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Discussion Starter #1
Alright so I'm sick of getting stupid answers on Yahoo answers and not being able to reply. I've been able to piece some information together but I will post everything I already have so I can get all the help I need.

I have these exact subs ported in my trunk currently not installed:
(2) Kenwood 12" subs
RMS Power Range : 200 Watts
Peak Power Handling: 800 Watts
Impedance: 4 Ohm
Frequency response: 28-800 Hz
Diameter: 12 Inch
Number of Voice Coils: Single
Kenwood KFC-W112S Component Car Subwoofers at

Here are some of the problems I have been running into. The guy that I got these subs from had them hooked up to a bridged amp. The way he wired the subs together was in a series like this, so the load is at 8ohm. (second image)

Now I've read that this is the lowest impedance and that it is fairly shitty for quality.
Option 1: Should I just take these subs out of the box and rewire them to have a 4ohm load/2ohm load? If so, how do I rewire them (literally) do I just yank the preexisting wires off, I would think they would be soldered to the sub so I don't know if this is possible?
Option 2: Should I just bridge a 2 channel amp? I would like to go with a mono amp but I don't believe those are bridgeable if I'm not mistaken. Which would be easier?

And since I will end up with the subs running to a single channel either way, will the RMS of the amps channel have to equal double the RMS of one speaker since there are two, or what?

Am I on the right path here, or am I way off with this whole ohm deal? Thanks in advance!

104 Posts
#1 running 8ohm load does not reduce "quality", but does reduce power in the same amp. Shouldn't be soldered, but if you look in you can see the connections plainly. Run them parallel for a 2ohm if you want more power. i.e. positives to positives, neg to neg.

Bridging depends on the amp. If it has 4 connections, it can most likely bridge. Either way if all the subs are wired together you would bridge them for a mono signal. Ideally you want your amp power to equal the total rms of all subs, but that stating it simply.

I think you have a lot more research to do. Learn series vs parallel and look up some amp manuals to see how they are setup.

494 Posts
Two four ohm subs will have a two ohm final load if they are wired in parallel.

If you have a two channel amp, to bridge the amp you will use the negative of one channel and the positive of the other channel.

Each sub has a positive and negative hookup. I imagine the parallel wiring will be like this:

To bridge the amp: One wire will come out of the amp's positive hookup of channel #1 and this wire will have the positive of sub #1 and the positive of sub #2 attached to it. The second wire will come out of the amp's negative hookup of channel #2 and this wire will have the negative of sub #1 and the negative of sub #2 attached to it.

But if you bridge the amp with a 2 ohm final load make sure the amp is 1 ohm stable for a two channel.

So I re-read your thread and now I see what your saying. I thought you already had a two channel.

Amp RMS watts should equal total sub RMS watts. So you have 400 total RMS watts so you need an amp with 400 RMS watts at whatever way you wire it. But you can get an amp that has more watts than the subs and turn the gain down which is better.

And you want a mono right?

Saying you wire the subs in parallel to 2 ohms, you should get an amp that does 400-500 RMS watts @ 2ohms. Or a bigger amp, maybe one that does 700w @ 2 ohms. With that you would just turn the amp gain down.

However big of an amp you end up getting just watch and listen to the subs. If they move a lot/are loud and sound good, however many watts you're using is good.

You should look into setting amplifier gain right and using subsonic filters with ported boxes. Realistically, you want an amp that has a subsonic filter/high pass filter AND a low pass filter. The high pass filter should be set at the tuning of your ported box because if not the subs will fly around wildly below the tuning of your box and could break. (For example: your ported box is tuned to 30hz, so you set the high pass filter at 30hz, and set the low pass filter around 60-100hz)

For that you'll need to get some test tones. Or even get every single dimension of your box: L x W x H, thickness of material, and then the area of the port: L x W, and the length of the port L.

With those dimensions some one here could tell you where to set the subsonic filter/ high pass filter.
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