I am a true beginner at crossover design. I am armed with edition 4 (1991) of Vance Dickason's cookbook and enthusiasm. I have fountek fr88-ex and dayton nd20-fb-4. Is the following design a good starting point or will it smoke my components? I was trying to cross at 5k. Thanks to anyone who spends the time to look over my attempt.
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Hey, I'm really not alot of help here, but the 15uf may be too big, and I don't want you to pop the tweeter. I would think 5uf and .25 might be closer. I could not find my copy of cookbook to see how you were calculating, but I plugged the numbers into some online things and could not get the cap much above 8uf, and did not hit 15uf till I went down to 1500. Looks like about 3.2 ohms at 5k.
Get more opinions before you give it much power. Basic config looks fine.
Dave
Get more opinions before you give it much power. Basic config looks fine.
Dave
The attenuation of the tweeter is not enough. The FR88EX has 84dB/1m and if you include baffle step 81dB attenuation. The tweeter has 90dB/1m sensitivity.
5KHz is a good point of crossover.
Tweeter : you need to remove 9dB with a LPAD 2.2 series and 2.2 ohms parallel crossover 5Khz LR2 : 4uF 0.22mH
The woofer I calculate 1mH 4.7uF
5KHz is a good point of crossover.
Tweeter : you need to remove 9dB with a LPAD 2.2 series and 2.2 ohms parallel crossover 5Khz LR2 : 4uF 0.22mH
The woofer I calculate 1mH 4.7uF
Erratum a schema is better : your woofer values are ok 0.5mH 2uF
For the tweeter C becomes 5.6uF
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Ya know. If you wanna really do this "right"/better. www.zaphaudio.com has FR and impedance plots of both those drivers on his site. You could use SPL Tracer to make .frd and .zma files. Then download Jeff Bagby's PCD, free. You could then design the XO based on real measurements.
Now, those are infinite baffle measurements. So, even better would be to simulate diffraction, baffle step, etc. before doing the XO design. It's take quite some effort, but will likely do better than just throwing some calculated values in there.
I recently did something very similar for the first time. I can link you to my build thread if you want some guidance on how to go about it.
Oh ya, I agree with the above. 15uF to big and 1.2ohm to small. Make the resistor swapable so you play till you have it right.
Now, those are infinite baffle measurements. So, even better would be to simulate diffraction, baffle step, etc. before doing the XO design. It's take quite some effort, but will likely do better than just throwing some calculated values in there.
I recently did something very similar for the first time. I can link you to my build thread if you want some guidance on how to go about it.
Oh ya, I agree with the above. 15uF to big and 1.2ohm to small. Make the resistor swapable so you play till you have it right.
I have some years of designing loudspeakers, there are a lot of tips.
I can give you useful links :
FRD Consortium
http://www.mh-audio.nl/index.asp
HOLM Acoustics
ARTA Home
You should read this first : crossovers
Hope this helps.
Note : Your set-up works and fortunately the theoretical values are closed to the actual values
I can give you useful links :
FRD Consortium
http://www.mh-audio.nl/index.asp
HOLM Acoustics
ARTA Home
You should read this first : crossovers
Hope this helps.
Note : Your set-up works and fortunately the theoretical values are closed to the actual values
I just watched some of the spots, couldn't stop somehow
... this is really really sick
I just watched some of the spots, couldn't stop somehow
... this is really really sick
Every time I hear the "Will it..." blend pops into my head, so you see I had to post the link. Pavlovian response methinks Definitely not a happy place if your an iPad owner.
<grips MacBook Pro tightly>Special thanks to Jerome as I used his suggestions for changing the crossover and the speakers sound great to me and everyone I have auditioned them for. I mounted the drivers in a 2.3 liter box with a 4.6" X 1.125" port tube. The port is bottom firing and the speakers are on spikes. This is my second set of DIY speakers as I have built a pair of Zaph's ZMV. The ZMV has a better overall sound because it handles the low end much better. I do like the mid range and upper midrange of the fr88-ex based speakers better just from listening. The new speakers will also work on a desktop. I have bought a calibrated mic and will struggle learning the measurement portion of the hobby. Thanks for the link to the arta page. I have a pair of Dayton Rs270s which I was going to bi-amp with another 2-way design but I am curious to hear how the fr88-ex based speakers will sound atop the rs270s but that would move the speakers from the desktop to the living room. I will probalby match these speakers with an 8 inch subwoofer. I really enjoy the sound of the smaller midwoofers and am considering a project with with a tang band 1052 or 1337. Thanks to all that offered useful advice and links.
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