Hi. I am building active crossover for system similar to Linkwitz LX521 Or Nao Note II RS. I will use sealed subs with LT.
So i need 4 way crossover. But I have doubts if my block diagram is correct. Order of blocks to be exact. Could some one with more experience check it? It will be one hell of pcb so I don't realy want to route it with mistake
I would be very thankfull. Diagram shows single channel.
Actual circuits here but i think they are not needed at this point, since only thing I don't fully understand is order of some circuits.
So i need 4 way crossover. But I have doubts if my block diagram is correct. Order of blocks to be exact. Could some one with more experience check it? It will be one hell of pcb so I don't realy want to route it with mistake
I would be very thankfull. Diagram shows single channel.
An externally hosted image should be here but it was not working when we last tested it.
Actual circuits here but i think they are not needed at this point, since only thing I don't fully understand is order of some circuits.
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How about just buying a Minidsp 4x10HD? It can do all that and much more. SL has his Challenge going on and many many diyers are using it.
Start here miniDSP tutorials
and Stereo 3/4way Xover
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Every new speaker needs lots of testing and modifications before it works optimally. I don't know about PCB and circuit design, but the key is easiness of modifications. When everything works optimally, one can replicate transfer functions etc. to a passsive line level xo-circuit.
Start here miniDSP tutorials
and Stereo 3/4way Xover
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Every new speaker needs lots of testing and modifications before it works optimally. I don't know about PCB and circuit design, but the key is easiness of modifications. When everything works optimally, one can replicate transfer functions etc. to a passsive line level xo-circuit.
I have built and used similar analog crossovers, and have moved to DSB based, mostly due to ease of getting exactly the slope and corner frequency I wanted, and not being "stuck" with standard values and tolerances. I find that the result is at least as good sounding as the analog.
If you really want to pursue the analog, why feed the woofer and sub portions from low-passed filters? Better to feed all from the buffer directly.
If you really want to pursue the analog, why feed the woofer and sub portions from low-passed filters? Better to feed all from the buffer directly.
When i seen it costs 500usd :O
Probably like 550usd with shiping, and with lovely lithuanian import taxes it would be well over 650usd. Buying it, my project cost would double. That means no music for me for atleast 1 year more. All drivers needed for this project together don't cost that much.
Thats crazy money for me.
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I just have no choice. I don't have money for DSP solutions. So only way for me is analog, because it is many times cheaper.
Talking about diagram, i based that from Rod Eliott circuit, forgot to mention: Project 125
I wonder why is he feeding sub and woofer like that?
Now i am confused, since I believe, that he knows hat he is doing
And here he says that it is better to connect it this way, because of phase shifts. Is he wrong?
But I still need to buy sound card then. And cheap one will be probably quite bad. I have pc with integrated 7.1 and i tried using it for 2way crossover, and I just don't like it that way. And having to wait for pc to boot every time i want to listen to music and fighting with pc fan noises
I just wanted to know if my diagram is correct. I am fully decided to use analog crossover. My only problem is, that I am not 100 percent sure if my diagram is correct. So I asked here. I hope you understand me. I just want to route it, etch it and solder it. It is fun for me. And it will be still cheaper than buying even half decent sound card and old pc.
I generally like your block diagram. I did a 3 way open baffle system with all 4th order slopes and OB EQ, all active of coarse. You show separate 12dB/oct blocks. The two cascaded blocks need to compliment each other to give you the right 24dB/oct. shape (they won't be identical). Also, the "Linkwitz transform" that extends the bass down to maybe 20HZ (?) is a little confusing. If I understand his graphs and notes, it creates a shelf response. I'd much prefer an active EQ that would ramp up below 100HZ and peak at 25-30HZ, with a fast rolloff (2 pole) below that, so any energy below about 15HZ is significantly attenuated. You don't want to use up Xmax on the woofer with something you can't hear or don't care about. There can be noise or high frequency envelop energy down there that does more harm than good.
Many people are recommending the Mini DSP thing, which is apparently fairly expensive. I don't know much about it personally. Apparently you program it with a computer, and then hopefully it runs on it's own, so you don't need to have another computer in your system full time.
I do know that certain thru hole analog capacitors and some pots are getting harder to get. Especially 1 % polypropylene caps that are needed for 4th order filter accuracy. I think that's the reason Linkwitz is now using the MiniDSP for some of his newer designs. I laid out and had made some circuit boards for a great tone control system I designed and was considering marketing (4 section Baxandall), and then Panasonic quit making some of the caps I needed (equivalents from another brand were physically larger than would fit), and then the Vishay pots I laid out the board for became much more expensive and no longer available in small quantities... So now my boards are obsolete. So watch out for that.
Many people are recommending the Mini DSP thing, which is apparently fairly expensive. I don't know much about it personally. Apparently you program it with a computer, and then hopefully it runs on it's own, so you don't need to have another computer in your system full time.
I do know that certain thru hole analog capacitors and some pots are getting harder to get. Especially 1 % polypropylene caps that are needed for 4th order filter accuracy. I think that's the reason Linkwitz is now using the MiniDSP for some of his newer designs. I laid out and had made some circuit boards for a great tone control system I designed and was considering marketing (4 section Baxandall), and then Panasonic quit making some of the caps I needed (equivalents from another brand were physically larger than would fit), and then the Vishay pots I laid out the board for became much more expensive and no longer available in small quantities... So now my boards are obsolete. So watch out for that.
valtra103, your biggest challenge is equalization and matching of each driver's response to make your multiway dipoles working! That is a battle even with minidsp, not just a struggle - believe me! You can't just copy LS's or JK's transfer functions. You must have a large supply of different components to try in an analog circuit. Total cost of components could be reasonable, but brainwork and installation techique is not!
If Minidsp 4x10HD is too expensive you can use two 2x4 modules. Then you will have less options of input signal and line level. Perhaps you can do with just a 2x8 board if you are capable of designing and installing other components of the system.
How will you feed the signal the system? Analog line level or digital stream? How many sources? How is input switching and volume control arranged?
I use a regular AV-receiver as preamplifier and source select. Stereo line signal L/R is directed to 4x10HD's analog input. Minidsp and amplifiers of main speakers are powered on 24/7. This way I (and even my wife) can use the system just like any AV-receiver in 2ch or 5ch mode with any source (FM-radio,CD, PC, TV, BD). All multichannel modes, tone controls etc. work. I know that this is not ideal, but just practical and with super sound quality and no extra hum or clicks!
If you are the only one who uses the system, you have more freedom.
My friend Legis had a system done with a Minidsp NanoDIGI board and several cheap 2ch DACs. His only source was his laptop playing mostly Spotify and Foobar.
(By the way Valtra factory is just 40km from my home!)
If Minidsp 4x10HD is too expensive you can use two 2x4 modules. Then you will have less options of input signal and line level. Perhaps you can do with just a 2x8 board if you are capable of designing and installing other components of the system.
How will you feed the signal the system? Analog line level or digital stream? How many sources? How is input switching and volume control arranged?
I use a regular AV-receiver as preamplifier and source select. Stereo line signal L/R is directed to 4x10HD's analog input. Minidsp and amplifiers of main speakers are powered on 24/7. This way I (and even my wife) can use the system just like any AV-receiver in 2ch or 5ch mode with any source (FM-radio,CD, PC, TV, BD). All multichannel modes, tone controls etc. work. I know that this is not ideal, but just practical and with super sound quality and no extra hum or clicks!
If you are the only one who uses the system, you have more freedom.
My friend Legis had a system done with a Minidsp NanoDIGI board and several cheap 2ch DACs. His only source was his laptop playing mostly Spotify and Foobar.
(By the way Valtra factory is just 40km from my home!)
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The four "filters" can be placed inside their respective power amplifier.
one with just the High pass & Eq
one with low pass and Eq.
two with band pass and Eq.
Then include a separate set of input RCAs that allow you to bypass for normal use/testing.
This breaks down each filter to a much more managable single small PCB.
Unfortunately this would break the cross links from Upper Mid to Mid to Bass provided to maintain the phase/
Q
do the phase links make a listening difference to the way the multiway crossover performs?
one with just the High pass & Eq
one with low pass and Eq.
two with band pass and Eq.
Then include a separate set of input RCAs that allow you to bypass for normal use/testing.
This breaks down each filter to a much more managable single small PCB.
Unfortunately this would break the cross links from Upper Mid to Mid to Bass provided to maintain the phase/
Q
do the phase links make a listening difference to the way the multiway crossover performs?
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Oh, thats quite cheap. If I had spare PC , that doesn't sound like jet turbine , I would try it. Thanks
Bob Richards said:
Linkwitz transform block includes input cap. And whole filter will have input cap. So it will be rolled of from 15-20hz.
I already have sources for parts. Will use wima caps, they are very nicely matched, when from single batch. And i can measure them too.
And pots won't be needed, i will just use header where i will be able to snap in another resistor. Thanks for concern.
But did S.L. go to digital only because of parts. I thought reason was greater flexibility with dsp
AndrewT said:
Big pcb is not problem, I actualy enjoy making something complex. I want a system with separate crossover / preamp box. And four amps.
And about that phase, I don't know for sure but I believe it would couse some dips / peaks. That should be measured to verify what happens.
I know that, I am reading about it almost every day. Problem was, that I was unable to find example for pcb like that. So i tried puting this diagram together, like i think it should go. Problem is, if this diagram is not correct, I can't go to next stage of selecting components.
For now I simply use my Galaxy S5 phone analog output. It can output digital through USB to, which enables use of external DAC.
Thats nice!
I really want to go analog with it will be like learning experience to. And I hate paying 30 percent import taxes arghh...
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I built a caps and inductors 5 way X/O a few years ago. Crossed at 90 / 330 / 1200 / 11000.
The inductors and caps are big and cost a lot at 90Hz!
I also needed Zobels...
I then went Diyaudio's own WAF Najda DSP. It's absolutely brilliant.
Not sure if its in your budget but the SQ, flexibility, future proofing for driver swapping and reliability are all second to none.
I've recommended it to several multi way users who are happily using it.
Proper time alignment of my system and manual measured room correction for my tapped horns and mid bass works like a dream. Unlike auto systems you can do it just the right amount / to your taste.
Good luck with your project.
I'll follow it to see how you get on.
The inductors and caps are big and cost a lot at 90Hz!
I also needed Zobels...
I then went Diyaudio's own WAF Najda DSP. It's absolutely brilliant.
Not sure if its in your budget but the SQ, flexibility, future proofing for driver swapping and reliability are all second to none.
I've recommended it to several multi way users who are happily using it.
Proper time alignment of my system and manual measured room correction for my tapped horns and mid bass works like a dream. Unlike auto systems you can do it just the right amount / to your taste.
Good luck with your project.
I'll follow it to see how you get on.
Thanks. I made some progress, It is almost complete single channel crossover. On top I will put copy & flip it to make second chanel on same board, this explains power line layout. Of course there will be loads of 0603 caps under apamps, and some electrolytics on main power rails.
An externally hosted image should be here but it was not working when we last tested it.
And to launch system I probably buy basic 7.1 USB sound card, which i plug to my laptop. Not very good, since laptop always travels with me, but good enough for setup. I might use Equalizer APO or something like that to get crossovers working. Then, when I get to nice setup i will copy it to my analog crossover. I hope there won't be some big limitions of analog. If theres no way, to make it work analog, i will find some old pc, to run it. But I really want analog processor. I just love how it works, how I can put fancy opamps in future and all that jazz
Not to mention instant ON of the system. Because i get anoyed if i have to wait more than 10 seconds for music to start (yeah I am realy impatient)About speakers:
Rockford Fosgate P1S4-10 10" Subwoofers in closed boxes, forming stands for dipoles.
Lower Mid : Scan Speak 22W8534
Upper Mid : maybe some Vifa fullrange.
High : front - Dayton ND16FA, rear - dayton PT Mini
I have tweeters already, so i will make use of them
And PT mini is realy easy to put in back - no hole requirement.
Probably it is easy to guess from price of drivers for this project, that 275eur for dsp is too expensive for me. Although it is nice that it is in europe atleast, so probably about 300eur with shipping. Ahh i really would like to have it of course.
For now I need to buy some drivers, make baffless, and make it work with cheap usb card. And rhen i will decide, if i want to go analog, or save up for DSP.
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You have also the good dsp from Hypex (not able of FIR and just 2 x 3 ways (but you can add a plate amp later with a single sub if the crossover is low enough (<80 hZ around !). Good because the ADC/DAC chips are better ! 275 euros without VAT ! Hypex Electronics BV - DLCP here you can assume that a good dac is also embeded !(surely better than the stock dac chip of the MiniDSP.
The good bet as said already is surely two Minidsp 2x4 ! miniDSP Kits : MiniDSP 2x4 kit
But if you copy an already made design (Troels Gravsen, Zaph Audio, Jeff Bagby, etc) : active will ever cost you less than many coils and caps if you have to redesign a passive crossover ! But at least if you copy the XO of the OB you talked about !
You could need a mic for measurement to set up the crossovers: it's my understanding Minidsp have one (for extra) which is good enough and with a factory calibration as I learned few days ago ! You don't need extra Phantom powersupply with it ! Acoustic Measurement Tools
There are also cheaper mic solution with a smartphone
here some recent (few days ago) discussions about mic by some experienced diyers : http://www.diyaudio.com/forums/full...2in-4in-drivers-round-4-a-73.html#post4473714 in the full section.
You could also consider a 3 ways instead a 4 ways (I have myself hesitation with the same question !), but of course if you stay on the OB designs of your topic post 1 !
regards
Consider
Notice I didn't heard any of them !
Pc + DDX amps could be also a solution for a trade off cost VS versatility ?!
The good bet as said already is surely two Minidsp 2x4 ! miniDSP Kits : MiniDSP 2x4 kit
But if you copy an already made design (Troels Gravsen, Zaph Audio, Jeff Bagby, etc) : active will ever cost you less than many coils and caps if you have to redesign a passive crossover ! But at least if you copy the XO of the OB you talked about !
You could need a mic for measurement to set up the crossovers: it's my understanding Minidsp have one (for extra) which is good enough and with a factory calibration as I learned few days ago ! You don't need extra Phantom powersupply with it ! Acoustic Measurement Tools
There are also cheaper mic solution with a smartphone
here some recent (few days ago) discussions about mic by some experienced diyers : http://www.diyaudio.com/forums/full...2in-4in-drivers-round-4-a-73.html#post4473714 in the full section.
You could also consider a 3 ways instead a 4 ways (I have myself hesitation with the same question !), but of course if you stay on the OB designs of your topic post 1 !
regards
Consider
Notice I didn't heard any of them !
Pc + DDX amps could be also a solution for a trade off cost VS versatility ?!
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Thanks.
I build my amps myself. And i have homemade measurement mic, that is quite good for ~30hz-15khz.
like I said i will try to launch system with ~20eur usb sound card.
later i will decide if I want to save up for some DSP (not from US, because i hate paying import taxes, they feel for me like paying for air
)Or just finish my analog crossover.
Oh, and i never wanted to use passive crossover. Not sure why few people already mentioned them.
And I technically could go 3 way, by not using tweeter, since upper mid will be 3.5"-4" fullrange anyway. But I have tweeters already, so no big deal to try to make it 4way. Just one more amplifier.
Holy cow! I would never consider making even two way passive crossover.
Wondering, why you needed 5way?
From freqs i guess:
subwoofer / 12-15" midbass / 4-6" midrange (fullrange) / super tweeter?
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