Sub Sound

[mylo]

Has anyone ever attempted to install a speaker/sound in their sub to mimic the sound of a running diesel while it's surface running (obviously) ? I'm thinking much along the lines of model railroading, and how onboard sound has become very commonplace, with sound systems even readily available for N scale (1:160). Is there such a thing as waterproof speakers ? I was just thinking sound would be a cool addition to submarines, particularly diesel boats. (I don't think the nukes make any sound.....do they ?).

Mylo

[anonymous]

Hi mylo

look here please.
And if

Hi mylo

look here please.
And if you build later an other sub in 1:25 a very good type IX is needed on the modeler horizont.

Gantu

[mylo]

gantu,

It's funny you mention

gantu,

It's funny you mention a type IX. I've been busy looking for a real good type IX plan set. I WILL do a 1:25 type IXC sometime.

Mylo

[anonymous]

Let me know i have

Let me know i have good refences pic´s.

Gantu

[tmsmalley]

There have been a fair

There have been a fair number of guys who have installed RAM sound modules http://www.ramrcandramtrack.com/rcsound.html that mimic a bunch of submarine sounds. Gene Berger (early SCR editor) had a 10 foot Gato with all the horns and whistles.

The trick is getting the sound through the hull and not being too muffled.

[bos10]

Although I haven't installed sound

Although I haven't installed sound in my sub, I'm planning on doing so. I haven't had time to experiment for the sub application, but I've played with audio in other areas. If you're planning on simulating diesel engines and gun fire, you're going to want enough power and something that has bass so that it sounds real. War is loud... a jack hammer is 100dB, pain occurs starts ~130dB and an M1 Garande fired at 1 meter is 168dB. I'm in no way talking about repoducing those sound levels, I'd just hate to see that big sub sounding whimpy

Note that we hear on a logrithmic scale, so you basically need to double the power to get an noticeable increase in volume! My guess is that you want to chose an efficent speaker technology rather than throwing power at it, we're running on batteries after all.

In terms of speaker technologies, I can think of the following options:

(1) "Underwater speaker" These are designed to be underwanter 100% of the time, but they aren't going to be useful in your application. They are designed to play music underwater for swimmers or as a way to communicate with divers. As such they are really more transducers designed to transmit vibrations into water or furniture rather that into the air. I have two massive ones under the sofa in my home theather. You can't hear them, but you sure are hell can feel them!

(2) "Water proof speaker" A standard cone-based speaker that's supposed to be water proof. Many of the marine speakers can deal with splashes, I'm not sure how well they will hold up once being fully submerged. I haven't looked hard, but I suppose there should be something suitable. The bigger the cone and/or the longer the excursion (speaker travel), the louder the sound.

(3) Pizoelectic -- I assume that's what Gato sent you. They have the advantage of being low voltage and enclosed so there is no issue with water. In my expereince they are used for watches and other low end audio applications. Better ones will be used as tweeters in less-expensive speakers. So, they have decent high-end, but, in my experieince, lack bass.

If you can find a pizoelectric that sounds, good that might be your best bet (please let me know). I was plannig on experimenting with water proof speakers.

As Tim points out the primary issue is to get sound that isn't muffled, there being two obvious obstacles: (1) the hull and (2) water on top of the speaker cone if you go with a water proof speaker. You can hear sound played through the hull, but you'll need more power and it might be a little muffled. I plan on putting all of the #$#&! holes I've milled into my VII/C deck to good use. Your deck is solid, so I assume that the sound will just bounce of the bottom of the deck and out the side slots.

As for water on the speaker cone, I figure there are at least two obvious options: (1) point speaker up and tilt so that water runs off or (2) point speaker down so that water can't sit in speaker cone. I have lots of holes in the deck, so I'm inclined to point my up, however you deck is solid so maybe no difference.

As for the technlogy to play the sound, I'm a tech guy and the hard-wired sounds available from RAM etc. didn't appeal to me. I looked around for something that was configurable, could play multiple concurrent sounds, loop sounds and featured proportional throttle. I almost started on my own... but I bought a device from Model Solutions of Canada http://www.modelsolutions.ca/. I have been too busy to even unpack it, but my understanding is that if your not a tech guy, you might want to wait for them to make it a little more user friendly to use. I'll post when I get some time to actually try it.

In addition to proportional throttle, crash dive alarm, deck gun fire, 2-cm fire, and torpedo fire (don't have torpedos yet), I will also have morse code. I wrote a program to convert text into morse code. I will have a couple of "audible messages" which I guess like the movies aren't scale and I will have a couple of other message which will be flashed through an LED (i.e., line of sight communication). I'm also looking at putting an enigma encoder option for the "audible messages"... yeah, I know, who will really know the difference... but I look at software like you look at scratch building a hull. If you're interested in the Morse stuff, let me know. Note that he Model Soultions product can be used to control a flasher in addition to making sounds.

[tmsmalley]

Talking/singing greeting cards also use

Talking/singing greeting cards also use piezo speakers - not much in the way of bass for throbbing diesels with those tiny units though.

There is a writeup on piezo speakers from Wikipedia. Interesting they are specifically listed for underwater applications such as sonar...
=============================================

Piezoelectric speakers
Piezoelectric speakers are frequently used as beepers in watches and other electronic devices, and are sometimes used as tweeters in less-expensive speaker systems, such as computer speakers and portable radios. Piezoelectric speakers have several advantages over conventional loudspeakers: they are resistant to overloads which would normally destroy the voice coil of a conventional loudspeaker, and they are an inherently capacitive electrical load so they usually do not require a complicated external cross-over network. There are also disadvantages: some amplifiers can oscillate when driving capacitive loads, which results in distortion or damage to the amplifier; and additionally their frequency response, in most cases, is inferior to that of other technologies. This is why they are generally used in single frequency (beeper) or non-critical applications.

Piezoelectric speakers can have extended high frequency output, and this is useful in some specialized circumstances; for instance, sonar applications in which piezoelectric variants are used as both output devices (generating underwater sound) and as input devices (acting as the sensing components of underwater microphones). They have advantages in these applications, not the least of which is simple and solid state construction which resists the effects of seawater better than, say, a ribbon based device would.

=========================================

There are conventional speakers listed as "waterproof" on this website http://www.rocktheboataudio.com/speakers.html - I wonder if they could be completely submerged?

Something also to consider - would the large (and heavy) permanent magnet associated with audio speakers adversely effect the boat's trim and the operation of any RC components? You'd probably want to mount them well away from other RC gear - maybe in a separate housing.

[raalst]

Piezo is good for high

Piezo is good for high frequency. modern active sonars use (very) high frequency (because the resolution gets better with freq).

The famous Ponnnnggg sound lives on in our collective memory, but
today you won't hear any sub pinging you with your own ears

[tmsmalley]

A favorite movie quote -

Captain

A favorite movie quote -

Captain Ramius: Give me a ping, Vasili. One ping only, please.

http://www.moviesounds.com/redoct/oneping.mp3

[mylo]

Tim,

Sean Connery at his

Tim,

Sean Connery at his best....for sure.


I agree completely with the need for a deep sound.

.....what about building a 1:25 scale diesel that actually runs, get the added bonus of the exhaust plume

I'll have to give the sound idea more thought/research.

Thanks a ton for the excellent writeup.

Mylo

[tsenecal]

mylo,

the 1/25th scale uboat is

mylo,

the 1/25th scale uboat is probably large enough that you could hide something from this website inside the hull:

http://www.rocktheboataudio.com/speakers.html

[Guest]

If you want to move

If you want to move air, then you need a large speaker.

Personally, I find sound units a bit irritating at the pondside, but that is just my personal preference.

These guys have a couple of good units-

http://www.modelsolutions.ca/catalog_sound_systems.htm

Also a good discussion on sound units here-

http://www.modelboatmayhem.co.uk/forum/ ... pic=7944.0

Andy

[mike dory]

Guy's, We did this back

Guy's, We did this back in the 80's, build a water tight speaker either with a 2.5 inch or 3 inch radio shack speaker this was fitted into a pice of laxan of the same I.D. and about 3/8 to 1/4 inch in thickness.Over the top of the speaker was placed a pice of thin Mylor plastic I believe 10,000th. thick. Around the thickness of both the mylor and into the sides of the laxan. I drilled 1/8 inch holes about every 1/2 inch along the edge.the cement used to adhere the mylor to the laxan was RTV the trick to getting it to stick to the mylor was to sand both edges and sides with 80 grit sand paper. THe RTV will fill in the holds drill out and through the holes in the mylor, covering both the sides and top of the speaker. It worked well on a number of my boats. I'm still using it on my Type XX1. Hope this helps.
Best Wishes Mike Dory

[crazy ivan]

Mike, do you have a

Mike, do you have a photo?

[Guest]

How about an article for

How about an article for the report, Mike?

I'd like to know more about this for the Yellow Submarine- I plan on drowning the beatles!

Andy