Series Filter Calculator

[Lars Clausen]

Many people have asked me if i could give a formula for calculating the simple phase linear x-over for 2 way loudspeakers.
The one published on www.lcaudio.com.

Well now i have come up with an on-line calculator for it...

Check it out on: www.oliveaudio.com

[jcake5]

Sir,

Thank you for your efforts to put your information onto the internet for all to learn from and use. However, I cannot get past your initial page. I will continue to try.

Thank you,
Eric

[Lars Clausen]

Can you tell me what happens when you press 'Series Filter' ??

[tool49]

It works good here!

Thanks Mr. Clausen!

Sébastien

[jcake5]

Lars,

The opening page just reloads. Putting the mouse over the "Series Filter" and clicking reloads the page in Microsoft Internet Explorer. I remembered that I also have the Netscape browser. Your page works in Netscape.

I have no popup blockers etc. in IE. Mr. Gates is taking care of me again.

Thank you for the information you have provided.

Best regards,
Eric

[jcake5]

Lars,

I was wondering how you implement Baffle Step Correction with this filter, additional Inductance in the woofer leg or ... ?

Also, could you post the formulas you use to calculate the circuit since I would like to model with other woofer impedances. I assume you are using 8 as the standard woofer impedance.

My goal would be to make a spreadsheet that accepts:

1. woofer z
2. tweeter z
3. desired crossover frequency

then calculate the component values.

Best regards,
Eric

[Lars Clausen]

Eric: For this formula i am using simple Fres for the LC network L1 and C1, and then a first order implementation for C2 and te tweeter. I use 8 Ohm for the Bass.

I also tried simulating a more complex system taking the Q, and DC resistances into account, and also the fact that C1 and C2 are in parallel from the woofer's standpoint, and with the tweeter Z in series with C2. But the simulations showed almost exactly the same results as the simple formula.

Best regards

Lars

[Cloth Ears]

Hi Lars,

I've been using Murray Hauschild's spreadsheet to good effect (available from http://www.geocities.com/mghsxo/) and also used Andy Graddon's site (whose address has somehow forsaken me for the minute).

Always good to see another series calculator or resource, as there are so few out there...

Thanks for sharing

[jcake5]

Hi Lars,

I have implemented a simple spreadsheet based on your last reply to me and I can get the same results as your calculator just by entering the values for tweeter z, and the woofer LC with no worry about woofer z. I calculate the Tweeter high-pass from the other results.

Again thank you for sharing your knowledge.

Best regards,
Eric

[Sjef]

Just simulated the series crossover in CALSOD.

I took a purely resistive value of 6 ohms for both the woofer and the tweeter. Frequency response of both drivers was set flat with the tweeter having a 3 dB higher sensitivity than the woofer.