Quote:
BoomieMCT wrote:
 I have a speaker I'm thinking of building and (as a learning experience) I want to make the crossover myself. However, before I embark on this journey I have some questions.
I am thinking of using an 8" Goldwood woofer in an open baffle with this tweeter. To cross this over, I was planning on using a second order Linkwitz-Riley circuit crossed at 2250 Hz. Because the woofer in an open baffle alignment can easily overexcurse itself below 80Hz, I was going to also put in a low order highpass.
Here are my questions:
1. The power handling of the woofer is 65 watts and the power handling of the tweeter is 40 watts. What can I assume is the total power handling? Do I use the lower value, sum them, or what?
2. The impedance of the woofer is 8 ohms and the tweeter is 6 ohms. What can I assume is the total speaker impedance? Is it calculated in the same way as resistors in parallel?
3. For the crossover capacitor and inductor values, do I calculate it using the "nominal impedance" (8 and 6 ohms) or do I use the DC resistance values?
4. Do I simply wire up the highpass circuit before the LR or will there be some sort of interation between the two? Perhaps should I only wire it up to the woofer's part of the circuit?
I apoligize if these seem real basic but I can't seem to find a good information resource that is more comprehensive then Wikipedia but more basic then the Loudspeaker Design Cookbook. Any additional comments are welcome. |
I can answer a few of the questions but you should read through the links that JCD listed.There is some great info in there.
1. The power handling will be that of each driver.But a poorly designed hi pass filter can reduce the tweeters power handling substantially .Also using the woofer on an open baffle will restrict the amount of power it can handle.
2.Generally the impedance will be that of the woofer below the crossover and the impedance of the tweeter above the crossover.Although the crossover will also have an effect on system impedance.
3.Honestly a crossover designed from a formula has very little chance of working well.Measurements and crossover CAD programs are really needed to get top notch results.But if you want to experiment then use the nominal values.
4. were you just going to use a large cap as a hipass filter?