High performance electronic crossover for SUBWOOFER amplifiers

[@lens3973]

Great vid!!! Rod Elliot's site has been a huge help in understanding the reasoning for why amplifiers are the quirky way they are. Thank YOU for sharing your knowledge, once again!

[@reinermunch5159]

I like the Snicker interruptions... The japanese filter site I use a lot for the first dimensioning of caps and resistors. For further tweeking I use LTSpice especially to "see" crossover behavior between more then one filter or part value variations. Rod Ellitt is new to me, really great project site

[@iNeedDrums]

Great video! The "Q" (drop-off/cutoff) of the frequency is a huge factor in how tight your low end / subwoofer will be. The crossover point is also where you want to roll off your component/mid-high end speakers at. Depending on your speakers/installation, the Q does not really need to be as sharp because they produce sound more evenly accross all frequencies. Though they will definitely have less chance of being overdriven/distorting with the low end rolled off somewhere between 50hz-80hz. All depending on your taste and opinion.

[@kevinlivingston9563]

Just watching this again after recommending it to someone. You should do more tutorials using these sites. Great stuff there.

[@CoolDudeClem]

I made a subwoofer amplifier circuit the other day, I have these speakers that although they can go down quite low, they're really only good for about 200hz and up. So I made a circuit using a quad op-amp, it actively mixes the left and right, and drives the output transistors for the subwoofer speaker. I dont have any kind of filtering on it though , so what I did was put the speaker I have it connected to under the bed to muffle the highs, and it really pumps out the bass.

[@BinjKomisar11]

Hey Clem, how are you doing? Hope your well. Are you going to make a video of your sub-woofer project? Haven't seen you for a while bud. Hope your staying healthy. Peace dude! :) Ben

[@ELECTROHAXZ]

Schematic?

[@aljosagajst8725]

I have builded it, running it on +-18v, i added 0.33uF poliester capacitor at the input and 470k resistor instead of 10k (from input to gnd). Works good :) I used NE5532

[@TBL_stevennelson]

I got one NE5532 I would like to try.

[@karlh.peterson8134]

Another excellent vid, thanks! For filter designs, it would be interesting to see phase shift due to filter action. Your scope has two channels so it could be observed. Mixing L and R channels for sub is acceptable but using two subs gives a lot more depth to sound stage even in a mid-sized room. Consider this a mild suggestion to anyone building a sub system.

[@arthureschner9319]

As always, great video. I know this video is old, but if you happen to see this comment.... would it be a possible to make the x-over point adjustable by using a pot instead of fixed resistors? Perhaps something like a dual 20K pot before each non-inverting input?

[@amitghosh6966]

What's "Dynamic Bass Boost" and "Mega Bass boost" which are there in some branded audio systems that can be enabled at flick of a button in addition to normal bass boost ?

[@SciPunk215]

Thanks John !! Any chance you could show how that sounded without the filter so we could compare ?

[@tubeDude48]

At 8:00, what Op-Amp are you using, and does it have a balanced power supply, or just a single rail power supply?

[@asunavk69]

idk witch one it is fr, but i think If you use 2 741 op-amps they will as an alternative do i think(did some tests and sound come out distorted tho). He did not explain in this video but he used single rail, rather he had said on the other one.

[@KingOfShenanigan]

I love it when he says frequency.

[@kevinlivingston9563]

I was going to suggest some crossover videos in the future. Good stuff here.

[@siddharthshekhawat5502]

This exactly what iam searching for

[@GeoBass-89]

I build 2.1 amplifier with 2 Tda2050 for speakers L and R and Tda2050 bridge for Subwoofer and work amazing from 2 years every day. i used TL072 for satelites, and NJM2068S for subwoofer. work amazing on 80% volume . thanks for sharing this good video. i look always on your video. you not test TEA2025B. this is good IC

[@KennethNicholson1972]

Brilliant video, and very well explained, thank you. I have been binge watching your videosas I try to catch up with your content. It really grinds my gears though seeing the comments of lazy, ungrateful viewers who can not even be bothered to pause the video, and copy the schematic that you show at the end. This generation can do nothing for themselves it seems. The components are all very clearly labelled, and the schematic is very clear. Thank you again.

[@anindyamitra5091]

I was hoping that if we use a quad op-amp chip and add the Left and Right channel after passing them through buffers then we can completely eliminate the possibility of mixing the channels elsewhere.

[@swarajbiswas3056]

I have an almost same cat as yours. Nice videos, you have good skills. One question, what if we need a variable frequency crossover ? Please share a video or schematic. Thankyou.

[@HillsWorkbench]

Yeah, I'm with Kevin if your scratching for ideas, do more crossover stuff. Why is a sharper cutoff desirable? What happens when different drivers overlap? Active VS. Passive, etc.

[@JohnAudioTech]

A 6db/octave filter would let too much midrange content pass though. Too steep of cutoff could have implications as well. Good questions for future videos.

[@karlh.peterson8134]

sharper cutoff is desired because if the filter is not of phase-linear design (i.e. the filter changes the phase of the attenuated signal), it will muddy several octaves beyond the crossover frequency due to phase cancellation distortion from consecutive drivers (sub and midrange or whatever is the next stage). Therefore, steeper filter is used to minimise the area where two speaker drivers are playing the same frequencies (this is one prominent reason). On the other hand, if the filter is very steep or a brick-wall type, the crossover will sound unnatural and abrupt and will be very difficult to mix into the overall sound performance. How steep the cutoff can be without this and other effects depends a lot on acoustic characteristics of the transducer/speaker system. In professional XO tuning, usually special tools are used, like the SMAART system from Rational Acoustics to find the best balance in between different and often contradicting factors. As John hinted in the vid, this is a separate area of science in itself. Cheers!

[@samfestusthepianist5204]

Amp to Sub connection Reversed/inverted? What about phase shift issues as it's 3rd order then 270 degree out of phase ? How to fix that?

[@yuvalabadi8728]

which opamp you use?

[@doctorcenk]

valuable video and source, got the key points thanks John

[@cezarlixeanu]

I used 2 of the 4 channels from a lm324 ic and the circuit doesn't work, it outputs a very quiet signal that sounds like a blown speaker. Any idea why?

[@crazymetallian]

this is an active crossover, so you need to use a power suply for the opamp

[@cezarlixeanu]

@@crazymetallian I did use a power supply. I think the chip isn't designed for audio, it sounded like the output was clipping, no matter the volume. I replaced it with a NE5532 and it sounds good now

[@crazymetallian]

@@cezarlixeanu well sometimes ICs are BOA or just defective, but is nice to know the NE5532 can work i'll do this project myself

[@yuvalabadi8728]

is this cross connect out to other amplifire ? or is it possible to add gain to the opamp?

[@sanjayheaven5230]

i'm very greatful for this video

[@amitghosh6966]

Please make a video on passive crossover for connecting one woofer and one tweeter

[@andrewdonvito9763]

Hi John. I have been making your low pass filter and what seems to be your power input for the Op-amp I do not understand is it to lower the current open apps for smoothing/filtering also I find curious the ceramic capacitor between ground of op amp and breadboard ground ? Regards Andrew. PS my cats name is puss. I always get a laugh when snickers jumps on the bench.

[@Padde298]

EXCELLENT video. What about the fase..? Is there any problems with that when using this design..?

[@JohnAudioTech]

Karlutt gave a good response to this in another comment on this video.

[@joohop]

good to know john cheers bud

[@zacharycarbon4312]

Do you know if this circuit can be applied to the RC4558 ? I know it is also ubiquitously used as a preamp, but I also know that I know nothing, lol. So I'm about to fiddle around with it. If you haven't responded by the time I finish, I'll let you know if the IC (and myself) are still living.

[@GeoBass-89]

of corse, will be work better with 4558 because 4558 have good response of bass

[@bobrourke5735]

Hello John. Your diagram shows two op amps, but actual build only shows one on the breadboard. Can you explain?

[@JohnAudioTech]

The chip contains two op amps.

[@shamanjitsingh7267]

Bro, what voltage capacitors should be used.?

[@diymaster1121]

I am a noob in op amps and i need some help. So basically i am trying to make 2 way crossover for subwoofer and top speakers and i want it to cross at 80 hz. I am trying to build one that you recommended in description but i can't figure out how do i power op amp because i do not see ground pin. Only thing i see is v+ and v- but where do i connect ground of my dual supply. Does it go together with audio ground.

[@PeterKese]

You'd connect only + and - to the op-amp (e.g +12 volts and -12 volts or whatever the voltage the op-amp or your power supply is). Op-amp will then try to reproduce the voltage that it sees on the input and will operate anywhere on the range from -12 to +12 volts (or slightly less, say -11 to +11 volts, depending on the op-amp internals). If you put 0 volts in, you'll get 0 volts out, to op-amp the 0 is just any value of the input signal between -12 and +12. It is not discriminating in any way where your operating point is. The only thing where you'll need ground in this circuit is where you connect one side of the input resistors and the capacitors. That will pull the median operating point of the circuit towards 0. Also it would be good to put a decoupling capacitors in inputs. See kzbin.info/www/bejne/o32rnqmgrdmlmM0

[@richardfay8298]

The op amp will require 5v DC ? I think your average 5v dc wall wort would introduce too much noise - so do you also have to build a power supply ? Was that a low level or high level input ? (guessing low level)

[@JohnAudioTech]

Yes the opamp would need power. 10v min (+/- 5v). Common to use +/-12 to 15 volts regulated supply. Line level input.

[@fernandocuarenta7004]

Hi 👋🏻 @John audio tech I'm Fernando from Mexico 🇲🇽 . You did a great tuto congratulations. So, I have a question... Can I use this LPF direct to the input Amplifier, I mean without "the function generator" ????

[@JohnAudioTech]

Yes you can.

[@fernandocuarenta7004]

Thank you so much !!!!!!

[@cortessarge5399]

tnx for sharing sir John..

[@IscleGaming]

How can I use it with a single supply?

[@MarcosLucas]

hey jonh I made that circuit and work so well. thanks you!! at first try I put a 9 ( 8,5) volts whit the simple-to-simetric voltage circuit and it work but with a lot of noise, then I increase the voltage to 12 volts and all noise just disappear, can you explain me why? again thank you very much!!

[@JohnAudioTech]

Possibly clipping distortion? Other than that, the circuit should work fine at that voltage.

[@lumppugootti]

do you know how to modify it to work with a single supply?

[@richardsinger01]

juubr you could use a voltage divider. Or just 2 9v batteries connected in series.

[@garygranato9164]

another good vid , thank you

[@rubabmubarrat]

well done sir

[@HectorDC02]

man is that a 100 ohm resistor on the output of the second OPAMP?

[@TBL_stevennelson]

Yes I think so

[@radiowallofsound]

just what I was looking for ;)

[@lee26carl]

high john. its sounds good. can you give me the ic value. and whats the power input of the circuit?

[@JohnAudioTech]

I used a NE5532. About any standard dual op amp will work.

[@lee26carl]

JohnAudioTech john. do I have to power up the circuit. like 5 volts or 12 volts?

[@karlh.peterson8134]

yes, 5V would work if your sub-amplifier expects the usual consumer -10dB signal (316mVRMS) and if you are not using some unsuitable opamp that only goes up to 2.5V of rails or the like... the difference between active and passive crossover is that usually active crossover is done before power amplification and requires separate power itself (e.g. the active opamp components in the system that John showed). Passive XO is usually done after power amplification and by using passive components (i.e. capacitors, inductors and resistors) to filter out the undesired content. Most often passive XO is included in your speaker system. This passive variant is in a sense operating on the power from the power amp output.

[@TBL_stevennelson]

@@lee26carl yes I believe you do

[@TBL_stevennelson]

@@lee26carl I see ppl using 12v with good success

[@aurthorthing7403]

What would you recommend for a high output bass guitar amplifier? Something in the 100 watt range.

[@BluCasper]

how to drive that circuit with single supply?

[@JohnAudioTech]

Covered that in another video I made around the time I made this one.

[@ashutoshkangralkar2804]

only one IC ? the diagram shows two ic

[@JohnAudioTech]

The triangle symbol represents an amplifier. There are two inside the one IC I used. The IC used was the NE5532 but any audio quality opamp IC can be used.

[@ashutoshkangralkar2804]

tq

[@Tbonyandsteak]

mmm no 1. order?

[@ruption9865]

GREATTTTT VIDEO !!!!

[@manojkonar3969]

Whats the number of the IC you used??

[@carlfranz6805]

Manoj Konar you should only need one as there are two opamps in the package

[@ashutoshkangralkar2804]

pl tell some another ic number please

[@electronicshelpcare]

nice expl

[@janred94]

Frenquency? :D

[@dilbyjones]

Woot TY !

[@atle5191]

I still do not understand .According to you, it limits the frequency from 106hz or 106hz or less or more.?

[@adryanyork3581]

Thanks... Cheers

[@ajdebezi802]

1.25x is the game changer

[@pitotoyo4568]

Goood👍👍👍

[@maitytokon2950]

can you give full this pcb schematic and diagram

[@KennethNicholson1972]

Use a permanent marker and make your own, following the scematic at the end of the video. Takes less than 5 mins to do. Not difficult to lay it out for yourself and you will learn something.

[@iceberg789]

nice stuff.

[@vishalpeddi8117]

can you give full schematic and diagram ???

[@MarcosLucas]

Vishal Peddi it is very complete schematic there. you may want the voltage in, but that's depends on your ic op amp.

[@KennethNicholson1972]

These greedy, lazy viewers really get on my tits. All they have to do is pause the freeking video.

[@HemantKumar-bo6yv]

can you send me a simplified circuit mine is not working

[@KennethNicholson1972]

The circuit shown is about as simple as it gets for this type of crossover. Use a circuit tester to see where you have gone wrong. Learn something.

[@qwertyasdf66]

10:20 Meow.

[@fatyeet6882]

Marvelous vid, dropped a sub ^‿^

[@xzxzt4]

HMMMM SOMETHING IS OFF OR WRONG CANT PuT MY FINGER ON IT

[@saifbinazad3710]

Can u just tell me about a low pass crossover subwoofer amplifier all components name and value for a 200 watt 8 ohm speaker? i wanna make my own subwoofer amplifier. I want my subwoofer frequency between 20hz-120hz. Thanks

[@KennethNicholson1972]

Geez, go spend $1 on a calculator, learn online about electronics and basic equations, and do it yourself dude. The guy is not a freelance consultant.

[@GeoBass-89]

This filter cut of frecuency about 100hz. litte better that you ask. but start frequency depends subwoofer speaker you use. not much driver play that low. (20hz). good luck

[@Mr_Meowingtons]

MEOW!!!!

[@kurtrozario1]

The impostor sir! Who is he, or she, pretending to be? ha ha ha , the voice behind the video?.... I have too many of those intruders in my life. One of them, is like a security baggage scanner in an airport. Nothing get in without her first checking it out.... Most of them, believe, that I am the intruder in their home. Seems, it doesnt matter who pays for boarding and lodging.

[@God-yb2cg]

What?

[@God-yb2cg]

Oh, the cat. nvm

[@dilipd.jkumar1689]

Hiii and

[@MrBrymstond]

I have a 2 ohm sub 800 watt and a 4 ohm 600 watt

[@StealHrtVideo]

Intruder..

[@michaeln5660]

Ultimate noob question for you (but I really don't know): is the ground for this circuit just the 'black' speaker wire, and the input the 'red' or do I need a separate ground connection? I feel like it should be the gnd of the DC power supply for the op-amp, so the 'black' wire should avoid this circuit and pass through to the speaker, right?

[@barttoth1127]

How can I use it with a single supply?

[@mik310s]

Use a voltage divider just like you would with a single supply op amp, I think that will be fine :)