Running a second amp
 

I have bough another amp to power my bow speakers, currently they are powered off of the head unit. Can I run the power, ground, and remote for the second amp from the first, or do you run whole new wire?

Thanks,

Abs

To be safe, I'd run whole new wire and make sure you fuse the hot lead.

run one wire to a two wire distribution block . simple chit

Depends on the amps, and the gauge of wire you have going to them.

For example, if your current amp is maxing out the gauge wire you have, adding a second amp to that circuit, will not be a good idea.

I am in the process of rewiring my entire stereo system. In the cabin, I have a 5 channel amp. However, down the road, I may add another amp, or two, if I want to expand my system. So, I decided to run 0 gauge power wire to the cabin, and then run a distribution block, which has a 0 gauge input, and two 4 gauge outputs. One of those 4 gauge outputs, will go to my current 5 channel amp. If i add a second amp, the other 4 gauge output will go to that.

One thing you must consider in a boat, is the length of wire, and material of wire, and its amperage capacity and voltage drop.

Lets just say for example, you have a 4 gauge power wire to your amp. Lets say that amp can draw 80 amps at peak power, and your amp is 20ft from the battery.

Your engine is off, and your battery voltage is 12v for example. At full load, your amp will see 10.4 Volts, due to the voltage drop. So, you're amps seeing 1.6 volts less than the battery is at. Now, if you are using 1/0 gauge wire, your amp will see 11.38 volts, or about .6 volts less than the battery is at. If using a 6 gauge power wire, your amp would be getting 9.5V.

Amps are pretty picky about voltage levels. Most amps if voltage drops too low, they simply go into protection mode. Some modern amps, will still play, but at a reduced output. To sum up what I am saying here, is size the power wires appropriately for the amp/s you are using. Consider amplifiers power consumption and length of wire. A quick look at the amps fuses will give you an idea. My modern alpine amp has two 40 amp fuses. My old school fosgate powerhouse amp, has one 150 amp fuse, as it can draw some power.

What he said is absolutely correct. But if you only adding an amp to power your front speakers I am envisioning a small amp and small output. You should be ok with putting a distribution block and splitting the power. If the amp starts to clip or go in to protection mode, then you know that you have to upgrade the wire from the battery.

Did you end up with a PDX V9? Mine is pretty damn sweet.

Agree with Mild Thunder 100%. The right size wiring and fuse protection is really very important. If you only have a single head unit, I'd be willing to bet that the positive lead on the head unit is connected to a 10 or 12 gauge wire at best. If that is the case, I would not split that.

I just upgraded my entire stereo system, installing two new amps and new head unit. I left the wiring alone for the head unit but for the amps, I ran 1/0 wire from the battery to the cabin with a 100 A circuit breaker near the battery. That wire is terminated in the cabin into a fused distribution block with 4 gauge wire going to the amps.

Size of the wire depends a lot on length of run and voltage drop along that distance. In my case, my hot leads were 35' long so I went with larger wire.

Sounds like we think alike! I also went with a circuit breaker near the battery, rather than a fuse. Never used them before, but figured I'd give it a try.

I did, I havent got to use it yet though. Pretty impressive little amp! Mine came with a birth sheet of 128w X 4 rms, and 584x1 rms to the sub. Hard to believe in such a tiny package. :drink:

Yessir. Circuit breaker near the battery to cut the current in the event the main cable gets severed or something really bad happens. I guess a fuse would achieve the same thing potentially, but because of the location in the bilge, I went with a heavy duty circuit breaker cause I knew I'd end up stepping on the fuse all of the time and breaking it. I also added a house battery for my amps and tied it to my center engine with an automatic charging relay that has starting isolation. Works like a charm. When the engine is running, it combines and charges both batteries.. if either battery voltage drops below 12.75 volts, it disconnects them and when I start the engine, it automatically, disconnects them as well...

sorry for the hijack, but this info could be helpful to OP..

picture of my amp wiring below...

[ATTACH=CONFIG]541241[/ATTACH]

Nice job on the wiring,very clean! Where did you get the distribution blocks with built in fuses?

Thanks. I'm a bit of nut when it comes to this stuff. It was a lot of wires so I wanted to keep it neat so I mounted everything on a piece of 1/4" starboard.

The distribution block is a JL Audio (XD-FDBU-4) 4-Way Fused Power Distribution Block. I believe I ordered it and the 50A fuses for it from their website.

Thanks, I got a bunch of new JL speakers and amp going in soon. I'ld like to make it as sanitary as possible!

Who runs a capacitor? What farad?

Doubt you need a cap.

Can you run off of the remote and ground from the 1st amp?

A cap is not designed for reserve time, and won't have a purpose in a boat. It stores energy for when current draw is needed - like when bass hits. That's only applicable in a car/truck, and it's to help take a little load off of the alternator. In a car, it's a band-aid at best.

I ran my second amp and I used the power distribution block for my power and ground. Now I am getting interference from my new amp when I run the blower. Do you guys think this is a grounding issue? It's weird that the ground is ran from the distribution block to both amps and only one is giving me feedback.

Any ideas?

Thanks!

Dirty power is fairly common in mobile systems. Could be a ground loop issue. How are amps grounded and the blower?

When you say you used the power distribution block for power and ground, does the block you used have a separate ground terminal post and what did you tie that back to ?

I used the ground that was ran for the first amp...ran that to the block. The block has two outs..one going to the original amp and the other going to the new amp.

I did trouble shooting yesterday and found out that the sound is coming from the input and has nothing to do with the ground or power. Here is how it is hooked up. I ran the bow speakers from the head unit into the high input of the amp, so now the new amp is powering the bow speakers. When I turn the blower on you hear the blower through the speakers. I then decided to try the RCAs that are running into the original amp, so I plugged them into the low input on the amp and the same thing, made no difference. I then unplugged the head unit input into the amp and just hooked my iphone directly to the amp and turned on the blower and nothing, so it isn't electrical on the amp, it is coming from the sound input. I then ran a channel from the original amp into the high input of the new amp thinking maybe that would condition the input, but it still did the same thing.

I am at a loss. Is there anyway to clean up the input signal?

I still think this is a ground related problem and it involves the head unit and the new amp. Can you try isolating the grounds from the head unit and the new amp?

I thought that too. I ran an isolated wire straight from the ground terminal on the battery to the amp and it still did the same thing.

Try running your trim pump up and down while listening to the front speakers. Any noise from the pump motors?