Wiring VHF and stereo to the same speakers

[PaulMcC]

Hi All,

At the moment my boat has internal speakers and two cockpit speakers. The VHF is wired to one of the externals and the car stereo is wired to the internals and the other external. This is a bit crap as to hear the VHF from inside I need the volume right up, To listen to music in the cockpit the volume needs to be at a level which is way too load inside, and in the evening having music on in the saloon annoys the neighbouring boats as it is coming from the cockpit speaker as well.

What I'd like is the option for sound to route to either inside, cockpit, or both speakers, a seperate volume control for one set of speakers when the stereo is playing through both sets, and an automatic override so than VHF messages interupt the stereo and play over whichever speaker is selected.

Does that sound reasonable (as in is the VHF interupting the stereo a sensible idea)?
And how do I do it (I'm competent at general wiring but know nothing about audio)?

 

[spannerman]

Most modern radio/cd players have a fader control between the front pair (saloon) and rear pair (cockpit), have you checked if it has this feature, as that's how we wire up most boats if they have that speaker layout. As regards the VHF, not sure its a good idea to wire that into one of the speakers, I think it would be better with its own dedicated speaker(s) and control the volume from the VHF itself.

 

[mikefleetwood]

Short answer - it can't be done.

If the "car" stereo has an "Aux" input, it is probably feasible to feed the VHF via that input, but there is unlikely to be a feature in the stereo to automatically switch between the two on incoming VHF, nor is it likely to be possible to have a mix of the two inputs.

Having said that, I doubt if this is a unique problem, so it is quite likely that someone, somewhere, sells a box that automatically switches the speakers or something like that. Have a good look around in one of the bigger car-audio stores or a well-stocked chandlers?

 

[prv]

If the "car" stereo has an "Aux" input, it is probably feasible to feed the VHF via that input, but there is unlikely to be a feature in the stereo to automatically switch between the two on incoming VHF

What you need is a "phone" input, intended for installed mobile phone car kits. When a signal comes in on that, the stereo mutes the music and plays the phone call out of the speakers. Used to be in vogue back when I was a sixth-former making a few quid fitting stupid thumpa-thumpa stereos in other people's Fiestas and Corsas; I don't know if current stereos still have them.

My own solution is just to have separate speakers for VHF and stereo...

Pete

 

[rogerthebodger]

What you are asking is in effect a VOX relay where the signal input normally cones from a microphone but feed from the speaker output and the relay change over contacts switch between the stereo and the VHF.

The main problem is the delay in the switching will cause you to loose the first few seconds of the VHF transmission.

The mobile phone switched overcomes this by using the incoming call to do the switching and not the voice output

This is the similar problem you get with a VOX half duplex radios

This is a VOX relay kit that available.


http://www.kitsrus.com/pdf/k126.pdf

here are some more including one using a Arduino micro

https://www.google.co.za/#q=vox+controlled+relay

I fitted multiple speakers with selector switches and both my fixed VHF radios have duel cockpit/nav station controls

 

[ShinyShoe]

I don't know if current stereos still have them.

Don't think so - Bluetooth has kinda taken over.

You can (I think) get a bluetooth device that you can probably connect to the speaker system and it could then interupt the radio. (A) That definitely will have a delay (B) you need a car stereo that can do it (C) it adds a whole extra layer of complication to the system that can go wrong. I'd at the very least want the ability to have my speaker play normally as well...

The main problem is the delay in the switching will cause you to loose the first few seconds of the VHF transmission.

I think the delay should be very small if you design the right system. Unlike VOX you don't have to filter off the background noise, so you should be able to have a latching circuit that detects any current on the speaker wire and latches the circuit open say for 5 seconds. Latching the circuit would simply throw a relay from Stereo to VHF. But I'd also want to switch it manually too

I fitted multiple speakers with selector switches and both my fixed VHF radios have duel cockpit/nav station controls

Doesn't silence the radio - I can see some attraction to that - although the Solent boys might get p***d off with their boom box being interupted ever 3 seconds by some muppet doing a Radio Check on 16 AGAIN.

 

[prv]

I still think a small dedicated VHF speaker in the cockpit is the right answer, and probably cheaper than some of the spaghetti being dreamed up. Don't interlink the stereo and VHF at all.

Or even better, if the budget will stand it, a remote handset. My "cockpit speaker" is actually one of these.

Pete

 

[pvb]

Or even better, if the budget will stand it, a remote handset. My "cockpit speaker" is actually one of these.

Totally agree. Messing about with relays and electronics is a recipe for disaster; the "KISS" principle applies. With a remote handset, you can also respond easily if necessary.

 

[William_H]

Firstly the OP needs to sort out the "fader" arrangement needed to get adjustable comparable volume between the outside stereo speakers and the inside ones. As said some stereos for cars have them installed if not you can get a pair of variable resistors (fader) to connect to the steroe speakers.
From there you need a relay driven by the audio of the VHF output to either switch the stereo speakers off or switch the VHF to the stereo spekers. (or just one). The so called VOX circuits in links might be OK but are essentially over done as you don't want a microphone and the audio output voltage of the VHF will be relatively high. Perhaps just a rectifier to switching transistor to operate the relay. (or the latter part of the VoX circuit. good luck olewill

 

[PaulMcC]

Thanks All. Lots of options. I was interested by the vhf with fm radio built in. A factory solution of a vhf with an audio in or audio via Bluetooth would be ideal but nobody seems to make this and I can see some of the reasons why.
I think I will follow the advice to keep the stereo and vhf on separate speakers but may invest in a smarter volume and speaker switching solution for the stereo and maybe independently the vhf as well.

 

[nigelmercier]

I built a VOX unit for my stereo, it mutes it (via the mute input) when the VHF has an audio signal on the output. Unfortunately it is quite sensitive to the volume of the VHF and picks up pops and crackles.

 

[markhomer]

Hi Nigel . My b38 had the dreaded , in my opinion rd 68 , with most expensive external,speaker on market , i could never remember how to use thing , hate radios and rd 68 less than intuitive .

Long short , replaced it with an stan h ais set and for price of an external rd 68 speaker bought the ram mike , which works as external speaker , also you can see ais info on it , didnt expect this to be of much use due to size of screen , but actually remarkably, handy .

So although not using stereo speakers , got very good remote speaker thats also a tx /rx radio with ais thrown in , saved a lot of mucking about and great additional features .

Happy xmas

 

[ga1135]

I connect the VHF (Audio Output) to one of my two cockpit radio speakers by using on-off-on switches.
(See photos)
I can select :
a) only the SB cockpit speaker works for the VHF
b) only the 4 speakers in saloon cabin for Raido / CD
c) 2 speakers in saloon cabin + 2 cockpit speakers for Radio / CD
d) 2 speakers in saloon cabin + Port cockpit speakers for Radio / CD + SB cocpit speaker for VHF
e) 2 speakers in saloon cabin + Port cockpit speakers for Radio / CD

 

[mlines]

Our Fusion entertainment radio has a VHF receiver built. It does not play both at once (ie. Music interrupted by VHF when a signal arrives). You can only have music OR vhf, however it does let you have VHF through the boats sound system