speaker setup and crossover help

[personinaboxthing]

Hi there, I'm new to building my own speaker setup but it seems like a nice idea so recently I've started looking into getting a set of speakers done.
I thought I'd ask here and hopefully get a few pointers from some people with more experience in the subject.

I found a few useful pages when doing some searching on the Internet, such as this one for information on audio crossovers.
I'm aiming for an 8 ohm load, not for any particular reason, but it appears to be common (is this really the case?)

So anyway, what I've done so far is draw out what I think would be valid wiring for a given set of speakers (I have not purchased anything yet, because I am not 100% sure and I don't want to make any mistakes.)

The low/mid range speakers are 4ohm impedance and have a max power rating of 100W each, using a pair of these in series I should be able to get an 8ohm impedance with a max power rating of 200W, I think.
The high-range tweeters are 8ohm impedance and have a max power rating of 50W each, and using 4 of these in series-parallel I should be able to get an 8ohm impedance with a max power rating of 200W also, right?

Using the information about crossovers in the link I put up earlier, I have a 2kHz 'cutoff' (second-order,) and while they are essentially in parallel, they should still have an impedance of about 8 ohms (again according to that crossover page.)

I've attached an image of my wiring as a circuit diagram, I couldn't get speaker components in the simulator I used so I used resistors instead. The 206.2Hz thing was a frequency sweep so I could see the current flow through the different speakers as a result of the crossovers.

If I did it right, as a whole I should have an impedance of 8 ohms and a max power rating of 200W.
Can someone check over what I've done? I'd appreciate some pointers on whether or not this will work as expected, etc.

Thanks!

[PeteMcK]

Multiple tweeters are not a good idea, google 'comb filtering', but the tweeters don't need to have the same power rating as the woofers, most power is in the lower frequencies.
You will also need to add an L pad to match the tweeter's efficiency to that of the woofers.
To get an accurate crossover, you need to use the actual value of the driver's impedance at the crossover frequency. (How many times has this been said...???) The impedance varies with frequency, so you need to get the correct value from a manufacturer's graph or measure one yourself.
Passive Crossover Network Design

[tinitus]

my best suggestion is throw in a more or less random and simple 6db filter
and listen
then make it work

[eyoung]

Go back to square 2...What is in your system, Playback source/pre amp/amp,what music do you listen to primarily,and finally what is your listening environment??? now let us make suggestions.

with much trepidation, Elwood

[DavidL]

Originally Posted by tinitus

my best suggestion is throw in a more or less random and simple 6db filter
and listen
then make it work

You're kidding right?
and you are a Moderator too? *sigh*
At least point him in a direction to learn something The Speaker Building Bible - Techtalk Speaker Building, Audio, Video, and Electronics Customer Discussion Forum From Parts-Express.com

[Jay]

First, you should know that there is no way you can build a speaker better than everybody else who have done it many times with proper tools and methodology. This means that, you can find plenty of available designs on the net that will better yours, whatever your speaker will be.

So, if you want to build your own but don't want to make mistake, buy the drivers used in any proven design, build the same enclosure, then you can make your own crossover. If you're not satisfied with the result, you can build the proven crossover. Or if you have talent, you can use the proven crossover as a benchmark to create a better one.

Simple crossover that will "work" is the ARSXO (or any series crossover). You only need a tweeter that is smooth enough. If the drivers work in 1st order paralel filter, it will 100% work in ARXSO. But rarely two drivers will work with 1st order filter. But it depends on your standard of quality.

[tinitus]

Originally Posted by DavidL

You're kidding right?

you are welcome to comment here too Classic monitor designs?

[tinitus]

misunderstanding
some people seem to believe I suggested to use the simplest 6db filter
that is not what I said
I suggested a 6db filter just to be able to power up the speaker, and listen to the drivers
and then correct it
please note that I said then make it work
if that means it ends up being 18db 3. order, then so be it

point is, a calculated xover using just a simple calculator is never going to work properly

you either need to measure, or alternatively use your ears
both will need work, and experience
but to think its just to calculate, and then that's it...no
it can get you started
but will still need adjustments

that is why I suggest that you could just as well start out with a simple 6db filter, and move on from there
most of the components you start out with will need to be changed, and thus be useless anyway
so you could just as well start with the simpler 6db filter
and apart from being cheaper, it may have another 'advantage'
it doesn't change the sound of the drivers much
you hear the raw driver, almost
so, you will have better impression of what needs to be done

next step is to find the mistakes caused by the filter itself, and correct it
typically its phase issues, peaks and dips, or 'ringing'

its about achieving a 100% controlled sound
and avoid a 'closed' sound, which typically happens too easily
the ultimate is perfect control, and still free flowing music
a bit harder to achieve, but still not too difficult
but its work work work
until you know how it works

Originally Posted by tinitus

my best suggestion is throw in a more or less random and simple 6db filter
and listen
then make it work

[DavidL]

Originally Posted by tinitus

misunderstanding
some people seem to believe I suggested to use the simplest 6db filter
that is not what I said
I suggested a 6db filter just to be able to power up the speaker, and listen to the drivers
and then correct it
please note that I said then make it work
if that means it ends up being 18db 3. order, then so be it

point is, a calculated xover using just a simple calculator is never going to work properly

you either need to measure, or alternatively use your ears
both will need work, and experience
but to think its just to calculate, and then that's it...no
it can get you started
but will still need adjustments

that is why I suggest that you could just as well start out with a simple 6db filter, and move on from there
most of the components you start out with will need to be changed, and thus be useless anyway
so you could just as well start with the simpler 6db filter
and apart from being cheaper, it may have another 'advantage'
it doesn't change the sound of the drivers much
you hear the raw driver, almost
so, you will have better impression of what needs to be done

Then I suggest next time that you explain what you meant with details other than just posting one silly sentence. you won't have to back track and make excuses after the fact

[DavidL]

Originally Posted by tinitus

you are welcome to comment here too Classic monitor designs?

All I see is a subjective opinion on how you think it sounds with no measurements at all. Anyone can throw together a crossover and "think" it's fantastic. Just saying