Installing 4 Channel Amplifier

I used Wet Sounds Wet Wire for all my cables. Great stuff!!! Not cheap,but phenomenal quality. Also it is all tinned wire so that helps a lot with corrosion issues. I highly recommend it. 
 
I have a question about this as well. Hope no one minds me tagging along to this thread. I've been reading through a bunch of older threads on what others have done, and I think I have it figured out, but thought I would post just in case. I'm looking at doing a pretty standard setup with two amps; one for my speakers and one for my sub. 

I have the power distribution block in my port lounger setup like this:

IMG_0975.JPG


Looking at that, it seems like they intend for you to run two separate feeds off the block; one for speaker amp and one for sub amp. Correct? I'm assuming it would be just as good to just run one larger wire from there to my helm and then split it out to the two amps? Is that correct? Is one way better than the other? I have lots of fish tape and fish sticks so I'm not too worried about getting the wires there. 

So I guess my question now is, what size wire and fuse would I use if I just did the one larger run? 80 amp and maybe 4 or 6 awg? Or should I just pull two wires with two separate 40 amp fuses to be safe and use 6-8 awg for each?
 
If you run one 80 amp set then you should probably use #4 but you would also have to find an 80 amp fuse to fit in the gap in the distribution panel.  I would run two sets of #8 for 40 amps each.  That would be 4 conductors.  Does anyone know the actual sustained current draw of these amps?
 
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Nick,

I'm no expert, but I would think the "block" could be rated for max amp pull from each "lug" which I would be concerned trying to pull "80" amps from one position vs 2-40 amp as shown. 2-4 ga wire may be able to handle the 80 amp capacity, but pulling that through one lug may cook the distribution block. I could be completely wrong, but I've done some sub setups in cars, and I ran my supply wire (0-2ga) from battery to a distribution block near the amps then dropped wire size (4-6 ga) at that point to the amps. Of course this was quite a few years back, so my memory could be ........ What were we talking about ???? :)
 
According to Blue Seas that safety hub 150 can handle up to 200 amp fuses in the larger section:

SafetyHub 150 Fuse Block
The SafetyHub 150 is an ignition protected fuse block with screw termination. It is safe for use on gasoline powered boats, reduces wiring connections, and consolidates up to ten fused circuits. It can be used for Main or Branch DC power distribution

  • Four 30A−200A MIDI®/AMI® fuses ideal for high-amp circuits including panel feeds, windlasses, and
    stereo amplifiers
  • Six 1A−30A  ATO®/ATC® fuses ideal for low-amp circuits including bilge pumps, electronics, and lights
  • Sealed cover protects fuses from the harsh marine environment: IP66 rating—protected against powerful
    water jets
  • Negative bus provides common location for negative collection
  • Circuit identification label with write-on capability
  • Fuse puller easily removes ATO®/ATC® fuses
 
Well that answered that concern!! I'm surprised that block would be capable of handling 6-200A positions.
 
It was the Blue Seas product photos of that Safety Hub that made me even think about putting in a larger fuse. I think Bennington must get that panel custom printed with their usual settings when they order hubs for the factory. 

So with that in mind, one larger fuse and a single wire sounds easier, I'm just not sure if there are benefits I'm not seeing to running the two separate. And for negative, I can just tie into the negative already at the helm, right? I don't think I need to re-run that up there. 

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So with that in mind, one larger fuse and a single wire sounds easier, I'm just not sure if there are benefits I'm not seeing to running the two separate. And for negative, I can just tie into the negative already at the helm, right? I don't think I need to re-run that up there. 
Definitely not on the ground.  It must be the same size as the positive 12VDC conductor as the current will be equal in both the positive and negative conductors.
 
So let me make sure I totally understand this... If I run a 4 AWG power wire from my block to the helm, I also have to run a 4 AWG negative wire? I thought for sure from reading other threads that people were ONLY pulling the power wire. Even some discussions about ground loop issues and having to move the stereo to the new power connection since everything was on the same ground. I'm apparently confused...
 
So let me make sure I totally understand this... If I run a 4 AWG power wire from my block to the helm, I also have to run a 4 AWG negative wire? I thought for sure from reading other threads that people were ONLY pulling the power wire. Even some discussions about ground loop issues and having to move the stereo to the new power connection since everything was on the same ground. I'm apparently confused...
The ground wire needs to be at least the same size as your hot wire. In the "standard" configuration it is quite small, just enough for the stuff in the helm and the M6, so can't handle the current load of the added amplifier.
 
When I talked to Bennington about my power needs they said they run one wire into the helm, then do a "sonic splice" . I believe they used 8G. I would run for sure 4G + and - and do a distribution block(well 2, unless you get one like the Wet Sounds that I have as it can do two separate inputs into four outputs. 1 4G + to 2 8G +, and the same for ground) and just run directly off your second battery. 
 
So let me make sure I totally understand this... If I run a 4 AWG power wire from my block to the helm, I also have to run a 4 AWG negative wire? I thought for sure from reading other threads that people were ONLY pulling the power wire. Even some discussions about ground loop issues and having to move the stereo to the new power connection since everything was on the same ground. I'm apparently confused...
Yes, you need to run two conductors of equal size, one for the (+) and one for the (-) since they both will carry the same amount of current.

The ground wire needs to be at least the same size as your hot wire. In the "standard" configuration it is quite small, just enough for the stuff in the helm and the M6, so can't handle the current load of the added amplifier.
That's correct and according to the Bennington wiring schematic the boat harness is protected by a 30 amp fuse which is probably a #10 conductor so the negative conductor would be the same size.  By running only one new (+) conductor back and tapping off the existing (-) conductor would overload the (-) conductor.
 
I'm not a stereo or electrical person but I just don't like the idea of connecting the variable load spikes that amps require to my helm electronics, I can loose the amps and be ok, if I loose all my helm electronics that may not be a good thing.


just another thought, if you play the stereo a lot while parked you might want to consider a deep cycle house battery to carry the stereo amps, especially if you only have one starting battery.
 
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