I have tried unsuccessfully to make an amplifier for my boat. I have used a couple of single board amps (XH-643 and LM386 off amazon) but the noise is just to great. Maybe the amp needs shielding..I don't know, but I do know I need help.
I used to know that stuff in year 1 engineering, but in this case, since I plan to use pre-build amps, my issues are more about how to build (or have someone else build for me) a system that meets my requirements. Ie. How to isolate from interference as the amp is near the boat's power distribution panel, now to get clean 12V power from the batteries, etc.
That's complex. I have zero knowledge about fishing boats & their engineering. What i know is you need a clean power supply. Can you tell me little more about power source? Regards.
Get a 12 volt car radio with matching speakers.
Or find someone to help you choose.
12 V DC from a battery means no noise.
Use shielded wire for speakers, ground the shield to cut noise.
Or find someone to help you choose.
12 V DC from a battery means no noise.
Use shielded wire for speakers, ground the shield to cut noise.
The power comes from a 12V distribution bar that is powered by 12V deep cycle batteries. The distribution bar also powers the "house" i.e. lights, cooler, pumps, instruments. So it might have a significant about of variability.
One of the input sources is the "rears" of a JVC radio, the other is an mono aux output from a VHF radio. I have a simple 2-pole switch to select between them.
Car boot amp then, with a selector head end.
Battery voltage does not fluctuate much, else put some sort of voltage relay to protect everything connected, like the cooler and so on as well.
Battery voltage does not fluctuate much, else put some sort of voltage relay to protect everything connected, like the cooler and so on as well.
1)Ensure a low impedance ground path(power).
2)Add a RC low pass filter at the input of your audio amp using 1kohm + 680-1000pf ceramic cap. This acts like a high frequency jammer. Good luck!
This should be doable, in a manner similar to modern auto sound systems,
which also have a lot of noise from the car electronics.
which also have a lot of noise from the car electronics.
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This is 100% "car sound", with extra water.
There are marine speakers and electronics that are nominally water resistant. If that is not enough to start your party, there is a vast selection of car-sound gear which can be mounted in water-sealed tubs. Since this stuff is MASS-produced it is not likely you can DIY cheaper or better than you can buy, at Walmart or at a boat supply shop.
There are marine speakers and electronics that are nominally water resistant. If that is not enough to start your party, there is a vast selection of car-sound gear which can be mounted in water-sealed tubs. Since this stuff is MASS-produced it is not likely you can DIY cheaper or better than you can buy, at Walmart or at a boat supply shop.
My local shop:
Housing for any car radio:
UNIVERSAL GIMBAL HOUSING
Basic radio, splash resistant:
MARINE MECHLESS BT COMBO WITH SPLASHGUARD, REMOTE, & SPEAKERS
Fancier:
RADIO AM/FM/BLUETOOTH MP4/MP3 USB
Fancy rig, manual, specs, 104W, IPX6-rated water-resistant front panel:
GARMIN FUSION RA210 MARINE STEREO ENTERTAINMENT SYSTEM
https://static.garmin.com/pumac/RA210_OM_EN-US.pdf
And this is really a lobsterman's shop. (Good deals on trap-winches, floating rope, etc.) Go where there is more recreational boating you may find much more choice.
Housing for any car radio:
UNIVERSAL GIMBAL HOUSING
Basic radio, splash resistant:
MARINE MECHLESS BT COMBO WITH SPLASHGUARD, REMOTE, & SPEAKERS
Fancier:
RADIO AM/FM/BLUETOOTH MP4/MP3 USB
Fancy rig, manual, specs, 104W, IPX6-rated water-resistant front panel:
GARMIN FUSION RA210 MARINE STEREO ENTERTAINMENT SYSTEM
https://static.garmin.com/pumac/RA210_OM_EN-US.pdf
And this is really a lobsterman's shop. (Good deals on trap-winches, floating rope, etc.) Go where there is more recreational boating you may find much more choice.
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LM386 ?
Makes less than 1 watt of power.
I would assume most the noise is Radio Frequency interference.
the internal gain is preset on the LM386 to 30
or some kits use the bypass method which turns it up higher to 200
so they are rather noisy.
otherwise yes use a shielded cable for the input.
and you could add a simple radio interference filter on the input with a small
capacitor.
otherwise no offense, it is a really horrible chip all together.
it was designed for very low power battery operation.
for very low quality audio, for kids toys or other similar applications.
dating back to the 1970s.
Makes less than 1 watt of power.
I would assume most the noise is Radio Frequency interference.
the internal gain is preset on the LM386 to 30
or some kits use the bypass method which turns it up higher to 200
so they are rather noisy.
otherwise yes use a shielded cable for the input.
and you could add a simple radio interference filter on the input with a small
capacitor.
otherwise no offense, it is a really horrible chip all together.
it was designed for very low power battery operation.
for very low quality audio, for kids toys or other similar applications.
dating back to the 1970s.
