I found a few things, but I want to make sure I have the right info!

This is my amp Rockford: P3001- 300 Watt Mono Amplifier

150W x 1 @ 4-Ohms RMS
300W x 1 @ 2-Ohms RMS

Now I think I might be getting confused, mono is different to a 4 Ch amp.


I have a couple of questions:

To get both subs at 300Wrms on the RF amp, should i be looking at subs with DVC @2 Ohms?


Now a 4 Ch, 4x100 RMS amp like the Jaycar:
Power / channel @ 4ohm 14.4V: 130WRMS x 4
Power / channel @ 2ohm 14.4V: 190WRMS x 4
Power / bridged @ 4ohm 14.4V: 380WRMS x 2

If I were to bridge Ch 3,4 on the amp for a sub, should the sub be a dual voic coil sub @ 4 ohms? Is that right?
Since the amp will read it as 2 Ohms each, is that correct?

you will only get 150RMS to each sub on the rockford amp, as it's 300Wx1

the jaycar amp will do 380W x 1 when bridged. the sub should be either single 4 ohm, or dual 2 ohm for 380W

For the RF amp - for 2 SVC subs, each sub would only get 150WRMS for 2 x 4 ohm subs wired in parallel ie half of the 2 ohm rating to each sub. If the RF amp isn't rated to 1 ohm then you won't get 300 per sub.

For the Jaycar amp - a 4 ohm DVC sub would present a 2 ohm load and each voice coil would get 190WRMS, therefore the 'whole sub' would see 380WRMS. Alternatively, a 4 ohm SVC sub would also see 380WRMS.

Keep in mind that these amp power figures are maximum ratings and aren't indicative for daily driving volumes.

Any way getting 300 RMS into a sub with the RF amp?

yes. buy a single 2ohm or a dual 4 ohm sub.

Can you please explain how the DVC 4 OHM sub will receive 300RMS?

The dual 4 ohm sub will get 300wrms because if you wire it in parallel it puts a 2 ohm load on the amp, the amp creates 300wrms @ 2 ohm

So the amp reconises how you have wired the subs up and thats the Ohm it puts out?

hrmmmm......not exactly.

The little gremlins in the amp that run on those spinny wheels that make the power to drive your subs recognise how you've wired the sub, and thats how many Ohms (where Ohms=a company of gremlins) the amp deploys.



option b:

The amp sucks power from your battery, and uses that power to amplify the signal coming from your cd player. The speaker acts as a big resistor, or lightbulb, and instead of putting out heat and light it puts out heat and....sound. Now the resistance of that speaker (or, more correctly, the voice coil) is mesured in Ohms. The lower the Ohms the greater the resistance.

So, when resistance is applied to the amp (ie you wire your speaker up to it) it creates sound. The more resistance you apply (ie the lower the ohms) the more power the amp will put out. That is why you see power figures that look like:

Power per channel @ 4ohm 14.4V: 130WRMS x 4
Power / channel @ 2ohm 14.4V: 190WRMS x 4

With a dual voice coil sub (DVC), each coil has a nominal resistance (ie DVC 2 ohm sub). There are two different ways of wiring those coils together.
1. The first way creates more resistance. You wire the voice coils in parralel, and you get 2/2=1ohm final load. then you wire that speaker to the amp, and it creates lots of power, because the resistance is very high.
2. The second way creates ......anyone......anyone......thats right.....less resistance. You wire the coils in series and you get 2+2=4ohm final load. Wire that to the amp, and it creates less power, because the resistance is low.

Think about "series" as lots of gremlins running through a passage. That passage splits into 2 equal sized passages, and suddenly there's more room for the gremlins to run, so they run faster and easier with less heat (gremlins get hot when they run!)

Parallel is where the gremlins are running through that passage, and the passage suddenly halves in size. Bastard! The gremlins have to run slower and they push and shove and get angry and create more heat.

Back to your original question. Uhhh...I forgot. what was your original question?

Something about gremlins, I believe. Thanks for that post.

When in parallel, to work out resistance its actual 2x2/2+2 = 1ohm. Just a note thats its not as simple as 2/2=1ohm, where as in series you just add up the resistances together.

my 2 cents worth