[Autophile]

Also your system needs tweaking. :-)

[navin]

I dont think you do. I'd check the wires and caps first.

[Bass&Trouble]

Originally Posted by Autophile

B&T

The rails of amplifiers operate at very high volatge which is dependent on the input voltage. Hence the output voltage (AC) on speaker terminal changes when the input voltage changes. So you have different values in your calculations.

For example :

Our 4 Ch TRU Technology Billet Series amplifier B-4.75 is rated as following

Load - 12.5 Volts / 14.4 Volts

4 ohms - 75W X 4 / 100W X 4

2 ohms - 110W X 4 / 150W X 4

4 ohms bridged - 200W X 2 / 250W X 2

These are also conservative figures. It can deliver much more than that which accounts for Headroom

Though you are right on the load being frequency dependent. It varies from one driver to another and depends on the type of enclosure used for the driver.

Rail voltage is the last thing low bass maker has to bother about. I was just pointing out why Navin couldnt come up with an ampere rating closer to realistic.

Mr. Low Bass Maker, a high-performance alternator is a pesky thing and unwanted in non-competitive circumstances. It has much higher rotation resistance opposed to the stock alternator. So practically, this is like driving around with 2 Sanden 507 airconditioner compressors running all the while. Unless you keep the system at full blast for extraordinary periods of time (in which case...helllooooooo..can you hear me? or are you suffering from partial hearing loss ..lol), you should do well with a higher performance battery (or 2, depending on how much reserve time you desire).

As for blokes in India knowing about car audio, trust me there are a lot of them and I see some sparkling examples in this forum itself.

[gunbir]

Originally Posted by Bass&Trouble

Mr. Low Bass Maker, a high-performance alternator is a pesky thing and unwanted in non-competitive circumstances. It has much higher rotation resistance opposed to the stock alternator. So practically, this is like driving around with 2 Sanden 507 airconditioner compressors running all the while. Unless you keep the system at full blast for extraordinary periods of time (in which case...helllooooooo..can you hear me? or are you suffering from partial hearing loss ..lol), you should do well with a higher performance battery (or 2, depending on how much reserve time you desire).

Egjacktly... LBM... You donts the needs the alternators. Upgrade your cables, tune your system properly and you will live happily ever after...

Originally Posted by Bass&Trouble

As for blokes in India knowing about car audio, trust me there are a lot of them and I see some sparkling examples in this forum itself.

B&T its nice to have you here... Are you a hobbyist or a professional?

[Bass&Trouble]

Originally Posted by gunbir

B&T its nice to have you here... Are you a hobbyist or a professional?

Thank you very much, actually I'm quite glad a friend enlightened me about this forum. Warm place.

Hobbyist/ Professional, both in varying degrees. Overall, a car audio enthusiast to the core. I'm just enjoying myself

[low_bass_makker]

I fully agree with Bass & Trouble. What he said is fully right how much time do i want to run the system. If i play my system for 30 min at full blast and then return to normal volume the voltage in my car drops to 13.6 against the normal of 14.6 volts it means that the battery has got discharge and need some time charging to come back to it orignal level. But If i had a big alternater the battery voltage would not have drop, this is also true there would be a extra load on the engine also.

[navin]

LBM, are willing to make the sacrifices (ghigher load on engine, lower battery life, etc..) for this?

If I were you and really needed that much more power I'd get a second battery and a dual battey isolator. cheaper. cleaner. and does not affect my battery's life or car's performance.

[low_bass_makker]

Originally Posted by navin

LBM, are willing to make the sacrifices (ghigher load on engine, lower battery life, etc..) for this?

If I were you and really needed that much more power I'd get a second battery and a dual battey isolator. cheaper. cleaner. and does not affect my battery's life or car's performance.

I would have done it very earlier but it will put load on the exsisting system and when would I charge the TWO battery. Right now if i play my system for 30 min at full blast the battery gets consumed and it needs some time to get recharge so if i put second battery it will double the trouble on the alternater. t will have to charge two battery. I think the only advantage of puttting a second battery in the car is have larger playback time nothing else.

Do u agree with me Mr Bass & Trouble , plz quote on this.

[Sam Kapasi]

I think Bass and Trouble is a superbly creative monicker. Superb. Superb. I will put it next to Steeroid's name in the list of Team-BHP nicks i like.

[Bass&Trouble]

Originally Posted by Sam Kapasi

I think Bass and Trouble is a superbly creative monicker. Superb. Superb. I will put it next to Steeroid's name in the list of Team-BHP nicks i like.

Is that a compliment? I guess I need to go visit dictionary.com.

[low_bass_makker]

Bass u did replyed my answer yaar !!!!

[Alpha]

Dear Sir
i am new to this site
but i have few suggestions
i will go for the bigger alternater because the load on the engine increases only if you extract more from the alternator otherwise the altenator is like the free barring
let me give you an idea
if one hp motor of 220volts drive a car alternator on pully the alternator can produce practically around 40-50 amperes easily and the motor will take the load of the alternator this means if your load is say 200 amps allways! @ 14 volts you will sacrifice only 4 hp of your engine power so the power loss is not so big u might even not notice it.
And a bigger alternator does not mean the u have to install a bigger battery as u can charge just 50 aH battery with a 5000 Amp alternator because every alternator comes with a cutout switch and the stock charging of any (world) car alternator is around 4-7 amps so therfore do not worry about over charging the Battery.
And let me tell all u guys one more thing
If we had a perfect amplifier (and it was plugged into an outlet that had unlimited current capability), its output power rating would double each time the load impedance was halved. For example, let's say the amplifier puts out 200 watts per channel at 8 ohms. At 4 ohms, it would put out 400 watts per channel, at 2 ohms it would put out 800 watts per channel, and at 1 ohm it would put out 1600 watts per channel. For the perfect amplifier, one could keep going with this until the load impedance approached zero, at which time the amplifier output would approach infinity! On the other side, if the load impedance was 16 ohms, the amplifier would put out only 100 watts per channel. In this direction, one could keep raising the load impedance, and the power output would grow smaller and smaller.
One More Thing Guys
There is another phenomenon called power compression which may be confusing the issue - as voice coils get hot their impedance increases therefore the power delivered by the amp decreases. Once the voice coil cools down the impedance returns to normal and the power available from the amp goes up again. This is an electrical function and has nothing to do with the magnets
if u measure the subwoofer impedence after heavy SPL u will see that your 2 ohm speaker is not 2 ohms now
so if your amp can generate 1000 watts @ 2 ohms check out the impedence After a major showdown and think of the power i.e Wattage of the amp now.
One more thing (last one) about battery
the 50 ah battery does not mean that it will provide 50 amps only
u can draw as many amps from battery as u like (more than 350 amps from a 45ah batt) it is like a reservoir of current
the 50 ah means that after continuous usage of 50 amps the battery will drain after 1 hour so if u use 100 amps the bat will drain in 30 mins and if u use 1 amp the battery will drain in 50 hours got an idea same way if we charge batt with 10 amps the batt will charge in 5 hours with 5 amp it will take 10hours with 1 amp it will take 50hours it is advisable that your charging current shoulb be 1/10 of the battery i.e 10 amps for 100ah 5 amps for 50ah

If I were you (bass) i would get a bigger alternator.

sorry guys for the large reply

[navin]

hi alpha,

long before power compression (which is electrical) most subwoofers face physical constraints from their suspension.

with a bigger alternator you wont over charge the battery but will charge the battery at a faster rate. this fast charging is what reduced battery life.

given LBM's setup and components used i would still suggest that he try upgrading the cables and elminating the cap. and only if this does not work consider a bigger alternator. he is obviously drawing more than 80A from the battery and hence the battery discharges in 30 mins.

[gunbir]

LBM... as explained to you by JB in person... Resistance quantifies the amount of current that will flow in a wire per volt. Power loss due to wire resistance increases as the square of the current and therefore decreases as the square of the voltage at fixed total power. The loss fraction in a transmission line increases with demand...

We have done many high watt systems without any kind of alternator upgrades. Never had to implement an Alternator upgrade cuz its never been necessary.

For example; the 'IMAGE' lancer has 3 Tru Tech class AB amps, and an Audison SRx2 class AB amp; consuming over 120 amps total with no alternator upgrades. Only good cabling, caps and a battery upgrade.

Similarly, check out the 'VEGA' Lancer, with 2 Audison SRx2S amps and 1 SRx4, consuming a total of almost 100A. Again, no alternator upgrades. Again, good cabling, caps and a battery upgrade.

And in my Getz, we have 2 Tru Tech amps consuming around 80A, without any stiffening capacitor, battery upgrade or alternator.

Let me say this again... Change your power cabling!!! This is the solution to your problem. Your high resistance AC cables are causing your problems.

[navin]

gunbir, as per LBM's calculations he is consuming about 200A. (2 1000W alpine amps and a smaller 4 ch. amp for the front and rear).

2000W/12V = 167A add power factor of 1/0.8 = 208A

All I am asking for is to try the setup without the cap and better power cables and then LBM, if you still feel the need for bigger alternators or even bigger capacitors go to it. It is your car, your money, and your ears. Remember you are building this system for your pleasure not anyone elses.

Thread closed.