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Connor97

Car audio aultinater upgrade

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Hi their  so my audio installer just told me that the stock power suply is one of the worst he's ever seen. Because of how much power the car uses to run it's self. 

With the amps I'm going to run having a combined power of roughly 2500w he says I'm going to have to get a aultinater upgrade or something to improve the powersuply? Has anyone had this problem before ? 

Amps I'm using is Rockford t1500 mono and Rockford t600. But both of them make more power than stated. Hense why I rounded then up. 

Thanks for the help.guys 

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I've had a pro-install in my car for five years. Only a measly 950W with a Hertz amp running three channels. The audio power supply is taken straight off the battery. Whilst I would make sure you have the 65Ah battery, I've not had to upgrade my alternator. As for a higher rated alternator, you'd probably have to look at the alternator used for bigger engined Subarus. 

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Even with amps connected directly to battery the only time battery is powering them is when the engine is off. With engine running Alternator is powering everything. Alternator usually specced with some reserve even with everything the car could be running switched on and the figure of 25% reserve springs to mind. I could get my gen7 Celica lights to dim slightly even with engine running when bass kicked in with 588wRMS (test certificate too) amp powering the subs and 400wRMS amp powering remaining speakers. Altenator not giving enough beans and I highly doubt the gt86 altenator is that different ☹️

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I suppose it only becomes an issue if you actually draw high output. Depending on the amp class, power consumption can be limited to what is needed to drive the speakers in the moment, in which case I would not expect to get anywhere near the specified maximum output. The Rockford t1500 is broadly a D type amplifier, which does not draw full power at all times. You need a big draw and a high amplitude signal to properly load up the supply, like NJay's sub making big wubs.

Ballpark is something like 50% efficiency at low volumes, so with only (!) 100-200w of bass noise, you're pulling up to 400 watts off the alternator, or say ~28 amps. That's still in the broad remit of the normal fuses and alternator. If you really really really want a kilowatt of bass, then you're going to start tickling the specified 100 amp continuous draw on their website.

At a guess, Lauren isn't totally deaf and isn't using the full capacity of the amp and it isn't one of the max-draw-all-the-time classes - lord knows I don't need all 40 watts of my home amplifier, but then I'm not waiting for the bass to drop.

I'm making a lot of approximations here, so don't trust me, but it is physics. Behaviour can be predicted.

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2500W rms wont draw anywhere near that with actual music unless it clipping enough to blow u pthe speakers. Nerds estimation of 28A i more likely to be closer to reality. 

Our alternator is 125A iirc and current draw is 20A steady state with engine running in our cars (heated seats and windows off). So youd have decent charging headroom I suspect but on short journeys, with it cranked up, then you may find the battery doesn't charge as fast. In reality unless you want your ears to bleed I think the stock alternator and a batter upgrade should work well.

I have a 75Ah AGM battery.

 

 

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From.what he told me to get the amps working correctly at the sub 1% thd they can pull 60 amps each so that's 120 amps for them both it will be a show car set up type of thing. Search for bass mechanix on Instagram or Facebook his work is amazing.. But no it won't be on full blast all the time. But at shows it will be lol and car meets 

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Spec is 140A for the amps (100A for the t1500, 40A for the 60), which could exceed the standard alternator output (130A apparently). You should look into an upgrade if you intend to run them loud.

Also 100A is pretty close to the maximum the specced cable can carry.

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On 2500watt you potentially can draw 208amp  current(2500)%volts(12) =resistance (208) that’s a lot of power🤪🤪 I have a healthy 500watt system and that’s loud to be honest. All JL audio . Gonna be one hell of a system 😁

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6 minutes ago, Gary p said:

On 2500watt you potentially can draw 208amp  current(2500)%volts(12) =resistance (208) that’s a lot of power🤪🤪 I have a healthy 500watt system and that’s loud to be honest. All JL audio . Gonna be one hell of a system 😁

Well I'm using everything Rockford. 

T2s 6.5s for the front . T1650s for the backs. Then 2 t1 10s for the subs. In parts it comes to 2500 pound haha. I hope it's good 😂

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You having the boot built to make the subs look part of the car? Iam thinking of doing this although I only have a poxy 8inch sub 😂😂 it gives a good bass line to be fair though. You will have enough power to push rear window out 😂😂😂😂

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3 hours ago, Rich said:

Spec is 140A for the amps (100A for the t1500, 40A for the 60), which could exceed the standard alternator output (130A apparently). You should look into an upgrade if you intend to run them loud.

Also 100A is pretty close to the maximum the specced cable can carry.

Usually the "spec" is for a sine wave output. Music has a peak to average power ratio of 10:1 so to avoid clipping average power is generally 5 time less than the rated RMS. e.g. 2500watts is more like 500watts. 

However this is for music to be enjoyed with a nice flat response and not bang bang music, crank the sub up and shatter windows loud.

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Yeah my system is running 500watt RMS and it’s loud you gonna make your ears bleed 😂 Rockford fosgate are quality gear you won’t go wrong with this👌🏼

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4 hours ago, Gary p said:

Yeah my system is running 500watt RMS and it’s loud you gonna make your ears bleed 😂 Rockford fosgate are quality gear you won’t go wrong with this👌🏼

I currently have the Rockford t1650 in the front and t142s in the rear powered by a Rockford p400x4 amp and the amp can't power the front speakers corectley. 

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6 hours ago, Gary p said:

You having the boot built to make the subs look part of the car? Iam thinking of doing this although I only have a poxy 8inch sub 😂😂 it gives a good bass line to be fair though. You will have enough power to push rear window out 😂😂😂😂

Yes mate go search for bassmechanix on Instagram and look at his work. Going to be a full build 

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15 hours ago, Ade said:

Usually the "spec" is for a sine wave output. Music has a peak to average power ratio of 10:1 so to avoid clipping average power is generally 5 time less than the rated RMS. e.g. 2500watts is more like 500watts. 

However this is for music to be enjoyed with a nice flat response and not bang bang music, crank the sub up and shatter windows loud.

Their "spec" is for some sort of "typical" output, a pure sine wave current is also given, it's 200A!

The specs are here: https://www.rockfordfosgate.com/products/details/t1500-1bdcp/

Average Current Draw (13.8V Music)  100 A
Max. Current Draw (13.8V Sinewave)   200 A
 
That sine wave would be over the recommended wiring spec mind you, as well as drawing a lot of current from the alternator.

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