Thread: Stereo mode for subs

so your amp is a sub amp? mono? or is it a multi channel amp that you are using?

I have a:

Power Acoustik FI2X-300
2 x 75 Watts RMS @ 4 Ohms
1 x 180 Watts RMS @ 4 Ohms Mono

I am not sure if there is an option on the amp that sets it to 2 x 75 and 1 x 180 that I'm just missing? Or if it's software related, or both? :P

I appreciate the help

What subs are you using? Plus there isnt a switch that turn on or off to tell the amp if its 2X75 or 1X180. Its how you wire it to the amp. For the 1X180 you will need to bridge the two channels together. How are you wiring the subs to the amp?

Oh ok,

I have 2 Kicker 10" subs. I am not very familiar with the wiring of the subs relating to how the wiring works, so I appreciate the help, as I'm new to that.

The wiring setup is as follows...

Amp has 2 wire channels, I have the wires from the amp going out separately to each side of the sub box. The wires then go into each sub from the box. (There are 2 Pos and 2 Neg connections on the subs themselves, with a separate wire linking one pos to one neg on each sub).

Given I have 2 subs, would I not need to have them setup as 2x75? If I had them in 1X180 that would only include 1 sub correct? (Or does it "combine" the subs somehow I'm not understanding?)

The wiring also changes whether they setup 2ohm vs 4ohm as well correct?


Thanks so much for the help.

Can you give me the model number of the subs? This way I can find out what Ohm the speakers are at and their RMS rating. And from what I'm getting (correct me if I'm wrong) the amp has two wire channels, meaning two positives AND two negatives and your connecting 1 sub to each channel? Or just two terminals meaning 1 positive and 1 negative and you have both subs hooked up to that 1 channel. Also, could you post pictures of the amp/your wiring/and subs? Specifically all the connections between the amp and your subs.

"Given I have 2 subs, would I not need to have them setup as 2x75? If I had them in 1X180 that would only include 1 sub correct? (Or does it "combine" the subs somehow I'm not understanding?)"

If your subs can handle 90watts RMS each then I will tell you how to set it up so that your amp sees it as 1 speaker and not 2. But I need to know the Ohms and RMS of your subs before I do this.

"The wiring also changes whether they setup 2ohm vs 4ohm as well correct?"

This is correct.

Here is the link to my Subs, they are Kicker CVR 10's (Item: 07CVR104 4OHM - I confirmed this on the box as I see there is a 07CVR102 as well, these are definitely the 4OHM). (Sorry would have mentioned earlier but I was not at home :P)

"And from what I'm getting (correct me if I'm wrong) the amp has two wire channels, meaning two positives AND two negatives and your connecting 1 sub to each channel?"

That is correct, you are not wrong . (unless I'm confused here)


Below are the images I took of the wiring/connections:


1. This is the image of the connections, I labeled each in Red.




2. Here is an image of the left side, RCA out to computer up front, and ?equalizer/crossover? settings (Obviously haven't looked into these much, new to this, not sure exactly what they all do, besides bass boost, got that one down ;P)




3. Here are the connections running to the box, each channel to each sub.




4. Pic of the subs themselves...




5. Lastly, I was too lazy to take the screws out and snap a photo, so I created this beautiful replacement image instead . Basically, all I wanted to mention in this "photo" was that as you can see there are 2 Negatives and 2 Positives on the subs themselves, and the "red wire" I have drawn on there is the wire I currently have between 1 of the negative and 1 of the positives. (This wire was connected when I bought them, so I left them there, though unsure of how they affect the setup...) Of course obviously my wires are then run to the remaining pair.




Thanks again for the help, and if I left any piece of information out, just let me know.

Thanks for the pictures,

Ok the way you have the subs wired up, each channel is seeing 8ohms.

Can you do a simple test real quick? Try swapping the L sub with the R sub at the amp. Meaning, take the speaker wire that is on the L -/+ on the amp speaker terminal and put it on the R -/+, and vice versa. And take note to which sub is working this time. If it is the same sub then that means the other sub is either not working or doesn't like 8ohms. If the other sub(the one not working previously) is working now, well that means the channel on the amp isn't working.

If you find that the sub that isn't working right now is still not working when you swap them then change the way the wires are on the speaker so that it is seeing a 2 ohm load instead of 8 ohm. After you do that, disconnect the good speaker and only connect the speaker you just changed to the amp. Here is a picture of how to make your sub into a 2ohm load.
http://crutchfield.custhelp.com/rnt/...no_1-4ODVC.jpg

If that doesn't work then that means your sub isn't working. If your sub is working now then do the same thing to your other sub and connect it to the other channel. Keep in mind it will be louder now, your amp pushes more power into the subs at lower ohms.

If they are both working now, then I want you to try bridging the two channels together. You will have to change the wires on the subs again though. To bridge the two channels together you connect the negative wires to the R- and then you connect the positive wires to the L+
http://crutchfield.custhelp.com/rnt/...no_2-4ODVC.jpg

Ok,

I tested changing the channels like you asked. (I took the R- and hooked it to the L- and R+ to L+ - (and vice versa) I just wanted to point that out cleary... that IS what you had requested I test correct?)

When I switched them, the other sub started up, and as expected, the sub that was working previously was now off.

I then set them up 2ohm style and they both were working. (And indeed, they were then louder)

So Now that they were both working, I took and bridged them 4ohm style as illustrated in the picture you linked. They are currently both working... but they are extremely quiet, I almost had to have my ears right next to them to hear it (I muted all my other speakers to ensure the subs were on, and they definitely were on, just very quiet)

I am then thinking that the quiet would be related to the software side setup then? I know the amp says "2 ohm stable" right on the front - but works when its connected as 4ohm, so I'm not sure which is better in this case?

Also, do you happen to know if I can use a multimeter to check the output from the amp on the speakers to allow me to see what kind of load per the volume I have on the subs/speakers? Or am I off here on some thought that doesn't quite fit with reality?


Thanks so much for the help man.

Originally Posted by Maegnas

Ok,



So Now that they were both working, I took and bridged them 4ohm style as illustrated in the picture you linked. They are currently both working... but they are extremely quiet, I almost had to have my ears right next to them to hear it (I muted all my other speakers to ensure the subs were on, and they definitely were on, just very quiet)

I know it's painfully obvious, and I don't want to seem as if I feel your stupid or anything, but is the car running?

My friend and I (both actually pretty knowledgeable with stereo setup) spent about an hour or two rewiring his new sub over and over with absolutely no luck getting it to work. Turns out his battery didn't have enough power, and as soon as we started the car and ran it off the alternator the sub worked just fine

So just want to point out the obvious, and suggest you try this with the car running, maybe the ohm impedance taxed the battery a bit too much, and that's why your getting really low sound levels.

Oh, and in my defense, he has two amps, one for his door speakers, the other for his sub, and the amp for the door speakers was working perfectly fine, hence our total lack of realizing it was the battery