You want to do active? Thought you were going with a passive x-over.
BTW, the curves at Loudspeakers Plus are FR, not impedance.
BTW, the curves at Loudspeakers Plus are FR, not impedance.
OK, got back to my main computer with the software. Had a good look.
Did come up with something if you are interested.
Cap, coil and L-Pad on the tweeter, cap coil and Zobel on the woofer. 7 parts per channel.
Let me know and I'll post it here.
Did come up with something if you are interested.
Cap, coil and L-Pad on the tweeter, cap coil and Zobel on the woofer. 7 parts per channel.
Let me know and I'll post it here.
Hey Pano, Thank you very much for taking the time to do this.
I would love to see what you came up with.
I would love to see what you came up with.
Hey Michael, I was looking at the image of you standing next to the Open Baffle 18"
Did you ever get that thing dialed in? If so please shear your thoughts.
Did you ever get that thing dialed in? If so please shear your thoughts.
That 18" coax belongs to John Busch, not me. But yes, at long last he got it dialed in. Now of course they stopped making the driver! 
The 15 has some of the same issues as the 18, namely a bump at ~1500Hz on both sections. John has done some good trapping on the crossover.
I'll work up a layout for you and post later tonight or tomorrow. Back to priming and painting I go!
The 15 has some of the same issues as the 18, namely a bump at ~1500Hz on both sections. John has done some good trapping on the crossover.
I'll work up a layout for you and post later tonight or tomorrow. Back to priming and painting I go!
The Christmas Coax Crossover
OK, here is what I came up with.
Some caveats.
That said, the FR and impedance should be very close. As stated earlier, the main trouble is that both drivers have a midrange peak that gives these P.Audio coaxes a "P.A" sound. That hump is right at the crossover region, too. So what I have done is to spread the electrical x-over points to achieve close to 3rd order (Butterworth) acoustic slopes circa 1100Hz. This should achieve a fairly flat summation thru the midrange with a slight downward slope, depending on where you set your L-Pad.
The compression driver breakup is not dealt with, but a trap can be added later, if you feel you need it. It will sound better with a trap, but you can run without. Disregard the response below 100Hz as this does not include box or room.
It's simple and the diagram should let you wire it up with ease.
A 2nd order low pass on the woofer, 1 coil, 1 cap + a Zobel (cap & resistor).
2nd order high pass on the horn, 1 cap, 1 coil, 1 L-Pad for level. Horn is wired reverse polarity. Not much too it. This will sound sooooo much smoother and better than the single cap filter. Imaging should also be much improved.
You'll also see the filter function plotted, to give you an idea of the electrical slopes.
Please let me know if you have any questions. Have fun with it!!
OK, here is what I came up with.
Some caveats.
This is done in software, not actual in room measurements or listening. It is important to understand that.
Response curves from P.Audio published FR. Impedance from P.Audio 18" coax.
Response curves from P.Audio published FR. Impedance from P.Audio 18" coax.
That said, the FR and impedance should be very close. As stated earlier, the main trouble is that both drivers have a midrange peak that gives these P.Audio coaxes a "P.A" sound. That hump is right at the crossover region, too. So what I have done is to spread the electrical x-over points to achieve close to 3rd order (Butterworth) acoustic slopes circa 1100Hz. This should achieve a fairly flat summation thru the midrange with a slight downward slope, depending on where you set your L-Pad.
The compression driver breakup is not dealt with, but a trap can be added later, if you feel you need it. It will sound better with a trap, but you can run without. Disregard the response below 100Hz as this does not include box or room.
It's simple and the diagram should let you wire it up with ease.
A 2nd order low pass on the woofer, 1 coil, 1 cap + a Zobel (cap & resistor).
2nd order high pass on the horn, 1 cap, 1 coil, 1 L-Pad for level. Horn is wired reverse polarity. Not much too it. This will sound sooooo much smoother and better than the single cap filter. Imaging should also be much improved.
You'll also see the filter function plotted, to give you an idea of the electrical slopes.
Please let me know if you have any questions. Have fun with it!!
Attachments
You're welcome!
I had fun with the diagram, it turned out nice.
If you have any questions, please let me know.
I had fun with the diagram, it turned out nice.
If you have any questions, please let me know.
Forgive me resurecting an old thread but I just bought a pair of BM-15cx38 on special.I'd love to know how the crossovers worked with the 13.6 boxes.
Are the "traps" mentioned steep roll-offs and what is the best way to implement them?
When put into the AJ Vented calculator,it gives Vb of only 59l and F3 of 106Hz! That seems high. Will the larger box lift the base frequencies,or should I run a pair of 18" subs with them?
thanks
Paul
Are the "traps" mentioned steep roll-offs and what is the best way to implement them?
When put into the AJ Vented calculator,it gives Vb of only 59l and F3 of 106Hz! That seems high. Will the larger box lift the base frequencies,or should I run a pair of 18" subs with them?
thanks
Paul
I really dig it. Sounds so much better then the single cap.I have wondered how a trap would sound but never looked into it. When ran on the DEQX ( that thing is great!)
I can do pretty much anything I want but you have to have two amps.
Next will be to try it OB. Pano im sure you know a thing or two about that!
I can do pretty much anything I want but you have to have two amps.
Next will be to try it OB. Pano im sure you know a thing or two about that!
Yep. 😉 And the DEQX will help you smooth out any wrinkles.
The OB crossover will be quite different, just FYI.
The OB crossover will be quite different, just FYI.
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