Hello,
I am new here, please be easy on me 🙂
I have to admit I am a complete newbie to making my own electronics. I however have some basic soldering knowledge, made some of my own cables and similar easy stuff like that; I am also a woodworker and work with metal...
Anyway, I have a pair of T+A A3D speakers, which are digital-active, and their active section is beyond reasonable repair. I have decided to convert them to passive speakers, which was once also available, as can be seen in this brochure:
http://tebert.com/dump/diyaudio/TA-P3_Speakers_LimitedEdition.pdf
T+A was kind enough to send me the schematics for building the necessary crossover. Here it is:
I also have a PDF version, if that's easier to read:
http://tebert.com/dump/diyaudio/Schaltplan_P3.pdf
OK, and now I am completely clue-less as to what parts I need, how to arrange them etc. I basically need a complete-beginners course, and I hope some of you could provide me with some good links to start off.
Google is my friend, but I believe people here can be better friends--saving me some time to try to hunt down some well explaining tutorials for the beginnner.
After looking at a few online tutorials I noticed that most of them have only one "-" and one "+" connection, while my T+A schematics have two separate ones? This is what confuses me the most at the moment... while I try to decipher the other symbols.
There are two woofers, a midrange and a tweeter, so shouldn't there only be one +- connection to the crossover?
Again, I am completely clueless at the moment, and just some good pointers to tutorials would greatly be appreciated.
Thank you,
DrTebi
I am new here, please be easy on me 🙂
I have to admit I am a complete newbie to making my own electronics. I however have some basic soldering knowledge, made some of my own cables and similar easy stuff like that; I am also a woodworker and work with metal...
Anyway, I have a pair of T+A A3D speakers, which are digital-active, and their active section is beyond reasonable repair. I have decided to convert them to passive speakers, which was once also available, as can be seen in this brochure:
http://tebert.com/dump/diyaudio/TA-P3_Speakers_LimitedEdition.pdf
T+A was kind enough to send me the schematics for building the necessary crossover. Here it is:
I also have a PDF version, if that's easier to read:
http://tebert.com/dump/diyaudio/Schaltplan_P3.pdf
OK, and now I am completely clue-less as to what parts I need, how to arrange them etc. I basically need a complete-beginners course, and I hope some of you could provide me with some good links to start off.
Google is my friend, but I believe people here can be better friends--saving me some time to try to hunt down some well explaining tutorials for the beginnner.
After looking at a few online tutorials I noticed that most of them have only one "-" and one "+" connection, while my T+A schematics have two separate ones? This is what confuses me the most at the moment... while I try to decipher the other symbols.
There are two woofers, a midrange and a tweeter, so shouldn't there only be one +- connection to the crossover?
Again, I am completely clueless at the moment, and just some good pointers to tutorials would greatly be appreciated.
Thank you,
DrTebi
The First thing I would do is assign a number to each node.
The schematic basically is a graphical way to tell what components are tied together.
There is only one + and one -. Simply consider them one node.
For example, the schematic for the midrange shows the 82 uF cap, the 1.8 mH coil and the 10 uF cap (With the wrong Symbol) are connected.
Hopefully, someone will have the link to a basics tutorial.
Its not rocket science.
Hang in there and you will get it.
Doug
The schematic basically is a graphical way to tell what components are tied together.
There is only one + and one -. Simply consider them one node.
For example, the schematic for the midrange shows the 82 uF cap, the 1.8 mH coil and the 10 uF cap (With the wrong Symbol) are connected.
Hopefully, someone will have the link to a basics tutorial.
Its not rocket science.
Hang in there and you will get it.
Doug
You have to make a complete list to order.
Various other list of materials (like solder for electronics).
List of components (a pair) needed for the crossover:
Inductors
L1 = 5.6 mH
L2 = 5.8 mH
L3 = 1.8 mH (mid)
L4 = 2.8 mH (mid)
L5 = 0.25 mH (tweeter)
Capacitors
C1 = 150 uF (35V/min)
C2 = 82 uF (32V/min) (mid)
C3 = 10 uF (MKT) (mid)
C4 = 12 uF (MKP) (tweeter)
C5 = 10 uF (MKP) (tweeter)
Resistors
R1 = 3R9, 10W n.i. (mid)
R2 = 3R9, 10W n.i. (tweeter)
R3 = 10R, 5W n.i. (tweeter)
Some basic links:
PE 101
NODAL ANALYSIS 101
Parts Express - DIY Speaker Crossover Assemb VIDEO 101
A complete LIST OF MATERIALS example by Troels for his speakers for the complete kit.
Crossovers 101
How to Rebuild Speaker Crossovers 101
Various other list of materials (like solder for electronics).
List of components (a pair) needed for the crossover:
Inductors
L1 = 5.6 mH
L2 = 5.8 mH
L3 = 1.8 mH (mid)
L4 = 2.8 mH (mid)
L5 = 0.25 mH (tweeter)
Capacitors
C1 = 150 uF (35V/min)
C2 = 82 uF (32V/min) (mid)
C3 = 10 uF (MKT) (mid)
C4 = 12 uF (MKP) (tweeter)
C5 = 10 uF (MKP) (tweeter)
Resistors
R1 = 3R9, 10W n.i. (mid)
R2 = 3R9, 10W n.i. (tweeter)
R3 = 10R, 5W n.i. (tweeter)
Some basic links:
PE 101
NODAL ANALYSIS 101
Parts Express - DIY Speaker Crossover Assemb VIDEO 101
A complete LIST OF MATERIALS example by Troels for his speakers for the complete kit.
Crossovers 101
How to Rebuild Speaker Crossovers 101
Thank you so much, that really helped me a lot! At least now I know what I will need to get.
I also went to the library today and got a few books... there was nothing specific on crossovers, but a couple of DIY loudspeaker books and I also got a "basic electronics" book.
A question that comes to mind which may not be in the books:
When I start shopping for these parts, how would I be able to tell whether e.g. one capacitor is better than another? I am sure there will be options...
Thanks again,
DrTebi
Passive is better in this case, that it was already sorted out (crossover layout). Active would need reverse engineering for different from original amp sections and attenuation slopes.
A couple of other pointers if you can't find the exact values:
Capacitors in parallel add their values.
Resistors in series add their values.
Inductors are more troublesome. You should try to get very close values.
For your purposes, PE's npe caps should suit fine: Non-polarized Electrolytic Capacitors in the Speaker Components Department at Parts Express | 293, although you can go more expensive than that if you want to.
For the larger value inductors, you may want to go with iron core. Air core for the smaller ones will be good.
Also, all inductors also have resistance but unfortunately your schematic isn't showing these. You should probably try to keep these as low as your budget will allow, ie, .2 or .3 or .4 ohms if you can.
Capacitors in parallel add their values.
Resistors in series add their values.
Inductors are more troublesome. You should try to get very close values.
For your purposes, PE's npe caps should suit fine: Non-polarized Electrolytic Capacitors in the Speaker Components Department at Parts Express | 293, although you can go more expensive than that if you want to.
For the larger value inductors, you may want to go with iron core. Air core for the smaller ones will be good.
Also, all inductors also have resistance but unfortunately your schematic isn't showing these. You should probably try to keep these as low as your budget will allow, ie, .2 or .3 or .4 ohms if you can.
Thank you... slowly but certainly I am understanding this a bit better.
I still have a couple of things I am uncertain about--what is the difference between a lower priced and a higher priced capacitor/resistor? Will it have a great impact on sound quality?
Also, I wonder why the T+A layout I posted above does have two times a + and - connection. Should these actually all go to one + and - terminal in the final install? Or are there supposed to be two binding posts that are bridged or something like that? That's what confuses me the most, as all crossover examples/tutorials I have seen only have one + and - connection.
I still have a couple of things I am uncertain about--what is the difference between a lower priced and a higher priced capacitor/resistor? Will it have a great impact on sound quality?
Also, I wonder why the T+A layout I posted above does have two times a + and - connection. Should these actually all go to one + and - terminal in the final install? Or are there supposed to be two binding posts that are bridged or something like that? That's what confuses me the most, as all crossover examples/tutorials I have seen only have one + and - connection.
Well there are pages and pages of debates written as to the sonic merits and differences of different capacitors. As a general rule, if you want to spend more money on better caps, do it on those that are in series for the tweeter and mid. Don't worry about the parallel caps. So, from the list in post #3, those will be C2, C3 and C4. But cap costs should be kept relative to the costs of the drivers. No sense spending big money on components if the drivers only costs a few bucks.
Dayton or Solen caps listed here should be fine I think for those series caps if you want to go that way. Metalized Polypropylene Capacitors in the Speaker Components Department at Parts Express | 294
For resistors, the Daytons here should again be fine. Audio Grade / Non-inductive Resistors in the Speaker Components Department at Parts Express | 301
I find the catalog pages helpful when I'm selecting inductors.
For air core - http://www.parts-express.com/catalog/pdf/2013/Parts-Express-2013-Catalog-Pg-162.pdf
For iron core - http://www.parts-express.com/catalog/pdf/2013/Parts-Express-2013-Catalog-Pg-164.pdf
For these, I think you're looking for the lowest dc resistance (dcr) that you can afford. These things can get kind of expensive.
As for the wiring, don't worry that the diagram separates the 2 xo's. Simply connect both positive ends to the positive terminal and both negatives to the negative terminal. Or to a common pos and neg on the xo board which can be easier.
Dayton or Solen caps listed here should be fine I think for those series caps if you want to go that way. Metalized Polypropylene Capacitors in the Speaker Components Department at Parts Express | 294
For resistors, the Daytons here should again be fine. Audio Grade / Non-inductive Resistors in the Speaker Components Department at Parts Express | 301
I find the catalog pages helpful when I'm selecting inductors.
For air core - http://www.parts-express.com/catalog/pdf/2013/Parts-Express-2013-Catalog-Pg-162.pdf
For iron core - http://www.parts-express.com/catalog/pdf/2013/Parts-Express-2013-Catalog-Pg-164.pdf
For these, I think you're looking for the lowest dc resistance (dcr) that you can afford. These things can get kind of expensive.
As for the wiring, don't worry that the diagram separates the 2 xo's. Simply connect both positive ends to the positive terminal and both negatives to the negative terminal. Or to a common pos and neg on the xo board which can be easier.
Thanks again, I am now putting my order together.
A 5.8mH inductor seems to be rare, would I still play safe by using a 5.6mH one instead?
It was also mentioned in this thread that capacitors in parallel add their values and resistors in series do as well--is that relevant for my order? E.g. do I need to re-calculate the uF values? Or... does this mean if I cannot find a certain value, I can split it into two with half the value?
Regarding the Resistors: I see
3.9 R 10W (2x)
10R 5W (1x)
So are these 3.9 Ohm, 10 Watts and 10 Ohm 5 Watt resistors? I cannot find the exact values... should I try to find one that is as close as possible in Ohm, or/and Watts? Or rather use several in series to get the exact values?
A 5.8mH inductor seems to be rare, would I still play safe by using a 5.6mH one instead?
It was also mentioned in this thread that capacitors in parallel add their values and resistors in series do as well--is that relevant for my order? E.g. do I need to re-calculate the uF values? Or... does this mean if I cannot find a certain value, I can split it into two with half the value?
Regarding the Resistors: I see
3.9 R 10W (2x)
10R 5W (1x)
So are these 3.9 Ohm, 10 Watts and 10 Ohm 5 Watt resistors? I cannot find the exact values... should I try to find one that is as close as possible in Ohm, or/and Watts? Or rather use several in series to get the exact values?
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You always have a little bit of wiggle room concerning xo values.
5.6mH will be fine.
For resistors, try these:
Dayton Audio DNR-4.0 4 Ohm 10W Precision Audio Grade Resisto 004-4
Dayton Audio DNR-10 10 Ohm 10W Precision Audio Grade Resisto 004-10
Here 4ohm is close enough and the wattage rating is the minimum it can handle so 10W instead of 5W is also perfectly fine.
If you can't find the exact cap values, only then start looking for other values that will add up to about what you need.
Test your xo before soldering everything together once you get all your parts. Treat your leads gently though, I'v heard of some of them breaking especially the Dayton resistors. Maybe post a picture of your final layout before soldering too so we can make sure everything looks ok.
Cheers
5.6mH will be fine.
For resistors, try these:
Dayton Audio DNR-4.0 4 Ohm 10W Precision Audio Grade Resisto 004-4
Dayton Audio DNR-10 10 Ohm 10W Precision Audio Grade Resisto 004-10
Here 4ohm is close enough and the wattage rating is the minimum it can handle so 10W instead of 5W is also perfectly fine.
If you can't find the exact cap values, only then start looking for other values that will add up to about what you need.
Test your xo before soldering everything together once you get all your parts. Treat your leads gently though, I'v heard of some of them breaking especially the Dayton resistors. Maybe post a picture of your final layout before soldering too so we can make sure everything looks ok.
Cheers
OK, I have now put together the following parts at parts-express:
I am not trying to save as much money as possible... hence some of the parts are chose are, as far as I know, of better quality and more expensive. Whether I have made the right choices or not, I don't know... it would be nice if someone could judge my shopping list 🙂
I also noticed that ERSE sells parts direct, and some are cheaper there than at parts-express. Would it be worth it swapping some of the parts here with some from ERSE?
By the way, since these speakers were active ones before, I have plenty of space in the bottom of the speaker cabinet for a crossover, I could make it about 8x9 inches in size. I have seen XOs where parts are just glued onto a wooden board and then soldered together, others with Tufnol boards, boards with holes, and of course PCB boards. I actually do have the necessary chemicals and tools for making a PCB board (I used it for metal arts), but I wonder if it's worth the trouble.
Thanks for all your help so far, I really appreciate it.
I am not trying to save as much money as possible... hence some of the parts are chose are, as far as I know, of better quality and more expensive. Whether I have made the right choices or not, I don't know... it would be nice if someone could judge my shopping list 🙂
I also noticed that ERSE sells parts direct, and some are cheaper there than at parts-express. Would it be worth it swapping some of the parts here with some from ERSE?
By the way, since these speakers were active ones before, I have plenty of space in the bottom of the speaker cabinet for a crossover, I could make it about 8x9 inches in size. I have seen XOs where parts are just glued onto a wooden board and then soldered together, others with Tufnol boards, boards with holes, and of course PCB boards. I actually do have the necessary chemicals and tools for making a PCB board (I used it for metal arts), but I wonder if it's worth the trouble.
Thanks for all your help so far, I really appreciate it.
I think you need 4 x 10uF and 2 x 12uF, no the other way around. Otherwise, everything looks great. Good low dcr's on the inductors.
Sorry, I can't tell you whether Erse would be any better or the same as what you've chosen.
I don't think making a PCB board is worth the trouble. To space things out, some people will split the xo's onto multiple boards. People often use whatever wood is handy and then drill, glue and/or fasten with zip ties, solder and just use speaker wire for jumpers if they need to.
Internal net cabinet volume is important to a driver's response especially on the low end. Do what you can to keep it (them) the same as when it was active. Glad you mentioned that. I hadn't thought of it.
Sorry, I can't tell you whether Erse would be any better or the same as what you've chosen.
I don't think making a PCB board is worth the trouble. To space things out, some people will split the xo's onto multiple boards. People often use whatever wood is handy and then drill, glue and/or fasten with zip ties, solder and just use speaker wire for jumpers if they need to.
Internal net cabinet volume is important to a driver's response especially on the low end. Do what you can to keep it (them) the same as when it was active. Glad you mentioned that. I hadn't thought of it.
I've found Clarity SA and ESA caps excellent in my cross over designs.
The Madisound Speaker Store SA Caps
The Madisound Speaker Store ESA Caps
Inductors here: The Madisound Speaker Store
Parts Express is another potential source for XO parts, particularly the inductors.
Your proposed choices look fine..
The Madisound Speaker Store SA Caps
The Madisound Speaker Store ESA Caps
Inductors here: The Madisound Speaker Store
Parts Express is another potential source for XO parts, particularly the inductors.
Your proposed choices look fine..
Yes, that was actually an error in posting... got it correct in the shopping cart.
Well, it just happens that I stumbled upon some negative opinions regarding Jantzen components... thus I was wondering if I should maybe do it all with ERSE, which is said to be better quality--but I am no expert, just trusting in what I have read elsewhere... price would be about the same for everything.
That should not be a problem--the active unit was in its own space; the drivers themselves are all sealed within their own compartment. It's basically a tower with one large compartment for the drivers, and a smaller one on the bottom for the active unit (which will now be for the crossover).
I will check these out, too.
Thank you, that's quite an important detail I suppose!
Just waiting for the parts now... I replaced everything with ERSE parts though, I heard good things about them and thought it might be worth it--it was hardly more expensive.
I will post an update here once I have the layout figured out.
I still wonder if it wouldn't be easier to use a "prototype board" to put it all together.
I also wonder whether I should use terminals strips for the speaker outputs and main input, or some other type of connection.
Any pointers on these questions would be greatly appreciated.
I will post an update here once I have the layout figured out.
I still wonder if it wouldn't be easier to use a "prototype board" to put it all together.
I also wonder whether I should use terminals strips for the speaker outputs and main input, or some other type of connection.
Any pointers on these questions would be greatly appreciated.
Pictures might help. Neat, organized and secure is best. I like hot glue and zip ties. Notice the strategic inductor placement in the examples.
If by prototype board you mean a PCB board, that seems like unnecessary work to me but it will work and if it makes you happier...... Some of the components can get large and heavy so be sure to still secure them solidly, not simply relying on the soldered leads.
Many people use some kind of terminal strips, like in picture 4. Troels does exceptionally neat xo work at DIY Loudspeakers. Take a look through any of his projects to get some more ideas.
If by prototype board you mean a PCB board, that seems like unnecessary work to me but it will work and if it makes you happier...... Some of the components can get large and heavy so be sure to still secure them solidly, not simply relying on the soldered leads.
Many people use some kind of terminal strips, like in picture 4. Troels does exceptionally neat xo work at DIY Loudspeakers. Take a look through any of his projects to get some more ideas.
Attachments
I got the parts! They are huge, I wasn't expecting that...
Anyway, I spend a few hours looking at crossover layouts and put together my own layouts as best as I could. I used VUE, which is actually a free "mind-mapping" program, that worked quite well for this purpose.
Since the parts are rather big, I decided to divide the crossover into two sections, one for the Woofers (T) and one for the high- and mid-range drivers (H, M). I happen to have two mousepads that are just a little smaller than the space I have available in the cabinet's "hole" (where the active part used to be).
Attached are two images of each layout, one is the computer drawing, the other the actual unconnected parts. Note that I put the "final" negative connection in black, and the "final" positive connection in dashed red lines. I hope it's not too hard to read. I believe I have the positioning of the coils right.
So my plan now is to use two MDF boards and drill holes where I need them for either putting the ends of capacitor/inductor/resistor, or where to attach cable-ties for holding the parts down. Then attach everything, and solder the connections with something like 16 gauge insulated copper wire. Is that correct? Should I leave the ends of e.g. capacitors as long as possible, or cut them off to make things fit neatly?
Please let me know if I am doing anything wrong. I wasn't quite sure about the negative connections, but as far as I understand, they can all run together into the terminal as I have it drawn out.
Oh, and another thing: Isn't it important which side I connect of the capacitors/inductors/resistors? I thought at least for the capacitors it's important, but I cannot find an obvious indication as to where positive and negative is.
And here the original schematics again:
Anyway, I spend a few hours looking at crossover layouts and put together my own layouts as best as I could. I used VUE, which is actually a free "mind-mapping" program, that worked quite well for this purpose.
Since the parts are rather big, I decided to divide the crossover into two sections, one for the Woofers (T) and one for the high- and mid-range drivers (H, M). I happen to have two mousepads that are just a little smaller than the space I have available in the cabinet's "hole" (where the active part used to be).
Attached are two images of each layout, one is the computer drawing, the other the actual unconnected parts. Note that I put the "final" negative connection in black, and the "final" positive connection in dashed red lines. I hope it's not too hard to read. I believe I have the positioning of the coils right.
So my plan now is to use two MDF boards and drill holes where I need them for either putting the ends of capacitor/inductor/resistor, or where to attach cable-ties for holding the parts down. Then attach everything, and solder the connections with something like 16 gauge insulated copper wire. Is that correct? Should I leave the ends of e.g. capacitors as long as possible, or cut them off to make things fit neatly?
Please let me know if I am doing anything wrong. I wasn't quite sure about the negative connections, but as far as I understand, they can all run together into the terminal as I have it drawn out.
Oh, and another thing: Isn't it important which side I connect of the capacitors/inductors/resistors? I thought at least for the capacitors it's important, but I cannot find an obvious indication as to where positive and negative is.
And here the original schematics again:
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