soundcards

[785boats]

I have a JJC soundcard of those three beautiful V12 packard engines, mounted in my 42" model of the Higgins 78' PT boat. Really loud with the superstructure & access hatch off, but very quiet with them in place. I've opened up the bottom of the machine gun turrets & cut out the door into the cabin & taken out as much of the deck under the cabin as I could through the door. (this was a retrofit) Still hard to hear out in the middle of the lake. There are 2 scale access hatches down the centre of the boat. I'm thinking of cutting them out &replacing them with something that will let the sound out.
The question is (finally they said in unison) does anyone know of a suitable material that will look solid, able to be painted, & still let the sound out?

Any advice would be appreciated.

Paul.

[Kmot]

You will have to cut open everything possible. All windows in the cabin should be opened up. Use speaker grille cloth to cover the openings. A tube mounted to your speaker helps amplifiy it.

I had to cut openings in my cabin that should not be there. it was the only way to get enough volume outside the boat.

[tim slocum]

785, just curious, how many volts are you running the sound system on? Also, what size speaker,the 2" or 4"?

[785boats]

Hello again.

Kmot. Nice pics. I'm afraid you told me what I didn't want to hear, but half expected. About cutting out the windows I mean. The thing is, this 'Higgins' is based on the British ones that worked the English Channel. One of their distinguishing features was that they had the windows painted out to stop sunlight flashes during the day & to stop the light from the maproom/cabin being seen at night. Both of which could be fatal. So I'm a bit reluctant to cut them out.
I see your speaker faces up into the cabin. Mine, however is mounted in the bulkhead under the cabin pointing back along the hull. Theres a couple of "breather" holes in the bulkhead. This uses the bow section as a sort of bass reflex resonance box. It certainly produces a deep, throaty, loud sound. It just can't get out. As for the tube. Good idea. I might try one of them with a couple of 2"pipes tapped off it up to the gun turrets, which would be directly above it. Some sound waves might bounce their way up there.
Thanks for the help.

Tim. How's the Bismark driveline transplant, & esc problem going? All well I hope.

The main drive batteries in the Higgins are 14.4 volts. The supply to the soundcard is connected directly to that. I think its voltage range is 6 to 18 volts.

I had just enough room to fit the 4" speaker, so thats what went in.

HEY! I've just had a thought. How obvious is this. cut out the "scale" access hatches & make them removable for when she's on a mission & drop them back on when she's in dry dock. Or do you, or anyone else, know how those two big hatches along the centre of the boat were hinged.

I'll Have to take some pics of this old girl, so you can see what I'm babbeling about.

Thanks for helping.

Paul.

[Hoghappy]

I would try what Kmot said...hide the port holes with colored cloth.

Does your JJC sound mod cut out like mine? See my post further down on this page.

Captain Slick

Back to your original question...I would try dying (Rit) a thin cotton to the color of your desire. Paint would look good but maybe not breathe enough to pass the air/sound waves.

[mfr02]

You can get acoustically transparent black cloth.
As hoghappy suggests, dye some thin cotton black, but back it with loose thin poly sheet. This should look invisible-ish (black is invisible down a hole - try finding a dropped servo screw) but still let sound through while helping keep the wet stuff out.
Also have a think about how many scale miles away the boat is when the sound gets faint. It could be that you shouldn't get a deafening roar over a mile away, which is about 75 yards in 24th scale.

[Kmot]

The acoustic cloth blocks splash water from entering the hull, BTW.

[785boats]

Thanks for the answers guys.

It's official then. Dyed thin cotton it is. British Royal Navy Blue will be hard to find, no doubt, so I'll try making some out of left over paint thinned down to coloured thinners. The colour is actualy a very dark grey with just a hint of blue. Just the deck hatches at this stage. I'm sorry, but I cant bring myself to cut out the windows.Along with the megaphone & the vents up to the turrets it might be enough. Good point about the scale/distance/decibel ratio mfr02, but no, you've got to hear it. Sorry.

Hoghappy.
No,mine doesn't have the same problem yours does. I'll check with the guy who sells them to our clubmembers to see if he has an answer. He has one for most things. Just a thought - if the volume pot is turned to maximum try backing it off a touch. Also is it getting at least 6v when the motors are under load. I'll go and check the other post. These things have probably already been mentioned there.

Did I read somewhere that there is a soundcard available with sequential startup of the three engines? Man, that must be a head turner.

Anyway gotta go. Kids need feeding.
Thanks for everything,

Paul.