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Old 6th March 2006, 14:40   #16
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oh thanks for the clarification about the woofer. even then it is 22A per amp.

in any case most woofers are not limited by their thermal/electrical capacity (Watts) but by the physical limits of their suspension (Xmax).

However if you dont hear any distortion and you have measured the Alpines output wattage (as 1000W) I assume the Pioneer woofers are better than what i expected to be.

I would still recommend that you remove the caps and change the wiring and see if that helps before investing in a 200A alternator and a big traction battery.

I also guess I read this wrong quote:
"14) 30 GB IPOD VDO NO NEED CDS OR MP3`S 15000 SONGS IN UR CAR IN ONE GO"

in any case i would recommend that you do investigate EAC and LAME and use VBR (alt preset extreme). It chould equal or maybe even better the quality of your existing MP3s and save some space as well. At a CBR of 256kbps you will fit fewer than 4000 (about 15,000 minutes of CD music) songs on a 30GB Ipod.

Last edited by navin : 6th March 2006 at 14:46.
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Old 6th March 2006, 17:35   #17
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Sir how did u calculate 22 Ampere per amplifier which method did u used to found out the average I will Be high obliged
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Old 6th March 2006, 22:41   #18
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W = I * I * R
1000 = I * I * 2
I * I = 500
I = 22a
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Old 7th March 2006, 13:25   #19
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Quote:
Originally Posted by navin
W = I * I * R
1000 = I * I * 2
I * I = 500
I = 22a
I have a few doubts about the calculations there. I would approach it thus..

W = V x I
1000 = 12 x I
I = 1000/ 12
I = 83.33

Account for some losses based on efficiency although the Class D guy must be reasonably efficient and i'd say you're looking at close to 90 amperes.

Boy I wish the 22A could stoke my amp's 1kW desires :P
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Old 7th March 2006, 13:46   #20
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Alpine delivers 700W @ 2 ohms at 12V and it gives 1000W @ 2 ohms @ 14.4V.
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Old 7th March 2006, 14:02   #21
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Quote:
Originally Posted by Bass&Trouble
I have a few doubts about the calculations there. I would approach it thus..

W = V x I
1000 = 12 x I
I = 1000/ 12
I = 83.33

Account for some losses based on efficiency although the Class D guy must be reasonably efficient and i'd say you're looking at close to 90 amperes.

Boy I wish the 22A could stoke my amp's 1kW desires :P

I agree with bass&trouble it close to 80 amperes goo man but the average is less but it goes near 80 when a bass note hits and that time the voltage goes low close to 11.7 volts.
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Old 7th March 2006, 16:08   #22
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Quote:
Originally Posted by Autophile
Alpine delivers 700W @ 2 ohms at 12V and it gives 1000W @ 2 ohms @ 14.4V.
JB, we have a disprepency here...

1000W at 2 0hms means 22A being dumped into the speaker or 44V across it.
but 1000W at 14.4V means 70A being drawn from the battery.
I know we are doing something wrong but cant put my finger on it.
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Old 7th March 2006, 20:23   #23
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Quote:
Originally Posted by navin
JB, we have a disprepency here...

1000W at 2 0hms means 22A being dumped into the speaker or 44V across it.
but 1000W at 14.4V means 70A being drawn from the battery.
I know we are doing something wrong but cant put my finger on it.
What are u trying to say we could now understand. I think we are talking about amp load not speaker output.
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Old 8th March 2006, 10:23   #24
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Ok. So the speaker output is 22A. The Amp load on the battery is 90A.
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Old 8th March 2006, 13:11   #25
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Quote:
Originally Posted by navin
Ok. So the speaker output is 22A. The Amp load on the battery is 90A.
How can that be possible the company states that amp is 80% efficient so how come 22A to 90A ratio it means the amp is 20% efficient this does not comes to nothing so i think there is some error in computing the power to the amp. Tell me if i am wrong.

http://www.crutchfield.com/S-TOaFZ99...500MRDM105#Tab

Last edited by low_bass_makker : 8th March 2006 at 13:13.
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Old 8th March 2006, 13:20   #26
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22A is at 44V while 90A is at 12V and the 90A is my estimate. It could be more.
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Old 8th March 2006, 17:49   #27
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The discrepancy can be understood if one pays a little more attention to the following:

Clue #1. Behaviours of the amps power supply: 12 V is input to the Power terminal, but that not exactly the voltage at which the mosfets operate.

Clue #2. (Not exactly as critical as the first, but worth mentioning) R in your formula is the DC resistance. You know how significant that is in an AC scenario (read as the output signal). We'd be more comfortable with impedance (but heck, that's frequency-dependent )

My calculations account for input current at the amplifier power terminals alone. Thats what I thought our low bass maker wanted.
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Old 8th March 2006, 19:13   #28
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Quote:
Originally Posted by Bass&Trouble
The discrepancy can be understood if one pays a little more attention to the following:

Clue #1. Behaviours of the amps power supply: 12 V is input to the Power terminal, but that not exactly the voltage at which the mosfets operate.
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.

Last edited by Autophile : 8th March 2006 at 19:18.
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Old 8th March 2006, 23:17   #29
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Thanks for such deep research stuff very good i could not believe that in india there are so many people who know so much about mobile electronics i am imressed but what about my problem it is not solved do i need to upgrade the alternater or not ????
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Old 9th March 2006, 11:33   #30
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No you don't. Stop using bass boost from your BW eq for subs and you will be fine. And upgrade your cables.

Last edited by Autophile : 9th March 2006 at 11:35.
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