Two different questions. Yes, could work sealed but would need a very big 90L box. Enter t/s parameters into here to have a look: http://sbp.softica.dk/2.0/en/
XT25 does not want to cross low enough for it, though; too much distortion without a high-order filter see http://www.zaphaudio.com/tweetermishmash/ comments
A26 variants cross about 2.2khz with tweeters like Morel CAT378 or Seas T35 e.g. Makako https://www.dibirama.it/home-page/d...-makako-2-vie-bass-reflex-8-ohm-300-wmax.html
XT25 does not want to cross low enough for it, though; too much distortion without a high-order filter see http://www.zaphaudio.com/tweetermishmash/ comments
A26 variants cross about 2.2khz with tweeters like Morel CAT378 or Seas T35 e.g. Makako https://www.dibirama.it/home-page/d...-makako-2-vie-bass-reflex-8-ohm-300-wmax.html
Thank you for the link. May be ignore P25REX and match XT25 with CA18RLY in vent box instead.
Another budget might be this one
https://projectgallery.parts-express.com/speaker-projects/birthday-build/
Thank you now i knew limit of 10" woofer in 2-way of P25REX
https://projectgallery.parts-express.com/speaker-projects/birthday-build/
Thank you now i knew limit of 10" woofer in 2-way of P25REX
You need better drivers to do what you want, the Seas T35, Morel CAT378 or maybe the SB26ADC can do relative low crossovers, but it will still be arround 1500Hz the lowest. For woofers you can also look at the Faital 10FE330 or the Beyma 10BR60V2. Both are good drivers for this also.
i still have Tang band W5-1611SA. Can i use with P25REX?
How to design crossover full range with P25REX?
I want seal box f3 50h w5-1611SA BASS is 60hz not suffice for my taste.
How to design crossover full range with P25REX?
I want seal box f3 50h w5-1611SA BASS is 60hz not suffice for my taste.
The Tang Band looks a bit rough. SB26ADC should work. Did you look at that website I posted before? Enter the Seas tsp in there under custom driver and it can show you the Fb based on desired Q or desired Vb. Vituixcad also. 61.6L gives a q of 0.6 and Fb of 50.5hz.
Sealed box has nothing to do with matching to any tweeter. Look at the Makako crossover also from my earlier post. Could use that as a starting point, tweaking for response differences of P25 vs A26 and CAT378 vs SB26ADC. Key issue is maintaining the wide, tall front baffle dimensions, then calculate the depth for 61.6L internal volume including stuffing. The main design principle is to run the woofer with no filter at all then just a shallow slope tweeter filter to match the rolloff.
You could of course do other things, but that's not how this driver is generally used.
Sealed box has nothing to do with matching to any tweeter. Look at the Makako crossover also from my earlier post. Could use that as a starting point, tweaking for response differences of P25 vs A26 and CAT378 vs SB26ADC. Key issue is maintaining the wide, tall front baffle dimensions, then calculate the depth for 61.6L internal volume including stuffing. The main design principle is to run the woofer with no filter at all then just a shallow slope tweeter filter to match the rolloff.
You could of course do other things, but that's not how this driver is generally used.
Having a look at the P25 datasheet, it has a broad peaking in the lower midrange, and it doesn't breakup the same way as the A26 at all. The A26 naturally drops where the P25 continues to rise. My thought is that you shouldn't run the P25 without a filter.
I plugged in the cabinet dimensions from the Makako and made some rough estimates of offsets, then came up with this.
I added a notch to the woofer to get rid of that peaking around 300-500hz
One nice thing is that you may be able to run the tweeter without a resistor. Impedance looks OK. Phase not so much. It's pretty rough but might help as a start.
I plugged in the cabinet dimensions from the Makako and made some rough estimates of offsets, then came up with this.
I added a notch to the woofer to get rid of that peaking around 300-500hz
One nice thing is that you may be able to run the tweeter without a resistor. Impedance looks OK. Phase not so much. It's pretty rough but might help as a start.
Y-axis -105mm is the position from center of tweeter? Then it should be about -180 mm.
Can you share .frd and .zma of P25REX. I use virtuixcad trace but it might be incorrect. Thank you
The XO point above is about 1.5k right ? but actual freq point from frd of both drivers XO is 2.2k
Can you share .frd and .zma of P25REX. I use virtuixcad trace but it might be incorrect. Thank you
The XO point above is about 1.5k right ? but actual freq point from frd of both drivers XO is 2.2k
You're right. I changed the y offset. It affects the vertical dispersion at wide angles. Vcad shows y offset of -215mm can improve this 40 degree performance a bit, but it will degrade the performance at 30 degrees. You can play with it.
Attached all my files.
I worked on the xo simulation a bit more, and get a better system response when lowering the XO point to 1700hz. This lets you do without the woofer notch, but you need more notching of the tweeter nearer to its resonance frequency. Can still run the tweeter with no padding resistor, which is nice, and it is also good to roll off the big woofer earlier cause of its breakup.
I previously chose around 2k based on hificompass distortion measurements of the A26, but the system here looks better matched at 1.7khz.
Attached all my files.
I worked on the xo simulation a bit more, and get a better system response when lowering the XO point to 1700hz. This lets you do without the woofer notch, but you need more notching of the tweeter nearer to its resonance frequency. Can still run the tweeter with no padding resistor, which is nice, and it is also good to roll off the big woofer earlier cause of its breakup.
I previously chose around 2k based on hificompass distortion measurements of the A26, but the system here looks better matched at 1.7khz.
Last edited:
While I feel the simulation looks okay at this point on paper, it likely will not meld well in directivity and require some major changes through the xover region to eliminate the directivity peak in transition. When I was designing the Pangolins 10" 2ways, I did as you have done here, using in box measurements and aiming for flat responses at one axis. I did this initially to show what the response does, and then adapted for directivity and changed the results to a more favorable outcome. You can read the process here:
https://diy.midwestaudio.club/discussion/2710/pangolins-a-10-2way/p1
https://diy.midwestaudio.club/discussion/2710/pangolins-a-10-2way/p1
All agreed, Ben. The errors could be very big, fairly big, or who knows, Based on 30 year old datasheets, assumed cabinet dimensions, and such. Adding even more simulated off-axis would not help much, neither. These are just suggestions based on some available data and proof of concept for the drivers mentioned, and it's relaxing for me to just fiddle with the sims. 😉
Here's my last one. As it seems the tweeter level doesn't need a series resistor, I remembered Tony Gee's series xos and tried following one of his topologies. It looks pretty nice with super low parts count. Don't ask me how it works. Every time I've fiddled with series xos, the driver pairs I used led to inscrutable jenga, but these two strangely seem to work well. I wonder how it might sound vs an A26.
Last edited:
I would place a 12-15uF on the top line between the 0.56mH and the 22 ohm resistor. It will help protect that tweeter better.
I just look at Mr. Waxx post about Faital 10FE330. I am surprise about its vent cabinet size which is smaller than Sealed of P25REX.
And bass reach 39hz!!!! I am thinking about it.
If anyone ever design 2-way with SB26ADC please share XO.
If it is nice, i might sell P25REX and buy faital 10FE330 instead and make 58L vent cabinet.
And bass reach 39hz!!!! I am thinking about it.
If anyone ever design 2-way with SB26ADC please share XO.
If it is nice, i might sell P25REX and buy faital 10FE330 instead and make 58L vent cabinet.
Not familiar with this style of XO with tweeter inverse polarity. But it seem fit perfectly both drivers
Attachments
Last edited: