Stereo into one Speaker

[Randog]

Ok so I know just enough about stereo installation to be dangerous. So bear with me when I say Huh?

I’m replacing the stereo head unit in my class A motor home. The existing head unit has a center channel which drives a center speaker just like in a home surround system set up. The new Kenwood DNX570HD will drive an amp by RCAs thus the four existing speakers but doesn't have a center channel. Easy enough. I know the Kenwood has front and rear high outputs that will still power up even with the amp installed. I want to drive my center speaker with stereo from a pair of these outputs and have a center channel like before. This is not to achieve surround sound but rather to help fill in the sound because the class A so large inside you can’t hear the stereo while driving unless you crank it all the way up.

I’ve read post on how to do this but I’m still not sure on what to do so I don’t blow the amp. I read two options that sound reasonable:

1) Connect the positive of both channels to the two terminals of the speaker. This sounds questionable to me, but me being stupid in these things I just don’t know.

2) Install two resistors one on each positive from both cannels and connect both to the positive on the speaker. Here this sound a little better but I don’t know the size of the resistors or do I know if it will work. I have done a similar installation on a custom motorcycle where I needed to indicate either blinker on the dash with a singular LED.

Suggestions? Any help would be appreciated, please use diagrams, photos and or hieroglyphics cause I get confused easily.

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[Side Show 10+ year member]

in the deck manuel it should say you can wire one speaker onto the two rear channels of the headunit, it should also show you what wires to connect and any settings that need to be changed in order for this to work, you may find it is only for sub and wont allow the full frequency range

 

[Randog]

Thanks I will look at that..

 

[keep_hope_alive Premium Member]

modern head units have balanced outputs (also considered bridged). that means there are signals on both (+) and (-) wires for each speaker. The (-) is just 180 degrees out of phase with the (+).

the idea of creating a mono signal is to wire the (+) of the left output to the (+) speaker terminal and the (-) of the right output to the (-) speaker terminal. the speaker should be 8 ohms.

 

[keep_hope_alive Premium Member]

that said, some head units may see this as a short and turn off. each amplifier in the head unit is an integrated amplifier chip and a protection circuit. the configuration will determine if the head unit can handle a mono wiring configuration.

 

[Randog]

Will the head unit reset if it sees it as a short?

 

[Side Show 10+ year member]

more than likely it'll blow the fuse on the wiring harness of the deck.... if I were u, don't even hook up the centre speaker

 

[Randog]

Like I said, because of the volume of the interior of a class A and the location of the speakers are 4ft behind the drivers seat its hard to hear the sound with out turning the volume all the way then its so load you cant talk to any of the passengers. This is a problem with class A motor coaches and Magadyne addressed the issue by offing a center channel. Magnadyne makes RV stereos and its what I'm replacing with Kenwood. Magnadyne is not the best made Chinese stereo and has lots of issues.

 

[keep_hope_alive Premium Member]

nah, if the deck doesn't like it it'll just shut down the amp, maybe turn off the unit. all of the modern IC's have short protection built-in.

 

[maylar 10+ year member]

modern head units have balanced outputs (also considered bridged). that means there are signals on both (+) and (-) wires for each speaker. The (-) is just 180 degrees out of phase with the (+).
the idea of creating a mono signal is to wire the (+) of the left output to the (+) speaker terminal and the (-) of the right output to the (-) speaker terminal. the speaker should be 8 ohms.

You can use 4 ohms. Remember that all 4 channels are the same - the HU doesn't care which pair of outputs you use, they're already bridged internally.

 

[keep_hope_alive Premium Member]

You can use 4 ohms. Remember that all 4 channels are the same - the HU doesn't care which pair of outputs you use, they're already bridged internally.

i recommend 8 ohms in case the channels are also used for stereo speakers (like a tri-mode configuration).