[lt5dude]

The F3 owner's manual has this statement, which has me confused:

"Note that the (+) red terminals are a ground potential, and that the (-) black terminals are live. This is important to remember if you decide to bridge the channels or if you are using the output of the amplifier to drive an active subwoofer's input."

I do want to use the output of the amplifier to drive an active subwoofer's input (two subs, in fact).  How does this affect the way I should hook up the subs?

In the past, I've connected them as shown in this picture from the sub's owner's manual.  Since I'm using two subs, I just twist the same colored wires together and connect as shown in the diagram.  Do I need to do anything different with the F3?

Thanks in advance for any help!

[randytsuch]

Hi
If the F3 is putting the signal out on the ground side of it's output, then you need to hook up the red wire from the sub to the negative output of the F3, because the signal output from the F3 needs to connect to the red wire going to the subwoofer amp.  This will invert the subwoofer by 180 degrees, but most subwoofer amps let you compensate for phase anyway.

Hope this helps.

Randy

[lt5dude]

Randy,
Thank you very much!  I'm going to give it a try the way you suggest (red and yellow sub wires to L/H and R/H black speaker outputs and black sub wire to R/H red speaker output).  The subs do have phase switches, so I'll see if changing those afterwards sounds better too.

Thanks again.

[randytsuch]

Randy,
Thank you very much!  I'm going to give it a try the way you suggest (red and yellow sub wires to L/H and R/H black speaker outputs and black sub wire to R/H red speaker output).  The subs do have phase switches, so I'll see if changing those afterwards sounds better too.

Thanks again.

 
Um, not sure if you got what I said.

You need to connect the red wire to the F3 right - out, yellow to F3 left - out, and the black to F3 + out (either side).  If you connect the F3 right or left - out to the black wire, you will most likely be connecting the F3 output to ground.  I am sure the F3 is protected, so it should not hurt it, but it is not something I would recommend.

Randy

[lt5dude]

Randy,

Thanks again.  I believe I hooked it up the way you've described.  The F3's speaker outputs are Red (+) which is ground and Black (-) which is live.  So, yellow and red sub wires to black F3 outputs and black sub wire to red F3 output is how I have it.
There we no sparks or smoke, and the subs are playing, so can I assume all is well?
I did switch the phase on the subs as well.
Sorry to be so dense, and if you see anything here that looks wrong, please do let me know!

James

[randytsuch]

Randy,

Thanks again.  I believe I hooked it up the way you've described.  The F3's speaker outputs are Red (+) which is ground and Black (-) which is live.  So, yellow and red sub wires to black F3 outputs and black sub wire to red F3 output is how I have it.
There we no sparks or smoke, and the subs are playing, so can I assume all is well?
I did switch the phase on the subs as well.
Sorry to be so dense, and if you see anything here that looks wrong, please do let me know!

James

Hi James,
No, that sounds right.  From the previous reply, I was not sure, but what you just said is right. 
And it works, which is the acid test  .

As for phase, you just need to play with it a little, and see what sounds better.  It depends on the distance from you to the sub.

Randy

[lt5dude]

Yep, it's all hooked up and playing and sounds great.  Thank you for the help- it was very frustrating trying to figure out exactly what that passage in the manual meant. I'm really glad you were here to supply the answer!