Amp & Hookup Advise

[blbarge]

We added a tower with a pair of single speakers to our boat over the winter. The boat already has 2 pair of speakers running off the head unit so I need some recommendations on an amp. We are not looking to service the entire lake with the sound system and have no intention of adding any more speakers or a subwoofer. Plus we only have one battery, so not sure how much of a concern there is adding an amp & listening while the boat is turned off - we are rarely parked for longer than 20 minutes.

In terms of connections I would like advice on which speakers (front, rear, tower) should connect to the head unit & which should connect to the amp. Is it better to keep 2 pair speakers running off the head unit (currently front & rear are connected to head unit) & one pair off a 2-channel amp, or one pair off the head unit & 2 pair off a 4 channel amp?

The specs of all our hardware is -

Head Unit - Sony DSX-MS60
- Output Power : 52W x4 Watts Max Power, Standard Power Output: 17 Watts RMS per channel into 4 Ohms
- Selectable rear or subwoofer pre-amp RCA outputs for external amplifiers
-Current Drain : 3 - 5 amps

Front & Rear Speakers - Sony XSMP-1620W
- Power Handling Capacity : 160 watts
- Rated Input : 45 watts
- Impedance 4 ohm

Tower Speakers - Aerial Single Bullet, Polk db series
- Power Handling (continuous) : 60w
- Power Handling (peak): 180w
- Impedance 4 ohm

All speaker wiring is 16-ga

Thanks in advance for your recommendations.

 

[mark1905]

Re: Amp & Hookup Advise

Leave existing speakers hooked up to deck. Get yourself an MB Quart NAU260 2 channel amp for the tower speakers. Use a dash mounted accessory switch to activate the internal amp turn on relay so you can selectively switch the tower speakers off and on.

Done deal.


If it was me, even though you don't think that you'll ever want more, I would spend and extra $20 and get the 4 channel NAU460 just to have the flexibility to do more with it if I wanted to in the future, but that's me.

 

[Silvertip]

Re: Amp & Hookup Advise

Even though you say you never anchor for more than 20 minutes with the boat off, that means the boat must be run at a fairly good speed for the same amount of time to replace the current that was consumed while parked. So it isn't how long the system runs while parked that gets you stranded with a dead battery. It is how MANY times and how LONG you run in between those sessions.

 

[blbarge]

Re: Amp & Hookup Advise

Thanks for the replies. Yes, for only $20 more the extra 2 channels seems like a no brainer.

I like the idea of adding a switch to power on/off the tower speakers. We have a dummy switch on our dash so would be an easy spot to add. I have not searched yet, but can anyone give some simple instructions or point me to a link on whether there is a specific type of switch & how to wire in?

 

[mark1905]

Re: Amp & Hookup Advise

On any external amplifier, there is an internal relay that will activate when 12V+ is applied to it. This is how the amplifier stays permanently hooked up to the battery, but only turns on when the stereo turns on. In the bundle of wires for the head unit, there will be a blue wire with a white stripe which is the amp turn on wire. In a normal case, this is what you would run to the amp(s) to turn them on. On the MB Quart amps, it's the terminal that's in between the main 12V+ and GND connections. You'll clearly see it when you get the amp.

In your case, since you would like to make your tower speakers selectable via on/off switch, you would simply take the 12V+ switched power from any of your spare accessory switches on the dash and run it back as this wire in place of the blue/white wire output from the deck. This way, you would simply flip the switch to activate the tower speakers and be able to only turn them on when wanted. The downside is that if you forgot to turn them off at the end of the day when powering everything down, you would drain your battery. Just an extra thing to remember to check when powering everything down.

If you wanted to be a little trickier, you could take the blue/white wire and power the accessory switch with it.. and then run that back. This way, the switch itself would only have power when the head unit is on and the amp wouldn't be able to turn on without the head unit on. Less chance of forgetting to turn the amp off or someone bumping the switch while docking and ending up with a dead battery.

Make sense? It's all really simple stuff, to tell you the truth.

 

[blbarge]

Re: Amp & Hookup Advise

Yes, makes sense. I'll probably to the extra effort & power the accessory switch to minimize leaving the switch on by accident. We have a 7 year old so buttons tend to get pushed every now & then.

I'll order the amp soon & post back if i have more Qs once I have all the parts.

 

[blbarge]

Re: Amp & Hookup Advise

It's been a few months but I've finally purchased my amp & I am ready to connect. I've initially connected as per 'standard' install instructions - ground from amp, remote input from head unit & power from battery. Everything works fine.

Now, I want to change the connection so it goes through an accessory switch on the dash allowing me toggle the tower speakers on & off. I want to make sure it's wired in a way that the remote out cable from the head unit still supplies on/off signal, the switch will simply act as an interrupter on/off switch. Ie. I do not want to have to remember to flick the switch off to ensure power is not going to the speakers when the head unit is off. Can some one clarify how I would correctly run the wires between the switch & amp?

Thanks

 

[PuddleJumper]

Re: Amp & Hookup Advise

Cut the wire from the head unit to the amp and connect to the terminals on your switch

 

[Slide]

Re: Amp & Hookup Advise

It's been a few months but I've finally purchased my amp & I am ready to connect. I've initially connected as per 'standard' install instructions - ground from amp, remote input from head unit & power from battery. Everything works fine.

Now, I want to change the connection so it goes through an accessory switch on the dash allowing me toggle the tower speakers on & off. I want to make sure it's wired in a way that the remote out cable from the head unit still supplies on/off signal, the switch will simply act as an interrupter on/off switch. Ie. I do not want to have to remember to flick the switch off to ensure power is not going to the speakers when the head unit is off. Can some one clarify how I would correctly run the wires between the switch & amp?

Thanks

Simply run the remote lead for the tower amp through a switch. No matter if the switch is on or off, the amp will never turn on if the head unit is off (that's the purpose of a remote lead).