Wiring an amp

[JTPain]

So, time to upgrade the stock system on the 2012 SX 210. Way over due.
I installed 4 Polk Audio DB651"s. Amazing difference over stock already.
Now installing a Boss Audio MR1004 amp. (400 watts) Not looking to rock the world, just looking for a bit better when hanging at the beach.
Question is, do I run both power and ground all the way back to the battery or is there a somewhere to connect the ground wire under the dash.
I plan on mounting the amp under the steering wheel area somewhere.

Also, the directions say to have an inline fuse on the positive power wire, but doesn't say what size fuse.
Ive searched and cannot find the specific answers.

Thanks in advance for the help.

 

[Kevin M]

You will want to run both Pos & Neg wires back to the battery. The fuse will be placed about 12" from the battery. Not sure on the size of fuse but your amp should say what it requires. Also, be sure to use the same gauge wire for both the positive and the ground.

 

[Drift Away]

Agree with @Kevin M. The rule of thumb is dont go to big with wire or to small. For a 400 watt amp you need to run either 6 or 8 gauge wire. This will keep your amp from getting too hot when parked on the beach. If you go to small with your power or ground wire you can literally feel the wire getting warm from the current going through it. I have two JL Audio 600 watt 6 channel amps running off a 2 gauge wire that is about as big as my thumb. Your 4 watt should run just fine off 6 or 8 gauge wire. Installing an amp in a boat is one thing you do not want to be cheap on. You can buy the stuff on eBay or Amazon from China but it's not worth risking Catching Fire on your boat.

 

[Mainah]

There is no chasis ground in a fiberglass boat so yes run the positive and negative to the battery. The inline fuse size will depend on the wire gauge and length of run as the fuse is to protect the wire from melting or shorting between the battery and amp. Wire gauge will depend on the draw of your amp and length of run.

The one place not to compromise in an audio upgrade is the wiring. Go to knukonceptz.com for real marine grade wire. The flexs wire is worth every penny and the best deal on real marine grade wire. Don't belive anything you read about the kits you see in walmart or on amazon or the like. Hardy any kits listed as 4 awg is true 4 awg not to mention the wire type and hype.

I think there is a link in the faqs to a wire gauge calculator or chart. With your boat and amp 4 awg is a safe bet and perhaps even leave some room to add more bigger amps in the future depending on length of run. Going too big on the wire is not bad, it just costs a bit more. 8 awg may cut it close for what I am guessing will be a fairly lengthy run so why risk it.

A 60 amp fuse will play it safe for the inline at the battery on a 4 awg run. If no onboard fuse on the amp you should install another block
or inline at the amp rated for 40 ot 50 amps.

Good luck

 

[JTPain]

Thanks a ton for the info. I almost bought one of those kits on amazon, but the reviews agree that they are crap. Not true gage as stated.
The amp does have a 15A onboard fuse & calls for 8 gauge but probably go bigger because my crystal ball says I may add a sub in the future.
got the speakers and amp from Amazon for about $160, looks like maybe another $50 0r so after the wires.
It"s all good. Is it summer yet?

 

[mark_m]

There is no chasis ground in a fiberglass boat so yes run the positive and negative to the battery. The inline fuse size will depend on the wire gauge and length of run as the fuse is to protect the wire from melting or shorting between the battery and amp. Wire gauge will depend on the draw of your amp and length of run.

The one place not to compromise in an audio upgrade is the wiring. Go to knukonceptz.com for real marine grade wire. The flexs wire is worth every penny and the best deal on real marine grade wire. Don't belive anything you read about the kits you see in walmart or on amazon or the like. Hardy any kits listed as 4 awg is true 4 awg not to mention the wire type and hype.

I think there is a link in the faqs to a wire gauge calculator or chart. With your boat and amp 4 awg is a safe bet and perhaps even leave some room to add more bigger amps in the future depending on length of run. Going too big on the wire is not bad, it just costs a bit more. 8 awg may cut it close for what I am guessing will be a fairly lengthy run so why risk it.

A 60 amp fuse will play it safe for the inline at the battery on a 4 awg run. If no onboard fuse on the amp you should install another block
or inline at the amp rated for 40 ot 50 amps.

Good luck

I used these guys and love their stuff:

https://tinnedmarinewire.com/wire/

 

[mark_m]

I used these guys and love their stuff:

https://tinnedmarinewire.com/wire/

Consider reaching out to @Earmark Marine. Odin may cut you a break on a higher spec amp. Consider JL audio marine amp to match off with your polks

 

[swatski]

I think @JTPain already has an amp.

Speaking of economy amp upgrades, I must say that the D class micro amp, Clarion XC1410 seems to work extremely well with up to four (4) Polk DB651s, in my experience. There are several other members that used it in their stereo upgrades and I have not heard a bad word yet. Don't know what it is about it, it just mates really well with the DB Polks. It is super cheap at some $70, and a breeze to install, if you are willing to do some soldering, and there is no tuning involved.
Just my 0.02. (I'm on my second, and about get a third).

--

 

[Mainah]

Thanks a ton for the info. I almost bought one of those kits on amazon, but the reviews agree that they are crap. Not true gage as stated.
The amp does have a 15A onboard fuse & calls for 8 gauge but probably go bigger because my crystal ball says I may add a sub in the future.
got the speakers and amp from Amazon for about $160, looks like maybe another $50 0r so after the wires.
It"s all good. Is it summer yet?

Amps X volts = Watts. Even assuming 14vdc nominal used for spec testing that is only 210 watts. Assuming the 15a fuse is for max rating you are looking at a true RMS of no more than 40 watts per channel. This is quite common with boss audio and a couple of others. MB quart or clarion marine amps are likely to be much better choices for budget stereo upgrades and true marine amps at that.

If you can return the boss audio amp you will be happier with this at $88.33

MB Quart NA360.4 Nautic Amplifier, 4-Channel 360-Watt https://www.amazon.com/dp/B00DJ677MQ/ref=cm_sw_r_sms_c_api_qG5GybJF5D85F

Edit - The above amp is a class a/b amp that will be less efficient and run down your battery quicker than a class D amp.

 

[swatski]

Amps X volts = Watts. Even assuming 14vdc nominal used for spec testing that is only 210 watts. Assuming the 15a fuse is for max rating you are looking at a true RMS of no more than 40 watts per channel. This is quite common with boss audio and a couple of others. MB quart or clarion marine amps are likely to be much better choices for budget stereo upgrades and true marine amps at that.

If you can return the boss audio amp you will be happier with this at $88.33

MB Quart NA360.4 Nautic Amplifier, 4-Channel 360-Watt https://www.amazon.com/dp/B00DJ677MQ/ref=cm_sw_r_sms_c_api_qG5GybJF5D85F

Ha! I think I won't be buying that xc1410 anymore!

--

 

[swatski]

Amps X volts = Watts. Even assuming 14vdc nominal used for spec testing that is only 210 watts. Assuming the 15a fuse is for max rating you are looking at a true RMS of no more than 40 watts per channel. This is quite common with boss audio and a couple of others. MB quart or clarion marine amps are likely to be much better choices for budget stereo upgrades and true marine amps at that.

If you can return the boss audio amp you will be happier with this at $88.33

MB Quart NA360.4 Nautic Amplifier, 4-Channel 360-Watt https://www.amazon.com/dp/B00DJ677MQ/ref=cm_sw_r_sms_c_api_qG5GybJF5D85F

This MB Quart is pretty cool, but I think I'll stick with the Clarion XC1410 for my current update. Efficiency is the key. With it being class D and pocket-sized -- hard for me to move on. I've used/installed those twice before and both times found the two (XC micro amp and 4 Polk DB651s) just mate up weirdly well, for some reason. With no tuning (there is basically none) -- it is a surprisingly decent sounding set.

IDK. Need to think about it. And just to be sure - MB Quart remote knob is just bass boost control, right?

--

 

[FloJet]

Now we are talking. My kind of conversation. Sorry but yes I will just be rude and invite myself into this interesting convo hehehe. Well I do agree with everyone's advise that bigger wire is better. But to be honest I would go bigger than stated above. You are on a jet boat forum that loves to give mod upgrades like they are going out of style, so I bet in the near future you would want to add more electronics, perhaps. I would use 1 to 0 awg as your main power source wires. I would run that to a distribution box located by the amps. That way what ever you add later on, you can use smaller wiring and have smaller runs to the power source. From the distribution the 8 and 4 awg would be suffice for most applications. But you don't want to run many applications from 8 or even 4 awg main power wiring in boats. But the only downfall of that is COST. The bigger wires will cost way more so it's about your budget goals. But I do agree with @Mainah about Kunz on ebay or amazon. Have ordered many wiring from them and price is the best around. But always thing big, way big IMO.

 

[FloJet]

This MB Quart is pretty cool, but I think I'll stick with the Clarion XC1410 for my current update. Efficiency is the key. With it being class D and pocket-sized -- hard for me to move on. I've used/installed those twice before and both times found the two (XC micro amp and 4 Polk DB651s) just mate up weirdly well, for some reason. With no tuning (there is basically none) -- it is a surprisingly decent sounding set.

IDK. Need to think about it. And just to be sure - MB Quart remote knob is just bass boost control, right?

--

What do you mean by bass boost @swatski? Bass control or actual bass boost setting? Typically you want to tune your stereo where you don't have to turn on bass boost on your amps or head Units. It's not necessary and can help bring problematic distortions to speakers and subs.

 

[swatski]

What do you mean by bass boost @swatski? Bass control or actual bass boost setting? Typically you want to tune your stereo where you don't have to turn on bass boost on your amps or head Units. It's not necessary and can help bring problematic distortions to speakers and subs.

Oh just the knob they show in the pics of that MB Quart amp:

 

[Mainah]

@swatski - I have never used that particular MB quart amp. The brand and some key things in its marketing and features lead me to belive that this is a good amp. I belive the knob is a remote gain control for a particular channel or pair of channels. Speaking about tuning I always want control over high and low pass for each channel or pair of channels. Without getting too deep this allows the speaker to operate more efficiently, cleanly and louder. The polk dbs will be louder and more efficient with a high pass filter.

@FloJet - I do agree with the whole 0 gauge and distribution block thing (that is what I ran in my boat from the get go). I like to base my recommendations upon what I think an individuals budget, intent, and priorities are. In many cases a simple 4 channel
Amp and 4 polk dbs will thrill someone. For those like us we always want more more clean power even when we can already cause hearing damage. FYI I buy directly from the knukoncepts website.

 

[FloJet]

Very nice. I have always gone to their store thru ebay's site. I'm not sure if that's off their real website or not. I am curious to hear the Polks in the Limited S. The Polk in the AR 240 seems very efficient to me. Or am I tripping? lol. But seems everyone upgrades them. Even with my 410's running high, my polks seem to give it a nice balance. I have thought about going the Wet Sounds 6.5 route, but I just don't know how of a difference it will be with my towers on.

That knob is just a gain control which is different than built in bass boost. Basically the same concept of remote gain in an equalizer like the WS420. I use my bass remote gain thru that rather than coming directly from the amp. More than one way to skin a cat! Let me know what your experiences are with that MB Amp. I've never used it and I am always searching for more efficient and power. If I ever upgrade my cabin speakers I will need a good 4 channel amp to run them. Not sure if I like my JL HD 250's right now.

 

[FloJet]

The interesting thing about the remote gain controller for the MB looks like it has 2 cat inputs on it. But the back of the amp only shows one input. What would the other input be used for? Daisy chaining the bass controls for multiple amps?

 

[swatski]

The interesting thing about the remote gain controller for the MB looks like it has 2 cat inputs on it. But the back of the amp only shows one input. What would the other input be used for? Daisy chaining the bass controls for multiple amps?

Noticed that, too. So, if that knob is for the gain and not just bass control, that is a nice feature -- kind of like the WS420 indeed.

I agree about the DB651s, aren't those lovely?

--

 

[Scuba_ref]

If I can hijack for just one moment? Any thoughts on this amp? I upgraded to Kenwood marine speakers last year and would like to have blue tooth and have wanted to add an amp. I thought this amp might be the way to go.

http://www.kenwood.com/usa/car/marine/kac-m1824bt/

 

[Mainah]

The interesting thing about the remote gain controller for the MB looks like it has 2 cat inputs on it. But the back of the amp only shows one input. What would the other input be used for? Daisy chaining the bass controls for multiple amps?

Notice they are showing bunched and tied wire with two end and a knob. One end of the wire goes in the knob the other end goes in the amp. Don't sweat it we all have those moments.