We all know this phenomenon exists, but this is the first time I can recall seeing it demonstrated in such a practical fashion. This makes a good argument for dividing a 3-way crossover into two separate boards in a higher powered enclosure if a large air inductor is used in the LF section. Most helpful. Thank you for taking the time to do this!
Great experiment! My beloved Tannoy Buckingham Monitors has three separate crossovers, thats original design. The weight of crossovers for one speaker is 13 kg. The Tannoy engineers didnt mess around back in the late 70-ties. You can single-wire, bi-wire and bi-amp them. Its a really large air coil for the bass elements and several alrge aircoils as well. Im about to build really good crossovers for my jbl 4350 speakers. I knew about the coil interference and now Im thinking of making two separate crossovers. These speakers are originally bi-amped. Therefore the largest coil is for the 12 inch midbass element, 2.4 mH. The plan was to make them on a large pcb. But maybe its easier and better to separate the mid bass corssover from the other two… I will certainly test out but there is alot of coils in this filter design…
There is a lot to learn about the video you made! The audio community will certainly talk about this in the months to come, at least I hope it will!@@Gabster1
Gaby, I used a music signal directly from an amplifier output. Same effect. Of note, at one point i placed the powered coil on top of the amplifier steel top cover. The cover produced an audio (music) signal. I enjoy you sharing your knowledge and experience experience.
Consider the intensity of the fields when 200W are going through the woofer inductor with real music. You could get out a real power amp, and load the inductor say with a 4 ohm (very) high power resistor. Then take the tweeter (shunt) inductor and load it with a typical 6-8 ohms and measure across it. Best solution is to have the woofer XO on another board placed a foot or more away from the others. The rest of the inductors should go in the corners, obviously to maximize the distance. VanAlstyne found significant crosstalk from the woofer inductor to the midrange in his B&W 801 speakers.
Totally agree best is to separate the 3 from each other if possible 3 separate boards or use distance on the same board. The woofer inductor is on the opposite side in my crossover about 10 inch apart. if you have not seen my previous videos where I demonstrate the crosstalk they are worth watching.
This gives me an idea of just using the entire inside of the speaker box as the base to mount the crossover parts and space hem really far apart. the wood board you used is too small. your inductos are uncommonly large, so that board is considerably too small for anything except this demonstration. 12 inches, that's really useful info
Wow, now I have even more audiophile nervosa haha. When using metal screws to secure the crossover board to the cabinet wall, should I avoid having the screw near certain components?
Hi Paul I am not big on simulators They may be good for a starting point but often reality is a bit different. I believe in keeping it simple less components is better. I made 2 videos on designing a crossover they may help you a bit. ua-cam.com/video/DMU3cxsseqE/v-deo.html
@@Gabster1 thanks for the reply, I watched the video before. I have no problem building crossovers, I just have problems designing them. I started with simulator and then actual measurements. The problem is without the acoustics silent room, I used the pluses method, not very accurate, especially the bass. Another problem is it's hard to buy a lot of crossover parts to try different combinations of them.
@@paulsochinfan A trick for not buying too many parts for inductors buy one cheap 4 or 5 mH and if you need less simply scratch part of the winding and solder to it you can measure the inductance first using a Dats V2 from parts express you can have multiple taps at various Values For Capacitors if say you want around 10 Uf get some cheap 6.8 then 4, 2 and 1 now you have 6.8 to 13.8 resistors same as Caps idea once you know what you need pay the big bucks for the good ones.
Interesting. What would happen if the biggest inductor were actually 2 smaller ones and you turned the 2. one 180 degrees in the same plane while running sound trough it? Would there be some kind of filter effect?
How will interference sound? With 2 inductors placed like a "T" with a 1.5 inch or so gap, how bad could it be if an oscilloscope wasn't used and they were interfering with each other?
@@ericschulze5641 not sure if I understand the question The big one is 10 gauge so bigger the gauge size is in reverse 10 is bigger then 12 or 14 Hope that helps
@@Gabster1 I know quite well about wire gages. My question was pertaining to the large red coil if I recall you said it was 4.5 mh or something close to that .anyway if I bought the same value coil from parts express in 14 ga. It would be about as big around as an old time silver dollar I just got an air cores of 2.25 mh & .27 mh and thier miniature compared to that. Why is that
@@ericschulze5641 ah I see yes they grow exponentially I was shocked when I got it 10 gauge is very thick wire a 12 would have been enough and would have been half the size of a inductor a 14 gauge about a 1/4 of the size approximately When you have thick wires you are forced to use a larger circle and that also adds to the size. They do grow very fast as the inductance go higher but if you need the dc resistance very low and don’t want to use iron cores be prepared to have a huge very expensive coil. that is why a lot of manufacturers use iron cores to save $ These are 3.7 mh from Solen.ca There is formula on the net about winding inductors it is very complex
@@impuls60copper does reflect magnetic fields. Dropping your magnet through a copper pipe and it slows it’s fall dramatically. There are videos showing this on UA-cam
You can but you will need more space specially the midrange enclosure and the tweeter has no enclosure in my case Also prefer not to subject the lo crossover to the extreme vibrations.
We all know this phenomenon exists, but this is the first time I can recall seeing it demonstrated in such a practical fashion. This makes a good argument for dividing a 3-way crossover into two separate boards in a higher powered enclosure if a large air inductor is used in the LF section. Most helpful. Thank you for taking the time to do this!
Great experiment!
My beloved Tannoy Buckingham Monitors has three separate crossovers, thats original design. The weight of crossovers for one speaker is 13 kg. The Tannoy engineers didnt mess around back in the late 70-ties. You can single-wire, bi-wire and bi-amp them. Its a really large air coil for the bass elements and several alrge aircoils as well.
Im about to build really good crossovers for my jbl 4350 speakers. I knew about the coil interference and now Im thinking of making two separate crossovers. These speakers are originally bi-amped. Therefore the largest coil is for the 12 inch midbass element, 2.4 mH. The plan was to make them on a large pcb. But maybe its easier and better to separate the mid bass corssover from the other two…
I will certainly test out but there is alot of coils in this filter design…
brilliant demo! nice coils you got there
Solen.ca
I was really surprised to see that even capacitors were affected by the magnetic field of an inductor! Great video! Thaks a lot!
Thank you I was surprised as well same with resistors.
There is a lot to learn about the video you made! The audio community will certainly talk about this in the months to come, at least I hope it will!@@Gabster1
Gaby, I used a music signal directly from an amplifier output. Same effect. Of note, at one point i placed the powered coil on top of the amplifier steel top cover. The cover produced an audio (music) signal. I enjoy you sharing your knowledge and experience experience.
Thank you it is cool to hear and see the interference
Very interesting video. I didn't know it made that much of a difference. Thank you.
Excellent presentation sir .
Great Demonstration, thanks for this.
Consider the intensity of the fields when 200W are going through the woofer inductor with real music.
You could get out a real power amp, and load the inductor say with a 4 ohm (very) high power resistor.
Then take the tweeter (shunt) inductor and load it with a typical 6-8 ohms and measure across it.
Best solution is to have the woofer XO on another board placed a foot or more away from the others.
The rest of the inductors should go in the corners, obviously to maximize the distance.
VanAlstyne found significant crosstalk from the woofer inductor to the midrange in his B&W 801 speakers.
Totally agree best is to separate the 3 from each other if possible 3 separate boards or use distance on the same board. The woofer inductor is on the opposite side in my crossover about 10 inch apart. if you have not seen my previous videos where I demonstrate the crosstalk they are worth watching.
Fantastic demosntration of this issue! thank you
Brilliant info, thank you for this video
This gives me an idea of just using the entire inside of the speaker box as the base to mount the crossover parts and space hem really far apart. the wood board you used is too small. your inductos are uncommonly large, so that board is considerably too small for anything except this demonstration. 12 inches, that's really useful info
Wow, now I have even more audiophile nervosa haha.
When using metal screws to secure the crossover board to the cabinet wall, should I avoid having the screw near certain components?
I would not worry about that
Make sure there are no vibrations to the crossover so well secured and components glued I prefer outside not attached
Good video bro, god bless you
That is a huge inductor.
Great tutorial!
Can crossover components like the inductor coils be 'shielded', to block these interference.?
Shielding will affect the inductance of the inductors proper positioning is a far more effective way
Appreciate if you can share how to design the crossover starting from the simulator to measurement and fine tune
Hi Paul I am not big on simulators They may be good for a starting point but often reality is a bit different. I believe in keeping it simple less components is better. I made 2 videos on designing a crossover they may help you a bit.
ua-cam.com/video/DMU3cxsseqE/v-deo.html
@@Gabster1 thanks for the reply, I watched the video before. I have no problem building crossovers, I just have problems designing them. I started with simulator and then actual measurements. The problem is without the acoustics silent room, I used the pluses method, not very accurate, especially the bass. Another problem is it's hard to buy a lot of crossover parts to try different combinations of them.
@@paulsochinfan A trick for not buying too many parts
for inductors buy one cheap 4 or 5 mH and if you need less simply scratch part of the winding and solder to it you can measure the inductance first using a Dats V2 from parts express you can have multiple taps at various Values
For Capacitors if say you want around 10 Uf
get some cheap 6.8 then 4, 2 and 1 now you have 6.8 to 13.8
resistors same as Caps idea
once you know what you need pay the big bucks for the good ones.
Interesting. What would happen if the biggest inductor were actually 2 smaller ones and you turned the 2. one 180 degrees in the same plane while running sound trough it? Would there be some kind of filter effect?
How will interference sound? With 2 inductors placed like a "T" with a 1.5 inch or so gap, how bad could it be if an oscilloscope wasn't used and they were interfering with each other?
With a T position 1.5 inch apart you should be ok
what is the gauge and value of that large air core inductor?
3.7 mh 10 gauge a bit of a over kill 12 or 14 gauge would have been fine for my project. but it has a very low dc resistance that I wanted.
Why is an air core of the same value of 14 ga. wire From any supplier so much smaller ? please respond this has been baffling me for years
@@ericschulze5641 not sure if I understand the question
The big one is 10 gauge so bigger the gauge size is in reverse 10 is bigger then 12 or 14
Hope that helps
@@Gabster1 I know quite well about wire gages. My question was pertaining to the large red coil if I recall you said it was 4.5 mh or something close to that .anyway if I bought the same value coil from parts express in 14 ga. It would be about as big around as an old time silver dollar I just got an air cores of 2.25 mh & .27 mh and thier miniature compared to that. Why is that
@@ericschulze5641 ah I see yes they grow exponentially I was shocked when I got it 10 gauge is very thick wire a 12 would have been enough and would have been half the size of a inductor a 14 gauge about a 1/4 of the size approximately
When you have thick wires you are forced to use a larger circle and that also adds to the size.
They do grow very fast as the inductance go higher but if you need the dc resistance very low and don’t want to use iron cores be prepared to have a huge very expensive coil.
that is why a lot of manufacturers use iron cores to save $
These are 3.7 mh from Solen.ca
There is formula on the net about winding inductors it is very complex
You could shield them with copper tape and Earth the whole lot out
Thanks for the Tip will try that may come handy specially when space is critical
@@Gabster1 be interesting to see what results you get on the scope how low the noise would be even close up! let me know if you do it
I think that trick works best with voltage fields and not so much magnetic fields.
@@impuls60copper does reflect magnetic fields. Dropping your magnet through a copper pipe and it slows it’s fall dramatically. There are videos showing this on UA-cam
if anyone can hear this interference on their system they have ears above human capacity. I am an audiophile myself but where do you stop??
You stop at the High Fi store😂
What about three separate crossovers separated
If you have the space inside or don’t mind 3 separate boards outside that would be the best
Or even a larger single board would work as well
Pretty big parts.
No cheese here
How about mounting the crossover sections (lo, mid, hi) in their respective parts of the cabinet to achieve greater distances?
You can but you will need more space specially the midrange enclosure and the tweeter has no enclosure in my case
Also prefer not to subject the lo crossover to the extreme vibrations.
@@Gabster1 cheers