# crossovers



## Guest (Jan 23, 2009)

hi

First of all im building two 2way speakers for now which will be my left and right.
Later ill build a 3 way and much later i wanto build like a 10 speaker left and right...but have to start at the bottom and work my way up.

Secondly i have a pioneer vsx-815 receiver ,does 100 W per channel, 8 ohms.
So i wanto build everything one day without blowing it up...:jump:

I guess ill start with crossovers.
I wanted to build my own crossover cause its the best way to learn but i ran into a little problem.

i ordered :

Pioneer FP66AP45-54F 8 Ohm 2-1/2" Cone Tweeters -2000 -20000 hz
GM-85/8 GOLDWOOD 5" Sealed Back 8 ohm Poly-Mica Midrange -500 - 15000hz

And for my crossover i wanted to use 6000hz 1st order butterworth.(very simple:no

So i dont know how to keep these 2 speakers at 8 ohms.

I called up and one guy ordered this 2way crossover that does 3000hz and keeps the 2 speakers at 8 ohms.

So this is my problem, i dont know what to put in the crossover to keep 2 speakers at 8 ohms, or later when i add many speakers how do i keep them at 8 ??


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## Guest (Jan 24, 2009)

*Re: New from fl*

I was wondering if anyone knows of a very good book covering crossover design in such detail i dont have to ask any crossover questions again ? :yay:


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## JCD (Apr 20, 2006)

This is JUST the beginning of your learning..


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## Guest (Jan 24, 2009)

:bigsmile: thanks JCD let me have a look

Oooh, wow this guy means business, he is strictly using a scientific approach with an audio oscillator, 10 w amp and a audio millivoltmeter to do all his testing with.

So if you must have this equipment to build a good crossover (which i dont have and dont know how to use either ) then it aint gonna happen and ill just have to buy a 3 way package.

But there is this link and this guy didnt use anything else than the specs of the speakers and a few calculations to build a 3way crossover.

I dont know enough to be able to say that his methods is completely wrong or not, is it a good crossover or not ? 

:dunno:

thanks for reading


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## JCD (Apr 20, 2006)

It is rather hardcore, but it gives you an idea of all that's involved.

I skimmed the link you gave. That, at least to me, over-simplifies the process. There are several spreadsheets on the net that you can plug the parameters into and get a crossover from.. however, it's all "theoretical", grounded in science, but won't usually exactly mirror the real world. When you get to the actual drivers, they behave a little bit different then the spreadsheets say.

I'm waiting for a buddy of mine to find some time and we're going to build my first from scratch crossover. My tools -- an LCR meter, a testing mic and and RTA. I plan on using the spreadsheets as a starting point, then tweaking based on the measurements and my (flawed) ears.

Also, a premade crossover, unless it's designed for the speaker drivers you have, WILL work, but PROBABLY won't give you a "good" result. It works along the same lines as the spreadsheet crossover.


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## digital desire (Dec 17, 2006)

Precisely why I went with a proven design the I knew would work.
It can certainly be done, but it won't be easy.


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