is 8 gauge too small?

[GreenBook 10+ year member]

Mtx's site just says "2Ω"Seems to me the enclosure as a whole is 2 Ω

That sure would make more sense, but you never know.

 

[BobbyDD 10+ year member]

Your wire is too small, here's a chart to figure out what ga you should be using.

And depending on the preout voltage from your headunit the gains may have to be set higher. The higher the preout voltage then the lower you set the gains. A 5 volt HU should have the amp gains all the way down. A 2 volt HU would need the gains 3/4 to full.

His wire is not too small for the amp he has. If he's going to upgrade he's going to need a bigger wire though.

OP, what's the brand and model number of your head unit?

 

[skipper89 10+ year member]

the terminals say 4 ohms. there is 1 terminal per speaker( a positive and negative).

 

[SPL Blazer 10+ year member]

the terminals say 4 ohms. there is 1 terminal per speaker( a positive and negative).

Then it's correct, your running it at 2 Ohms.

And your sub amp might be 300 watts, but your also running a 200 watt amp on the same power wire, so depending on the length of power wire the 8ga would be too small for the current demand. 8ga wire is fine for that power on short runs, but as a main power wire it might not be right. Is your ground wire the same ga as your power wire?

 

[BobbyDD 10+ year member]

Then it's correct, your running it at 2 Ohms.
And your sub amp might be 300 watts, but your also running a 200 watt amp on the same power wire, so depending on the length of power wire the 8ga would be too small for the current demand. 8ga wire is fine for that power on short runs, but as a main power wire it might not be right. Is your ground wire the same ga as your power wire?

Where do you see that?

 

[SPL Blazer 10+ year member]

It's in his first post, try reading them all.

 

[BobbyDD 10+ year member]

It's in his first post, try reading them all.

Read it again slowly.

 

[IDSkoT 5,000+ posts]

Turn your gain down, amp wont cut out on you i bet.

x2

You're over-loading the amp, causing it to go into protection mode.

As we say in the computer world: UE.... user error. =|

 

[IDSkoT 5,000+ posts]

Your wire is too small, here's a chart to figure out what ga you should be using.

And depending on the preout voltage from your headunit the gains may have to be set higher. The higher the preout voltage then the lower you set the gains. A 5 volt HU should have the amp gains all the way down. A 2 volt HU would need the gains 3/4 to full.

That chart is VASTLY over-zealous. To say the least. For 1.5K watts, you need 0/1 AWG?

Let's do the math...

@ 12 volts (Which is the lowest volts that your amp should run at), runing 1.5K watts, we'll find the amperes necessary...

The watt formula is simple, and goes as followed:

W=V*A where W = Watts, V = Volts, and A = Amperes.

1,500=12A, 1,500/12=A, 125=A

Now, let's use this chart:

http://www.powerstream.com/Wire_Size.htm

Based on the chassis wiring...

As you can see, the 2-AWG clearly shows a 182 amp capability.

Those completely voiding that whole 0/1. Now, using 0/1 would be safer, sure, and give room for head room. But please don't use that chart ever again.

There are a lot of factors, though. (Like there is with everything, including length, original input, the resistance of the wire, the jacket thickness, etc.)

As a "rule of thumb", for systems over 1K watts, I'd suggest 0/1 awg. But, you can easily pull upwards of 1,750 watts of 2-AWG, maybe even more depending on the quality of the wire and it's conductivity.

NOTE: I used 12 volts because at higher volts, you need less amps to reach the same watts, I.E. 1,500 running at 14 volts only runs at 107 amperes.

Oh, and also... amps have different sensitivity, so saying "3/4 of the way" for a 2v pre-out is ludicrous... the lengths of the RCA should be taken into account... but either way, gains should be set with either a DMM or by an Oscillator Scope. Even when you do the math and 3/4th of a spectrum from 6v to .2 volts, is 1.45, you still shouldn't tell someone who doesn't know much about the hobby "3/4 is good."