Subwoofer

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Norm01

***
Joined
Jul 28, 2017
Messages
20
Hi all, just purchased in Canada a 2017 eGolf. I have a class D amp and sub I would like to install in it. Question: would the sub have a significant impact on mileage range?
 
If your Car propulsion was from a 12 Volt battery, the car would draw about 17 Amps while driving along.
You can now compare that 17A to the draw expected of the Subwoofer, to decide significance on cars range.

Barry

Oh- and welcome to the forum!


Below is for those.......... well you know who you are!
YES I KNOW THE PROPULSION IS NOT REALLY 12V
But.....
12V x 17A x 4.9Miles = 1KWh
And I average 4.9Miles/KWh
 
Barry, can you dumb that down for me. Let's say the amp draws 17A, what does that do to my overall range per charge. Thanks for your help.
 
Norm01 said:
Barry, can you dumb that down for me. Let's say the amp draws 17A, what does that do to my overall range per charge. Thanks for your help.

WTF 17A Amplifier? That's roughly a 1700w amp.
Are you really sure about that?

That's more draw than your headlamps.
 
forbin404 said:
Norm01 said:
Barry, can you dumb that down for me. Let's say the amp draws 17A, what does that do to my overall range per charge. Thanks for your help.

WTF 17A Amplifier? That's roughly a 1700w amp.
Are you really sure about that?

That's more draw than your headlamps.

P=VI, so 12V x 17A = 204W, my amp is actually a 500W but on average I think Barry got it pretty good.
 
Let's do the math. 200W for audio is a lot, but let's say the whole audio system including the head unit and the sub take that much continuously on average. If you run it for an hour, it will take 200Wh of energy. Driving at 4mi/kWh takes 250Wh/mile. So for each hour of loud audio playback, you will use 200Wh/250Wh/mi = 0.8 miles of range.
 
Gadz I'm about to sound like JT but

P = VI but that doesn't apply to car amplifiers....because that's not pure power, that's converted power.
(But yes I did get the 1700 w thing wrong, I knew that for 17A, 1700w was way to high but didn't want to spend the exact amount to figure out what it drew)

Rockford Fosgate P500 500w Subwoofer amp.
http://www.rockfordfosgate.com/products/details/r500x1d

Note this part
Average Current Draw (13.8V Music): 25 A

So you might be drawing more power than you think. Now can the Car fill the normal 12V battery when such a large draw (Assuming the lights and A/C is on as well)?
 
forbin404 said:
Gadz I'm about to sound like JT but

P = VI but that doesn't apply to car amplifiers....because that's not pure power, that's converted power.
(But yes I did get the 1700 w thing wrong, I knew that for 17A, 1700w was way to high but didn't want to spend the exact amount to figure out what it drew)

Rockford Fosgate P500 500w Subwoofer amp.
http://www.rockfordfosgate.com/products/details/r500x1d

Note this part
Average Current Draw (13.8V Music): 25 A

So you might be drawing more power than you think. Now can the Car fill the normal 12V battery when such a large draw (Assuming the lights and A/C is on as well)?

Had it fused at 30A and I don't play the music that loud, it's just nice to have proper bass. My guess is avg current draw will be about 15-25A. Does anyone know the charging capacity of the DC to DC charger?
 
Norm01 said:
Barry, can you dumb that down for me. Let's say the amp draws 17A, what does that do to my overall range per charge. Thanks for your help.

To directly answer you question.

If the car takes 17A and you add an amp drawing 17A, the range will be 50%.


Barry
 
The car uses 12-15 kW to drive down the road at freeway speeds. At max 85 mph average power can exceed 20 kW.

Few amplifiers will equal this power draw, to say the least. The onboard DC-DC converter is described as 2.5 kW here.
 
NeilBlanchard said:
I cannot imagine that an amp will have any noticeable on the range. None.

I agree, it should be next to nothing. Just to be safe I will install a switch to turn it off if need be.
 
Norm01 said:
NeilBlanchard said:
I cannot imagine that an amp will have any noticeable on the range. None.

I agree, it should be next to nothing. Just to be safe I will install a switch to turn it off if need be.
You don't need a switch and shouldn't put one in. If you think there's going to be an issue simply pull the fuse from the amp.
 
bizzle said:
Norm01 said:
NeilBlanchard said:
I cannot imagine that an amp will have any noticeable on the range. None.

I agree, it should be next to nothing. Just to be safe I will install a switch to turn it off if need be.
You don't need a switch and shouldn't put one in. If you think there's going to be an issue simply pull the fuse from the amp.

Easier to install a switch from the blue turn on wire up front during installation.
 
290822_2017_volkswagen_golf.jpg;w=960;h=640;bgcolor=000000


I think a factory subwoofer is available. This is a photo from a 2017 canadian model.
 
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