Passive low pass RL filters
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- Опубликовано: 22 авг 2011
- An intro to passive low pass RL filters. An example of a 2kHz audio crossover circuit for a woofer is given, where the low frequencies are allowed to pass through and the high frequencies get filtered out.
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Straightforward with no filler, yet all the important ideas are taught. Great videos
@Afrotechmods I'll always like your vids before seeing them. So far you made only awesome stuff!
this is the best video that I saw this last year on youtube... I did look for hours and hours on internet searching for "how to make a audio filter" , you made my day :-)
Very simple but clear explanation with convincing example provided. Thank you.
Great video. I loved the practical example you gave us
Ive been looking forever for how to design crossovers and how they filter out the frequencies and ive finally found it
Sir ! you're the best teacher I have ever seen. I'm about to graduate in couple months, and all I did in school was dry and boring concepts and analyses. None of my professors would mention anything real life applications for Christ sake, they're so damn boring to listen to. You're the boss.
thanks - simple and to the point, you have the best tutorials
Great video. Very well put together and you made it very understandable. Thanks and keep them coming!
Just watched the new inductor videos.
You are the man.
Thank you.
These videos were very helpful. Please continue to make videos :)
Thank you so much. I have been struggling to find video that explains inductance clearly....
Great video and explanations... good moment for me to watch it and to learn the right thing.
Thanks from europe
Very nice presentation, thank you!
Thank you so much for these videos, so useful for someone new too electronics
My Speakers at times do sound harsh and I was thinking about replacing tweeters but your practical/theory has given me another idea.
It's been a while since I've been on the forums. I remember how much I wanted to be an electrical engineer just BECAUSE of how awesome your projects were.
On a side note, I was looking up overclocking a core 2 duo and came to your videos.
Fate, my friend.
did you become an electrical engineer ?
@@nopda4095 No.
You are a god among men. Thank you so much for these
Thank you for making such great videos.
Thank You! This was very interesting to listen to as I must produce some high pass and low pass filters at low cost for a project I'm doing for college. I may even post a video response if it goes good!
Very informative. Thank you for sharing your knowledge.
Nice vid yet again, looking forward to new ones :)
@Afrotechmods you get used to good videos, all videos that i saw on your channel ware good so if i see that you put something new i already know i will like it. And yes, by some linked videos its so interesting that i get soo deep in watching it that its possible to forget to klick like button before switching to new part, thats another reason to klick on begin from vid. Thanx for sharing your knowledge btw.
TBH I don't have any idea what he's saying but I'm still watching.
It's your voice!
Excellent and informative.keep it up!
So that's how filters makes sound on the synthesizers! They filter out higher frequency sounds. Cool!
Great job in your videos! Thank You!!!!!!!!!!! I have a Qualcomm interview this Monday and just touching up on everything =)
Did you get the job?
dude your awesome... love your stuff... u make it so fun and ez
thanks. is there a video about low pass LC filters?
Your way of explaining thinks is awesome. You should be professor in some university teaching electronics.
Very goods videos!! Like the you explain it. Keep on this way please. Thanks!
Thank you for your clear tutorials. Subscribed Now ! And marked your
Equipment Page as Favorites!
Cheers, Greg
@Afrotechmods We are a dedicated audience
Great video! Thanks alto for that!
What type of capacitor for a low pass filter to drive a sub? 4 ohm speaker?
Your voice is fabulous. How do make your voice so clear and bulky in your videos?... no surrounding noise. Do you use any kind of voice modulating software? If yes please tell me for my future videos.
Thanks, this really helped me get a better understanding
I'm trying to design a low pass filter for a speaker but I'm not sure if I understand the formula properly, what do I do with the numbers that are under the line? I think I have to multiply those, right? so trying that out with the filter example in this video 2 x pi x 2000 = 12566.3706. Then do I take the speaker impedance and divide it by the number I got? So 8/12566.3706? But I get 6.36620, so 6.36 henries? That cant be right.
8 divided by 12566 is not 6.36
Kind of a long time don't see you around! Hope all is good for you sir!
very great video!
i love your vids
I can't thank you enough!
Thanks for awesome videos but could you explain me why i found that filters in shops are made from Inductor and Capacitor there isn't any resistor like i've seen in your videos?
good work
when does inductive reactance come into play?
it was very usefull. .thank you so much. .
great video but what about the cap connected to te the tweeters!!! can anyone tell me the easy way thank you
@Afrotechmods haha, guilty as charged! Its because we know you won't disappoint us. :)
Really amazing
2000hz low feq? thats rlly low lol
anyway great video and i love all of your videos. keep up the good work !!
very good vids. thanks.
Nicely demonstrated. I am looking for LC low pass filter working principle. Do you have any video on that ?
Where did you learn that L is for Lenz? Do you have a source? I am doing research on Physics Symbols, thanks!
Im brand new into spekers and sound systems and I need some help because I am very confused. I want to have the same cutoff as you bit I have a 4 ohm driver what capiciter or capiciter would I need???
yo bro nice music!!!
This is very interesting.
@Dappy666 and on top of that the the eqation is L1+L2+L3+etc...=total inductence. for capacitors if you put them in seirs the capacinece is divided by the number of capacitors and thats how you got you number....
@afrotechmods shouldn't the filter go on the positive terminal of the speaker? Or does it not matter?
If inductors are more efficient than RC filters, in what application would it be better to use an RC filter?
I think that capacitors are cheaper then coils so cost savings is probably the main reason.
I had this same question until the tail end of this video. From what I understand, RC filters would generate more power loss proportional to higher currents. On the other hand, it's easier/cheaper to build a RC filter than RL. So the RC filter would probably come in handy before the amplifier stage in a circuit. I guess...
You can use RC filters for low frequencies such as audio frequency filtering. Inductors are more preferred to be used in high frequencies for their size varies inversely to their frequency, making them bulky and costly in low frequencies.
@Afrotechmods I wish you lived near me. We would have already solved the energy crisis by replicating Thomas Henry Moray's Radiant Energy Device. :)
I learnt more from a 3 minute video than a one semester university course. You saved my life.
well just before the end i found myself thinking whats the advantage of this compared to a rc filter and then he jumps straight in with the perfect explanation
can you swap inductor and resistor components to filter low frequency and let through high frequency at a cut off point? similiar to the way you demonstarted on RC low pass filter video.
So inductors are used for sound filtering, right? What else can inductors be used for?
and is it possible to use inductor on audio input? for example if i solder it before amplifier, and use speaker without inductor. If i'm correct i should get same low pass effect (with high power speakers you need big inductors)
Nice video!! But yeah might be difficult for beginners to understand it... Nevertheless it gave me better understanding of these filters in practical usage...
You kidding me?
I consider myself a "beginner" and this TOTALLY BLEW MY MIND!
HELL YEAH I'M SHOUTIN'
Way to go, Afrotechmods.
Way to freakin go!! Whoo!
(By the way. I am not a close personal friend of ATM, but he sure shakes up my marbles!)
ya... lots of questions....
Cool that you are dnb lover )))
it can output and higher freq sound, amplifiers already have lowpass filters installed in them. try conecting subwoofer to normal output, you will hear higher tones than on subs output
I'm assuming that instead of incorporating a potentiometer in the circuit as your variable resistor, you could just put in a variable inductor? Wouldn't that give you controll of the cutoff frequency "on the fly"? I'm making a bass cab for my amp... The goal is 1x15", 1x10", 3x8"... (i have a cab w 1x12", and 2 tweeters already...)
I have the wiring figured out so that there are two series-pair branches for the 4 smaller ones, and then those two branches and the 15" are run parallel... Overall load of 4ohms to match my other cab...
I'm basically assuming here that I can just throw the variable inductor on the + side of the 15", and mess with it... So I guess my follow-up question is about that little capacitor by the tweeter... What is the purpose? Is that to keep the inductor from affecting the freqs getting to the tweeter?
Sorry for the interrogation.... :)
I assemble AC converters for a living and we use massive coils in the larger units. Weighing like 200+ Kg at least. :) Then again I work with the smaller units, but they are quite hefty also.
If I connect a 4 ohm speaker to a 4 ohm high-pass crossover does my head unit read it as 2 ohms? Also how do I connect two 4 ohm speakers in series with one of them connected to the 4 ohm crossover bypass to get a total of 8 ohms?
Isn't the 'R' in the eqn really the impedance of the inductor itself and **not an external** resistor?
IE. given R=2*Pi*f*L (which of course is just a rearrangement of f = R/2*Pi*L from the video), the R is really impedance and is actually known as XL.
What am I missing here?
Count me in!
How will i design a LC pi and T low pass and high pass filter?
hey, i don't want's a crossover as such, as a variable LP, HP,BP filter ideally with resonance. plus 12,k is not LOW in audio terms. all filter variable between 20Hz and maybe 18kHz - protect the kids and dogs and all that. passive and running on 9v-12v would be ideal. can you adapt these circuits? or is there a better or alternative (and still cheap way of building this)?
while we're here square wave to PCM using a COMS inverter? or even cheap Sine wav circuit? All Audio and Sub Audio frequency well down to 20hz 8hz might be risking it! Basically RC variable Cut Off Point (with resonance idealy).
I get how the inductor stops high frequencies, but what’s the use of the resistor?
The inductor and the resistor _together_ attenuate frequencies. The formula was in the video: freq = R/2πL Hz. For a given inductor you can change the cutoff frequency by changing the resistance (using a different resistor or resistors)...and vice versa. With no resistor the cutoff is basically 0 (either almost all frequencies or almost no frequencies are attenuated depending on whether it's a high-pass or low-pass configuration).
got it
thanks
Just a question; there was a hidden circuit attached to your filter circuit made of a capacitor and a 'tweeter' at 1:34, what is it exactly for and why is it hidden like this? Note that I'm not an electrical engineering student yet :)
Good on ya mate! ... you have an awesome gift! Don't forget to keep them coming.
By the way ... what is the cat's name ... maybe Catastrophe ... poor bugger never gets any credit for his participation in your clips. :-)
okay smart ass:D if i get a 400W Subwoofer crossover and connect it to my 400w mid range amplifier will it filter the sound Wave+get rid of sound distractions. ?
i'm a complete noob but woudlnt this be an LR filter? I am trying to understand some graphs from my class and they show the frequency rising on an RL filter and decreasing on an LR filter
Which program do you use to make those bode plots?
+fede142857 LTspice
+1 for my knowledge. :D thanks
thank you
Is the '29% reduction' a marked percentage for gauging low pass filters? Why not more or less or is 29% the set standard?
Bandwidth, by definition, is set at a 3dB drop
@Afrotechmods For me it works with 1 inductor of 1000uH (200mA, 2.3Ohms) reduceing the sound volume but then I connect the second or third....nothing happends? I have a 4ohms 3w speaker conected to my pc jack+ usb 3.0 port. Should I try 2-3 inductors in series with more amps and less Ohms like (800mA; 844mΩ) ?
Alexandru Breazu maybe they are inducing each other, (dont trust me)
@L DB I'm a noob...I dont even know if you are joking :P i guess I need to make a 2nd order filter but I am building a micro subwoofer and I dont have the space.
so if I use 4 ohm speaker the cutoff point will change?
gracias des de mexico
⭐⭐⭐⭐⭐Great !!
nice
What song did you play with the woofer?
You had a resistor in your diagram, but not on your speaker. What's the point of the resistor?
Quick question:
Do high pass filters work off similar principles? And are they just as easy to make? I need one for VHF Ham radio transmissions from a crude transmitter I made.
Also, after taking a PSAT test today, I just wanted to make sure I'm not completely stupid. For the questions regarding frequency, the unit used was Cycles per second. I just put Hz. They are the same thing, right? 1 Cycle per second = 1 Hz?
1 Hz = 1 cps True
Well we are stupid for using imperial units, I'll give you that. Who thought it was a good idea to put 12 inches in a foot 3 feet in a yard and 5280 feet in a mile. Doesn't any sense.
" It's either mean or ignorant to replace a standard unit Hz with "Cycle per second" ... cps came first , Hz came later to honor the man , check the history ...
What ! The guy asked if cps & Hz were the same ... answer Yes ... end of story ....
I am making a project and I need a filter in my loudspreakers to cut the frequency between the two speakers. Unfortunately I can't find the exact name of the filter neither on Ebay. Can someone please guide me through this.
I think you are referring to a crossover.
@Dappy666
the capacitors are measured in FARAD not in henry
how many Watt can pass in a RC FILTER??? i'm building a 3w portable speaker. i choose RC Because it's hard to find a specific value for a inductor in my country???
jUst put bigger wattage resistor
@BASEM434 Yes i know but, the pic of these two inductor looks like cap's, so i mixed up with the a cap. Also i build a low pass filter with capacitor. So, sorry for my mistake ;-)
thx you
I think generally the speakers have an impedance of 8 ohms or you can find speakers of 4 ohms and 16 ohms. So I will say that the 8 ohms are just the speaker
video on class d amplification?