Fitting car radio on boat

[frahkn]

I plan to fit a car radio on the boat but I have never owned a car radio so would like help with two points please.

 

Any advice on which radio to pick?

 

How do I wire it in? I imagine it will expect a "negative earth" connection, how do I get round this?

 

For the curious, I have always owned motorcycles so only have experience of the very occasional hire van.

[Jen-in-Wellies]

They aren't as common on boats as they used to be, but still a fair few around. Run a +12V and a 0V wire to the radio as usual for a boat. Car radios usually have a continuous supply to keep stations stored in memory and an ignition switched, but you can have both connected to the boat house batts via a suitable fuse, possibly bypassing the master switch with the continuous wire (+ fuse), if you are in the habit of switching off the house batt master switch.

The question is, what are you planning to use as an aerial? Will this pass through and electrically connect to the boat steel roof as a ground plane, assuming your boat has a steel roof? This can lead to a ground loop.

 

 

27 minutes ago, frahkn said:

Any advice on which radio to pick?

What does the nearest unattended car have fitted? A retro 1990's crime!

[Sea Dog]

It may not suit your purpose, but I and many others use a rechargeable Bluetooth speaker and stream radio or music from a mobile phone. More versatile, no additional wiring, no drain on your batteries when moored up, recharge as you cruise. A 12v car stereo can draw quite a heavy current.

[Hudds Lad]

5 minutes ago, Jen-in-Wellies said:

What does the nearest unattended car have fitted? A retro 1990's crime!

Back in the days of double income and no kids, the one time i left the flip-off front on my lovely Sony CD/Radio it got nicked  Heard car window smash, jumped out of my chair about three feet to the window and they'd already gone. They left the main unit though, so unless they had exact same model it was useless to them.

 

Oddly our boat has a little rubber duck aerial on the roof (well, the bottom half anyway, top bit has snapped off), nicely done aerial cable into corner cupboard, but has never had a radio or speakers fitted 🤷‍♂️ I won't be adding one.

[Jen-in-Wellies]

6 minutes ago, Sea Dog said:

It may not suit your purpose, but I and many others use a rechargeable Bluetooth speaker and stream radio or music from a mobile phone. More versatile, no additional wiring, no drain on your batteries when moored up, recharge as you cruise. A 12v car stereo can draw quite a heavy current.

The other thing about car stereos is that you also need to arrange speakers too. Modern bluetoothy things have all that covered and streaming music is available pretty much everywhere with a mobile signal.

[bizzard]

My radio has a speaker built in. A Tokal tractor radio. Normal size.

[Tigerr]

A nice car radio is a good idea - plus a full set of nice quality speakers, full quad sound.  You need to put a decent ariel in for DAB, and also make sure it has full bluetooth.

In time i suspect bluetooth speakers and phones will take over but phone signal coverage is still a bit patchy. 

Get one with a simple interactive head, nice and big. Not one with mystery codes that you won't remember.  (Pioneer should burn in hell). 

The wiring is fairly easy to do, just get a crimper set, and a 12v inline fuse. 

I have a builders site radio for the stern and I love it. Unfortunately doesn't get signal inside but lovely for cruising. 

[Tony Brooks]

The JVC Dab radio I bought worked perfectly well on a Halfords mag mount aerial. Whereas the previous all singing and dancing amplified AM/FM/DAB Aerials seemed to fail after a few years. the mag mount should get around the "earth" thing as well, although a capacitor in the braid would do as well for an aerial fixed into the boat's metal.

 

It will probably have a 0V cable connection, but I would also make a 0V connection to the meal case, especially if you use LED lamps in close proximity.

 

I totally disagree about them using high currants unless you add extra amplifiers etc. We never had battery problems with ours. Once you get the radio the programmes come free with no data charges, such as you might spend with a mobile phone. A phone may be fine if you just want any music you stored on it, but in that case get a radio with a USB connection and store your music on a USB thumb drive.

[Tracy D'arth]

You must isolate the aerial ground connection from the hull otherwise you will find that you have a -ve battery connection and ground loop on the hull that is not allowed and comes with all the corrosion problems that you were trying to avoid.

It will also bypass a negative battery isolator if you have one, risking a serious wiring burn out.

Edited September 26, 2023 by Tracy D'arth

[GUMPY]

I have given up with car radios as getting a decent signal can be a problem. Fitted two Bluetooth Stereo/Quad amps on the boat to replace what was rhere and now have the choice of just about anything off the internet.

For a cheap and simple fix a Betron Bluetooth speaker works well.

https://betron.store/products/d51-bluetooth-wireless-speaker

 

[Arthur Marshall]

DAB car radios are very heavy on battery use, as well as needing a dedicated aeriel. I've still got an FM one wired in, though I mainly use it to play cds or off a memory stick.

I didn't know about isolating the aeriel earth off the hull, so that's been doing whatever it does for thirty years ! After the post above I may change that. That being said, reception is pretty poor and I now have a Roberts Dab radio which works fine without an external aeriel.

[David Schweizer]

When I decided to fit a new radio in our boat, I spent some while in Halfords, listening to various radios within my price bracket, they were very helpfull and I was never dissapointed with my choice. With regard to the aerial, I did not want to drill a hole in the roof, and eventually decided upon a Magnetic based Taxi Aerial. The base had rubber on the bottom surface, which not only protected the paintwork but also insulated it from the boat's steelwork. The cable was initially passed through a window when it was in use, although I eventually rigged up a connection through the front bulkhead. Just google "Taxi Aerial" and loads of them come up at around £25. The one i chose was very effective and often worked well as a TV aerial !.

[blackrose]

1 hour ago, Sea Dog said:

A 12v car stereo can draw quite a heavy current.

 

Mine is 35w per channel so reasonably loud with the right speakers but only draws 1A on 12v. I don't know how that compares with charging a Bluetooth speaker, probably about the same. Anyway if someone's batteries can't handle a 1A draw they've got serious problems.

[Alan de Enfield]

32 minutes ago, David Schweizer said:

When I decided to fit a new radio in our boat, I spent some while in Halfords, listening to various radios within my price bracket, they were very helpfull and I was never dissapointed with my choice. With regard to the aerial, I did not want to drill a hole in the roof, and eventually decided upon a Magnetic based Taxi Aerial. The base had rubber on the bottom surface, which not only protected the paintwork but also insulated it from the boat's steelwork. The cable was initially passed through a window when it was in use, although I eventually rigged up a connection through the front bulkhead. Just google "Taxi Aerial" and loads of them come up at around £25. The one i chose was very effective and often worked well as a TV aerial !.

 

Cut to the correct length to give an SWR of ~1 they also make perfect 1/4 wave Marine band VHF aerials.

 

It just came out for river use, on the canals it just lived in a cupboard.

 

 

 

 

 

Edited September 26, 2023 by Alan de Enfield

[Sea Dog]

4 hours ago, blackrose said:

Mine is 35w per channel so reasonably loud with the right speakers but only draws 1A on 12v.

Well, sound power and actual electrical power appear to have a very strange relationship, but a straightforward 2 X 35w is 70w, which would be almost 6 amps - if there was no other consumption. I think 5 to 10 amps is a more typical range, but, even if it's only an amp as you suggest, I would still stick with my more versatile Bluetooth speaker. Just my own opinion - others are allowed. 

[Ianws]

I just use an older version of this Majority Petersfield Go 2 Pocket Portable Radio, DAB radio with USB Charging | Headphones Included, Lockable Buttons, 20 Presets | DAB+ Radio Pocket Radio, Running Radio https://amzn.eu/d/8cj7QvY

[pearley]

15 hours ago, Tigerr said:

. Not one with mystery codes that you won't remember.  (Pioneer should burn in hell). 

 

Actually it was Phillips who should be burning in hell as they first introduced security codes to car radios.

Edited September 27, 2023 by pearley

[blackrose]

10 hours ago, Sea Dog said:

Well, sound power and actual electrical power appear to have a very strange relationship, but a straightforward 2 X 35w is 70w, which would be almost 6 amps - if there was no other consumption. I think 5 to 10 amps is a more typical range, but, even if it's only an amp as you suggest, I would still stick with my more versatile Bluetooth speaker. Just my own opinion - others are allowed. 

 

I don't know the relationship between the wattage output of a 12v car stereo and the amps drawn from the batteries, but 1 amp is definitely all my 12v car stereo draws according to my shunt battery monitor. Anyway, like many things in boating equipment fortunately we don't have to stick with one or the other. I also have a rather loud Bluetooth speaker and I find both systems equally useful and versatile. After all, any system is only going to be truly versatile if you have a signal or WiFi in the first place, so I'm just increasing my options.

Edited September 27, 2023 by blackrose

[Ray T]

Choose one with a USB port and / or an auxiliary jack, you are not limited to just what is on the radio then.

 

e.g.

 

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Click to open expanded view

 

 

 

Car Radio Bluetooth 

[BEngo]

Modern car radios tend to come as a plug-in unit which fits to a DIN housing.  Unfortunately not all DIN housings are the same  so buy the radio first and sort out the housing after.  Then sort out the right number and mountings for the speakers.  Make sure the speakers are the right impedance and  can handle the power of the amplifier or turning the wick up will  likely cause problems.

 

All the connections are made to the housing.  Generally speaker wires ( 2 per speaker, polarity sensitive), switched power,  permanently live power, aerial, maybe aerial auto extension  A negative wire will also be needed.  Adaptors are available to connect the DIN housings to various car/truck/tractor manufacturers  standard radio fit connection but you will just need one with wires to crimp to your boat cabling.

 

I second the suggestion of Halfords.  Usually have a selection of models available to listen to. 

N

[Ronaldo47]

Audio power ratings of consumer electronics tend to refer to the peak power that can be delivered when reproducing audio. The average power delivered will be much lower, unless you are reproducing a constant amplitude signal such as a sine wave. 

[booke23]

12 hours ago, Sea Dog said:

Well, sound power and actual electrical power appear to have a very strange relationship, but a straightforward 2 X 35w is 70w, which would be almost 6 amps - if there was no other consumption.

 

In theory. But to actually draw that much power the radio volume would have to be turned up to maximum and be connected to suitable speakers that could actually handle that level of power. In real life you'd never even get close to that amount of power when casual listening. 

[Jen-in-Wellies]

55 minutes ago, booke23 said:

 

In theory. But to actually draw that much power the radio volume would have to be turned up to maximum and be connected to suitable speakers that could actually handle that level of power. In real life you'd never even get close to that amount of power when casual listening. 

Whatever you buy, make sure all the dials go up to eleven.