seaker design 1

[kimbo1]

does anyone know of a good resource and / or speaker kits to assist with speaker box design - i want to build a sub woofer for home theater use, and would get some elemnt of pleasure from doing some calcs without resorting to first principles or finite element analysis!

 

[Egress]

"The Loudspeaker Design Cookbook" by Vance Dickason gives an excellent snapshot of the art & science of speaker building for the home constructor. It is published by
"The Marshall Jones Co., Publishers, Francestown, New Hampshire" unfortunaely I dont have an ISBN number. I have
an old edition and have been meaning to get the latest version which is available in Australia for $34.00. If your
in the US it probably sells for a measly $12.00, Any way you look at it, its a bargan!

There are a number of software programs for bass reflex design on the web. They can be quite useful because of the
gaphs that they generate but at the end of the day they are only implementing some basic formulae that can be handled on the average scientific calculator.

http://www.jaycar.com.au

have a number of kits if you dont mind ordering form an Australian Supplier.

I am currently developing a new sub woofer design, however
until the interlectual property protection is in place I cannot give any detail in forums such as this.

After reading the book you will find that there are a number of general designs that you can use. The differences
generaly relate to the trade of between the low frequency roll-off point, bandwidth and the size of the poweramp that you need. The best possible sub bass unit would be the closed box (infinite baffle) type because the 2nd order
roll off would give better transient response than 3rd or
4th orders which are characteristic of vented designs.
The only problem with this is that the roll-off frequency
of an infinite baffle box is higher than an equivelent bass reflex type so that manufacturers find that small vented boxes appear to make more bassy noise than small closed boxes, so by the time the marketing departments had its say the vented box wins every time.

 

[kimbo1]

Thanks for the excellent reply, and I had just found out about Vance - it seems he is the guru so i will look for the book - as you point out I'm sure I could generate graphs myself from formulas with excel. I was going to build a cheap unit but may as well build it properly first time. Do you have a reccomendation on a reasonable quality amp with low distortion (say 250 W or so - is this enough?)and a good speaker? is the Jaycar stuff you mention quite good?
Thanks
Kim