Wiring Cockpit Speakers to Existing Stereo with 4 Speakers

[Patrick_DeepPlaya]

I searched around and all the previous cockpit speaker discussions are about box speakers or surface mounts. I have a different conundrum.

I have a stereo which can handle 4-8 Ohm speakers and will deliver 50Wx4.
I currently have salon speakers (4 Ohm) on the front channel and aft cabin speakers on the rear channel (4 Ohm). I want to add a set of cockpit speakers to the rear channel (also 4 ohm).

I know if I wire the new speakers in parallel with the aft cabin I will get 8 ohms and everything is fine.

But the problem with that is I also want to be able to turn on\off the cockpit speakers or the aft cabin speakers so that I can have all four rear speakers or just one set of them on.

Anyone know of a switch which can handle this kind of configuration?

Thanks!
-patrick

[westwinds]

A double pole double throw toggle switch that includes an off position should do it. Radio Shack or amazon probably has it.

[Patrick_DeepPlaya]

Another person told me I could accomplish this with 2 DPDT relays and a SPDT ON OFF ON switch, but I can't figure out the wiring. Any hints?

Gracias
-patrick

[ozskipper]

Originally Posted by Patrick_DeepPlaya

I know if I wire the new speakers in parallel with the aft cabin I will get 8 ohms and everything is fine.

-patrick

Your incorrect. 4 + 4 ohm in parallel = 2 Ohm.

Resistance kinda works back to front mathematically when wiring parallel.

If you wire them in series your math would be correct.

However, I would suggest that you reconsider your stereo head. Most standard heads allow you to adjust Balance (left right) and Fade (front back). This would be your best and simplest option.

[H3LlIoN]

Originally Posted by ozskipper

However, I would suggest that you reconsider your stereo head. Most standard heads allow you to adjust Balance (left right) and Fade (front back). This would be your best and simplest option.

As ozkipper stated, just wire your saloon speakers to the front channels on the deck, and wire the cockpit speakers to the rear channels. Fading one way or the other will allow you to select between saloon, cockpit or both. Simplest and easiest. Switches, relays, etc is just more stuff to corrode and/or break, and is wholly unnecessary.

[David M]

The loudness in each area of the boat can be controlled using only the volume and the fade control. This keeps things simple and has worked well on my boat.

[Lake-Effect]

Dumb idea: if the cockpit speakers are mounted with their ass end pointing into the aft cabin(s), you're now feeding both areas, yes? You might want additional tweeters to help put enough treble into the aft cabins.

Originally Posted by Patrick_DeepPlaya

I also want to be able to turn on\off the cockpit speakers or the aft cabin speakers so that I can have all four rear speakers or just one set of them on.

I've done this before.

If an amp can handle 4-ohm speakers, it will also handle an 8-ohm load (two 4 ohm speakers in series) with no problems, other than the fact that each speaker will only get about half the level. The front-back balance will help balance out the sound from every speaker.

So - each of the L and R rear channel loads will consist of one aft-cabin speaker in series with one cockpit speaker. Like this, the amp sees an 8 ohm load and both the aft cabin and cockpit speakers will work.

Now if you want to kill the cockpit speakers, short them out, leaving just the aft cabin speakers receiving drive. Similarly, if you want just cockpit speakers, short out the aft cabin speakers.

All of the above can be achieved with a double-pole double-throw center-off toggle switch. At the center-off position, both speaker sets are on; throw the switch one way and you short out the cockpit speakers, throw the other way and you short out the aft cabin speakers.

I'm away from where i can easily do a schematic, but i hope the above description will get the idea across.

[ozskipper]

Originally Posted by Lake-Effect

Dumb idea: if the cockpit speakers are mounted with their ass end pointing into the aft cabin(s), you're now feeding both areas, yes? You might want additional tweeters to help put enough treble into the aft cabins.

Snip.

Too true. The best resolution for this, is a couple of speakers on brackets mounted on davits/targa or what ever external structure "if" there is one.

[swisscraft]

Just another point: I remember reading an article about the fact, that cockpit speakers can be a issue if the cockpit fills with water and they give in so water finds the way into the boat. Found that interesting, so as far I recall they recommended to ensure you could close them somehow - or maybe seal the back. Never tough about that and think worth sharing...

[ozskipper]

I have been sailing for 35 years and never considered that! Really Really good point. It would take a very strong water tight encasement behind them to really prevent water getting in, considering the weight of Sloshing Water.

[Lake-Effect]

Originally Posted by ozskipper

I have been sailing for 35 years and never considered that! Really Really good point.

So that idea was even dumber than I thought.