help building a 3 way crossover

[harrisni]

Hi,

I need to build a 3 way crossover. I will be running a Tweeter, Midrange and Woofer.

Crossover Frequency 350Hz, 4kHz

Any idea on what the best components are to use?

[Sonusthree]

Hi Harrisni,
Firstly, It would be wise to search the net to gain a good understanding of how crossovers work and which types may be suitable for your application. First order networks are the simplest with few components so I recommend that you start there.

Perhaps you could look here: http://www.colomar.com/Shavano/crossover6db.html
But there are plenty more resources around.

Secondly, It is impossible to recommend components for a crossover without at least knowing which drivers you will be using and to a lesser extent in which enclosure.

You would at least need to know the nominal impedances of the drivers since they will seriously affect the crossover frequency.
It would be very usefull if you have the model numbers of the drivers that you will be using together with any specifications that you may already have.

What makes you say "Crossover Frequency 350Hz, 4kHz"??
Cheers,
S3.

[Shaun]

Any idea on what the best components are to use?

Answer: "the right value components".

Seriously, you'll get more value out of getting the crossover right than going for "high-performance" components. That being said, there are certain rules of thumb to obey, first. (1) Avoid using electrolytic capacitors if possible. (2) Air-cored coils are best (virtually saturation-free), except that for high inductance values (>2mH) they become quite expensive and/or series resistance becomes significant. In this case, use iron-core (laminated) or C-core types. (3) Be mindful of magnetic coupling between adjacent inductors; don't orientate them in a way that allows them to interact.

Once you've solved all the basic problems with your crossover you can start experimenting with alternative-grade components. Your results will depend on the quality of the drivers and that of the rest of your system.

Good luck.

[v-bro]

filtering round 4k is exactly in the most sensitive part of the average human hearing curve.......

[audiomanics]

http://www.lautsprechershop.de/english/index_tools.htm

go for multiple way crossover..
This java applet is easy to use.

tuning your filter has to be done with measurements....

Kees

[noodle_snacks]

sounds like you are still trying to emulate those b&w speakers, for the most part with conventinonal drivers, 4khz is too high for a tweet/mid crossover, i think even a 4in woofer would be beaming significantly at this frequency. The b&w speakers you like so much use a fixed surround, the woofer becomes a smaller and smaller point source as frequency goes up, therefore keeping smooth power response. In reality you will have to aim somewhat lower with your crossover frequency here.

[v-bro]

Don't know if you have allready purchased a tweet, but choosing one with a (very) low fs. would have my recommendation...

I like the vifa ht-275/d2, this one has a hole drilled through the pole core connected to a dampened chamber in order to lower te resonance frequency (fs). When compared to the standard ht-275 (same dome) the difference is clear...

Google on "dampened chamber".

Same thing for the woofer, don't choose one with a hard cone (they often show nasty peaks in the midrange) to be able to filter with 6db/oct (first order) slopes..

To sum it up, use drivers with little strange behavior even near the x-over frequency.