Active Sub Wiring (Kenwood) with pics

[lambo]

Hopefully someone can help me with this

I have a Kenwood head unit and have bought a Kenwood active sub to give the car some base, I'm just having a bit of a problem understanding the instructions that come with it as far as wiring goes. These are the wires i have.

Now i know how to connect the phono leads to the back of the headunit and the blue wire is easy enough as the headunit has the same cable coming out the back. Black is obviously ground which is fine, but the one I'm confused by is the yellow (power) cable. I'm not really sure how to connect it up and what to, as its not really the right type of connector to go to the battery. In the instructions it seems to suggest connecting it to the fuse box but I have no idea how. Here are the instructions and the back of the sub.

Any help would be great

Thanks

 

[Dink]

have a look on the wiring loom on the back of the head unit to car wiring

i reckon there is a place to plug the yellow in there

but if the fuse operates in the car fuse box you'll need to find alternative power supply

 

[SimonR.]

I can't see your pictures but you will need an inline fuse and connect it straight on to the battery. You will need a ring connector that you can pick up at halfords. This will run down the side straight into the sub.

 

[paul6]

Hi mate. As your power lead already has an online fuse, no need to go to the fuse box. Snip the end off, attatch a terminal that will fit the battery, and poke it thru passenger footwell. Job done.

 

[AliasOmega]

leave the battery alone, connect it to the back of the radio.

there will be a permanent live present, probably a spare bullet connector..

 

[lambo]

Now I'm confused lol. I couldn't see anywhere on the back of the head unit that I could connect it to. There was a red wire that looks like it has a blank but I didn't want to connect it up and hope for the best.

I'm in halfords getting a connector so I can connect to the battery, but if there's an easier way I'd rather do that. I will post up pics of the headunit connections when I get home

Thanks for the help so far

 

[Dink]

is there a yellow on the wiring loom aswell?

it's the loom you need to look at not the head unit as that is why there is that connector on it all ready

 

[lambo]

Yeah there's a yellow wire On the head unit wiring loom (connecting head unit to car wiring) bur not a spare one. Am I meant to strip it back and just attach it??

 

[AliasOmega]

i would not mess around with the bulkhead/battery run etc.

you could scotch lock it into the headunit loom.

+

 

[Dink]

have you got a photo of the loom ?

mainly showing the red and yellow wires ?

 

[lambo]

Oh ok cool that sounds like a better option. This is my wiring loom.

I'll scotch lock it to the yellow wire?? Now I know what I need to do I'll start running the wires etc.

Thanks for all you help everyone I'll let you know how it goes

 

[Dink]

plug it into that loose red one

 

[lambo]

Ok I'll give that a go when Ive got it all in

 

[Dink]

yeah just make sure the ground is connected first and you'll be fine

 

[lambo]

Just done a quick test before running all the wires and it seems to work fine.

Thanks for your help I'm glad I didn't have to run to the battery

 

[Knuckles]

Under seat sub? Sorry this won't be any help lol but when you get it working will you post pics of it placed and how you got it working, I'd love one of these

 

[lambo]

Yeah it's an underseat sub there pretty good it fits under the drivers seat perfectly. I havnt set it up properly yet but first impressions are it's pretty damn good for what it is. I'll post more when I've sorted it tomorrow.

Thanks for everyone's help to get it up and running, it's actually very easy to install now I know where to plug things in

 

[MT AUDIO]

DO NOT CONNECT THE SUB PERMANENT TO THE STEREO WIRING FFS!
it needs more juice, you'll end up cooking your wiring. Go to the battery!

 

[Dink]

lol not with a 10A fuse built in to the sub wiring

 

[Lagerlout]

It won't cook it - That's what fuses are for, but agreed it's bad practice to take a supply for an amp from the back of the stereo - Especially with the relatively high power output head units you get these days, that's a potentially big load on the cable supplying the HU.

 

[lambo]

Ok so what I have done is wrong??

Why has kenwood supplied that type of connector On the end of the power cable if it's meant to go to the battery?? I know I don't know a great deal about it but surely if they supply a connector that fits into the headunit wiring loom (and it works) then that is where it's designed to go??

 

[Dink]

they know that it doesn't take much power and thats why they fitted that connector

an other sub/amp combo would be a big no no

as i said in a previous post if the fuse operates in the car fuse box for the head unit you'll have to take the supply to the battery

 

[James28]

Tbh with a sub that size you'll probably be fine regarding power from there. If not just find a live in the fuse box, and connect it to that. That's what I'd do,
Seems to pathetic a cable to bother wiring all the way to the battery.

 

[lambo]

Yeah I'll just leave it as it is then, it's got and inline fuse so if it starts poping that I'll have a re think. I know you would normally connect to te battery for amps/subs but hopefully this will do the job with alot less hassle

 

[drumdom1]

Dude.
Don't wire it to the HU power supply.
Please!

It's not worth the risk.
If we say the hu is 100 watt max plus the 150 watt max sub.
You could draw pushing 20amp.
The headunit wiring will not be designed to take that sort of current.

Run it to the fuse box. Or to the battery with an in line fuse.

I don't care what the numbers say, electronics is my thing and it's friendly advice trying to avoid any probs for you.
Ita not worth the risk.

 

[Dink]

the size of that sub i doubt it's got a step up psu circuit so that is a 4 ohm load on 14 volts = 3.5 amps x 5 = 17 amps at the very max

take into account that it is a sine wave so 17 * 0.707 iirc = 12A ish if you played a 50hz tone @ 0dB

 

[drumdom1]

Ish yeh.
But don't forget you have the current drain from the hu and display aswell.
And the ac part will have little effect on the current that the amp draws so it can be worked out using dc quantities. If you want a proper estimation then you would have to look at an instantaneous current value for a wide frequency range and also take into acount the phase of the load due to n audio signal whether it be amplified or not being basically a big jumble or ac wave forms. plus it wint be a true sine so that equation is too simple for the problem and could be under (or over granted) estimating the current.

It's not worth the risk what ever the actual power requirements of the amp and head unit are.

 

[drumdom1]

Not going into where the numbers come from.
But if it's 150watt max.
Work on 106watts rms.
It's a signle channel amp so that is the wattage value we shall use.
Double that then divide the total by 13.8.
We get approx 15.4amps.

That's too much to safely ask from the head unit wiring.

 

[lambo]

Sorry for taking so long to reply again

I have been running the wiring to the head unit and everything seems fine, but
i cant help worrying about it now after what Dom has said. I dont know what to do now.

How would I wire it to the fuse box if I went down that route?? I'm not sure the cable will easily reach the battery

Thanks for the help

 

[Dink]

don't worry about it trust me

the cable for the hu is fused @ 10A at the fuse box

if the fuse operates then change the wiring but until then it's not a problem

 

[lambo]

Ok cool, so ill wait. If it blows the fuse then do something about it

Cheers