More woofer = more gas?

supraman7mgte

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Apr 1, 2005
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actually,the percussion of the bass helps propel the car forward if that is the way it is faced. up to 20% better fuel economy can be achieved....nah,im pulling your chain now
 

bigaaron

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Jeff Lange said:
A point worth noting, even if you have a max lets say 2000 watt setup, you will almost never hit 2000 watts, and if you do, it will probably be for less than a few seconds at best.

Now typically you will be producing more than 12V, but lets assume 12V for arguments sake.

1HP = 745W (62A in a 12V system, not 25A -- not sure where 25A came from). So 2400W = 3.2hp.

3.2hp isn't that much, especially in a Supra. Of course that's assuming perfect transfer to electrical energy from mechanical (alternator), so it might be a bit higher, but still, not all that much IMO.

Ok, now consider that the alternator is only about 50% efficent, so make that 3.2hp into 6.4hp.
 

Jeff Lange

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bigaaron said:
Ok, now consider that the alternator is only about 50% efficent, so make that 3.2hp into 6.4hp. Then consider the pulley ratio, and our alternator pulley
is much smaller then the crank. Let's say it is 3 to 1, so make that 6.4hp into 19.2hp!

Then consider that gearing doesn't change power (aside from losses), so it having a 3 to 1 ratio leaves it at 6.4hp ;).

Then there's still the fact that very rarely will you ever get even close to using all 2400W in a system rated for 2400W.
 

bigaaron

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Jeff Lange said:
Then consider that gearing doesn't change power (aside from losses), so it having a 3 to 1 ratio leaves it at 6.4hp ;).

Then there's still the fact that very rarely will you ever get even close to using all 2400W in a system rated for 2400W.

I think you are right about my estimate being incorrect, but it still could be enough to create worse gas milage. :eek:

The system will draw more then 1800w from the battery to make 1800w of speaker power though, but you are right that most power amplifiers will not make 1800w unless its an instantaneous peak. The average current draw can easily be over 50 amps with a large power amplifier.


http://www.svapowerproducts.com/html/pulley_ratio.html
QUOTE:
"...This is because an alternator requires approximately 1hp for every 22.5amps of output, times the pulley ratio. So the lower the pulley ratio, the less the hp the alternator needs to take from your engine."

I have heard that it takes around 50-60hp to keep a large vehicle going 70mph, so if that is true a 6.4hp additional load would mean about a 10% reduction in gas milage.
 

trucker

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Feb 18, 2006
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i'm bad, i'm nationwide
y'all are of course assumong that the amp is a constant load..it isn't

transient peaks are drawn from battery, not the alternator as such, and alt re charges battery.

i've been out of the stereo game(last system i built was when hlcd's were all the rage)for a while,but the idle current for amps is very small, and you are only using a small percentage of that amps peak most of the time

that being said...i doubt that that amp is really anywhere near 1400 watts.

most of those numbers come from the marketing dept, not the lab

i imagine that amp would pale in comparison to something like an old school orion 225 hcca(btw i need four of these if anyone has one)

rated at 25 wats by 2 chanels it could run something like guarter ohm mono, real output like 800 into 2 4ohm dvc subs....and that setup would shake windows and set off alarms from a couple of blocks away. i doubt that this "1400" watt amp is even close in performance.

my vote is the weight has much more to do with fuel than electric drain ever could..
 

bigaaron

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trucker said:
y'all are of course assumong that the amp is a constant load..it isn't

transient peaks are drawn from battery, not the alternator as such, and alt re charges battery.

i've been out of the stereo game(last system i built was when hlcd's were all the rage)for a while,but the idle current for amps is very small, and you are only using a small percentage of that amps peak most of the time

that being said...i doubt that that amp is really anywhere near 1400 watts.

most of those numbers come from the marketing dept, not the lab

i imagine that amp would pale in comparison to something like an old school orion 225 hcca(btw i need four of these if anyone has one)

rated at 25 wats by 2 chanels it could run something like guarter ohm mono, real output like 800 into 2 4ohm dvc subs....and that setup would shake windows and set off alarms from a couple of blocks away. i doubt that this "1400" watt amp is even close in performance.

my vote is the weight has much more to do with fuel than electric drain ever could..

Maybe the music playing in your car is different then the majority of customers I had when I did car audio, because the bass line of rap music can draw some serious comtinuous amperage. And sorry but those old ass hcca red amplifiers don't even come close to some of the new class d mono power amplifiers that can make the same output into 4 ohms, and have FAR better damping and overall sound quality. Those hcca amplifiers running at 1/4 ohm make great subs sound like a muddy underdamped pos.
 

trucker

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how many people loading those old ass red amps into their cars would you say were audiophiles who could tell the difference?

shure technology changes, i cant tell you how the "new" stuff sounds, i was getting out when infinity started pushing class d.


but back "in the day" if you werent using hcca's, refrence class a's,
ProMos, or what ever the hell r/f and zapco called their equivalents, you didn't stand a chance at the shows, in any format.

many championships were won with this equipment, i know it is years past, but i would bet pretty good money 75% of your customers, listening to competently designed system of both types, wouldn't be able to tell the difference in sq


ands anyway the point of the discussion was about how overrated the equipment is these days, and i think we both know i'm right on on that point...and anyone having a conversation that started this thread prolly isn't at the level to have a couple of human reigns or McIntosh in the trunk
 
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bigaaron

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trucker said:
ands anyway the point of the discussion was about how overrated the equipment is these days, and i think we both know i'm right on on that point...

That is true, there are many amplifiers that will not output anywhere near the peak power displayed on the box :biglaugh: