Ohm question

[crankinaway]

So I am running the factory Ford amp right now with a 4ohm Pioneer sub. It is my understanding the way I have it currently wired the amp is producing 2.4 ohms.

Is this going to damage the subwoofer? Or am I okay to run it like that until I get the amp?

 

[corkey]

how did you come to the 2.4 ohm conclusion, ??

that would help us out a bit,

 

[crankinaway]

Since no one has been able to pin point the output of the factory amp, I am making an assumption only. My factory sub says 60w 1.2ohm x 60w 1.2ohm. So I twisted the wires together on each side then hook it to my Pioneer sub.

I am guessing that the amp was built specifically for the factory sub so I think the amps output probably matches the speakers capability.

 

[rjcooperss396]

If you have a 4 ohm speaker connected then the amp is only seeing a 4 ohm load. The speaker determines what the ohms are, not the amp. The power rating you mentioned means the amp will put out 60 watts at 1.2 ohms. At 4 ohms it will put out less watts.

 

[Opera House]

So I twisted the wires together on each side then hook it to my Pioneer sub.

Sounds like a quick way to blow out your amp! That should never be done.

 

[aznboi3644]

for clarification...amplifiers do not "put out" ohms...ohms is the measure of the load presented to the amplifier.

 

[Scotty J.]

Ohms law. In series Rt = Ra + Rb, in parallel 1 / Rt = 1 / Ra + 1 / Rb.

If you don't understand what is stated above, there is a good likely hood that you will have a fire.

I can't count the number of times that I've heard "you add to total in series and divide by two in parallel". Very dangerous...

To give you an example, you're saying you're going to connect this sub to the stock setup. Let's say the stock speakers are 8 ohms, in parallel that's 4 ohms. If you add a speaker that's rated at 1.2 ohms in parallel to that circuit, you will be running a total of 0.92 ohms total load. That's how fires are made.

 

[crankinaway]

Okay then, so I went and bought a Pioneer 3300T amp today to avoid any problems.

Sub is rate @ 120w RMS 300w max 4ohm DVC
Amp is 2 channel 60w @ 4ohm or 1 channel 150w @ 4ohm

Is 150w too much for the sub? Read a little extra power won't hurt. Is this true?
Can I just adjust the gain down?

 

[aaronajb1981]

With that sub you either need to get a mono amp or get a 8ohm dvc to get tht most power out of that amp. If you run the 4ohm dvc in series to the "bridges" output of the amp its going to get 8ohm load at the amp. So about half the power of the amp rating. It you wire it parallel the final will be a 2ohm load. this low of an impedience will cause the amp to cut out (maybe not right away, but after time).

So to sum it up. if you want to keep that sub get a 2ohm stable amp (1 channel, mono amp), or get a 8ohm DVC sub.