# X-Over For DIY Main



## Endesereth (Sep 15, 2009)

Hey everybody I have been thinking that I am going to be building a main speaker lately, it'll use 2xSilver Flute W20RC38-08, 8" Wool Cone, Eminence ALPHA-6A, 6" Midrange, and a Audax TW025A20 1" Titanium Dome Tweeter, all from madisound. 
I'll be using highpass 1st order 80hz and lowpass 600hz 2nd order for the woofer
lowpass 6000hz and highpass 100hz both 2nd order for the mid 
highpass of 1800hz 2nd order for the tweeter
Really my only question is I've been using http://www.termpro.com/articles/xover2.html as a reference for the x-over components and i just wanna get a confirmation that this is a decent site...
Thanks!


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## looneybomber (Sep 20, 2006)

Endesereth said:


> Hey everybody I have been thinking that I am going to be building a main speaker lately, it'll use 2xSilver Flute W20RC38-08, 8" Wool Cone, Eminence ALPHA-6A, 6" Midrange, and a Audax TW025A20 1" Titanium Dome Tweeter, all from madisound.
> I'll be using highpass 1st order 80hz and lowpass 600hz 2nd order for the woofer
> lowpass 6000hz and highpass 100hz both 2nd order for the mid
> highpass of 1800hz 2nd order for the tweeter
> ...


Wait what?
Woofer frequency, <600
Mid frequency 100-6000
Tweeter freq >1800hz
:scratch:


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## Endesereth (Sep 15, 2009)

ya i figured that, that would give me the most equed response...since you split the signal 3 ways and each one gets its own line(sorry if i am really confusing:gulp am i doing it wrong cause this is going to be the first crossover ive ever done...


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## looneybomber (Sep 20, 2006)

Well a basic crossover design would have the crossover points match.
For example,
Woofer <500hz
Mid 500-2500hz
tweeter >2500hz.

Looking at your drivers, you're right around the same cost as would be proven DIY designs. One's which they did a lot of driver testing, baffle designing, and quite a few different crossover tweaks after measuring on and off axis. For a first DIY design, you may want to cut your costs down, or look at existing designs for a better sound quality.


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## Endesereth (Sep 15, 2009)

ya i have been looking at different designs, on winisd each time you do that it'll have a dip when the x-over switches form driver to driver...so is my design a big no no?


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## looneybomber (Sep 20, 2006)

Endesereth said:


> ya i have been looking at different designs, on winisd each time you do that it'll have a dip when the x-over switches form driver to driver...so is my design a big no no?


Your design had crossover points with a couple octaves of overlap. I don't know enough to design a good crossover, but I know enough that lowpassing your woofer at 600 and high passing that mid at 100 is a bad idea; low passing the mid at 6000hz is much too high, and high passing that tweeter at 1800hz is pushing. It's resonant frequency is ~1150, so you'd want to stay one octave above that = 2300hz.

Now designing the crossover with proper baffle step compensation, phasing, and having your off axis response nice and pretty is beyond me.


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## Endesereth (Sep 15, 2009)

lets see ok ill change those...the biggest question that i have though is the site on my first post, is it a good site to get recommendations for the inductors and capacitors from? if it isnt know any good crossover calculators?


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## 1Michael (Nov 2, 2006)

I can't speak about that web site, but if you are planning on designing a crossover for your first project I will give you my opinion. DON'T.
Pick a design that someone has designed and build that. It seems too many people think that all there is to designing a speaker is picking a few cool looking drivers, use a xover design program they downloaded from the net, and bamm, a speaker that rivals the best commercial offerings. Good luck with that. Outside of that, spend 3 years learning the basics, and I do mean ''The Basics", then you might be prepared to start your own project from scratch.
http://techtalk.parts-express.com/showthread.php?t=211558&AID=1482282&PID=2777698:T


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## Endesereth (Sep 15, 2009)

ok but i do know their is more to speaker building then that lol
thanks


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## looneybomber (Sep 20, 2006)

Well, I sorta agree with Buggers. Go ahead and buy speakers, play around with them, do some testing, try your hand a crossover design, have fun, and learn! You gotta get your feet wet eventually right? Just don't be too mad if they don't best some B&W 802's 

I found after a couple of years surfing/participating on DIY threads, I learned enough to know I don't know enough to design a proper crossover. If I had more time, I could do it, but life is just too hectic.

Maybe plan on building an established design and build one of your own designs. That way you can have a good sounding speaker and a speaker to tinker with.


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## lsiberian (Mar 24, 2009)

There's nothing wrong with building your own crossover as long as you're willing to learn a few ways not to do it first.

But you want to share the same point between 2 drivers. The idea is you want to breakup parts of the music with the driver that does it best. 

As far as your points go. 2500khz is much too low for a 3-way. I suggest a 4khz or higher point in a 3-way build. 

The bottom is best below 500hz. The reason for this is human hearing is most sensitive at the frequencies we speak at. As a result we ideally want those frequencies coming from only one source. Our ears notice when it doesn't. 

For a midrange driver I suggest the Dayton RS252 dome midrange. For the woofer the Anarchy-X and for the tweeter you have several options. Building a crossover requires trial and error. If you like that sort of thing then it will be easy for you.


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## Endesereth (Sep 15, 2009)

looneybomber said:


> Well, I sorta agree with Buggers. Go ahead and buy speakers, play around with them, do some testing, try your hand a crossover design, have fun, and learn! You gotta get your feet wet eventually right? Just don't be too mad if they don't best some B&W 802's
> 
> I found after a couple of years surfing/participating on DIY threads, I learned enough to know I don't know enough to design a proper crossover. If I had more time, I could do it, but life is just too hectic.
> 
> Maybe plan on building an established design and build one of your own designs. That way you can have a good sounding speaker and a speaker to tinker with.


That's exactly what I thought about doing! I am going to get some things to test them too since my bdays coming up
lsiberian
I had another project that sounds just like that, very good woofers and mid...


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## fbov (Aug 28, 2008)

Endesereth said:


> ...
> Really my only question is I've been using
> http://www.termpro.com/articles/xover2.html
> as a reference for the x-over components and i just wanna get a confirmation that this is a decent site...
> Thanks!


It's a nice historical site, but not suitable for designing a crossover since the time amateurs got T/S and FR measurement gear and everything went computer simulation. 

Your site shows you how to make a filter. This site gives you the tools
http://www.pvconsultants.com/audio/frdgroup.htm
and this site (linked above) shows you how to use them to make a crossover.
http://www.rjbaudio.com/Audiofiles/FRDtools.html

This is the sentiment behind buggers' recommendation; there's a lot that goes into speaker design. You can design something without perfect knowledge, but then the result is only good if you're lucky. Conversely, you learn more when it's you that makes the mistake. It just seems like you're headed for a good learning experience....

Put another way, why aren't you looking for proven, 3-way, dual woofer speaker designs?

Have fun,
Frank


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## lsiberian (Mar 24, 2009)

fbov said:


> It's a nice historical site, but not suitable for designing a crossover since the time amateurs got T/S and FR measurement gear and everything went computer simulation.
> 
> Your site shows you how to make a filter. This site gives you the tools
> http://www.pvconsultants.com/audio/frdgroup.htm
> ...


The whole point of engineering is you discover a lot of ways not to do something before you discover how to do it. I'm thinking the OP has an engineer/inventors mindset. I say more power to him.


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## Endesereth (Sep 15, 2009)

Thank you guys this has really helped, the reason why I don't go for already proven designs is because, I don't get that much enjoyment copying someone else lol if you understand what I'm trying to say.


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## 1Michael (Nov 2, 2006)

I believe that encouraging people to design a 3way speaker for there first build is ludicrous and irresponsible 
advice:rolleyesno: But hey if you have the expendable cash to throw away, then go for it:spend::spend::spend::rant:
I have given you my advice with your best interests in mind so I will bow out of this thread. Good luck.


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## looneybomber (Sep 20, 2006)

Endesereth said:


> Thank you guys this has really helped, the reason why I don't go for already proven designs is because, I don't get that much enjoyment copying someone else lol if you understand what I'm trying to say.


On the flip side, building an established/proven design that has coherent phasing and pleasing FR gives you a baseline or point of reference. Build it and listen to it. Build yours and listen to differences. Try to recreate what you like about the kit and modify that which you don't. In the end you may change driver layout, crossover topologies, and even drivers.

I do agree with buggers. Starting with a 2-way design is better.


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## looneybomber (Sep 20, 2006)

lsiberian said:


> As far as your points go. 2500khz is much too low for a 3-way. I suggest a 4khz or higher point in a 3-way build.


If he wants a 6.5" mid and a tweeter with a large OD flange, the center to center distance between the drivers will be too great for a 4khz crossover point.


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## Endesereth (Sep 15, 2009)

Ok I will go with my 2-way anarchy design which I still need to modify a little, and I will do some crossover testing...Ill continue to look at the parts diy site to see if theirs any enclosures that Ill like too...By the way this isn't my first diy speaker I've already built some it's just I've used pre-fab crossovers.
By the way does anyone know anything about the Dayton WT3 Woofer Tester, I'm thinking about getting one to test crossovers, unless their is a better one(sorry I don't get around that much lol)

OK here is the part that I am really confused about on crossovers. On most of the schematics that I've seen, they put the inductor or capacitor linked to the negative line. I am confused on why you do this because you would think that the electricity would take that route and not go to the speaker at all...


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## lsiberian (Mar 24, 2009)

Endesereth said:


> Ok I will go with my 2-way anarchy design which I still need to modify a little, and I will do some crossover testing...Ill continue to look at the parts diy site to see if theirs any enclosures that Ill like too...By the way this isn't my first diy speaker I've already built some it's just I've used pre-fab crossovers.
> By the way does anyone know anything about the Dayton WT3 Woofer Tester, I'm thinking about getting one to test crossovers, unless their is a better one(sorry I don't get around that much lol)
> 
> OK here is the part that I am really confused about on crossovers. On most of the schematics that I've seen, they put the inductor or capacitor linked to the negative line. I am confused on why you do this because you would think that the electricity would take that route and not go to the speaker at all...


The circuit determines all the values. Also current alternates.


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## lsiberian (Mar 24, 2009)

looneybomber said:


> If he wants a 6.5" mid and a tweeter with a large OD flange, the center to center distance between the drivers will be too great for a 4khz crossover point.


There is no sense in building a 3 way with a crossover lower than that IMO. You kind of lose the advantage.


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## looneybomber (Sep 20, 2006)

lsiberian said:


> There is no sense in building a 3 way with a crossover lower than that IMO. You kind of lose the advantage.


Well that's all part of the designing stage. If wanting to use a XO point that high, a 6.5" mid is not the driver that would be used. A 4" would be better or a dome mid.


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## ironglen (Mar 4, 2009)

Yeah, a 2 way usually necessitates the use of a lower xover point while a 3 way affords the builder to fully utilize a mid's higher range, such that vocals don't change focal points, as isiberian pointed out. So, in essence, one will get a flatter response and better imaging with a 3 way, eh?

I contemplated diy speakers, as several members have seen; I then decided to use 2 ways atop bass bins. I'm having trouble getting the bass bins done! lol Perhaps full-blown towers later down the road. Many good points here- I'd recommend re-reading them, then think it over and have a go at it!


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## Endesereth (Sep 15, 2009)

lsiberian said:


> The circuit determines all the values. Also current alternates.


can you explain a little lol sorry


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## fbov (Aug 28, 2008)

Endesereth said:


> Ok I will go with my 2-way anarchy design which I still need to modify a little, and I will do some crossover testing...Ill continue to look at the parts diy site to see if theirs any enclosures that Ill like too...By the way this isn't my first diy speaker I've already built some it's just I've used pre-fab crossovers.
> By the way does anyone know anything about the Dayton WT3 Woofer Tester, I'm thinking about getting one to test crossovers, unless their is a better one(sorry I don't get around that much lol)
> 
> OK here is the part that I am really confused about on crossovers. On most of the schematics that I've seen, they put the inductor or capacitor linked to the negative line. I am confused on why you do this because you would think that the electricity would take that route and not go to the speaker at all...


Did you look at the FRD site I referenced? Did you read Roman's how-to? 

This is how experienced amateurs design speakers. It's a multi-step process, but each step gets you closer to ideal response. The only legitimate shortcut is to measure the drivers _in the intended application._ This incorporates baffle edge effects and compensation needs; you measure the effects then design them out as you merge driver response in the crossover design software. 

A WT3 is half of the require measurement suite to gather data from your own drivers, but you can also use manufacturer's or other measured data. WT3 does impendence vs. frequency, and is a useful measurement and circuit testing tool. The other half is a calibrated mic, which usually needs a mixer and sound measurement software to record sound output vs. frequency. This is getting into it pretty deep, and there's lot of understanding that goes with it (and most of us are just learning ourselves). 

It may not seem obvious that you can short components to ground and get only a desired effect. Try to think in terms of a time-varying signal, not DC, and realize that caps and coils behave differently as you change frequency - they have impedence. It's this variation in resistance with frequency that makes passive crossovers possible in the first place. 

HAve fun,
Frank


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## Endesereth (Sep 15, 2009)

fbov said:


> This is how experienced amateurs design speakers. It's a multi-step process, but each step gets you closer to ideal response. The only legitimate shortcut is to measure the drivers _in the intended application._ This incorporates baffle edge effects and compensation needs; you measure the effects then design them out as you merge driver response in the crossover design software.


Yes I have looked at them and I am going to download them when I get the chance.
So if I'm getting you right on the quote I should test the speakers impedance, then start to build the crossover, and keep testing it after every component has gone in?
As for the mixer and all that to test the output vs frequency do you have any suggestions? 
Sorry I'm a little out of it today I have a calculus test that I have to take tomorrow:crying:
Thanks


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