Discussion on what materials to build speakers out of

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:DThe XS is the best British bike the Brits never built, as it´s Japanese. The crankshaft is a very solid affair, so taking it apart needs some serious oomph. Shows that you were on the right track with your idea, just a wee bit pessimistic about how much power is yours to wield.
 
Indeed, after scoping out a '72, I sold my '66 Bonneville for one. Put well over 100 k mi. on it before parking it in the shed, where sadly, it's (not so) slowly rotting away due to lack of funds to either restore it or convert it to a flat track style sportster that was the prime reason for keeping it.

GM
 
Indeed, after scoping out a '72, I sold my '66 Bonneville for one. Put well over 100 k mi. on it before parking it in the shed, where sadly, it's (not so) slowly rotting away due to lack of funds to either restore it or convert it to a flat track style sportster that was the prime reason for keeping it.

GM


lol well what about the real best british bike...

the triton.....

and on a side note: i think 5/8" (16mm) shackles are only good for SWL of around 3.25 tonnes
 
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GM,

:yikes:! Knowing you, I´m afraid you´ll feel tempted to do nice&nasty things to the engine. For motocross with sidecar the crazies over here bored and stroked her up to 950cc and went chasing Nortons. Might give you that bit of unfair advantage that that carb in your Hog got you.
 
frugal-phile™
Joined 2001
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Pit,

You can't change parts?

The same bike also had a front end (with disk brake) from an RD400, also with a big Venom. Less than 300 pounds wet, handled incrediably well, stopped like crazy. Wasn't overly fast thou.

I'd like something similar in a 400. This would be a good start. Be better if it wasn't water cooled thou.

dave
 

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Dave,

not impossible, but very difficult. Any changes need the go-ahead from an engineer (and Ingenieur is an academic title here, so no cheating) and/or the OK from the maker/importer of your bike.
Mind - I´m not always unhappy with our harsh safety standards. We are next door to the ex Iron Curtain, and some heavy trucks from "over there"...rolling time bombs, believe me. They are allowed 80 Kmh (50 mph) and I wouldn´t trust some of them at walking speed.

Hmmm...air cooled big four stroke single with decent brakes and tires - yes. By all means, yes.
When stii allowed we did that with 2strokes. Maico were a very small firm without a bureaucratic hydrocephalus, and all of them bike crazy. You just phoned them, and no matter how deviant your idea, they had already tried it. Crowning glory was a 125cc road bike with the 500cc motocross engine...talk about soiled underwear!

Pit
 
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Crowning glory was a 125cc road bike with the 500cc motocross engine...talk about soiled underwear!
Boring. Not 20km from me is a mid series RGV250 with a worked RG500 motor in it, all street legal. Scary but wicked fun to ride. Looks stock too, until you count the exhausts.

Not his, but sweet looking anyway.

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.
 
Open baffle board size for a 12" driver?

Can anyone point me to a thread that might tell about what is the optimal size board to use when building a 12" driver open baffle speaker? My brother in Alabama tells me that the open baffle design with one full range driver is a good stater project as well as a reasonably well sounding one. Thanks for any help you can give me.
 
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Hi all
You certainly have used the packaging paper for some proof of concept enclosure.
Used as a single sheet, is rather air leaky and doesn’t hold it’s shape above some large lengths.
But this material is IMHO capable of doing more than this.
It is very neutral in terms of own sound (it doesn’t support any appreciable amount of sound waves traveling over it’s surface).
It can be used to build rigid shapes by using it in sandwich: Two or more sheets glued one over the other, with their waving either parallel (so you can form it into curved shapes) or with an angle (90d for 2 sheets, 120d for 3 sheets, e.c.t.) for flat surfaces.
It can be “voiced” by brushing it with -or immersing it into- a varnish. The kind of varnish and the amount of it absorbed into the paper, alter paper’s acoustic properties dramatically.
In sandwich form, mechanical and acoustical properties are affected also by the way that the sheets are glued together (the kind of glue and how it is applied).
In sandwich form again, a given flat shape can be sectioned in unsymmetrical fashion in each layer to effectively kill any traveling waves through it by spreading the waves into different size and shape sections in each layer.
It can also be used as a core for sandwiching it with harder surface panels.

All these, added with it’s low cost (~0.4 Euro/sq.meter) and ease of cutting and shaping (*PS), makes it a very useful material for real speakers built in the spirit of diy.
I hope I am not repeating anyone’s input so far

Best Regards
George

*PS. It can also be shaped into some difficult shapes (up to a limit) by forming it over steam and then drying it with hot air
 

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I'm reviving this thread to ask if we could update some of the information on other materials like the following:

- using 4mm aluminium as a baffle, bolted on to the wood underneath. Changing the aluminium front plate would allow for trying out different units if the cutout behind were generous. what effect would this have on sound? It would be stiff, of course.

- bamboo. Looks nice and available as worktops for instance, as well as flooring

- various plastic laminates. High-density polyethylene HDPE for instance or Tufnol - see 20mm - Direct Plastics Online

- sound deadening Green Glue as a filler between layers - see What is Green Glue? | Green Glue Shop: Sound Proofing and Acoustics

- any other interesting materials

We've had a lot on MDF, ply and solid wood but could we widen the discussion a little?

andy
 
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