Which Amplifier for Loud Hailer?

[Talulah]

The VHF radio outputs a 25W foghorn signal. The loudhailer on the mast is rated at 40W.
Any suggestions for an amplifier to go between the VHF and the Loudhailer?
The current loudhailer volume sounds very mediocre.

 

[Alpha22]

Your issue will be the input to the amp. Most amps expect a 'line' level input. Like a headphone socket or even lower level. Your VHF is outputting a speaker level signal. Totally unsuitable to feed into any 'normal' amplifier.

I don't have the solution, but hope someone knows of a product for you........

 

[Lodesman77]

The loudhailer is presumably rated to 40W maximum; 25W input isn't unreasonable - is it really too quiet? Are the connections good and the wiring big enough?

 

[Talulah]

The loudhailer is presumably rated to 40W maximum; 25W input isn't unreasonable - is it really too quiet? Are the connections good and the wiring big enough?

With the whole setup sitting on the chart table and connected up you could comfortably listen to the horn without covering your ears. Wiring is all new with good connections.

 

[viago]

the loud haler is an amplifier. as is the vhs it seems.

you want more noise to announce your arrival in port then you are going to have to get more powerful kit.
the only way you could amplify the sound would be to mic up the speakers and run it through a sort of pa system. then, the sky's the limit.
something like this might work http://www.ebay.co.uk/itm/100V-LINE..._HomeAudioHiFi_Amplifiers&hash=item484612fc49

 

[Lodesman77]

With the whole setup sitting on the chart table and connected up you could comfortably listen to the horn without covering your ears. Wiring is all new with good connections.

I was thinking that your assessment was with the loud hailer up the mast - in the circumstance that's definitely not loud enough! Out of interest, which VHF set is it?

 

[Talulah]

I was thinking that your assessment was with the loud hailer up the mast - in the circumstance that's definitely not loud enough! Out of interest, which VHF set is it?

It's an Icom 603. I just don't believe it's outputting 25w.
Instead of connecting the hailer I connected a stereo speaker as in car speaker. Again, sound level was easy listening level.

 

[viago]

It's an Icom 603. I just don't believe it's outputting 25w.
Instead of connecting the hailer I connected a stereo speaker as in car speaker. Again, sound level was easy listening level.

are these output figures peak or rms?

 

[Talulah]

are these output figures peak or rms?

I'm guessing they are peak but I don't actually know.

 

[malcp]

The ICOM603's spec says the Hailer output is rated at 30W when the Radio is powered at 13.8V and the speaker impedance is 4ohms. I suppose the first question is what is the impendance of the Hailer you were using? And same for the speaker? If they are 8ohms the output will be less loud.

BTW, I assume you've discovered that the Hailer (and Fog horn) output level can be adjusted by turning the SELECTOR knob whilst in Hailer or Foghorn mode? See here: http://www.icomuk.co.uk/files/icom/PDF/productManual/IC-M603-0.pdf

 

[Lodesman77]

The setup is similar to my IC-505; the manual says mine is 25W output but the IC-603 is 30W. Both are rated at 13.8V/4ohms. 25/30W should be enough output to drive a 40W hailer but perhaps the one you are using is greater than 4ohms? Car speakers are possibly 8ohms? If it is significantly more then it would be harder to drive and therefore quieter - not my area of expertise so I couldn't say how much, but worth checking?

http://www.icomuk.co.uk/files/icom/PDF/productManual/IC-M603-0.pdf

Edit: looks like I was beaten to it...

 

[Talulah]

The ICOM603's spec says the Hailer output is rated at 30W when the Radio is powered at 13.8V and the speaker impedance is 4ohms. I suppose the first question is what is the impendance of the Hailer you were using? And same for the speaker? If they are 8ohms the output will be less loud.

BTW, I assume you've discovered that the Hailer (and Fog horn) output level can be adjusted by turning the SELECTOR knob whilst in Hailer or Foghorn mode? See here: http://www.icomuk.co.uk/files/icom/PDF/productManual/IC-M603-0.pdf

Speaker is a Diamond Hex s600. (Connected to one only. These are 4 ohm speakers.)
(I was aware of the volume function and had it set at max. No harm in mentioning it though as it is easily missed.)

 

[BruceDanforth]

A 40W rms amp will only be marginally louder than 25W rms amp. Are you really that insecure/self important that you need to be able to make people cover their ears? I've never needed a loud hailer in over 30 years of sailing. If someone shouted at me with one I'd most likely just moon at them.

 

[viago]

A 40W rms amp will only be marginally louder than 25W rms amp. Are you really that insecure/self important that you need to be able to make people cover their ears? I've never needed a loud hailer in over 30 years of sailing. If someone shouted at me with one I'd most likely just moon at them.

as would i, but i remember leaving faversham creek in the early hours in thick mist and hearing the sound of a fishing boat returning to port. i had an aerosol type fog horn which sounded loud to me but i remember worrying that it might not be that audible when stood in the wheelhouse with the diesels at full throttle.
does anyone know what the decibel level difference is between that system and a 25 watt amplifier system?
what sort of amplifier would be needed to compete with a hand held compressed air fog horn?

p.s. as it happens, after three long blasts the boat throttled right down and we passed in comfort. i was worrying too much.

 

[davidpbo]

Your problem might be frequency response of the loudspeaker. If it is intended to be used for comms/speech these tend to be very efficient at higher frequencies for clarity of speech.

For use as a fog horn something efficient at a lower frequency may be needed.

The Diamond Hex s600*looks like an in car speaker I would not expect them to be efficient at converting watts into sound. I would look for horn type outside loudspeaker.