Adding a Sub

finman · Outlaw Joined: 16 Feb 2005 Posts: 106 City: Tulsa

I was thinking of adding a powered sub to my system.
Right now I have a Kenwood 400W amp.
Would I take RCA cables from the line out plugs on the amp to the powered subwoofer? Then hook up my power and ground on the sub?

Thanks,
Fin

TP83 · Addict Joined: 31 May 2006 Posts: 739 City: Woodside

rca cables go from the head unit to the amp if there is a sub channel on the HU. you would take normal speaker wire from the amp to the sub, there is no need for a ground if connected to an amp.

finman · Outlaw Joined: 16 Feb 2005 Posts: 106 City: Tulsa

right now there are 2 sets of RCA outputs going from the Kenwood Head unit to the Kenwood 4 channel amp.
http://inform2.kenwoodusa.com/manuals/KDC-X679.pdf

Would I disconnect a set of the RCA jacks going to the amp and feed them to the sub?
http://inform2.kenwoodusa.com/manuals/KSCWD250T.pdf

will that effect the performance of the amp?
I have 6- 6.5" speakers hooked to the amp.

Thanks,
Fin

McQuesten1 · Guest

Y would you have 2 sets going from the HU to the amp?

TP83 · Addict Joined: 31 May 2006 Posts: 739 City: Woodside

2 sets probally means your running a left and a right channel to the amp, not sure on that tho. but because your going to be using power off the same amp as your speakers it will lessen the power on them. you could wire the amp so you put the sub on 1 channel and the put 2 speakers to every other channel but your sub will require alot of power. not sure on a budget but if possible try to pick up a mono amp(1 channel) and a sub that way, you wouldnt be loosing your speaker power and your sub will hit.

finman · Outlaw Joined: 16 Feb 2005 Posts: 106 City: Tulsa

McQuesten1 · Guest

Oh well I really don't know. If that is how it was when you got it It would probably need to stay that way. I would do like he said and just get a monoblock amp to power your sub, that way it will be louder, and you won't loose power to you speakers.

Wakebrad · Ladies Man Joined: 11 Dec 2003 Posts: 12257 City: Dallas

Is your amp built for a sub or is it a full frequency amp? Are you using a stand-alone amp for your speakers or are you using the head unit currently?

The best way to run it would be to have the sub have a dedicated amp for it. To do this you need to run + and - power from the battery to the amp. Run RCA from your other amp or your head unit to your amp. Run your cutoff power wire from the existing head unit or amp to your sub amp (so that when the stereo turns off your amp turns off) and run speaker wire to the sub.

Voila.

Just make sure you are using enough gauge wire for the distance you're running it (for the power and speaker wire). They should be able to tell you at the store how much gauge you need when you purchase it.

finman · Outlaw Joined: 16 Feb 2005 Posts: 106 City: Tulsa

WattsBar=Perfect · Newbie Joined: 24 Jul 2007 Posts: 48 City: Kingston

what kind of powered sub are we talking about exactly? if it has a built in amp and places made especially for rca cables to go in then that might work.

kmagnuss · Posted: Aug 08, 2007 3:04 pm Post subject:

You guys are all giving this kid BAD information. There's 4 rca cables going to your amp because it's a 4 channel amp, and ALL four channel amps have 4 inputs. The RCA's coming off the receiver are front l/r and rear l/r. You might have another set back there for a sub output, or you might be able to change one set to be crossed over for subs instead of full frequency. Either way, you don't need to mess with that. Just run your line out from your amp to your new amp...then turn on the low frequency cross over on the new amp. Hook it up power/remote/ground (use 4 ga. wire now PLEASE) and go to town.

PM me for more info, as I won't me subscribing to this thread.

ps-I used to own a car stereo shop...I'm not some stupid kid that hooked up my friend's stereo.