How does a port work? Myths Busted!

[@THE8K47]

I started a business a year ago building custom bass boxes with 0 prior knowledge but I studied your videos and utilized all the knowledge I took from them. Now I have a solid reputation for my boxes performing perfectly

[@DIYAudioGuy]

That is awesome! Nice work.

[@applejack2374]

That's really cool! More power to ya! 👊

[@eldrickejleest]

This awesome..

[@sonus289]

what about custom bass guitar cabs?

[@fredymredy]

Why some boxes have membrane instead of ooen hole?

[@bennettshapiro2965]

Great description of the beauty of the band pass design. I have rarely heard it so well articulated. Just a pleasure to watch and listen to. Some of us are old hats with some of the science, but hearing it explained succinctly and clearly is still a beautiful experience. Thanks for that.

[@DIYAudioGuy]

Thank you!

[@easydiy_beginners]

OMG 10 mins of non stop technical words, need hours to understand the basics of the port, wonderful explanation!! thanks for sharing the knowledge!!!

[@DIYAudioGuy]

Glad you enjoyed it!

[@jamband4230]

This was a great video. So much information packed into a few minutes. No fluff just the facts and it was explained in simple enough terms you don’t have to be a engineer to understand this information. This is why I follow this channel. Thank you

[@DIYAudioGuy]

Thank you!

[@wally7856]

Wow, super impressed! I've never seen so much correct information condensed into 10 minutes on audio as this. In a sea of audio half truths this was refreshing to see not a single misunderstanding of the physics/engineering of how ports operate. My background is live sound engineer/speaker builder/car audio way back when and I spend more time on the math and physics of audio that I care to admit and you hit all the bases. The only thing I would of added would be some of the pro's/cons/trade off's of ported enclosures. Things like efficiency, size, distortion vs group delay, phase, f3, harmonics.

[@DIYAudioGuy]

You are far too kind. As far as the pros and cons, my original plan was to make a video covering that topic. I just haven't gotten around to it yet. But you're exactly right. I need to make that video.

[@dannylewandowski2822]

Just ported a box this weekend after watching your video! I added 3 smaller ports instead of one large one due to the size of the speaker and allowable drilling on the sub box. It sounds amazing. as I added each port 1-2-3 it got better sounding each time. I did the math and found the correct ratio to surface area and volume of the cone in order to convert to smaller ports. I see a lot of air but barely see the subwoofer speaker moving. I would say this is most efficient sound I can get out of my setup. Tuned to 59.7 hz.

[@jimmiejamese.4006]

That's sweet, I was looking for information on the exact same idea, and I figured the ratios were easy to calculate. Looks like you found out it's pretty simple.

[@jimjones3287]

is adding an extra identical aero port the same as making the original port longer?

[@jimmiejamese.4006]

@@jimjones3287 it seems so theoretically, I tried a design the same way, but I didn't calculate port noise yet. I would see that as being the biggest difference, but haven't put that theory into practice yet. Did you try to search for answers online?

[@incredifunk]

Why do you have it tuned to 60 Hertz?

[@nunyabusiness2127]

Great video! You covered a ton of material in a very short period. I started studying the body of work by Theil & Small in the early 1980s. I began plotting freq response charts and then building a lot of "tuned" boxes back then. Amazing how much speakers have changed since then. Would like to see you do a video on passive crossovers as well. Most folks do not understand a simple 6dB/octave let alone an 18 dB/octave x-over or when to use each.

[@DIYAudioGuy]

I tried reading the original papers. I don't have enough background in the subject to understand them.

[@DIYAudioGuy]

I have always wondered how to the TS parameters to generate the plots. I am sure somebody out their has this posted online, or it is in a book. Can you point me in the right direction?

[@muttBunch]

Beautifully detailed ❤️. I’m a sealed box kind of guy and have been into car audio for over 25+ years. I remember long before “bazooka” tubes, Kicker actually made speakers back in the late 80s that were of an oblong igloo. What was amazing about that design was it include a port, but sort of a hybrid port/sealed enclosure as it came with a port plug. I’m surprised I haven’t seen them since.

[@DIYAudioGuy]

I remember those.

[@hispls]

Generally speaking a subwoofer is going to perform better in either ported or sealed alignment and even with some of the fence-sitters you'll wind up with either larger than optimum sealed or smaller than optimum ported by just plugging the port.

[@beerman9807]

@@Mr.Robert1 some were , depending on model some weren’t

[@beerman9807]

What was the model , I never knew and would like to see it if it’s on line

[@mephInc]

Port plugs are still a thing in the home theater world. Each of my 15s, for example, have 3 ports and I have the ability to plug each one. This helps with fine tuning to fit your room acoustics.

[@cmosdaboss]

Wish I knew all this 20 years ago, so many years of bass wasted. Great video bro. Lots of people don’t know and your video help people build an enclosure the right way before making a costly mistake

[@DIYAudioGuy]

👍

[@Clobercow1]

Great video and great explanation! You're explaining this at next level and I'm certainly going to link this video when people start with the subwoofer myths!

[@DIYAudioGuy]

You are far to kind!

[@ryanmichalski7420]

You’re educational videos are really well done. Your teaching style makes topics easier to understand.

[@DIYAudioGuy]

Glad you like them!

[@TheUniversalid]

The humble paddleball is a representation of this. The paddle is the driver, the ball is the air inside the port (in my case, it's instead a passive radiator) the air inside the cabinet is the rubber band. In the ideal scenario, both the ball and paddle should be traveling in opposing directions for as much of the span of said desired wave, as to transmit the most energy into the action. Same as a driver and port air should do the same. The most phase offset I have seen is up to 170°, which is amazing!

[@DIYAudioGuy]

That is a cool trick.

[@riazmoosa8320]

Next level stuff... Love this videos... Everything Audio makes sense for a sound fanatic as myself... Keep it up...🤩

[@DIYAudioGuy]

Thank you! Will do!

[@halrichard1969]

I havent watched any Subwoofer building Videos for just about one year. I was determined to learn just about everything I needed to know regarding the technical aspects of it. And I did. The point is having watched your video here and a couple others of yours today I can gladly say that you have improved your video presentation in 2023, not that it was bad by any means. You are much appreciated. Your videos are music to my ears. Please keep it up.

[@DIYAudioGuy]

I try to get a little better every day. I use the money provided by my patrons to (www.patreon.com/DIYAudioGuy) to upgrade camera gear, lights, microphones, software, etc...

[@Morgan-vl4dg]

That was an EXCELLENT explanation of the ported enclosure !!! Extremely informative and well done. A bit fast w the info. so I slowed down the speed so I could stay w you in the info. but I guess that’s what rewind is for too huh ?!?! It awesome job explaining a ton of great info. in a short video clip. Well worth listening to and paying attention to as well as making a note or two. Thank you very much !!!! 👊

[@DIYAudioGuy]

Glad you enjoyed it!

[@ajc-th5ei]

Great video. Erin's Audio Corner also had a talk on use of Finite Element Method for design of drivers and enclosures. In it, they mention at one point when there is a high pressure or low pressure at the surface of the cone. Aside from that recent video, there is something else I've been playing with: Changing the Qa (absorption) value in the advanced settings in the box tuning tab. With an absorption value of 20 (what Unibox and BassBox Pro use for an enclosure lined with insulation), this changes the excursion of the driver in such a way as to suggest the absorption makes the box act more like a sealed enclosure, which also allows for more power to be given to the driver before reaching X-max. That may be a fun video, discussing box absorption and the effects on different types of enclosures, rather than the standard of using it to make the Q of the box seem to approach that of a larger box. But, this means some of the negatives surrounding ported enclosures may be able to be combated through the use of insulation. Either way, love the videos. Hope you are having a great weekend.

[@DIYAudioGuy]

Definitely something to think about! At some point I'm going to do some experiments with box stuffing. Just need to do some more research and build some enclosures before I jump on that.

[@BabyCharlotteschannel]

Sounds like fun and what could certainly be an awesome learning experience! Especially since I am probably going to have to build my next box so I can have exactly what I'm looking for! My goodness I can't wait to have a Rocking system in my vehicle again!!

[@Rene_Christensen]

What I mentioned on Erin’s video is that steady state the cone moves outward and at it outermost displacement you have the lowest pressure in front of it, not the highest. A big misconception but often not of much consequence. The current video here is really good, great job.

[@ajc-th5ei]

@@Rene_Christensen - The way I remember it is thinking about the system in a ported enclosure. When the cone is at its innermost, it creates the highest potential or vacuum within the enclosure (lowest pressure) which then pulls air in to fill the low pressure as the cone moves outwards. Meanwhile, when the cone is at the outermost displacement, inside the box has the highest pressure at that point because it just filled the box and now that air is pushing back against the cone that is at its peak excursion outwards. But that is just how I think about it to keep it straight. And obviously, what is true on one side is the opposite on the other side (so when low on the inside of the enclosure, it is high on the cone on the outside of the enclosure).

[@TimpBizkit]

There's actually 2 resonances. One around the mid band where the driver is moving the most and the port and driver are in phase. This happens from a combination of the driver springing against its share of air in the box and the port springing against its share of air (I'm not sure how this air is divided but it is some fraction that changes with speaker parameters, box sizes and tunings). The second resonance is that of the port springing against almost all the air in the box and the driver barely moving. The port output will be 90 degrees behind the output of the back of the speaker (or 270 behind the front). The net 90 degree phase is still additive, especially when the port is making most of the sound. You can actually see two resonances with a mass on a spring and your hand. One where your hand moves up and down a lot and the weight does the opposite of your hand. The other where the weight does most of the motion and your hand moves only enough to make up for losses and may as well be a fixed point. Below the tuning, the port will be making some sound but will begin to act like a leak in the box, meaning the driver will act like it is in free air. In fact it resonates even more at very low frequencies due to the momentum of the air in the box and the port increasing the effective moving mass of the speaker. You can damage your speaker if it's playing too loud down there. I have pa subwoofers that are tuned between 35 and 40 Hz depending on boundary loading and they can move like crazy at 10-15 Hz with just a handful of watts.

[@DIYAudioGuy]

Yes, I've only barely scratched the surface in this video.

[@clearme2]

Hexibase did a great job explaining port variations. This is another good example for explanation 👍🏻

[@DIYAudioGuy]

His stuff is entertaining.

[@lordhostile]

Wow alot of good info, I never saw a port like a passive radiator before but it makes sense the way you explained it. thanks!

[@DIYAudioGuy]

Glad you liked it!

[@jasonchapman2845]

I just discovered your channel. Out-effin-standing work, info, and presentation! New subscriber here!

[@DIYAudioGuy]

Welcome to the party.

[@johnenglishIII]

This was excellent and helped me a lot to understand a bunch of stuff. Thanks you so much.

[@garethfoulkes768]

Love the bass use to enclosures in the 90s on my metro

[@MYNAME_ABC]

The main problem is that below the tuning frequency, the port goes out of resonance and DOES cancel the speaker output. It is an acoustical short circuit at very low frequencies. That is why a lowcut is needed with a BR woofer - to not over-excite and damage the speaker.

[@DIYAudioGuy]

Yep, very sharp roll-off below tuning frequency.

[@mtj8alienartandteck867]

Dude you have been compressing .. my chamber with .. knowledgeable .. comprehensive .. notions .. tha As motions ... thank you .. Duee

[@DIYAudioGuy]

Happy to help

[@fortwisers6070]

Best video I've seen on the subject without going into the math involved, great job!

[@DIYAudioGuy]

Glad you enjoyed it!

[@stout7668]

So much awesome info. I always built boxes to hrtz by size I would degree the main port tunnel. From opening it up to a smaller opening or a very small opening to a larger opening. It works phenomenally well and just a few degrees makes a huge difference

[@DIYAudioGuy]

You mean like a flare. Yeah, that works great.

[@gsxroyce256]

May i suggest an idea for a future video? Would you make a video on how you learned all this? How you got started in audio. How you got involved/ inspired/ influenced/ interested/ esc. Schooling / collage on the subject if so. (You seem professionally educated on the subject) I think it would be cool to see how you got started and what you were interested in when starting out. And the difference on the equipment from them until now. And how that effected what you know / learned. Thanks 🙏🏼

[@Poekieman]

It was interesting to see what's happening to both woofers and the port of an old JBL Northridge 100 at different frequencies. Both woofers are not always in phase, as I had expected. And I heard a lot of rattles and stuff resonating in all kinds of places, at different frequencies.

[@DIYAudioGuy]

Odd

[@travisbroughton7773]

Thank you for giving me your subwoofer knowledge

[@slvice14]

Dude! This was so educational, I learned so much just now! Thanks for posting this.

[@icekid099]

Based off of your explanation of port size and pressure at different frequencies would it be possibl to adjust the port length with say a consitina setup which is controlled by a stepper motor for different frequency ranges using a frequency controller, e.g. At higher frequency shorten/lengthen the port a few cm (inches - I work in metric) and then at lower frequencies adjust the port again so that the optimal Fb works over a broader range, and the effective frequency range for maximum bass range is widened? Not sure if you understand the question... I'm not technical by any means, but it sounds like a logical approach to expanding the bass range for full enjoyment without compromising choice of the size of the product. Could be overkill, but does such a active port setup exist? Should not be a massively expensive alternative in my mind. Would be interesting to hear your feedback. Very good video BTW, explaining the port logic, even for a non techie like myself!

[@RenLacerda]

Just wanted to find out what those tubes on my speaker do. This video got me more confused than when I started! 😂😂

[@rrios283s73]

😅🎉

[@richtomlinson7090]

When I was looking to make a speaker for my Bass guitar and I had a 15" woofer from an older cabinet, I bought a book at RadioShack and started to research how I would do it. I eventually became intimidated by the math I needed to make the perfect cabinet for a speaker of relatively unknown specs, so I made a solid and airtight box with insulation stuffed into it. I learned what the tuned ports were for back around 1984 and I've cringed a little every time I have seen poorly controlled woofers, just sitting out in the open in some idiots car, and they thought their music didn't suck. I've since learned that speakers for the original production of music, can add character to the sound, and that's sort of okay, but when we want to reproduce the original sound, it really pays to have perfect well thought out speakers that produce a flatter well controlled sound that sounds like the original recording. I would like to produce some interesting speakers with tight bass, and it's probably easier now because bare speakers often come with the important information and recommendations for proper cabinet volume and design.

[@killabee623]

I flip my speaker box cone facing up, place some rice on the cone and play a test tone. When the rice stop moving that's my tuning frequency.

[@DIYAudioGuy]

Yep!

[@robertquinlan9297]

I've owned both sealed design speakers or air suspension speakers like older Boston acoustic, and I loved the tightness and defined response of bass, was all that traded for the loudness and efficiency of ported designed speakers? Because I believe the sealed design sound a lot more pleasing.

[@DIYAudioGuy]

A lot of people like that sound.

[@broken51N]

Thank you for showing people how to Do the Math! Win ISD is the best. You truly are a great builder and very knowledgeable. As I normally post. Do your math! Fantastic Brother!

[@DIYAudioGuy]

I agree! A little math goes a long way!

[@tsomer07]

We're fish swimming in our own sea! Your remarks on air pressure provided me an intuitive impression of something that before now I could only accept as theory. Thank you!

[@DIYAudioGuy]

Well said!

[@ChrisWard64658]

I learned a lot, thanks.

[@DIYAudioGuy]

Glad to hear it!

[@shawnsanderson3695]

The explanation is legit my man!

[@DIYAudioGuy]

Thanks!

[@atlantajunglepythons1744]

Such a great info-dump. Totally new to this, so trying to pick up some bits. I know you covered a lot, but as I sip information, and don't get a chance to swallow, my thimble just chokes then overflows. I'm left with a bit of the flavor, but most of the nutrition is gone (when people cover advanced topics and go _so_ fast!) I realize for much of your audience this is all 'old hat', nothing new, no need for pace-pause-repeat [[Teaching -->Learning]] because they all know it already. Hey, maybe I can watch 6 more times, keep stopping it and take notes! Meanwhile, thanks for putting the info out there.

[@DIYAudioGuy]

👍

[@ppitowman]

Ah yes, well spoken educational videos about audio, I’ve been searching for this for months

[@timmyfingaz100]

Wow, I watch a fair bit of youtube tutorials and your way of explanting things is great!! Thanks for the info's!!

[@DIYAudioGuy]

Thanks for watching!

[@narmale]

i JUST made the connection between the sub and the port listening to you talk about the "not a fan, because its pushing and pulling" so the port is 101% tied to the T&S of the speakers due to Vas, Fs, BL and MMS... all have a direct effect with the port, both shape and length are affected by each other due to the interaction of air molecules inside the port, change the length and shape, you just changed everything about it

[@DIYAudioGuy]

Yep, it is an interesting bit of physics!

[@narmale]

@@DIYAudioGuy i just never made the connection, easy way for newbies to think of it would be the air acts like a passive radiator... only not solid... but gas particles

[@GamingShiiep]

3 questions: 1. What if we placed the port OUTSIDE of the box? (literally thinking outside the box, pun intended) 2. Can a port be bend too? Gradual bend vs. abrupt bend? 3. Would it be beneficial to dampen the port by glueing anti resonance material to the outside walls of the tube?

[@DIYAudioGuy]

1) Yes 2) Yes 3) It could not hurt, but it would probably only be worth the money if The porch were made out of something flimsy.

[@GamingShiiep]

@@DIYAudioGuy 1.) Anything special to consider when the port is outside? 2.) Does the bend in a port have a big effect on something (if so, what?)// like can I make a "snake shaped" port which is flat on top of my box? 3.) I was thinking about that material which you can use to dampen the inside of car doors for example.

[@jimbobdobbs1597]

My issue with ports- is you come to find out half the songs sound like crap and you find yourself playing the same 5 songs that sound "great" in your range, not the music you enjoy- IF you listen to actual music. Thats why i am going back to sealed box this build.

[@SendingFreedomTM]

Hey Jim let me help you out there, you are judging ported enclosures and the mechanism based on poorly made or specifically designed ports. IF you make the enclosure Large enough, and you design the port to have the proper area and length, then you can make better and louder sound across the board. Period. If you make the box large enough and design it properly, then you will have absolutely better sound. The cost is more space needed for the box assuming you design it for “full spectrum”. Mainly, where you tune a subwoofer to in frequency it can be nearly twice as loud with the same or better quality at the same volume level. BELOW the tuned frequency the subwoofer won’t play as it doesn’t have enough “suspension” from the air. That’s the easiest way to explain it. Sealed will make more similar suspension across the board of frequencies. Here is the key: to make it sound better and play louder at good quality, you will need to tune the box to a frequency basically low enough that it’s as low as you would want. Now if you want high frequency sound and you tune a box low, it may sound worse. One thing you can always do is to use a digital or amp filter to remove sounds you don’t like. Now to tune a subwoofer to like 26-28 hertz then you will easily cover most frequencies you would like to hear for most music. The rest would be adjusting the digital filters because songs may have notes or sounds in frequencies that you dont really want and they’re noise. Now if you are super picky you can still port the sub and tune it to 18-20 hertz. That’s as low as a human could hear, and generally it can play much louder across the board up until you get to higher notes which would usually be equal to what a sealed subwoofer would play without clipping or distortion or whatever else. But to design it that low it won’t be as loud as a higher tune at max volume. Many prefabricated boxes and designs tune to 36-40 hertz to get max loudness but they miss the key low notes. They also do this because to port lower you need a larger box with the correct well designed port area and length to match. So look you can easily get louder sound overall with zero loss across the spectrum in any frequency compared to sealed subwoofers as long as you tune it low to the minimum frequency humans can hear at. Anything else you do or want can be adjusted by filters to remove the lower notes for certain music, remove higher notes, and even out the volume across the board even. You also want to ALWAYS cut out certain frequencies on your amp before the sub, which would be anything below hearing level and anything above whatever the recommended levels are for your sub. I dont personally know what the cutoff should be for highest frequencies but it’s below 80-100 hertz for sure for most subwoofers. Anyways, if you have the room for an appropriate ported box and you tune and design it properly with enough size and port design, then you can play much better than any sealed box and louder across most if not all notes. The key there is space for the box, the amp you have, the songs and sounds you like, and the availability or affordability of the subwoofer and it’s RMS level of energy it can take. Like many premade boxes are shitty and can only play to 40hertz and up. A ported box should be studied and compared by sound level and curve, and the type of music that you like to play. Most people end up realizing without clipping they are restricted by the energy their alternator and battery can handle. So the best option is to go for bigger subwoofers, and ported with a large box if they want lower notes and full spectrum. Many people actually want 20 hertz for hip hop. The thing is you can change a port to have a better curve you like and be louder with all of the notes by tuning it higher and cutting off lower notes. Anything below the cutoff curve is a sharp decline and is almost impossible to play after 1-2 hertz below. You MUST program your amp to cut off all frequencies below your subwoofer boxes tuning level, and always should cut off any sounds below the frequency of human hearing capabilities. Mainly, if you know your music you can know it’s okay to tune it to 35 or 40 if you don’t want anything lower to play anyways. You should be cutting off the minimum based on tuning and maximum based on the limits of the sub and the general maximums based on an instrument easy Google search. Then a ported sub is still superior or equal at any given frequency at its tuning level or above to a sealed sub, assuming you build the box correctly and don’t make it too small. But listen many people actually have a subwoofer and amp setup that can play as loud as they want at every frequency they want without clipping their amp or overpowering anything and draining their car. In that case as long as you have a pass through filter you can also use your audio input or the amplifier to adjust the filters to your desires based on what you listen to or even have different filters for different music. There is nothing inherently worse about a ported sub and a ported sub if built to the appropriate size and shape will always be superior in its capabilities even when it’s tuned to the lowest possible frequency of human hearing. If you have more capabilities for clean sound at a louder volume across the board, or in the ranges you listen to, then you can always adjust the filters to decrease the sound signal sent for certain frequencies. If you don’t have room for the large box in your car but have room for larger subs and more expensive subs and have the amplifier and alternator to fuel it, then you would definitely want sealed. It’s also more affordable and more simple and has a generally good sound curve. What we really need to be considering here is not what attributes ported boxes have, but rather what trade offs we need to make and what benefits we need to make. Frankly anyone who wants louder sounds across the board full spectrum and they cannot afford higher watt subs or amps, or their car doesn’t have the electrical output, and they have the room for a bigger box then they will always benefit from getting a ported sub tuned to a lower range especially if it’s done to the lowest frequency that can be heard. Then if someone doesn’t listen to music that uses lower notes, or maybe even they already block lower frequencies because they don’t like them in their music, then they can have louder subs ported to a higher range cutoff with a smaller box. If not, then they could still tune it to a lower frequency if they make a large enough box designed properly. The problem is ported subs are always associated with scam sales of boxes super small with horrible designs that are tuned to 40hz or higher which cuts out major frequencies if not the most important for some, and people don’t realize this so they don’t change their pass through filter higher and their sub free wobbles and bottoms out and damages itself. Ported subs can be very much like sealed subs but louder when designed correctly. The question is whether you have space for a box, whether you need frequencies and how low of frequencies do you need, and whether you want louder noise.

[@MadLadCustoms]

Wow, just found your channel. No bs straight to the point and in an understanding way for the rest of us. Subbed!

[@DIYAudioGuy]

Thanks.

[@rpaip]

Excellent video! One of the best and most comprehensive overviews of bass reflex systems 👍

[@DIYAudioGuy]

Glad you enjoyed it!

[@turboduckhead6179]

This video is jam packed full of information

[@DIYAudioGuy]

Jammed for sure.

[@markfischer3626]

The best tool for understanding woofer enclosure performance is Newton's second law of motion applied to forced oscillation. In this equation three factors are important, moving mass, damping factor, and spring constant. In a ported design the port acts like a pipe in a pipe organ tuned to one frequency. The same is true for wind instruments, reeds and horns. You change the notes by changing the length of the air column. At the tuned frequency air moves easily through the port. Half an octave higher and lower air won't move easily through the port at all. So at the tuning frequency there is low back pressure resistance to air moving and the cone continues to vibrate for awhile. Light cone weight tend to reduce this effect but lack of strength leads to breakup of the cone into harmonic modes called Bessel functions like the membrane of a drum. The spring constant and damping factor are largely controlled by a fairly tight outer suspension and the spider. Differences in restoring force varying circumferential tends to twist the cone while differences in force radially tend to shear it. Therefore the spring force and damping factor vary with both frequency and amplitude. IMO it's not a good design. Not all sealed speakers are acoustic suspension which should have been called pneumatic suspension. Those which are and are optimized overcome these problems. Further advantages are explained by the ideal gas laws.

[@JaykUS354]

Wow, I still have so much to learn! I’m tearing down the Roku wireless subwoofer and looking into using the components in a total upgrade of the woofer and enclosure… going to be a fun project!

[@DIYAudioGuy]

Does that subwoofer have any kind of DSP applied to it?

[@JaykUS354]

I should add: a simpler project we had in mind was to splice in some RCA jacks exposed in the back of current enclosure and hook up a small external amp to power some buttkickers… that would be our main preference just given our current setup.

[@johnviera3884]

Best and most digestible explanation I’ve ever heard.

[@DIYAudioGuy]

Thank you!

[@psyphonyxaudio]

Air Mass - ..anyone ever been close to a Tornado know that Air can express a force / pressure. .. same with walking near a building during a windy day. ( wind tunnel ) Very nice, detailed and well explained video on the physics of how this works.

[@DIYAudioGuy]

Or just roll down one car window part of the way. Then roll down a second window a little bit and notice how the resonance stops.

[@psyphonyxaudio]

@@DIYAudioGuy - Through flow. Yes! See, I like what you've just done here. This gives most regular people who happen to enjoy audio an everyday experience that relates to how sound functions and a practical WAY to recognize and listen for in an audio specific situation.

[@fredgeitner713]

Very interesting. You explain it in a way that actually makes sense to me. Thank you.

[@DIYAudioGuy]

Glad you liked it!

[@chef_boi_ar_teej6969]

You really do give off a sub character from mythbusters and i enjoy it

[@DIYAudioGuy]

Your comment made my day.

[@dragan3290]

I love your explanation! Very informative 🙂👍👍👍

[@DIYAudioGuy]

Thank you! 😃

[@shawnsanderson3695]

I'm already loving this one.

[@DIYAudioGuy]

Glad you liked it.

[@johnhandcock7744]

I've always loved music, of all genre's and styles, but lately I feel like an ignorant poser. My gosh there's so much to it. From speaker's polarity, to the sounds frequencies and the human ears abilities, to that "warm and fuzzy" tone old amps/receiver's have that I searched for only to find out its not necessarily a good thing. I have some really nice old receivers from the 70's that come to find out all need, at least, recapped. The Sansui 9090db being my first and favorite garage sale/thrift store, or in the 9090db's case, dump score. The more I learn from people like yourself the more hesitant I am to jump in and start soldering on priceless vintage stereo equipment.... but, gotta start somewhere!! I'll start on the old technics SA-303, and cross my fingers! Thanks for sharing the priceless experience and information with those of us less endowed than yourself!!!

[@DIYAudioGuy]

It just take some time to learn everything.

[@djs1809]

Thank you for a very detailed and professional explanation brother, I love your passion.

[@DIYAudioGuy]

Thanks!

[@jimmyjam5588]

Hey thank you I needed this video I'm doing a spl build for next year and this put everything into perspective, very detailed 👌 been following you for a year now and always something to learn 😀

[@DIYAudioGuy]

Glad it was helpful!

[@jimmyjam5588]

Keep up the good work

[@DannerPlace]

Wow, this is really good stuff, thank you for posting.

[@DIYAudioGuy]

Glad you liked it!

[@PetarBozic]

You just scored yourself a subscriber my good man. Amazing video, thank you!!

[@DIYAudioGuy]

Thanks!

[@leiferickson3183]

Mind Blown. Crystal clear description. Thanks!

[@DIYAudioGuy]

Good! I was not sure if I was being clear.

[@roscius6204]

I'll be a bit picky and give you a chance to clarify, you started out by saying the port is not a speaker but by the time we arrive at the 'resonating air' section you kinda say it is.... I'm in the guitar cab world, so the desired outcomes are different, I personally like to run an open back (free air??) cab and a closed back with a small slot port. Now you've got me thinking about the volume of air in that slot.🤗 The closed back is definitely tighter and more focused. There's no 'better' though.

[@donaldglaser7686]

I read Great Sound Stereo Speaker Manual many times cover to cover in the 90's as a teenage box builder. People were always amazed at the output of a single driver in a properly tuned ported box. Then I started building single reflex bandpasses. Same thing. I'd get 18" sound out of a single JL12W1 driver over a fairly narrow band.

[@DIYAudioGuy]

Knowledge is power.

[@victorpin4957]

Do you build for sale?

[@greengamerguy623]

this was very well explained thank you

[@DIYAudioGuy]

Glad you enjoyed it!

[@Adam_Adamsky]

3:25 It's frequency what you measure in cycles per second. You measure the wavelength just as any other length. In meters.

[@DIYAudioGuy]

Correct

[@HifiVega]

Great info

[@DIYAudioGuy]

Thanks

[@topixfromthetropix1674]

I suppose I'm a DIY guy, too. I built a sound system that could play to 50,000 people. Although people have transmigrated through a lot of sub-woofers, we worked with the old JBL single 18" folded horn ported speaker enclosure. When stacked in a 4 X 2 configuration, it goes to 40 CPS almost flat. It only occupies 16' to 20 feet of wing space in a coliseum stage and sounds as tight as JBL L200 studio monitors.

[@DIYAudioGuy]

Impressive!

[@vmontalvo5591]

All of this in under 10min😱😱😱 👍

[@ksb916]

Great video and lots of great information!

[@DIYAudioGuy]

Glad you enjoyed it!

[@jamesfair9751]

So a subsonic filter can help from playing to low of frequency and bottoming out your subs in a ported box. Is it true that a sealed enclosure wouldn’t need a subsonic filter to be set since there is no port to push all the air out and therefore you always have that air suspension on the subs?

[@gordythecreator]

@3:00 I've never heard that explanation... thanks!

[@DIYAudioGuy]

Thanks!

[@dudders___1684]

From my experience, with a 12 inch kicker sub, I’ve tried both ported and non ported. Non ported hit harder the the system I have and there’s a lot more resonance. Maybe the ported box I tried was made for a lot more power, idk

[@johnnycarter6196]

I am doing now a x2 12 inch Kickers L5, and DIY a ported box with a port in the middle. I had one of them in a sealed box, and sound was good, but heard same speaker in a ported box, and the sound and bass was 10 times more intense and deep then mine. So now i building it.

[@jckf]

Whether the out of phase sound from the back of an element cancels out the sound from the front will depend on the length of the path it has to take. You can theoretically tune an enclosure to get these two waves in sync at certain frequencies, and even though we don't do that and the sounds we play are rarely just a single frequency - we'll probably very rarely see 100% destructive interference

[@DIYAudioGuy]

Yep, transmission line.

[@soostdijk]

Drums will not sound correctly with a resonant system, it is mainly a loud “boom” box.

[@DIYAudioGuy]

That sounds like a testable hypothesis.

[@turdfurgason8476]

Awesome information. No BS either. 🎉

[@DIYAudioGuy]

Thanks!

[@PeterMilanovski]

Speaker port's for speaker port's but the science here is strong! So strong that I haven't come across science channels that get it this correct! Buddy, I'm impressed... The scientific community could learn something from this video and then some... The majority of people don't know how much mass is weighing apon them... And a tube is never empty!

[@DIYAudioGuy]

That is exactly what I was shooting for.

[@youngfeezy7969]

Wow I love this explanation. Subbed!

[@DIYAudioGuy]

Welcome to the party!

[@whydotheathensrage]

thanks, I am in the process of building my first box with some left over drivers tweeter/mid-range from a JBL 4412. I Have a pyle 12" blue wave woofer that i got for near nothing. This will be fun, in fact I will probable use this creation(combined with the software) as a dedicated sound physics experimental box. Thanks again, as i am sure your teachings will spare me from much trial and error.👍👍

[@DIYAudioGuy]

I have a good video on box building that you should check out! kzbin.info/www/bejne/iYe9Zqh6lNigpsU

[@whydotheathensrage]

@@DIYAudioGuy thanks, I was going to .45 degree cut my box, but decided not to on my first try with a 3 way box. I decided not to go with the Pyle bass, and used a 12 inch from an l100, it sounds better combined with the tweeter and mid from the 4412👍👍

[@olbluetundra881]

I build custom boxes on the side for friends. My first question is what king of music do you listen to. Next is how loud do you like to listen. 3rd is what vehicle do you have. The space inside the vehicle matters on sq. I then design the box to this. I've never had a disappointed person. Nor a box returned because it's not what they wanted.

[@DIYAudioGuy]

Yep, exactly.

[@robertliskey420]

Outstanding!! If viewers look at speakers made prior to the AR-5 it brings this home big time amps were low power tube yet they thundered the speakers of the day

[@DIYAudioGuy]

Modern car subwoofers with their massive and stiff suspension are just not very efficient.

[@SparkedEd]

I love this, great explanation

[@DIYAudioGuy]

I appreciate you saying that.

[@kierenalvarez]

Thanks for this video this is fantastic

[@DIYAudioGuy]

You're very welcome!

[@lyricalcoma1979]

Dude I’m 2 mins into this video and still understand what the heck your talking about, great job I’m quite simple so I’m gonna keep watching and I’m sure I’ll learn something 🎉

[@DIYAudioGuy]

Thanks.

[@ronnieorr10]

Great video .. What state are you located in?

[@dilbeckskate]

great video man

[@DIYAudioGuy]

Thanks!

[@peters8841]

In the beginning you pointed out that sound emanating from the back of the driver (and then enclosure) would be 180 out of phase; why doesn't this also apply to the 'second driver' formed by the column of air? Basically why doesn't the port create phase cancellation?

[@DIYAudioGuy]

It does, but only at specific frequencies.

[@peters8841]

@@DIYAudioGuy Oh makes that sense, thanks!

[@jimbohnenkamp5082]

Yes, I took Science classes in school, but, no, I don't remember much of it at all. I'm a prime example of youth being wasted on the young.

[@DIYAudioGuy]

Now that I'm old I understand what is meant by that. Yep youth was wasted on me as well.

[@bass305-HCCA]

You're an excellent teacher. 😎👍

[@DIYAudioGuy]

Thanks.

[@tritop]

Best explanation

[@DIYAudioGuy]

Glad you think so!

[@MrHalomaster8]

I love all the videos that you make I have a couple questions I need to ask you I have Dayton Audio TCP115-4 4" I have a 2008 Scion xB I purchase four of these small woofer what kind of box do you recommend ported or sealed and if you could help me out a little bit thanks

[@DIYAudioGuy]

Are you trying to use them as a subwoofer? I don't think I would recommend them for that purpose. This is really designed to pair with a tweeter in a bookshelf speaker for your home.

[@alferro3149]

I prefer sealed boxes. They don't go as deep, but are faster, better defined and an easier load for the amp.

[@newENIO11]

I simulated a dayton woofer in Speaker Box lite. But the diameter of the port is a bit odd. The closent diameter of tube i can find is about 3mm wider. Would that be ok? Is there a tolerance for speaker port size? TIA

[@supakrunch]

Excellent explanation of ports!

[@DIYAudioGuy]

Ports are a ton of fun.

[@clayinosaint3964]

I want to order a sound town KALE-112BPW but im so skeptical about the built since its says made of Plywood,but it still looks like a high quality thick plastic finish,. I have a doubt that the plywood made or wood finish cabinet is not durable than the plastic made cabinet for a PA system. Please enlightened me. Thank you

[@zoomzoom8704]

Would a box that is essentially a bandpass but both chambers are ported work? EDIT: apparently it's called a dual reflex bandpass enclosure. Still I can't find much reliable information about how it would perform.

[@ladjkaoz]

lots great info... something I keep getting lost is the octabe.. 1/8 etc... not sure what it meams...

[@justlooking6898]

If you mean 'octave' and I'm not a speaker expert, then if you were to talk to a guitarist or musician, an octave, or the plateau that IS an octave above or below any pitch, is twelve notes above it, so, let's just say that an octave above 40 Hz is 80 Hz, 40 is an octave above 20 Hz, and as such. Think of Tom Sawyer by RUSH - When the bass guitar kicks in, those 2 distinct, XXX-X....notes are an octave apart - They sound the same but are so different in frequency. '18 dB per octave'? That would mean 'that much over that far' if it were about an EQ or bass dropoff in response, etc. Hope I helped. Need more BV and Coke! 🤪🤪🤪

[@25hztolife14]

Can it be a Hexagon or Star shaped port? Even my initials? Good video.

[@DIYAudioGuy]

Yes.

[@Roof_Pizza]

Manufacturers are forever playing with their port sizes, lengths, flares, openings and whatever else they can come up with.

[@deviant4life25]

Speaking of Stars,BEARDIE IN THA HOUSE!!!!

[@DodgyBrothersEngineering]

It can be any shape you want but it comes at the price of efficiency. A round port is the most efficient design possible, from there it comes down to how much efficiency you are prepared to trade for the design you want.

[@RandoManFPV]

Any suggestions for getting a slot port to stop chuffing without completely redesigning my box?

[@MrTubeman123456]

How come we never had this in school ?

[@joshalexander6697]

Most likely you did, you just never applied the science to speakers 🔊 Or you just happen to be sleeping or skip school that day… 😅 Even in health class, you learned about a diaphragm this is working in the same way if you pulled on the diaphragm pulled in air if you pushed on the diaphragm and pushed out air..

[@TXSTYLE750]

Redoing my Home Theater. Simple question: Ported vs Sealed for "Deepest, Rumbling, Bass for lower frequencies"? 🤔 I have a dedicated HT Room complete with insulated walls and ceiling.

[@DIYAudioGuy]

Either one will work, you just have to approach it differently. If you go ported you will want a big driver and a huge enclosure with a very low Port tuning frequency, 20 hertz, maybe even lower. The other option is to use a huge driver and a sealed enclosure and then use equalization to bring up the low end.

[@TXSTYLE750]

Thank you for the quick reply! Great channel and content by the way. 👍🏽