5KHz passive crossover

[ruijorgemoreno]

Hi!

I need to make a 5Khz crossover for a 2-way speaker.

woofer 30W, tweeter 15W.

Can you people help, please?

Thanks in advance.
RJ.

[prickears]

Hi there,
To have a fighting chance of making a crossover you will need to know what the impedence of the drivers is at least. Do you have ALL of the driver specifications or model numbers and brand? If you have these, post them here, or go to google and find an online calculator, Simple as that!

Regards, Mick.

[ruijorgemoreno]

I'm sorry, I fogot that detail :S

Each woofer/tweeter is 6ohm.

Well the problem is that I don't know what to use!
Butterworth, Chebychev, Linkwitz-Riley, Linear phase design?
What order?

Thanks.

RJ.

[prickears]

With such limited info, your best bet is probably a L/R 2nd order. Try, c 3.3uf, L .47mH, That will xover @ 4000 hz (5000 hz gives hard to get values). Hope this helps.

Mick.

[ruijorgemoreno]

ok.
Just one more thing.
The resistors shall I use metal film? Witch wattage?
What about the capacitors? 40-50V would be enough?

Thanks.

RJ.

[prickears]

5 watt resistors will be more than plenty, 40-50v should be ample. 100v would be better.

Good luck, Mick.

[PeteMcK]

re:'Each woofer/tweeter is 6ohm' - you need to use the ACTUAL impedance at the crossover frequency, not nominal, or Re....
do you have manufacturers impedance graphs?

[tinitus]

Originally Posted by PeteMcK

you need to use the ACTUAL impedance at the crossover frequency, not nominal, or Re....

Yeah, ok, but even that isnt enough really

We need more info on your woofer, especially response curve, but impedance would be good too
But at least some info on size and type
Also a picture may help

Hey, maybe just mount a small cap in series with tweeter +, and maybe a series resistor
That way at least you will experience whether your woofer is capeable of 5khz
I have once made a small speaker that worked fine that way

[prickears]

RJ,

As these guys are trying to point out, your trying to walk on water without getting wet!

Basicly, without manufacturers specifications, your flying blind, ie, its next to impossible to build a cabinet that will give any meaningful bass performance, and the XO I suggested post#4 would probably be the best you could hope for, (rough at best), bass aside.

Bottom line; A long way shy of 'ear candy'.

Sorry I can't be of more help, Mick.

[ruijorgemoreno]

Hi!
First thank you all for your replies and I'm for my delayed reply...

The speakers in question are a pair of Technics SB-HD501. (http://is.gumtree.com/ad_image/live/big/239779020.jpg)

the thing is... The original amplifier had an active xover @ 5KHz...
Since I'm working with another amp, i would like to add them a passive xover...

I don't know any more specs than what it said on the back of the speakers:
Impedance: high 6ohm, low 6 ohm
power: tweeter 30W(music), 15W(din)
woofer 60w(music), 30W(din).

Thanks.

Rui Jorge.