Learning the hard way ...
Hi Dirk: That's wonderful -thanks for that.
Clearly I must change my current 15/7.5nF to 150-220nF/75-110 nF as you and others appreciatively replied.
Must I also change the resistor values (from the one's listed) on the 6-24 build?
Loudspeakers are KEF Reference-3, subwoofer KEF KF-92 (single -for now)
(Incredibly, the KF-92's built-in LP/HP is remarkably good ! We'll eventually see "how good" ? lol )
Thanks kindly,
pete
I was playing around with Mike Rothachers simulator for a crossover frequency around 45-50Hz (24db-slope).
I would assume you will need caps between 150nF to 220nF.
This was only a short try. I don't know if this would work in real life!!!
So, don't take that pic of the sim below as a recipe!
And I don't know what speakers you want to drive? What the phase response will do....
You can play with the cap values and the resistor values on your own.
CodePen - PASS XO5
And there are also other simulators out there in the web for calculating
Sallen-Key-filters.
Greets
Dirk
Hi Dirk: That's wonderful -thanks for that.
Clearly I must change my current 15/7.5nF to 150-220nF/75-110 nF as you and others appreciatively replied.
Must I also change the resistor values (from the one's listed) on the 6-24 build?
Loudspeakers are KEF Reference-3, subwoofer KEF KF-92 (single -for now)
(Incredibly, the KF-92's built-in LP/HP is remarkably good ! We'll eventually see "how good" ? lol )
Thanks kindly,
pete
Last edited:
Thank you. I realize this crossover can do a lot more than what I’m trying to do.
I’m trying build a good frequency divider to use a tube amp without losing too much sound quality and keep the top end frequencies analog. I assumed this was higher quality than the op amp filters. My subs already have electronic DSP adjustments. There doesn’t seem to be an affordable high quality analog box to divide the frequencies for subs vs 80hz or so on up. The bryston 10b, Pass Crossover and JL audio CR-1 are way too much. The first watt is too rare to find.
Maybe I’ll just get a miniDSP instead or buy a car audio crossover and feed it with a decent 12v power supply.
I agree ...
Hi Bilah: I too agree about your assertion that the crossovers you listed are far too expensive and the B4 is impossible to find/purchase -used of course.
If only someone with the required skill-set (and time/interest) could build one commercially -decently priced- I believe it would be a great success.
pj
Hi Bilah: I too agree about your assertion that the crossovers you listed are far too expensive and the B4 is impossible to find/purchase -used of course.
If only someone with the required skill-set (and time/interest) could build one commercially -decently priced- I believe it would be a great success.
pj
Dirk/Mr.P
Hmmmm ... you say (very accurately I might add -lol):
" ... But the result (of an active analog electrnic x-over) is more than worth the effort - my experience.
And you gave us 'greedy boys' a very versatile 'tool'. Thanks!"
Well then, get on with it !
There appears ample talent here on this site and all know the amazing skill-set of NP. And here (on this site), we also know of the tremendous interest in active crossovers (anallog).
Have you guys ever searched for a used x-over ? Any that 'pop' up -no matter the age/vintage or quality- gets scopped up in no time flat -record time in fact.
And yet no one 'out-there' sees this (commercial) opportunity ?
Make it smart. Make it flexible. Make it 'modular/updateable-ugradeable -Modular, with respect to fixed x-over frequency. For the most part, as Bilah' myself (and countless others) require: a subwoofer/sat x-over that should have a user-adjustable x-over range; a 'dial' that sets x-over at 35,40,45,50,55,60, 70, 80 Hz (LR 24/oct.) -unless of course a 6 db HP at 180? Hz coupled with 24 db LP is doable/sensible.
This should be esaily doable (and somewhat profitable) if one can keep the price about/around $1K USD -or more with options such as display screen, better P/S, discrete resistor gain adjustment, etc.
Bottom line: If there are enough of "us" that are willing to purchase a B4 board, perhaps First Watt folk can get 100 pieces or so built/made. I'll
sign up/and pay for two on the spot.
Or, perhaps an adventurous, hungry, talented, skilled businessman -we're looking at you Dirk- can commence the manufacture of said unit.
Be well all -Happy Easter Weekend ...
pete
Hmmmm ... you say (very accurately I might add -lol):
" ... But the result (of an active analog electrnic x-over) is more than worth the effort - my experience.
And you gave us 'greedy boys' a very versatile 'tool'. Thanks!"
Well then, get on with it !
There appears ample talent here on this site and all know the amazing skill-set of NP. And here (on this site), we also know of the tremendous interest in active crossovers (anallog).
Have you guys ever searched for a used x-over ? Any that 'pop' up -no matter the age/vintage or quality- gets scopped up in no time flat -record time in fact.
And yet no one 'out-there' sees this (commercial) opportunity ?
Make it smart. Make it flexible. Make it 'modular/updateable-ugradeable -Modular, with respect to fixed x-over frequency. For the most part, as Bilah' myself (and countless others) require: a subwoofer/sat x-over that should have a user-adjustable x-over range; a 'dial' that sets x-over at 35,40,45,50,55,60, 70, 80 Hz (LR 24/oct.) -unless of course a 6 db HP at 180? Hz coupled with 24 db LP is doable/sensible.
This should be esaily doable (and somewhat profitable) if one can keep the price about/around $1K USD -or more with options such as display screen, better P/S, discrete resistor gain adjustment, etc.
Bottom line: If there are enough of "us" that are willing to purchase a B4 board, perhaps First Watt folk can get 100 pieces or so built/made. I'll
sign up/and pay for two on the spot.
Or, perhaps an adventurous, hungry, talented, skilled businessman -we're looking at you Dirk- can commence the manufacture of said unit.
Be well all -Happy Easter Weekend ...
pete
OMG!
Lovely ! Call me with a price -if you care to build/sell another !
(I require a 4th order LP/HP sub/sat x-over. 120V)
pete
mrpjasz@gmail.com
I am getting closer to finish line with my second 6-24 - AXO build for subwoofer...
Cheers
Dirk
Lovely ! Call me with a price -if you care to build/sell another !
(I require a 4th order LP/HP sub/sat x-over. 120V)
pete
mrpjasz@gmail.com
allhifi here are the numbers I entered / used in the calculator. give it a try,
R1 11250 R2 22500 R3 11250 R4 22500
C1 156 C2 156 C3 156 C4 156
R5 19900 R6 30600 R7 19900 R8 30600
C5 156 C6 68 C7 156 C8 68
The R values represent a 10K resistor plus the pot value so your lowest pot value is 1250 Ohms.
How did i get those numbers? Start with a symmetrical value for C and C/2. So here I started at 156 and 78nF then as I would lower C6 and C8 I would raise R6 and R8. Little by little trying to keep the humps small but more importantly the Phase tracking as close as possible. Finally I would adjust R5 and R7.
The simulator omits the level control that is on the crossover so the final adjustment are usually done with that pot, but keeping the phase tracking is what is important.
When I changed my first build from 12 dB to 24 dB it put a big smile on my face to have the drivers working in phase instead of inverted.
Here is the calculator / simulator I used .
R1 11250 R2 22500 R3 11250 R4 22500
C1 156 C2 156 C3 156 C4 156
R5 19900 R6 30600 R7 19900 R8 30600
C5 156 C6 68 C7 156 C8 68
The R values represent a 10K resistor plus the pot value so your lowest pot value is 1250 Ohms.
How did i get those numbers? Start with a symmetrical value for C and C/2. So here I started at 156 and 78nF then as I would lower C6 and C8 I would raise R6 and R8. Little by little trying to keep the humps small but more importantly the Phase tracking as close as possible. Finally I would adjust R5 and R7.
The simulator omits the level control that is on the crossover so the final adjustment are usually done with that pot, but keeping the phase tracking is what is important.
When I changed my first build from 12 dB to 24 dB it put a big smile on my face to have the drivers working in phase instead of inverted.
Here is the calculator / simulator I used .
Hello members,
I made myself a easter-present- the baby is up and running...
I have to solder 2 pairs of RCA-cables and perhaps this evening I will have a first
soundcheck?
Cheers
Dirk
I’ll start with those look great! I don’t know where to start with what did you use to build those and what is your crossover frequency? That linear power supply also looks great. I assume the volume knobs replaced the small pots intended to be mounted to the PCB. Great job!
to Billah #753
Hello Billah,
the crossover frequency is at 80Hz with 24dB-slope.
The PSU has a CRC-filter followed by a regulator for 24V DC. And there is the massive CRC-filter on the mainboard of the active crossover. More than enough.
And the pots are Vishay/Spectrol high accuracy pots with liner taper (10-turn) which replaced the trimpots on the mainboard.
Cheers
Dirk
Hello Billah,
the crossover frequency is at 80Hz with 24dB-slope.
The PSU has a CRC-filter followed by a regulator for 24V DC. And there is the massive CRC-filter on the mainboard of the active crossover. More than enough.
And the pots are Vishay/Spectrol high accuracy pots with liner taper (10-turn) which replaced the trimpots on the mainboard.
Cheers
Dirk
Dirk, I collect Hobbies as a Hobby. As far as DIY Audio... I went off the deep end and continue swiming away from shore building speakers. With electronics... so far I've built an ACA, Korg B1 and F5. Now I'm building the 6-24 and another F5 to use for additional channels with the 6-24. I think you're preaching to the choir.