quick question about ohm loads...

[B 4 You]

i'm just about done with my subwoofer setup, all i need to do is wire it together. but before i do that, i had a couple questions. my amp is 2ohm stable as is my sub:

pic 1


so i will be wiring them both for 2ohms. to wire the subwoofer to 2ohms (dual 4ohms) you would do this:

pic 2


to wire the amplifier for 2ohms, you would do this:

pic 3


and if i follow that, putting the amp and sub together would end up looking like this:

pic 4


now, i could wire it that way, but since both my amp and sub both have 2 (-) and 2 (+) outputs, could i simply wire it like this to get 2ohms?

pic 5


if that messes up with the ohm loads then i'll just splice all the wires together like shown in picture 4.

hope this makes sense!

[kwren]

I pick 5...

Keith

[Cam]

Without looking at any of your actual equipment or manuals, I would agree with Keith. It sounds like you need to bridge your amp to reach a 2-ohm signal. Your last diagram would properly bridge your amp.

[B 4 You]

it does need to be bridged. the last picture seemed to be an easy way to do it to me. maybe too easy i thought? but they are both equipped for 2ohms so i guess that makes sense. just wanted to make sure i wasn't being an idiot.

[Lookin4SVX]

Ok, so you have 1 sub which has 2 4ohm voice coils and a 2 channel amp.
Wire them like this to make your amp see a 2ohm load:


If you want to bridge the amp to get the power from both channel into the one sub:
Wire the positives from the sub to the positive on one channel of the amp.
Wire the negatives from the sub, to the other channel of the amp negative terminal.
This will be at 2ohm mono.

BTW, If you don't wire it bridged, you are just wasting the other half your amp.
So I would wire it bridged into mono, unless your sub cant take the wattage.

This will help you, bookmark it:
http://www.rockfordfosgate.com/rftech/woofer_wizard.asp

P.S. Bridging an amp does not effect ohm load.
The increased wattage output in a bridged setup comes from both channels being dumped into one, not a lowering of the ohm load.

BTW, Your Pic 5 would be 4ohm stereo. Each voice coil is 4ohm, running one to each channel of the amp would make it 4ohm stereo.

[B 4 You]

well my amp says for 2ohms to wire it like this:


and the sub says 2ohms is wired this way:


i understand that putting all 4 directly into the sub would make it stereo now.
so would i wire it like this:


or this:


or is there another way of doing it?

ps that last picture was not in the first post i put up.

[92snowmachine]

the second to last picture would be a good setup but you could make things easier if you just wire the + and - in series to your speaker. tie both + and - channels together at your amp into one wire to + and - at your speaker, then run a second set of wires between the other terminals on the speaker. what changes the ohm load is if the speakers are wired in series as described or in parallel which has them wired seperately

[Lookin4SVX]

That new last pic would be 2 ohm bridged mono.


Its odd your amps terminals are ++--, normally I see +-+- so you know which is which channel.
The amp may care which + and - use to bridge.
Read the book for the amp for which 2 terminals to use.

This would be normal:

[B 4 You]

that's the image from the manual. so i should just wire 4 to the sub, connect them to each other to make 2 wires, and connect it to the 2 outer outputs? i'm still trying to figure out all this ohm stuff. it's confusing.

[icingdeath88]

In your case, all of the positive terminals should be connected in some way and all of the negative terminals should be connected in some way as well. How you connect them is up to you and what you find to be convenient. Remember, where they connect and the length of the wire between connections is pretty much irrelevant.

Pic 4 from your first post would do fine. Personally I'd do the speaker part like the picture Lookin4SVX posted, just because it's easier. Less connections to make.

[B 4 You]

alright. will it make any difference that there's a wire in each of 4 amp outputs in mine and in lookin4svx's there's only two?

try not to use big wordz. newbie to the audio stuff. but i think i'm doing okay

[Lookin4SVX]

Ok, just looked at the pdf for your amp.
I thought this was a 2 channel amp..

Now I understand... this is a mono block amp.
So the stax2000 is not bridgeable, its only 1 channel.



The extra terminals are just for convenience, the ++ & -- are joined inside the the amp.

So, 2ohm load can be wired like this:


Or you could wire it like this, either way the amp sees a 2ohm load:


If you wire one wire from each voice coil to a terminal, then you will need a 4 way terminal on your sub box, and twice as much wire.
So I say just wire it in 2ohm in the sub box, with a 2 way terminal on the box, and then run one + and one - to the the amp.

Either way, just wire all the - on the sub to a - on the amp, and all the positives on the sub to a + on the amp, and your done.

[B 4 You]

gosh i'm sorry i forgot to mention that it was a mono amp... what you said makes perfect sense to me now. thanks so much for the help!