ticky

I trying to help my younger brother to improve his sound system.
At the moment when he plays any heavy bass the sound is flabby & its seems as if he hasnt got enough power to drive his four 12" subs.
From looking at his set up (just subs)
2 subs push & pull run by a 1000 watt (500 rms) (bridged 2 ohms) X 2
2 Farad cap 1.0
4 awg power cable & huge battery
Also his cabin light & even headlight dim when he plays heavy bass. His amps are rated well but sounds like there not getting enough juice.

Can you get uprated alternator at 150 amps or more?
What are the standard alternators rated at?
Where would you get an uprated alt? & how much roughly £££
Would he be better off by having a second battery (split charge etc)

BigRed

Go for split charge system, i've also been told that caps are no good for your system as they discharge too quickly and just when you need the kick from them ,there also taking current to re-charge themselves, check talk audio forums for more details.

I'm running a Viper d600.1 mono class d amp capable of chucking out 600W RMS into 1 ohm load , this is runnig a Rockford Fosgate 2215 single 15" sub 1OHM impedence and a kenwood KAC 923 for front comps capable of 260Watts RMS.

My battery system is split charge with the standard Subaru battery under the bonnet and a deep cycle marine battery in the boot. The cables are 0 AWG for earthing and 4 AWG for +12volt power. This system sounds great with nice clean bass but turn it up too much and the lights do dim even with 2 batteries, i've not upgraded the alternator and have never had a flat battery to date, approx 3 years.

What amp are you running and are the subs a good quality name?I think the standard alt is 100amps.

ticky

The amps are Kenwood, cant remember the model no. It was a choice between rockfords amp & kenwood, due to his budget he went for a pair of kenwoods. The subs are pioneer, I use to have infinity's which I gave him but done a swap deal for some from mids & tweeters etc. Shame as I thought the infinity's had a good low bass.
Anyway just finished dynamating his complete boot yesterday.
I agree with you about the caps, they need the juice too. They play a few bass notes clearly then its back to normal flabby sounds.

How does you split charge work, what sort of charger have you got, cost etc.
Could you explain the deep cycle battery, what amp rating is it, cost etc.

Oh we just found out that his amps have a warning lamp in regards to low voltage (14volts) or something , they keep flashing up.

BigRed

Normally an amp will operate down to around 10.5 volts before cutting off because of low voltage, 14volts is slightly over the normal 13.8volts, so don't know what the LED is for, OVERVOLT possibly?

Sounds to me like the alternator is not charging the battery properly or overcharging, have both the alternator and the battery tested, the battery is the likely one, how old is the car?

My split charge system has a simple split charge relay under the bonnet that , when the car is running engages and sends the charge from the alternator to the second battery in the boot and the oringinal battery, MORE CURRENT IS SUPPLIED BY BOTH BATTERIES, so less strain on the original battery and less flat batterys when you need cold start cranking amps.
My deep cycle battery was purchased from a camping shop, it is recommended for boats, caravans ETC and is 85amp/hour so give plenty of kick also keeps it's charge really well, even through winter. It has a little viewing window on the top with a light inside, this light changes colour with the charge state of the battery, it normally stays green for full charge, sometimes during winter it turns black for half charge. It has never turned red for low charge. This cost around £40 and came with a 3 year warrenty.

EDITED to say

You can get Optima yellow or red top batteries but cost a small fortune so no go if your on a tight budget.

Also another thought on the LED ,it's not a warning for signal clipping is it?

LEA

ticky

The car is old E30 Alpina, but battery is new, will get the alternator checked.
Whats signal clipping?
I will have to try to get the maunal on the amps as he has managed to lose them, cant remember what all the features do?
Was the relay easy to fit, cost etc

Thanks Ticky

BigRed

Signal clipping is when you are introducing distortion into the signal or to much voltage on the RCA for the amp to handle, resulting in 'clipping'.

Relay is dead simple as long as you know what you are doing with car electrics that is.

You need some 4 awg cable to run down the car into the boot, by the sounds of it you already have some in place. The relay is fitted as close to the battery (under the bonnet)as possible in the +12 feed along with a fuse, i have 100amp circuit breakers on my set up at BOTH ends of the cable. The coil of the relay is then connected to an 'aux' +12volt feed, a +12volt feed that is on when the engine is running and goes off when the engine is switched off. A good place to find this feed is at the back of the radio. The relay will also require an earth point for the coil as well.

Fit your second battery in the boot, then attact the +12v terminals and earth leads and will need another fuse as close to this battery as possible in the +12v as well. Find a GOOD earth point for the second battery preferably straight to the chassis.

REMEMBER to fit all fuses and connections correctly as a car battery will set fire to the car if mistakes are made.

Your amps will also need a good earth point as well.

My relay was brought from Maplins but they dont sell them now, it cost around £15 a few years ago now. You can get these relays from Car Audio Direct but I don't know how much they are now. I fitted all my ICE myself so don't know how much it would cost you to have a split charge system fitted at an ICE installer.

LEA

ticky

Thanks BIGRed Im sure my little bro appreciates all the info.
His battery is already fitted in the boot but luckly there is space for another on the opposite side. Yo cant beat Maplins lol
Its better if I get one of my pro sparky's on the case dont wannna cause any fires.

Once again Thanks Ticky

luddite dave

Hiya Ticky just regarding split charging systems and car alternators.When the engine is running the alternator supplies all the power required up to its given output say 70 to 100 amps when you exceed the max output of the alternator then you start drawing off the vehicle battery,so regardless of how many batterys you fit they only act as a reserve for when the alternator runs out of steam.What you could try doing is uprating the power cable from the alternator to the battery this is normally like crap 8 gauge ,also run the same gauge cable from the earth terminal on the battery to the engine block where the factory earth is.This will improve the current supply from the alternator.As for power caps they are designed to discharged much quicker then any vehicle battery can when excessive load demands such as when a bass amp kicks in, they do make a difference but they also put extra load on the electrics but i would still use them none the less.

ticky

Hmmm, so its still looks like he will need a uprated alternator?
Any pointers where from?