Memphis 4kd Current Draw at 2ohms?

[Joe89 10+ year member]

Will I be okay running a memphis 4kw on a my truck for time being at 2ohms with the following electrical upgrades?

KnuKonceptz 200a HO Alt

2 runs 1/0 power, 2 runs 1/0 to frame ground

Optima Yellowtop front

Kinetik HC2000 rear

big 3 1/0

I am goin 16v and adding more 4kws soon but I want to know if the 4kw will be okay temporary if I run it at 2 ohms I hear these are very current hungry so I just want to be on safe side. I will also be running a Kicker 850.4 for speakers.

Also, in testing a ground with a dmm, does the guage wiring matter of the "extension" from the negative terminal on the battery? Could I use 16gauge or must it be 0 gauge?

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[2000LaDe 10+ year member]

hmmm.... at 2 ohm u might be ok. just keep an eye on ur voltage. u will know if its enough or not the first time u play it. dont go cheap on electrical when you are dealing with 4kw's or u will regret it because its cheaper to buy 2 large batteries for the same price it will cost u to replace the 4kw u just blew for not having sufficient electrical

 

[Lil Poot 5,000+ posts]

i thought these were supposed to be pretty efficient? is my electrical looking good enough to run one at 1 ohm?

 

[Joe89 10+ year member]

Looks like the same as mine except for the 40 extra amps you got from your alternator. and if the D3100 is comparable to an HC2000. I'm running a pretty large speaker amp also.

 

[DBBOOM 10+ year member]

The amp is rated at 2000watts at 14.4v at 2 ohms. Whats its rating at 2ohms on 17.5v?

 

[Joe89 10+ year member]

I'm not sure, but I will only be running them at 2ohm on 14 volts.

Once I get my electrical upgraded, I will have plenty of batteries and a second alternator and .5ohms wont be a problem.

 

[DBBOOM 10+ year member]

I'm not sure, but I will only be running them at 2ohm on 14 volts.
Once I get my electrical upgraded, I will have plenty of batteries and a second alternator and .5ohms wont be a problem.

Should be under 200amp draw on 14v @ 2ohm.

 

[Joe89 10+ year member]

And when testing resistance in a ground to the frame, does the wire touching the probe to the battery negative need to be 0 gauge or can 16g speaker wire produce an accurate reading?

 

[DBBOOM 10+ year member]

Are you measuring across the connection, or are you measuring the total from the amp to the chasis?

 

[Joe89 10+ year member]

I am measuring across the connection.

One probe of the DMM to the location of the frame ground, another to a wire connected to the battery's negative post, to measure if there is any resistance.

 

[DBBOOM 10+ year member]

I am measuring across the connection.
One probe of the DMM to the location of the frame ground, another to a wire connected to the battery's negative post, to measure if there is any resistance.

You're measuring the entire run. Put 1 lead of the DMM on each side of the individual connections. That will measure each connection. Then you wont have to extend the meter leads. You can add all of your results if you want a total.

 

[Joe89 10+ year member]

So I've had it in for almost a week. plays full tilt and my voltage stays strong at 14.6x for around 2 minutes if the batteries have been charging (me driving on hwy) for a couple hours.

How much difference is there between 1 ohm and 2 ohm? Correct me if I am wrong, but since it is just double the resistance, there should be no difference on the amount of current drawn...

I know this is the real world and different from theory but will the efficiency difference be noticeable on my current electrical?

 

[n2audio 5,000+ posts]

How much difference is there between 1 ohm and 2 ohm? Correct me if I am wrong, but since it is just double the resistance, there should be no difference on the amount of current drawn... I know this is the real world and different from theory but will the efficiency difference be noticeable on my current electrical?

You're thinking of going from 2 ohms to 1?

That's half the resistance, not double.

Is it 3000@2 and 4000@1?

If you assume the amp is super efficient, say 80% at rated power you're looking at 277A peak at 2 ohms (RMS for music around 90A)

370A peak at 1 ohm (RMS music around 120A)