few questions for a newbie who is trying 1st speaker build please help.

[w513mfs]

hi all new to this site and in need of some basic help as im not much of a technical person but very good at wood work.

i am trying to design a three way passive speaker as more of a challange than any thing else and my intentions are as follows.

1) 3 & 1/4 inch mdf box which is 14" wide 2' high and 10" deep.
2) 10" sub at bottom 5" mid in middle and piezo horn tweeter at top and two reflex tubes at bottom corners
3) intend to finish front with a nice stained oak fascia.( this is where i come to my own)

but have a few questions about wiring and technical issues,

1) i have purchased a 400w crossover from skytronic but have two points im not sure of the are lablled a+ & - any ideas what these are?
2)what would the wattage breakdown be i.e. how many wattsusually to sub, mid , tweeter?
3) i am using a denon amp pushing 150 watts per channel will this be ok ?
4) apart from box, crossover, drivers and wiring what else would i need,

many thanks and any help would be much appreciated i am reaaly looking forward to making something that does something rather than just sit there chairs and tables get a bit boring you see,

many thanks

[singa]

Hi, Like any endeavour it's better to have a reference book to guide you so
Designing,Building and Testing Your Own Speaker System (with projects
) by David B. Weems is a good book to start with.

According to the author comercial ready made crossovers are not a good idea
as they don't take into account different drivers rather a one size fits all
kind of approach.But since you bought one I guess you would want to use it
just for experience sake.So test it without installing into the box as that will
allow component change without tearing into the cabinet time and again damaging the wood.

The stock crossover would have appropriately spec the components to handle
the rated 400W and most likely wired in parallel for the 3 way.Anyway your amp can only put out 150 Watt so you have to make sure your individual drivers are capable of 150W to be safe or at least use a volume that will not stress them.

And you forgot damping material like cotton or synthetic equivalents like aircon insulation but some may not approve as the fibres have a habit of flaking off and gets into the magnet assembly.How much to use and where
to put it ,all you will learn by trail and erorr.Please check that your box has
sufficient volume or dimensions for the size of drivers as it will affect the sound output.That you will find in David's book and on the internet speaker sites as well. Have fun.

[w513mfs]

CHEERS SINGA

DO YOU ALSO HAVE ANY IDEAS WHAT THE EXTRA CONNECTIONS ARE ON MY CROSSOVER?

YOU HELP IS MUCH APPRECIATED

[singa]

Originally posted by w513mfs-
1) i have purchased a 400w crossover from skytronic but have two points im not sure of the are lablled a+ & - any ideas what these are?

Hi, I not sure but common sense says you will have 3 pairs of outputs (to speakers) or at least the ground or return connection is common and a pair of inputs as labeled a+ & -.If you are familiar with crossover circuits just trace the input pair to the components to low,mid and high frequencies.

Oh, you might like to space the centers of the drivers using the golden,divine
ration known as PHI (pronounced fee) which is 0.68,1.68,2.68 etc. and relative to the sides as well to their dimensions.Believe it or not there is a natural order to things and nature and what we consider to be beautiful are
related to this golden ratio.Check out renasiance art and their proportions
are mulitiples of this ratio.That goes for sound.Don't forget to minus the thickness of your panels for accurate box volume.

PS the longer length divided by the shorter length should give you the 1.68 and etc. and 0.68 vice versa.