Car Audio and the Alternator of High Output

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#2259134 16-Jun-2019 15:29

Aredwood:
Get class D amplifiers instead of Class AB. As class D use less power for the same audio output.

Looks like the OP's sub amp is class D 600 w RMS in to 2 ohms at 14v supply, so probably pulling 45-50 amps continuous under a reasonably high load, excluding head unit of course. That's probably a sizeable increase on load on a standard alternator, especially with 13 year old wiring.

Getting an auto sparky to troubleshoot is the best solution, especially if you don't have access t the right tools etc.

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#2259272 16-Jun-2019 22:35

Looks like the OP's sub amp is class D 600 w RMS in to 2 ohms at 14v supply, so probably pulling 45-50 amps continuous under a reasonably high load, excluding head unit of course.

Seriously, who needs that much audio power in their car?

We had a neighbour for a short while who operated his car stereo at rather high volumes, so much so it must have had a detrimental impact on his hearing. Fortunately he didn't stay around very long.

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richms

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#2259274 16-Jun-2019 22:38

When you are trying to get bass out of a small box then you need lots of power - that's just the laws of physics. 600 fantasy car audio watts is probably only 150 of actual average power delivered to the speaker.

Richard rich.ms

Ge0rge

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#2259283 17-Jun-2019 06:47

RunningMan:
Getting an auto sparky to troubleshoot is the best solution, especially if you don't have access t the right tools etc.

Surely taking the car back to whomever installed it is the best solution. The OP paid for something that doesn't work as intended, get them to rectify it.

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#2259320 17-Jun-2019 09:50

Ge0rge:
RunningMan:

Getting an auto sparky to troubleshoot is the best solution, especially if you don't have access t the right tools etc.

Surely taking the car back to whomever installed it is the best solution. The OP paid for something that doesn't work as intended, get them to rectify it.

You could argue it it working as intended BUT when it is used other items aren't working as well as they should. The installer could say my installation is OK, if you want me to fix the underlying problems that are the cause of your issues then I will be charging for that.

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#2259321 17-Jun-2019 09:56

Yeah, good call. Perhaps the OP had advice from the installer that it'd cause problems but went ahead anyway - hence not wanting to take it back?

Aredwood

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#2259323 17-Jun-2019 10:15

Technofreak:

Looks like the OP's sub amp is class D 600 w RMS in to 2 ohms at 14v supply, so probably pulling 45-50 amps continuous under a reasonably high load, excluding head unit of course.

Seriously, who needs that much audio power in their car?

We had a neighbour for a short while who operated his car stereo at rather high volumes, so much so it must have had a detrimental impact on his hearing. Fortunately he didn't stay around very long.

Since the factory alternator can output around 80A, Surely it would all work fine. While driving on the motorway during the day (headlights off), Aircon off etc.

The solution might be as simple as connecting the amplifier power cable to the alternator output terminal. Instead of the battery.

As for why the OP would want so much audio power in their car. You could ask the same Question as to why lots of people need a car with an engine that is bigger than 1.5L Or why some people modify the exhaust, solely to get more noise. If you are going to modify the exhaust, it should be to get more engine power.

edit to add

Imagine what things will be like when EVs become more common. Having 600V or so available from the main batteries. Will mean lots more power available for running sound systems.

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porkbone

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Wannabe Geek

#2259388 17-Jun-2019 10:55

Thanks to everyone who had attempted to help me, I went ahead and booked my car into the place where I originally had it done to get them to check it and see what can be done about it.

I see some are questioning my motives as to why I need car audio... Well, I mean, why not?

The package I bought, I'm told, is considered entry level. And my intention was really to put in a decent sound system because, as I stated previously, the car only had two terrible speakers in the front. I could have made better speakers out of tin foil, a dry lemon peel and some pavement chewing gum, OG MacGyver style 😂

Anyway...

I had no idea what was about to happen to my car electrics. Had I known then what I know now I might have chosen a ported box so I can get the same/similar sound with less power. I might have sorted the "big 3" prior to installation. I just assumed that the people who do it for a living would sort it, I mean it was what I thought I was paying for after all 🤷‍♂️

Technofreak

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#2259389 17-Jun-2019 10:58

Aredwood:

As for why the OP would want so much audio power in their car. You could ask the same Question as to why lots of people need a car with an engine that is bigger than 1.5L Or why some people modify the exhaust, solely to get more noise. If you are going to modify the exhaust, it should be to get more engine power.

edit to add

Imagine what things will be like when EVs become more common. Having 600V or so available from the main batteries. Will mean lots more power available for running sound systems.

If you want to use engine size as a comparison I'd consider a 1.5 litre engine to be the equivalent of a 25 - 30 watt amp. For me 600 watts was more like shoehorning a 27 litre V 12 into a car.

600 W RMS is a lot of power when it's considered that 150 watts is enough to give permanent hearing loss in your average room at home and 100 watts is ample for the average home theatre. With the smaller size of a car and the fact you're most likely sitting closer to the speakers these numbers will be be much less as the sound level (dB) experienced increases/reduces as a square of the distance. Granted speaker speaker sensitivity is also a big factor when it comes to the sound output (dB) achieved with a given wattage.

Agree on the exhaust, no point in making extra noise without extra go.

On the EV front, Yes much more power for sound systems, but from what I've heard a lot of EV owners drive around with as many accessories turned off as possible in order to extend their range.

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Technofreak

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#2259397 17-Jun-2019 11:17

porkbone:

Anyway...

I had no idea what was about to happen to my car electrics. Had I known then what I know now I might have chosen a ported box so I can get the same/similar sound with less power. I might have sorted the "big 3" prior to installation. I just assumed that the people who do it for a living would sort it, I mean it was what I thought I was paying for after all 🤷‍♂️

I expect there was a mismatch in expectations.

What exactly were you paying for? What did they quote to do for you? I'm guessing just the installation. Granted if they thought there might be other issues as a result of the installation you might expect they would give you a heads up.

On paper you cars electrical system was likely adequate enough so there was nothing for the installer to sort out. For example, they probably never drove it at night to see the problem with the lights.

The fact you say you think the car is about to stop when idling indicates there is a pretty big load on the alternator and while a good check of the wiring and more particularly the connection points is a very good idea I suspect a bigger alternator may be part of your solution especially since the lights also dim. A bench check of your current alternator might be worthwhile to ensure it's giving its rated output.

I see nothing wrong with tweaking up the idle speed in fact I think it is a very practical idea. The only consideration will be if the car is an automatic, then it will be more likely to creep forward when you're stopped at the lights etc.

By they way I wasn't questioning your desire to install an audio system. Most OEM car systems are average at best so installing an after market system isn't unusual. I was questioning the amount of power.

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Aredwood

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#2259412 17-Jun-2019 12:07

The car audio company might have sold that particular amplifier to the OP, as it would still work even if the input voltage sags. (which is exactly what is happening)

The sub woofer is probably 4ohm, meaning the max power that the amp would be able to deliver would be 300W. And anyway, actually trying to put 300W RMS into a 12” sub at say 70Hz. The sub would probably get destroyed instantly due to excessive cone movement.

I doubt that it would be possible to easily increase the idle speed through. As the ECU would almost certainly be doing PID closed loop idle speed control. Meaning that if you want to change the idle speed. You either need to reprogram the ECU. Or you need to do something like fool the ECU into thinking that the aircon is turned on, when in reality it is turned off. As the ECU normally increases the idle speed when the aircon is running. Some early 90s Japanese cars had PID idle speed control. So I would be very surprised if a 2006 car didnt have PID idle speed control.

porkbone

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Wannabe Geek

#2259454 17-Jun-2019 13:17

Technofreak:

I expect there was a mismatch in expectations.

What exactly were you paying for? What did they quote to do for you? I'm guessing just the installation. Granted if they thought there might be other issues as a result of the installation you might expect they would give you a heads up.

It practically went down like this:

I went there and I told them about the garbage I had installed. I said I wanted to be able to play music using my phone, so I needed a head unit with that ability. I told them that I wanted to put speakers in all 4 doors, 2 for replacing the front and then 2 for the empty holes in the back. I also said I wanted there to be some nice bass and asked if they recommended a sub and if so, which amp it would need.

So after looking over my car, they said they could do it. We went into the shop they recommended speakers for my doors, a sub and the amp I would need for it. I said 'Ok' and now here we are 3 months later.

Aredwood:

The car audio company might have sold that particular amplifier to the OP, as it would still work even if the input voltage sags. (which is exactly what is happening)

The sub woofer is probably 4ohm, meaning the max power that the amp would be able to deliver would be 300W. And anyway, actually trying to put 300W RMS into a 12” sub at say 70Hz. The sub would probably get destroyed instantly due to excessive cone movement.

I doubt that it would be possible to easily increase the idle speed through. As the ECU would almost certainly be doing PID closed loop idle speed control. Meaning that if you want to change the idle speed. You either need to reprogram the ECU. Or you need to do something like fool the ECU into thinking that the aircon is turned on, when in reality it is turned off. As the ECU normally increases the idle speed when the aircon is running. Some early 90s Japanese cars had PID idle speed control. So I would be very surprised if a 2006 car didnt have PID idle speed control.

This is the sub: https://www.pioneerelectronics.com/PUSA/Car/Subwoofers/Champion+Series+PRO/TS-W3003D4

This is the amp series, theres a little table down the page with some numbers on the one I have (DK600): http://www.soundmagus.com/prod_view.aspx?TypeId=144&Id=243&FId=t3:144:3

Make no mistake, I am happy with the overall sound Jonvy delivered with the package, its just the power issues I want to sort out as best I can.

Edit to add:

The sub box I have is the only one they had available at the time. It's small and sealed roughly 0.77 cu. ft, IIRC.

RunningMan

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#2259494 17-Jun-2019 14:43

Aredwood:
The sub woofer is probably 4ohm, meaning the max power that the amp would be able to deliver would be 300W.

Specs of the model posted indicate it's 2 x 4 ohm voice coils. Assuming they're wired in parallel, the amp can drive at 600 w RMS, and the speaker is rated for that power level too.

Technofreak

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#2259520 17-Jun-2019 15:42

It seems to me the OP's problems only occur at night, when the volume is wound up and the lights are on. No wonder when you consider if the woofer is in the 2 ohm config the amp will be drawing in excess of 45 amps, add in the head unit draw of 10 amps and it's the same has having seven 100 watt spot lights fitted, bearing in mind headlamps are usually only 55 watts.

Add in the other stuff that will be drawing current, particularly at night, and it's very easy to come up with another 20 to 25 amps probably more. It's not hard to exceed the alternator output.

The only solutions I can think of are either a bigger alternator or assuming the speakers are in the 2 ohm configuration, reduce the load by changing the speakers to the 4 ohm configuration to reduce the output from 600 watts to 400 watts. This will reduce the power consumption by about 15 amps.

You won't notice the difference between 600 and 400 watts. There needs to be a 3 dB change for the human ear to notice a change. 3 db is a doubling or halving of the power, so at 600 watts you would need to reduce the power output below 300 watts before your ear would pick it up.

Actually one other option is to turn down the volume when you're at the lights. 😄

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porkbone

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Wannabe Geek

#2259562 17-Jun-2019 15:55

Technofreak:

The only solutions I can think of are either a bigger alternator or assuming the speakers are in the 2 ohm configuration, reduce the load by changing the speakers to the 4 ohm configuration to reduce the output from 600 watts to 400 watts. This will reduce the power consumption by about 15 amps.

You won't notice the difference between 600 and 400 watts. There needs to be a 3 dB change for the human ear to notice a change. 3 db is a doubling or halving of the power, so at 600 watts you would need to reduce the power output below 300 watts before your ear would pick it up.

Actually one other option is to turn down the volume when you're at the lights. 😄

Assuming the speaker IS wired @ 2ohms, if I asked the car audio place to swap the sub into a ported box (swap raw power for spl) and wire the speaker into 4ohms instead, would that work? Or maybe add a 1 - 2 farad cap as well? What do you think the difference in overall sound would be, similar or much different?

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