Ported subwoofer box explained

In this video I'm going to explain how does the bass reflex enclosure works.
Learn more about loudspeaker and crossover design : audiojudgement...
Another awesome video 1 : • Transmission line subw...
Another awesome video 2 : • Isobaric subwoofer box...
Subwoofer image source : www.monoprice....
Music Credits:
"Werq" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
creativecommons...

[@TanChoonHong]

The best explanation I have heard on this subject. Clear and incisive, well illustrated. Thanks for sharing.

[@mikecurry6847]

I appreciate the lack of overly technical jargon. If I wanted that, I wouldn't be clicking a thumbnail that says, "what does this hole do?" 🤣

[@hks20psi]

💀

[@ShortsFormula374]

helpful tip when watching this turn it to 1.25x speed or 1.5x it helps

[@scivirus3563]

best explanation of speaker encloses in English from someone that's not English

[@dalemyrie8208]

Yes my brother , I just get a lesson there. I always build my boxes to the right cubic feet according to the size of the speaker I am using . But you mentioned some things that will further improved my sound quality. Thank very much and continue to keep us informed.

[@SambitTripathy]

Thanks for making a video with a clear and concise explanation of bass reflex.

[@JagadishTalluri]

I must say. This is a Gem. A video made with extreme passion and has a lot of value. Really Simplified the concept. Bravo.

[@ChasingTone666]

Fantastic video. Great explanation. Keep it simple is best. Learned quite a bit. Thanks

[@FLOREPSINOSA]

Thank you, I looked a lot in YT before finding the answers to my questions.

[@roypeters6125]

Thank you i learn something from you thank verry much

[@rahuketukachannel]

Frickin finding help in KZbin then suddenly you came and solved my problem thank you mr stranger ❤❤❤

[@THEALLNIGHTGAMER]

Very nice explanation

[@Masterked]

Don't ask me why I understood this video so well. Thank you sir, I got the main idea now

[@niharadawade4442]

Best explanation...thank you!

[@naorl8866]

This is the best explanation great video!

[@larsgunnarsson260]

You are a brilliant pedagogue/teacher!

[@Enginemount]

First time I understood the whole thing. Kudos 👌👍

[@TheUnvain]

Excellent explanation. Didn't even know I needed to know this, but now Im glad I found this video :)

[@audfrknaveen2256]

Thanks a lot !!! All your videos and your online course is also awesome !!!

[@rthdmaster5183]

I learned something different I even know , thanks

[@RayBabani]

Thank you for your videos! Truly appreciate them. I am a very low-level noob, but useful even for me.

[@mrfordman9999]

Dude I appreciate the simplified version. I'm sitting here thinking to myself if this is the simplified version I'm absolutely fucked

[@brightelectronics4207]

nice explanation sir.

[@stephenndungu1551]

Beautiful bravo always helpful you r a real utuber

[@southern_merican]

Great video! Never knew about tuning a box! I built a box 10 years ago but dont know what frequency it is. Its 15"x16"x17" with a 1.5" x 14" rectangle port on front/sub side. Port wall stops about 2 inches from the back. Running a old school 12" l5 solobaric. If anyone knows i would appreciate it.

[@abelscaliber7969]

You need to provide a little more info on the box How long is the port. I know you says it stops 2” from the back , but which wall does it reside in? There’s calculators online that can do this math for you

[@gotsu21]

Now i am ready to rip the guts of a broken active subwoofer and turn it into a passive one. Thanks for the "my way" explanation.

[@MOZOGuitars]

those popping sounds popped my ear drums

[@peterxyz3541]

THAT WAS SIMPLE! Thanks, that was great!

[@arefmohammadzadeh8560]

very good... thank you

[@omkarmhatre1912]

Really good explanation.👌 If possible please make one video on passive radiator enclosure. There is not a lot of information available about passive radiator enclosure.

[@sahltysahil]

Bare basics. Simply awesome. Thank you.

[@ciobanualexandru7357]

Thank you for your very nice explanation!

[@RobHTech]

Great vid. Finally someone who see and explains things from a practical point of view without over complicating things, micromanagement. --I am trying to use winISD Pro. In the port section, it has width, length, and "1rst port resonance." Is that the port resonance/tuning? --And, if I run sealed, do I lose some SPL?

[@AudioJudgement]

You setup the tuning frequency in the box section. The 1st port resonance is not something that you should concern yourself. It's something that should be avoided, but if you are building subwoofers, it usually is outside of the playable range of the subwoofer anyway. So, don't sweat about it. And yes, if you run sealed you will have a lower SPL. In normal conditions it's - 3dB.

[@RobHTech]

@@AudioJudgement thank you.

[@jameskeller8459]

Very Very Good Explanation. Thank You !! ..Please do a 3-Way DYI Presentation.

[@bikesandbeats4693]

Amazing video and explanation.

[@fubartotale3389]

As far as my 3 year old grandson is concerned, it is for putting all his "Bluey" and "Sesame Street" fugurines in.

[@rekrexacosta4331]

Thanks for the best explanation thanks a lot❤️👍

[@VINNY5674]

Best explanation I ever heard 👍

[@Ro-ni7nm]

I really enjoy this content

[@joyfulmvakali8462]

Man you good Just what I was looking for ✌🏽

[@jessicaembers924]

I like to port a little below audibility for a little more punch, no cancelation, a little more efficiency, and a Lot of cooling to the voice coil.

[@sibusisombatha1451]

Well explained 🙏. If you dont mind me asking.. I don't know much about these things but I've recently installed sound in my vehicle & in doing so, my uncle gave me a subwoofer that already has a enclosure that is ported, very similar to the sketch of the ported one in your video.. sounds nice but we've once blocked the port and it actually sounded a bit better for me . I was wondering if me blocking it from now on will somehow harm the subwoofer or not ? Thank you

[@AudioJudgement]

No, it will not do any harm. If it sounds better, you can block the port.

[@georgem6359]

Hi. Your videos are pretty good. I got a couple of questions 1-What is better - tune port to higher frequency or to a lower one than the Fs? 2-if able to tune below the fs, how much lower, 5,10 or 15hz lower than Fs? Thanks.

[@b-17wingman37]

great video. Thankyou !

[@dagobject]

Great video! Can you explain why on yamaha hs sub the speaker is facing down, and the hole is facing forward? How does it work?

[@ronalcasid3844]

Please explain transmission line. Thank You!

[@praneeth8304]

Good explanation!

[@tt._.7857]

Really good video so easy to understand keep it up 💪🏾🔥

[@andrewkratz226]

Thanks, good info. I had no idea thats what it did

[@jaeheich2240]

This is very informative! Thank you very much

[@droper683]

Great and clear explanation.

[@dracomedia9481]

Excellent explanation. Greetings!

[@rmkumaragridoctor8146]

Great👏, well explained.

[@kalangototal]

Ah yes, finally, a video about this, thanks a lot ^.-.^ 😄

[@ReferenceFidelityComponents]

The port size should be such that the resonating air mass stays laminar. Turbulent airflow starts at circa 11m/s so with maximum displacement = max permissible power input you then need to check port rear flow velocity. The other crucial point is the point of tuning. The Fb should be close to the Fs of the driver and not permit the max permissible cone excursion to be exceeded as this risks the voice coil former smacking off the rear plate if the pole piece and damaging the voice coil plus increases distortion. The box should be sized to the t&s parameters of the driver to ensure Fb is +/- 5hz or so of Fs in free air. You can alter the box “Q” to play with port alignment, the ideal being BB4 alignment for lowest group delay and phase shift. Typically this involves a reduction of Q by introducing damping to make the apparent box volume greater than actual which increases the acoustic line of the vent tuning beyond actual vent length. Its a clever means of generating greater depth of bass more accurately than conventional tuning but isn’t to be confused with extended bass shelf tuning. I normally employ bb4 tuning using this method for rfc speaker designs with a tuning point of Fb slightly above Fs. It also removes bass peaks at tuning by altering the alignment for more linear bass response. Not easy to get to grips with as anyone attempting a diy ported design can attest to. Sealed boxes are far easier to design for if going the diy route.

[@shiernanpapin85]

The video discussed about inphase & out phase wave direction of speaker...

[@alisepehrjavan4239]

tanks. that was great video

[@abeginnerspov5968]

Only 7000 views? This video should have more.

[@abdulbacarat7804]

Nice explaination thank you nice 👍

[@davidgonzalez3008]

Hahaha the guy with excessive technical language, good one and so true, good job dude👍😀

[@DMC428]

Hi Marius, can you explain why the woofer moves less, when the port resonance kicks in? I don't get the physics behind that. I mean, when the port (better: the air in the port) is moving vigorously to gain output, then it has to be pushed by something. So it's somewhat counter intuitive that the woofer moves less in in the ports resonance frequency. Thank in advance for an explanation!

[@AudioJudgement]

It’s like having a weight attached to a rubber band. The weight being the mass of air inside the port and the rubber band being the air inside the box. If you hold the other end of the rubber band (your hand being the speaker) and try to bounce the weight, your hand will start with ample moves. But as soon as you are close to the resonant frequency of the system you hand will make slight movements while the weight will bounce with ample movements.

[@DMC428]

@@AudioJudgement hi Marius, thank you! This analogy of Port resonance is pretty good and should find it's way in your udemy courses. As far I remember you said in one of your videos that the port ist "stealing" the energy from the woofer at Port resonance. that's why woofer excursion goes down. This "stealing" is the missing part I'm looking for. I mean as long as no one turns the volume knob down, the woofer should move, let's say, something around 2cm excursion between 45 and 20 Hz in free air. But the lower the frequency goes, excursion gains some additional millimeter. There's a big box with a port next to you. The port is tuned to 23 Hz. As soon as you put the Woofer in the box and play some reverse sine sweeps down to 20 Hz, the woofer is moving like expected until it hits port resonance. I expect the excursion to rise because the port "opens" so there's less spring-effect from the air inside the box, but it's the other way around. Still, no one has touched the volume knob.

[@DMC428]

@@AudioJudgement I finally got it! this is the behavior above port tuning frequency. The port is closed: - kzbin.info/www/bejne/qqOue2OPpZt6g9k this is the behavior below Port Tuning Frequency, so basically the port is "open": - kzbin.info/www/bejne/qqOue2OPpZt6g9k and this here is right at port tuning frequency: - kzbin.info/www/bejne/qqOue2OPpZt6g9k Obviously the resonance frequency has to be phase inverted, otherwise it would cancel out the woofers output. => And now it's clear for me WHY the woofer excursion decreases at port resonance! I somehow thought, the resonance frequency opens up the port but because of the length of the tube the pressure waves will exit phase inverted (in phase with the woofer) and at frequencies below port tuning the wave is too long to be inverted by the port. I'm just starting out with speaker design and build my first Sub-Enclosure just last week. Your videos and courses are nice to have as a reference and very helpful. Thanks for that!

[@linandy1]

I learned something 😁

[@warunanarasinghe4015]

WELL-EXPLAINED VIDEO.. 👌

[@IND1PRAJWAL]

Make video about on passive radiator.

[@markpennella]

Have you ever looked into Cathedrals and CHurches designed to a resonant req?

[@Kjhose]

This is good video.. thanks

[@vaishnawdeorukhakar6164]

So useful information sir ❤️

[@emceljoe1420]

in car audio which is best bass..aeroport or slot port?

[@SuperSteamengine]

Thank ypu for the video. Just having this doubt, am having a dual klipsch R 121 Sw sub in my home. The gain is about 50 % and avr trim at - 8. Is it ok to cover the port with plugs or using some socks to get some good punch. Mine feels bit boomy some times. And if its designed to wrk ported , any problems if i restrict the air flow ? I knw big brands having port plugs and all. Thanks

[@AudioJudgement]

If you cover the port there is absolutely no problem. It changes the acoustics but there is no concern of speaker failure of something like that.

[@bigsquatchsasfoot1964]

Thanks dude really appreciate that you appreciate we’re not all rocket scientists , thanks for your knowledge brother 👍✊

[@ebeb9156]

You are a good man 👍

[@anandshah71]

Buddy have you tried open Baffel Would like to see some videos from you on that

[@just_curi0us]

Yeah. I liked your video and subscribed too.

[@acerhanslee1269]

I have a question..do you have any Speaker Box Plan for a Hard Kick Bass?? Cause here in the Philippines we're using Cerwin Vega box and Modified Cerwin Vega box which is also called L36.. Do you have any suggestions or advice to make it sound better and Make the bass more harder? i hope you'll see this! Your reply is much appreciated, Thanks in advance!

[@3DIYOriginal]

Awesome !!! Thx you !!! 😎👍🏻👍🏻👍🏻

[@stivengarciaflorez3135]

Ola amigo si usamos el máximo litraje ejemplo 70 litros para un sub 12 y sintonizar ah 60 hz o 65 hz para tener un pico de frecuencias muy alto si es posible para tener un buen spl en una sola frecuencia como competir en spl usando cajones grandes entonado alto gracias saludos desde Colombia

[@AyushChaudhary-qc9gd]

Hi there Can you create a video on box calculation for a ported speaker to hit Lowest Fs

[@SanFranciscoFatboy]

don't worry about ur critics...... we all have them... just carry on with ur good vids :) (and get rid of the lil chirps ... u are an audio expert, wtf r they doing n your video?

[@lorainecross]

Very good video, thanks. The one thing I don't follow is, at around 8:00, you say that a larger diameter port will increase the resonant frequency of the box. Since a larger diameter port will contain more air mass, and in a mass/spring system a larger mass typically results in a *lower* natural frequency, it would seem that the opposite would be true. What am I missing?

[@westelaudio943]

Because the surface area of the air column in the vent is greater, which couples to the air cushion inside. Thus the "suspension" is stiffer (less compliant). Think of it like putting you finger in water, and then putting your flat hand in water which requires more strength (not the best comparison maybe but you get the point)

[@Rene_Christensen]

You need to look up the concept of acoustic mass.

[@purshottamoraon96]

Very helpful

[@mohammedq906]

Thank you so much

[@JoSe-cs7ip]

Thank for the video! I had to speed up to 1.5x though

[@leonardo-mg1uc]

I have a 6 and half inch driver, box dimension is 16(depth)x7(width)x11(height), driver mounted in rear panel downside on width side and port on front panel upwards suggest me the port size, length and tube dimeter coz flare will increase the port size bit more than diameter of port tube

[@AbhishekTiwari-rh5ke]

Sir What is LF 7 and LF 9 cabinet Can you please make a video on it

[@merchantier4219]

очень хорошо объяснил, мистер волк

[@rajdutta5274]

I want to make 10 inch subwoofer box, pls suggest everything to get sweet bass in my room size 10ft x 11 ft. to watch hollywood moveis with 200+ RMS ampli.

[@colbydolby6559]

So basically if you wanted to achieve true infinite baffle at 20hz you would have to have a rolling billboard as long as a semi trailer and just as tall? Gee..you would knock down all the power poles and street lights..really not cool. It doesn't matter if your content is grossly simplistic or overly exaggerated, you make it possible to understand. You are an excellent teacher. How do you spell your name anyway ?

[@AudioJudgement]

In the first 5 seconds of my videos you can hear it and also read it :)

[@MannyGunzz]

Can i port a sealed box and invert my subs??

[@stephenyoud6125]

Have you tried doing this with an isobaric enclosure like LINN use? And looked at the bass extension obtained. I wonder if there are calculations you could for ideal volume between the two drivers and the volume behind the rear of the two drivers

[@fareedahmed3897]

Would you please explain the field coil drivers. The dimensions of the coil and wire gauge, l.v.r calculations for max magnetic flux? Thanks

[@AudioJudgement]

I'm sorry but I have no expertise in this area. You might find information about this topic in old books. Or you can play around with speaker driver design applications, but those are pretty expensive.

[@CharlesDowiot-qv7pp]

Bass flow located in front or black if located in back bass will go to back wall if located in front more Direct

[@FattaDan592GY]

👏👏👏 well done g

[@djambush360]

Nice explanation. 1:10 only the sourround and the voicecoil spider should flex. Not the whole membrane. I think you did it like that because it's much easier to animate. [I'm not concened about it i just wanted to give meinen Senf dazu. Greetings from Germany ^-^)

[@AudioJudgement]

Haha, you're right. Those are just 3 still images, just to prove a point.

[@champipy]

Question: can I use multiple "holes" on the box, instead of a single tube? For example if tube required would be 10 cm long and 3 cm diameter, can I simply drill 5 pieces of 3 cm diamater holes on the front baffle which is 2 cm thick? I guess the resonating “air mass” would be similar. Yet no one uses holes! Why?

[@AudioJudgement]

It’s not the same thing. If you make 5 holes the total area is 5 times larger and the port needs to be very long (each of them). It’s not just the mass air inside the port, there must be a certain impedance for the air movement. That is achieved by making the port longer. If the diameter is too large and the length too short, the air escapes without any impedance and no resonance occurs. You would have a leaky sealed box not a bass reflex :)

[@kennethalambra9146]

Nice video. However, the popping sound whenever you pop some icons or images is painful to the ear, both in terms of its pitch and volume.

[@AudioJudgement]

Sometimes I get that feeling as well. I’ll make sure to fix that on future videos.

[@THEMADPROFdj]

@@AudioJudgement yeah, it's pretty bad. i kept looking for a notification. L0L

[@md.muradhussainkhan592]

If i keep my hand on air hole or aero and stop airflows of subwoofer will it harm the subwoofers speaker!?

[@AudioJudgement]

Not really. You are transforming a ported box in a sealed box (a leaky sealed box if you don't sealed the port perfectly), and that's just fine for the subwoofer.

[@md.muradhussainkhan592]

@@AudioJudgement Yeah, thanks. My speaker model is Creative Cambridge sound works SW 320, has not such leaks though.

[@genrock6756]

Damn this commercial. Who’s gonna buy that at 3am in the morning huh?

[@fareedahmed3897]

One thing i forgot to mention that i am planing to make one. Once i understand the calculations, I will try make one.

[@faysalusman]

If my woofer Fs is 35hz can i make a box for 20hz and get this low frequency?

[@AudioJudgement]

You have to model the frequency response and see if it will play that low.

[@Patrik4441]

I have a bass reflex speaker box but it hasn't got any lining/damping. If I take damping into the box it Will be better or it's worst for the bass reflex?

[@AudioJudgement]

It will most likely sound the same. I wouldn't bother. If you don't have any obvious problems (standing waves, high frequency sounds escaping through the port), I would leave it alone.

[@Patrik4441]

The bass tone is not strong enough, i can't tell it in English very well :D but the box make echo or peal.

[@AudioJudgement]

@@Patrik4441 Maybe it can help with the echo thingy you mention, but you won't get stronger bass by placing dampening material.

[@Patrik4441]

@@AudioJudgement Thanks!! :D

[@audioelectronics542]

does tunning frequency and resonating frequency is same or different?

[@AudioJudgement]

Tuning frequency (of the box) is the same with the resonating frequency (of the box)