sec) The formula to find the answer is
W (Joule) = (F (farad) / 2) x U (Squared Charge voltage)
with a extremely big condensator... (20 Farad)
(20F / 2) X (14x14) = 1960 joules (196watts for 1 sec, i.e. enough to power your headlight for almost 4 sec... and if you have a 1kw amp, 0.2 sec)
so, thats the extremely overkill one, probably bigger and more expensive then a battery and alternator... so here is the calculations on a 1F (normal one)
(1F/2) X (14x14) = 98 Joules (98 watts for 1 sec, i.e. headlamps for almost 2 sec, or 1kw amp for 0.1 sec)
If we compare that to a battery, thats badly discharged would be like 2M Joule... this is because battery does not "store" energy, it "makes" it with chemical reactions (gel batteries does not make gasses, but water batteries does).

That explained how it works...

Battery/Alternator = 14,2v

If the potential is getting lower over the battery/alternator then it is over the amp, then the condensator will discharge the other way, so that it will be utterly useless. (potential is not current...)

AND, since the capacitor have a potential above itself all the time, it means it will never go below 10volts, that means on our oversized capacitor, most of the Joules becomes unusable, around 1000 of them... that means we only have 960 Joules...

Because of the Heat it develops when we discharge the Cap, we will lose 13% at 100 amps.. that means we dont have 860 joules (34) any more, but

If the capacitor is 0.017 ohms (No capacitor will get this low) and 100 amps is flowing through it that means it will have 1,7 volts over it... this means you have less voltage over the amp... 12,5 volts... That means the amp will require more power because the voltage dropps.

The Load (100 ohm) will consume 1250 watts from the Capacitor. Since there is some Voltage over the Capacitor, there will be 1420 Watts over the Cap and Amp. This means that 170 Watts go to waste in heat in the capacitor.


This means that the cap can work if there is ONLY alternator and a Amp... but there is just so much more to it than that... i have just written down ESR and the amount of Joule it delivers, but how the alternator/battery works and the different systems on the car require power as well. when everything is mashed together, it is so little difference that it is not worth spending the 100 bucks on a Capacitor... either play the music lower when it is dark, or change your alternator/battery and check connections...

And, the lights flicker because the voltage dropps... and the voltage has to dropp for the capacitor to discharge, but it can only substain the headlights for a half secound if it was ONLY Headlights when you have a big ass capacitor on 20F...

BTW, i have a amp on 2500watts and one on 1300watts, i can play on max volume without any flickering on the lights... and i have original battery and alternator.

But beyond all other things, your arguements fail to realize that the point of the capacitor is not to totally supply all the power of the amp for x number of seconds, it is to suppliment the defecit of the cars electrical system.
Totally made up numbers but say his amplifier was consuming 15 amps, but the alternator/battery only had 10 amps available due to the demands of other electrical devices(headlights, etc), there would be a defecit of 5 amps. Therefore, the capacitor would only need to supply the difference, 5 amps, and only for a few fractions of a second.
Another consideration you fail to be able to digest, the human ear cant hear below 20Hz and the music really isnt going to hit below 40Hz. 40Hz means that it goes high to low 40 times a second. The amperage draw of the amplifier will be an average of these sine waves(your house's 120volts is actually 300volts, but because its a wave it averages 120), the current will increase as the music reaches the peaks and valleys of the sine wave, but it will become zero as it crosses zero. So at 40 Hz, the amplifier will draw maximum current 80 times per second, and will draw zero current 80 times a second. The capacitor will charge and discharge as often as it needs to, 40 times a second at the lowest level of human hearing and 34,000 times per second at the highest frequency of human hearing.

Yes adding a more powerful battery or alternator will improve this problem he is having, but so will a capacitor. A capacitor is not a lead/acid battery. The battery is more akin to a deep cycle battery in relation to a capacitor. The CCA of a battery is in the hundreds, the CCA of a capacitor is in the thousands or millions, it is designed to totally expend all of its power and recharge in just fractions of a second, an area where the battery falls flat on its face. Just because you read that "capacitors dont work" on google doesnt make you or the person who wrote it an expert. Have some common sense instead of regurgitating information you copy/pasted

This post has been edited by Special_Edy: Jan 20, 2013 - 12:16 AM

200amps in the car...wtf

Maybe it was watts?

Caps in an car audio environments cause large amounts of issues if done incorrectly. Now if done correctly the benefits are there.

One of the most common issues I've seen with caps is it draining the battery on people while the car is off. Wouldn't some simple steering diodes remedy this? No idea never tried to fix them, I just take them out, and check to make sure the system is running how it should without.

The starter uses 100-200 amps on most vehicles, and most batteries are designed to supply 300-800 amps to the starter. Amperage x voltage = wattage. So 10 amps of 120v power in your house is the same as 100amps 12v dc in your car.

This same equation in mind, a 2400 watt amplifier would be hooked up to 12 volts. 2400watt / 12 = 200 amps.
So if you believe the advertising, a 2400 watt amp would require 200 amps constantly. I doubt that the 30 amp fuse you have hooked up to it could handle 200 amps. Its because they advertise peak power, a 1 farad capacitor for instance can deliver 10,000s perhaps millions of amps worth of electricity, but only for the tiniest fraction of a second so why use this figure except to false advertise.

Most amplifiers I see have a 25-50 amp fuse on the main power cable.
50amps x 12volts = 600watts Maximum before the fuse blows
25amps x 12volts = 300watts Maximum before the fuse blows

I was actually discussing this with my friend the other day, I suspect that newer cars will start to switch to 24volt or higher.
A 24 volt car would require half the copper wiring, half the size starter, half thesize blower motor, etc. Because twice as much energy could be transfered through the same size wire.
Imagine if we switched to 120volts as an example, we could shave the weight of the electrical system to nearly 1/10th the weight. Power supply and SSR technology has reached the point where cars will soon make the switch from their barbaric 12volt systems.

Its a 300watt (peak power, not rms) Sony Amp, running a 1000Watt sub. I did read, and think about a capacitor. But there are both cons and pros to it.

Is it worth moving the earth first? Then putting in a new battery? At the moment i have the earth connected to the bolt that holds the rear seat to the body of the car.

Annnnd that would be why I have not seen a 200 amp circuit in a car...

No intention to make my ears bleed.


I'm running a 800 watt in my car atm, maybe 600...can't recall just swapped it. Either or, I don't have a cap, all stock alt...fresh standard battery. No issues.

Peak power is a useless number.

Its like saying all Celica GTs are 500 peak horsepower. Because the 5sfe engine block is capable of withstanding 500 horsepower before it literally cracks in half.
In reality a Celica GT is 135hp, RMS or continuous if you will.

Saying you have a 2400 watt amp or a 1000watt sub means the maximum amount of energy physically it can handle before you risk damaging it.

for the flickering, your alternator cannot recharge the battery or maintain itself rather faster than your sub bass hits. you fix it by getting a good battery like optima, get a higher amp alternator, a capacitor, and upgrade the big three wires.

He is correct, if you're having power strains from your system you should do the big three, then the alternator. You can take your alternator to a rebuild shop to have them beef it up. After that if you still had power problems you can add some dry cell batteries like these or or this, while running bigger gauge copper wire to your trunk. Batteries though are not needed for most people, even when the think they are needed.

Also where/how did you ground your amp in the trunk? The best way(that I know) is to get yourself one of these to remove all paint around your ground point. Check the ohms at said location with a DMM, the lower the better. Good locations are the strut bolts, or any spot that's not spot welded and is more in connection to the frame. But this is all based on information that I've read/heard over the last few years since I got into car audio, which some may have different view points/suggestions.

Thank you again for the replies! I have to now upgrade my stock speakers in the car too so they can handle to music haha. Anybody recommend any brands of 8inch speakers for the doors (not subs....) Because im not wanting to make a mount for 6 inch speakers.
Im asking as i will have to import some for the US as NZ doesn't seem to sell any 8 inch speakers for cars

Search instead for marine audio. It's a bit more expensive than car audio but there are plenty of 8" speakers available.

What Richee3 said but also water can get to the backside of your door speakers. The wiper/seal between the door and the window doesn't work perfectly.

Just ordered some new speakers from Amazon. Made sure they will fit (depth wise) So im hoping they will be decent. Anythings better than the stock ones xD

Marine audios not a bad idea. Might be a good idea for me to get some when i get a 4x4 one day

I've got a set of Focal 210 CA1 (8") full-range woofers in my doors. Glass fibre cone make them pretty hardy, and Focal is distributed globally so you might find a set closer to home.