Model Boat Mayhem

Mess Deck: General Section => Model Boating => Topic started by: john44 on December 31, 2012, 10:38:22 am

Title: speaker enclosure in 1/12th lifeboat
Post by: john44 on December 31, 2012, 10:38:22 am
Hi guys,
I am fitting a Action noisy thing & amplifier to my Trent.
How can I get the best sound out of my speaker?
Do I fit it in an enclosure? into a tube, etc.
What is the best speaker? or should I use 2 speakers?
Where is the best place to fit it/them?
Photo,s or drawings would be brilliant.

Cheers

john
Title: Re: speaker enclosure in 1/12th lifeboat
Post by: Stavros on December 31, 2012, 10:44:15 am
What I would do is to put up a 10mm ply in the bow right accross to seal off the bow(Like a bulkhead).Drill the hole for the speaker BUT alos drill some 10mm holes in the bottom of the ply to let air in and you will be rather surprised with the sound quality.
 
As for a speaker get it off ACTion as they sell the proper one for your sound system
 
Dave
Title: Re: speaker enclosure in 1/12th lifeboat
Post by: malcolmfrary on December 31, 2012, 11:08:59 am

Like Stavros said while I was typing.......Fitting a speaker into a boat is not quite like designing a speaker cabinet for home use, but some of the principals are still there.
Sound comes off the back as well as the front of the cone.  If allowed to mix with the front sound, they will cancel out, so you need to separate the two.  Having one with free access to the rest of the world  (so you can hear it) and the other enclosed (so you can't) works.  So does having a long air path between the two.  The deepness of the sound that the speaker can produce depends, among other things, on the longest dimension of the rear enclosure. 
On a boat, this usually means finding a flat surface that you can make a big enough hole in so that the hull becomes the enclosure and arranging to hide the speaker cone with something that doesn't muffle the sound.
Deeper sounds often means bigger speakers, not always feasible in a model.  Small speakers can handle low frequencies, but do not shift the same quantity of air for the same travel.  This means that the smaller cone has to travel further to be as loud.  This in turn means a lot more engineering in the quality of the build.  More solidly built, more weight, costs more and a monstrous magnet, and costs more.  Speaker sizes are often quoted in diameter of the cone, not the chassis diameter, a point to watch out for.
The cones are normally made of paper, and, as one side needs to be exposed to probably damp air, needs protection.  Putting the speaker into a plastic bag before mounting keeps water away from the paper, but lets the sound out.  There are mylar cone speakers, but I haven't seen any yet that would do a good job of handling motor sounds on a 1:12 lifeboat.
Title: Re: speaker enclosure in 1/12th lifeboat
Post by: Circlip on December 31, 2012, 12:22:36 pm
Not a problem with a tug, you can always tow a Wharfedale "Linton" behind it.  :-))
 
  Suppose a Lifeboat could "Rescue" one.
 
  Regards  Ian.
Title: Re: speaker enclosure in 1/12th lifeboat
Post by: john44 on December 31, 2012, 01:04:22 pm
Wow,
thanks guys, what a speedy response.The idea of putting a (paper cone) speaker in a plastic bag I like as I have a few quality Hi Fi speakers with tweeters & woofers,would
that sort of system be o/k? or would it be too much, it/they are going in a 4 ft model.

john
Title: Re: speaker enclosure in 1/12th lifeboat
Post by: Netleyned on December 31, 2012, 01:25:26 pm
If you are using the 101 amp at 12 volts then an 8ohm 10W speaker is what will match it.
A 4ohm speaker is a nono a 16ohm will be a lot quieter.
The instructions with the 100 should tell you all this.

Ned
Title: Re: speaker enclosure in 1/12th lifeboat
Post by: inertia on December 31, 2012, 02:11:37 pm
http://www.action-electronics.co.uk/pdfs/Monster.pdf (http://www.action-electronics.co.uk/pdfs/Monster.pdf)
Title: Re: speaker enclosure in 1/12th lifeboat
Post by: john44 on December 31, 2012, 02:49:06 pm
Thanks guys. :-))

john
Title: Re: speaker enclosure in 1/12th lifeboat
Post by: Mrs Stav on December 31, 2012, 04:19:19 pm
Thats the one reccomended by My ACTion himself when I bought a full sound system off him
 
Dave(on Kelly's cmputer)