Transmission / T-line boxes - How they work!

Brief explanation of t-line boxes and how they compare to sealed and ported boxes! This information is all based on hours of web research and personal experience designing and building them, but there is still much more to learn! The world of acoustics is confusing and doesnt always behave how it does on paper.

[@drc97086]

This fellow really understands how to convey an otherwise difficult concept, in a very easy to understand manner. Thank you.

[@cinilaknedalm]

More of these please mate. With internet full of technical mumbo-jumbo, nice to see someone explain it in such manner to get us novices enthused :)

[@jamesmason4361]

science mate its not

[@Live_Loud]

After 9 years I still found this information very very valuable!

[@saxmusicmail]

As a saxophone player, and a speaker builder... GREAT explanation!

[@Vitaliuz]

Much obliged! Perfect explanation. Short, straightforward, filler-free, and easy to understand.

[@coreyellisart6877]

Wow you are by far one of the most intelligent well spoken individuals I've heard on this subject you have been able to touch every basis and answer every question I have regarding a transmission line speaker cabinet all wrapped up in one video I would love to see where you are these days and what accomplishments you have made in your personal life thank you so much for taking the time to explain in layman terms the basic concept of a transmission line box

[@barevids]

Wow thank you so much for the kind words my friend! Since this video I have taken to repairing amplifiers; I'm about 5 years in now from zero knowledge on the subject, I have loads of very recent videos and live stream playbacks, with the intention of teaching and raising interest in component level repair! 😊

[@seekssean]

Bro we need more people like you in the world t line box designs are way less complicated then most try and convey you explained it flawlessly.

[@timdiebert7128]

One of the BEST descriptions on those enclosure designs!! Kept very simple & followable...well done! :)

[@cameronverissimo2511]

This video has been the answer for many years when people ask me about subwoofer audio. Thank you for making this video.

[@leskorcala4898]

Great analogy and straight forward explanation of T Line , love it ! Thanks from Montana

[@Figgbot247]

Great video, I love that you are willing to accept criticisms! You should try folded horn enclosures, they are crazy efficient and incredibly low distortion! I built one for a 2 inch speaker that was able to hit down to 40 Hz.

[@machinedred]

Finally a real life explanation ! ,I've been building boxes for 20 years and this is the best description I've heard ,but please elaborate on the "room size " for frequency and how this applies to my car thanks ! Excellent!

[@RobbinsRacing]

do you know how that effects it?

[@machinedred]

I'm waiting for an explanation myself , I know the room has its own frequency but I don't know how to match a box to it

[@seaco33]

That was the best explanation of how different speakers work that I've seen on the net, well done that man!

[@proffski]

Excellent, a few important omissions but I fully applaud the incredible enthusiasm and confidence shown. One of the best presentations I've seen on KZbin in years. Well done!!!

[@josephmuniz9959]

Dude due dude check the hair out. So I’ve been watching for about 5-6 years now. Look where you are now. Awesome man, love your work

[@almostoldfarts]

I "logged in" after watching this video JUST to say.... Great Video Man! Good info and your personality and presentation was Awesome!

[@rcarendsen]

Explained perfectly in a way everybody understand.... Thumbs up

[@BlueBonnetAudio]

Very nicely done. In a sea of barely watchable informational videos, this was nicely produced, and you did a great job with the explanation.

[@joebell9908]

Brilliant! Thanks for simplifying a rather complex subject. Best explanation I have ever heard in 12 minutes that is both reasonably accurate and satisfying to our common sense. I wish I had heard this first before reading volumes on the subject!

[@gregt5996]

Great way to explain without confusing people with Fs Vas xmax Q etc

[@FlamingBeatsOfficial]

The reason why ported boxes sound less tight is because you are delaying the sound waves from the soundwaves coming directly from the woofer. The sound waves coming out of the port can also be out of phase with the soundwaves coming directly from the woofer depending on the tuning of the port and the frequencies produced, this can cause certain frequencies to be cancelled out.

[@georgem6359]

Great explanation. I think it is the easiest one to grasp on for a non technical person.

[@demartis63fd]

I think that no one could explain it better. grate job mate

[@shaunbillman6852]

the best vid on youtube for explaining enclosures thanks much! :)

[@MaxTheCenturion]

Thank you very much for this video barevids, i am in the process of building a t-line for my car (Yeah its VERY big) that fills most of my trunk and after watching your video i am going to start over and re-design the box to how you described a t-line actually works. Keep the great videos man, and thanks for saving me a wasted box that would not hit low notes!

[@valvenator]

Thank You, well done! Coming from a musician, you made this very easy for a musician to understand. Sometimes there's too much 'mystery' associated with some aspects of music, speakers, electronics etc. that can be easily explained by the right person, and this is one of those mysteries solved :)

[@captrajesh]

Young lad has explained the basic principles well using good analogies. May be he can follow up with some more explanation of each of the topologies.

[@customcaduceus3276]

Best explanation of t-line boxes and standing sound waves. Awesome!

[@davidcmoffatt]

Good Job! I am like you. I watched lots of videos on speaker building and design and most of them were either adds for 3D printers (hexbase) or forums to show off their woodworking skill. I really really wish I had found yours first. It would have saved me a ton or reading. Just simple things like why people add wadding or how they choose the length of the t-line. Now If we could just get a video on how to model the wadding !!

[@gooberclese]

Thank you mate for making this easier for me to understand. I have wondered for quite a while how these worked but most audio experts like to use technical jargon that is hard for the average person to truly understand.

[@georgem6359]

This is the video that made me a fan of yours. Hopefully you can recreate this format for other topics.

[@wertigus]

it's fun to learn that all this also applies to radio waves, light waves and such, so cool to learn that the universe speaks the same language throughout the different energies within it, thanks for a great video again man! i love learning! i hope more people will get bitten by this curiosity bug too! :D

[@ffrob2001]

I learn something new even when watching videos for the 2nd and 3rd time. Thanks again for your great channel.

[@Collinormous]

Thanks for the explanation! I recently 3D printed a t-line box for some 3" full range speakers and have been playing with other audio things as of recent.

[@lonestarlucas]

this is such a simple and perfect explanation. this answered so many questions I had about speaker building. and so easy to understand. thank you so much.

[@AvocaSingleTrack]

Thanks much for this vid . The bottle and the Sax conveyed the principals of ported and T Line very well. I finally "get it" !

[@carspeakerreviews]

From my experience, unless you're running huge power, then SQ and SPL there's always going to be some sort of compromise. When it came to designing for my Hybrid Audio I6SW, it played well in my first enclosure designed fro 43hz response, but no where near hit low enough for my tastes. The last enclosure I designed was for high 20's which it does comfortably, but it doesn't quite have the energy the 43 box does. Aim for mid 30's, shove some power into the sub.

[@DodgyBrothersEngineering]

Ok so first things first, dude cut back on the coffee!!! lol seriously though that was a brilliant video, probably well over the heads of people with little knowledge, but direct and to the point for those of us somewhat in the know. I particularly enjoyed you explanation of quarter, half, three quarter and full wave. For years I have had trouble getting my head around that concept of that, and you explained it so easily. Great work will definitely keep an eye out on your channel.

[@JamesBrooks1975]

Awesome video! You said that you’d his was a “ basic “ explanation but what I find was that it was a very detailed explanation video. Great job at giving some reference examples to how sound versus volume works.

[@zeroice00]

Those were great demos and explanations.

[@JaysonAkersAZ]

Wow! Excellent video - very well explained, very helpful - thanks!

[@arthomer6535]

Good job; covered a lot of basics in a short, understandable way.

[@DRXxUziixX95]

the reason is a 1/4 is because the transition line is delaying the sound that is comming from the rear of the sub (which is 180° out of phase) by 1/4 wave length at the tuned frequency. this means that at the tuned frequency the front of the subwoofer is in phase with the rear of the subwoofer. this is why t-lines enclosures are so efficient

[@rmanzanog1]

I think that 1/4 wave is 90 deg and sounds are not added exactly in phase, and total sound is 1.4 times.

[@sethh8892]

DRXxUziixX95 true

[@iandrobertson]

Brilliant explanation. Even this simpleton understood. Thank you for making this!

[@joeytoribio2035]

great explanation. clears up a lot of the confusion on the web. nice job.

[@Xpp.]

Very good basic explanation !

[@Skarfar90]

My friend and I built a large t-line box for a pair of Pioneer 5000 SPL's All I can say is, that box turned out perfect for those subs.. While testing the subwoofers at only half power, they put out some ear-crunching dB's The frequency-response of that setup goes from 15-80 Hz, with a smooth peak around 27 Hz, but stays linear all the way.. Perfect for decaf and low-hitting songs. - Your "Basso Profondo" rebass songs is a good match.

[@TheReynMan77]

Exactly what I have been looking for. Excellent explanation.

[@AudioTalk]

Brilliantly explained! Thank you, more of this please!!!

[@speakerzedan103]

dude he is quite good in explaining keep it up man

[@666xXxXxXx666]

The wadding vibrates WITH the air. This is why it has the effect of increasing the internal volume of a sealed box, because all of the thin, light fibers move WITH the internal air pressure. However, in a t-line application, the air is able to escape through the port thus generating much more air pressure from allowing the speaker to move more. However, the fibers are static. They generate RESISTANCE to high levels of air pressure thus slightly decreasing air movement.

[@armandocamorra2488]

Love your explanation and your enthusiastic

[@PA5cAl1]

I have come to a point where I can actually sim a t-line enclosure quite accurately with programs like LspCAD. You need to take a lot of parameters into account and that's where something like LspCAD will come handy. One big advantage of t-lines is reduced distortion because the pipe will help the driver at a broader range of frequencies. It will also give an overall flatter response compared to vented. In general a t-line sounds faster and punchier when tuned right

[@rustyvideas8312]

Very well put! Excellent job explaining how the enclosures work. Enjoyed your video, now it's off to the workshop😁

[@DraGma]

Thanks a lot. This was easily the best explanation of the transmission line box.

[@SanDiegoRider]

Excellent explanation. I took away several points I was unaware of. Thanks.

[@FlamingBeatsOfficial]

Btw, the way a port works is by delaying the soundwave to add it back in in phase with the soundwave coming from the woofer but since diffrent frequencies need diffrent lengths of ports its impossible to tune every frequency and to prevent other frequencies from getting out of phase.

[@richardthompson3899]

here is my take, the air moves back and forth down the length of the transmission line and resonates at the tuned frequency. The wadding doesn't slow down sound, but slow the air speed. The wadding is a restriction. So if the air cannot travel as fast, it can not resonant as fast.

[@ajjeanson]

Awesome video! Well put together and very understanding! This helped my understanding greatly, thanks a bunch!

[@RobertJeffersonBased]

I have 6.5 inch car door speakers in some T-lines I built for my desk. I'm happy with them. They hit really low bass for being door speakers or 6.5 inch speakers in general. I tuned them to 75Hz on a guess and for size reasons.

[@tobymarol7329]

Great Video! I'm about to build a pair of transmissionline speakers so I've been reading a lot about box design and math lately and I think your idea with the saxophone is a nice application to explain the function of T-lines. Keep it up :)

[@bradgriffiths7507]

I found the analogies of sealed and vented boxes very easy to follow Parts of the T line box explaination I understand; I was once a radio tech and in particular wavelengths are directly translatable... but I'm afraid I'm still looking for another description of how the T Line works. I do however understand much more than I did before this video, for that thank you :)

[@barevids]

thanks haha this is a very very old video now 😂😂

[@bradgriffiths7507]

​@@barevids I looked at the age of the video before submitting but thought the info is still very relavent. Honestly, thumbs up for that venturi effect on the wine bottle... I can literally see how this works now! I'd like to connect on LinkedIn, I promise not to bother you with crap... but there's a lot of non-direct/relatable things we do...

[@barevids]

@@bradgriffiths7507 haha thanks! I don't have a linked in, but you can message my page facebook.com/barevids

[@ShaoLinSniper68]

thank you for this vid, mate. i watched 10 vids before i got to yours, but i learned the most from yours. good show, mate.. cheers.

[@stevenhiphop123]

thank you, best explanation i've seen on youtube!

[@powripper]

best explination I've evwr heard. I had a decent understanding to begin with, but this cleared up a lot of things that always confused me. wicked video dude. cheers!

[@toddtownsend3860]

thanks buddy. you provided alot of info ive been searching for all in one quick video. much appreciated !!!

[@paynebabes123]

Slowing down the speed of sound doesn't change the frequency. It just changes the phase angle of the terminus. Even so recent studies have shown in a speaker box it hardly slows it down at all. First thing you should have said in this video is that you are talking about vented t-lines. Closed t-lines are actually more 'hi-fi' but are half wave resonators requiring even larger enclosures. Look up 'Martin J. King' and mass loading transmission lines. You might like that if you like deep bass!

[@upliftingmusic5702]

Really like your explanation, thanks for sharing.

[@jorgequincy]

Ah... so thats why i didnt learn from my teacher because of complicated teaching :), unlike yours is ethusiastic and well explained with visual demonstration easey to cath even the topic is hard to understand.... and now ill build my own bottle with saxophone.... cheers to all only graduated fifth grade from public skull sori for may bad inglish

[@TimpBizkit]

I've heard different things about T-Lines. Some of the sound quality oriented ones, I've read on forums about people lightly stuffing the line, so they function like an aperiodic enclosure at higher frequencies and a quarter wave resonator at lower ones.

[@edwardmatt1606]

Really informational. You give exactly the information that I was looking for. Cheers.

[@TimpBizkit]

It seems like this is describing a tuned quarter wave pipe. I've heard people say that the other function of a T-Line is to provide a resistive air load to the back of the speaker to give tighter bass (stuffed lines), whilst using the quarter wave phenomenon to extend the lower bass response. I'm not that knowledgeable on Transmission Lines so take what I said with a pinch of salt.

[@echadmiyodea]

Great vid /explanation! you've been here a long time.

[@MickeyMishra]

oh man the good old days

[@pedroquiroga2552]

you're not kidding that a 12'' sub would need a large enclosure. a friend of mine built one for a single 12 in his honda crx and it's all of 7 cubic feet. and on only 250 watts it got decently loud. thats the best part of these types of enclosures. you do not need a ton of power to get great results.

[@hyperdriverr]

A tline is a rear loaded horn except there is an inverse flair or no flair wich helps make the box smaller than a regular horn. Tline is another alternative you can pick depending on how much space you are limited too. Horns aren't practical sometimes because of size. Ported or tline shrink down better than a horn so for smaller sizes they might work better than horns. An example is the auto tuba, its small but its basically a 60 hz horn.

[@TechTimeWithEric]

Very useful information, thank you.

[@PacmanBasshead]

Hey Sam, HAIR! Still revisitng this video.

[@barevids]

My precious 😭😭 Tbf some of this video is inaccurate especially the ported box part 😂

[@Bassotronics]

I recently made two t-line tube systems and was testing how low I can go with a pair of 6.5" subwoofers. I'm astonished at the fact that I could actually feel the bass shake me at 14hz with such small sub's. And the diagrams were only moving half an inch. The tubes were around 112" long each approximately. I'm also thinking about adding a ported chamber in front of the subwoofer to further aid in creating an added bass boost between 40hz - 80hz.

[@ruikazane5123]

The air movement can really shake people up. Much more if put on a car, with larger drivers

[@HS786UK93]

Great video. Learnt about t-lines AND saxophones. Lol.

[@carspeakerreviews]

I always like to stay somewhere in the middle and say; I've heard good and bad versions of both, even though I do prefer my SA-12 in the sealed enclosure at the moment.

[@nixoone28]

Very nice, clear and educative video thx man!

[@Chris_Wolfgram]

Excellent explanation ! But just some food for thought... I have plans for a future build on my desk right now, for Two 15" subs in a T-line enclosure... but by running the subs Isobarically (face to face in a clam shell configuration) instead of the T-line build being so massive Id need a moving van to put it in, it actually becomes considerably smaller. Not tiny, but doable in the rear of my F150 Supercab :) Ran this way, the cross sectional line only needs to be 1/2 of what a single 15" sub would normally need, and 1/4 of what two 15"s would need :)

[@barevids]

Hi! Yes, Isobaric is useful for situations like this. I'm not sure about halving the line area though. I predict high restriction and noise. Also, if your goal is output, then you'll achieve better results using the two 15s in a regular ported box or even 6th order if you can fit, than the iso t-line. Like, considerably more output. I tend to only use tlines when trying to make smaller drivers do rather crazy things.

[@DJDickieH]

You've taught me something new Sam. =)

[@HS786UK93]

You could stick one of those mobile phone speakers into that saxophone. Now that would be an interesting video

[@MrGroundpounderz]

thank you so much sam this really helped me. really appriciate the effort u pit in your videos

[@ruikazane5123]

I made myself a T-line box with a tight slot port(hybrid), placed a Sony 'dimples' woofer on it, and at 24Hz, the windows on the next room started to vibrate, i can hear it. 0.9 or more cubes, would fit a Punch P2 8", hope for a great massage!

[@juststuff5216]

Interesting. I'd love to see the design if you have it?

[@ze_german2921]

Instead of a Bass knob, you could make a Port Knob, Adjust the port by length and open and close it, depending what music you listen to

[@levienmark]

Thanks for this, much needed, explained nicely man!

[@petr8068]

Respect to you....perfect explanation!

[@paynebabes123]

Oh and they stuff the pipe because it gets rid of the higher out of phase harmonics of the fundamental. You can see all this by getting MJK's mathcad worksheets and modelling the line

[@IronMonkeyPimp]

Clever guy !!! Well done mate.

[@djndoe1ianrabbetts796]

Very nice explanation mate! I wish I had you talent for knowledge to voice. I have a JL Audio 13w7 and was pondering whether to change to a T line box.. No! Not enough space in the boot!

[@19pritz]

you should do this video but using the acctual boxes as examples so we get a better idea and understanding.

[@covolt882]

You are a god dor doing this. It explained PERFECTLY. THANK YOU SO MUCH!!!

[@Bassotronics]

Watching in 2️⃣0️⃣2️⃣1️⃣!

[@gritsnsand]

Good presentation. Thanks!

[@pablolopez-sr5cb]

Thanks for the video... can do you more videos and build speaker box t-line

[@cblakecollier28]

Happy with my T-Line box I built for 2 12s

[@bornfree1794]

Nicely done!