3rd Order vs 2nd Order: Folded Horn vs T-Line

This video is the second in a Playlist called Counting Acoustic Orders. This video shows you how I learned how to count subwoofer enclosure orders. I discuss the differences between multiple subwoofer enclosure models; based upon which 'acoustical' order they were designed after.
This video features:
* 2nd Acoustical Order: Infinite Baffle
* 2nd Order Enclosure: Sealed Enclosure
* 3rd Order Enclosure: Folded Horn
These interesting enclosure design styles may or may not have been something you or someone you know have used in the past. This series is meant to get a conversation started and enable us to teach each other in this field of acoustics.
Please enjoy, and feel free to leave a comment in the section below.

[@OpeKoney]

I once downvoted one of your videos because I was too foolish to understand the purpose of a bench test. I'm sorry. You are a master and an educator, bringing us all up.

[@BudgetBassHead]

No worries, we have our moments.😉 This channel is all about sharing the experience and helping each other learn more about our passion. 🥳 I'm glad I was able to help. 😁

[@Grommet2007]

A decent rule of thumb is that (1) there are no "odd-order" passive alignments (long explanation, not going to get into it here), and (2) there's usually a direct relationship between the number of major impedance peaks around their passband and the system's "order" (take the number of major impedance peaks and multiply by two). So, speaker - 1 peak, infinite baffle - 1 peak, sealed - 1 peak, vented - 2 peaks, 4th order bandpass - 2 peaks, 6th order bandpass - 3 peaks, 8th order bandpass - 4 peaks, etc. TLs, like vented enclosures, usually have two impedance peaks, hence 4th order, which makes sense because a TL can also be looked at as a vented enclosure with a vent that's the same csa as the chamber :-). Front-loaded horns with a sealed rear chamber are also 4th order (like 4th order bandpass), which makes sense because a FLH can be looked at as a 4th order bandpass with a small chamber and an expanding "vent".

[@djturntablestilltheend5159]

If I remember my horn theory correctly, a front loaded horn (with sealed back) are made so that the enclosure acoustical capacitance (sealed chamber + woofer impedance peak) cancels the horn throat to mouth acoustical inductance, at the horn cutoff freq. An analogy is acoustical transformer - transfer high pressure (small volume) air at the throat to a low pressure (high volume) air at the mouth. The "3rd order" has to do with the filter rolloff, say HPF, at the horn cutoff freq. A third order rolloff is 18dB/octave, this can be measured on a properly sealed back front loaded horn. Built correctly the horn measured impedance will show a flat line and no impedance peak. The horns sound excellent but requires use in multiple to get to very low frequencies. These horn types sound the best in my experience. There are several other horn types with different characteristics than described.

[@axs307]

Hi good evening in your opinion how would you rate the 0verall performance between a transmission line enclosure vs a folded horn enclosure as far as bass/sub application?

[@djturntablestilltheend5159]

@@axs307 folded horn wins every time. folded horn are more efficient, with a transmission lines you get in-phase (0degree say) and out-of-phase (180 say) combining at a certain frequency depending on the line length. A sealed rear chamber does not have that cancellation if build correctly.

[@djturntablestilltheend5159]

the roll-off of sealed back horn is 4th order not 3rd as I mentioned above.

[@arena_rock_man9030]

Excellent educational vid! U was just thinking what the difference between a 2nd order and a 3rd order was.

[@gsxroyce256]

Seems like a second order horn would be better than a horn / line alone

[@ronaldomaynard4816]

Would love to see a tutorial on how to make a folded horn

[@jianboo]

Same here, if there's a computation based in the driver and size of the box plus the front and rear of the horn. Also does the folded horn sound differently from the other 3rd order like transmission line?

[@csj9619]

search keyword "Hornresp"

[@ronaldomaynard4816]

@@csj9619 that software is hard to use much less understand

[@casestyer1166]

You are the most articulate bass head I've ever heard lol.

[@detonationpyrotechnics4156]

Him and barevids are spot on. Don't sleep on mbe enclosures either

[@jonanderson4474]

Hexibase can get down too.

[@degenerateboofer]

So for the horn I’m confused... the sealed enclosure section would never interact with the sound waves of the horn section. Why is its order any different than a normal sealed enclosure? Because the sound waves are modified by the horn?

[@RandoManFPV]

Ah I know this is old and heck you probably know now but like he said in the video. The front side is not a loading chamber it's just a horn. So in this back loaded horn the back side is sealed and acts similar to a fourth order build except with a really efficient front side. I'm curious what this would look like on winisd

[@BigGus87]

I’m thinking of getting a 4th order band pass for my woofer. I was told that when there is limited air flow from trunk to cabin it’s the best enclosure to get the bass in. Would you be able to make a video explaining why that is true or not true?

[@jessicaembers924]

I just love horns, horns are cool. But i've come to the conclusion that i can fit 4 of the same speakers wired series parallel in 1 box without the horn, and get More output. Oh well?

[@LidellFrasier]

I'm not sure I agree with the idea of a sealed enclosure as a second-order system; the movement of the driver is going to induce pressure waves inside the cab; these waves can interact with the cone as they propagate and reflect in the sealed cabinet, potentially causing both constructive and destructive interference. I would argue that this constitutes the waves interacting with each other across the plane of the driver, precluding this system's consideration as an 'infinite baffle' system.

[@diylithiumguy]

Sir, a T-Line is a 4th order enclosure. I had to stop the video there, so no telling what you had to say about the FH. :(

[@NathanOakley1980]

IB is only 6db per octave roll off, it’s the main reason for doing it. Sealed box is 12db per octave roll off. You have an additional 6db per octave roll off per order…..so 3rd is 18db 4th 24db etc.

[@NathanOakley1980]

Sealed or IB (if you have the space and money) are the best for SQ because of the smooth roll off. Furthermore there are no timing issues with the first wave from the port as there is with ported designs. I have a sealed sub, needs a tonne of power (definitely a downside from a cost position) sounds great, it would dig into the lower frequency ranges (below 18hz) if it was IB but then it wouldn’t handle the power. Everything is a trade off when it comes to subwoofers. I have never listened to an IB set up. I’d love to hear if the extra lows actually improved the quality of the listening experience. Knowing what sub 20hz did to the reality of the sound I can hear, I could only guess weather or not that extra oomph below what we actually hear would improve the quality. Somehow, just felling a bit more pressure (often removed from music at mastering strange anyway) doesn’t make me want to convert the next room into an IB enclosure. But who knows, it might sound fab 😁

[@BudgetBassHead]

@@NathanOakley1980 technically most automobile rear deck speakers are infinite baffle. Of course there is a ton of filtering there as well but infinite baffle are more prevalent and make more sense when Incorporated within a home audio system with equipment designed to dig into the lows.

[@medschoolvisual6954]

Agreed 💯 this is why guitars have a hole, a box guitar with no hole does not sound as good

[@izzzzzz6]

The way i look at it is the transmission line is the speaker cable. Because in radio the coax or the ladder line is the transmission line. The rest is tuned ports, tuned boxes or tuned horns. Nice to see this time you have an image of. real folded horn with the sealed box at the end. I want to know more about high excursion speakers act in a folded horn like this. Any videos of any working?

[@BudgetBassHead]

Checkout this video: kzbin.info/www/bejne/iZDJqmSbndyDh7c

[@jckc2633]

Lamer terms break it down one at a time nmw

[@csj9619]

"Quarter-wave" enclosure nomenclature can get VERY technical. Just ask the professor bullshit degree holders out there. Good video, BudgetBasshead.

[@daveruston1354]

I'm planning to build a b&w sealed subwoofer into a couch making it a 3rd order rear loaded subwoofer. This video was helpful in conceptualizing how in going to build it. Thankyou for your presentation 👍

[@johnnycorn7225]

I'm going to do a third order horn enclosure with three SQL 12s. Ultrasound quality and should be plenty loud

[@BudgetBassHead]

I would love to see a setup like that!

[@johnnycorn7225]

@@BudgetBassHead those sql's use xbl2 motors and will take 3K all together they are super nice! I've got 13 cubes to work with total and the sql's only need three cubes so I should have plenty considering the end of the horn is continued by the back of the SUV. There is nothing like that concert sound of the impact coming at you and making your pants flap and hair move. I calculated the path length of the fs and it's right super close to the quarter wavelength function so I'll be able to run it perfect.

[@otilbarcu478]

Hi whioch it°s better for garden sound?Folded Horn vs T-Line,i here horn it°s the best for outside?thank you

[@bisnathlinc]

ok i get it about these Enclosures T line Folded Horn with sealed Rear etc.. but which is best bass

[@connormcinerney7503]

What's your reasoning behind designating a free-air driver and infinite baffle as 2nd order? My understanding goes that a free-air driver would have no order, as there are no boundaries (outside of the driver itself) to modify the sound waves. And infinite baffle is 1st order, as it only provides complete isolation of the front and back waves, which makes it distinct from a 2nd order sealed enclosure which provides both isolation and capacitive reactance of the chamber the back (or front) wave fires into

[@Zionslayer1]

That's a front loaded horn, not rear loaded.

[@BudgetBassHead]

I stand corrected. Thanks

[@Raulley27]

How can i design a horn enclosure? I really want to make one but i don't know how to design it to sound good, can you please give me some advices?

[@axs307]

I would like to see some calculations in determining the length and taper of the line... Ty

[@jeanfernandes7897]

I've leaned something with you... Brazilian channels don't teach thats things

[@Izzymeyokee1]

This shit is science. Wtf is he saying

[@BudgetBassHead]

😄

[@artmediasciencedesignfabri322]

Great video short direct informative I'm just getting into DC audio but I luv my surround hifi I'm just getting into auto audio and vocabulary db fairides is new and I stay interested in the different filters capacitors you might have some good advice or suggestions & as always Im looking for a definitive guide breakdown in amps or recommendations great video thank you for time knowledge and effort

[@BudgetBassHead]

Glad it was helpful!

[@RB-ve7sr]

Спасибо за подробное объяснение этого акустического оформления

[@hippo-potamus]

So in your horn enclosure I guess once the subwoofer is in place its trapped forever. That box design is unrealistic.

[@BudgetBassHead]

These are just mock-ups. Of course you would design a service door.

[@iisreallughtkingsun4360]

Thanks for this information brother

[@jay1185]

Thanks for this. I'm staying in the same class but am looking to make a better box!

[@BudgetBassHead]

Hope this helps👌

[@Superficial_david]

. I always learn something watching your videos.

[@BudgetBassHead]

Thanks for tuning in 🤟

[@Louisiana_aceofspades]

Is a infinite baffle better for sq than a sealed?

[@scottbe1]

Yes

[@ogairbender808]

I do love these videos

[@larryboles629]

LOVE YOUR VIDS

[@bigamp2527]

Sound like Steve Harvey as a basshead

[@crucial0072]

I just discovered this dude today and said the same thing.

[@joemamma6138]

So cool this is so interesting

[@BudgetBassHead]

Glad you liked it.

[@ricardombr]

Does anyone know a speaker that is better without any enclosure? Not accounting for twiters

[@BudgetBassHead]

That depends on whether you are talking about full range, mid-range, mid bass, or Subwoofers.

[@ricardombr]

@@BudgetBassHead When i think of a speaker without any enclosure i think tweeters, specially electrostatic, so im asking towards mids and wether it would be a viable solution on the buddget.

[@aw_creamsoda]

kzbin.info/www/bejne/hqGwmXlrqauLmtE

[@lazyh-online4839]

By "without any enclosure" are you referring to something like in wall speakers (infinite baffle) or do you mean something more like an open baffle design?

[@thetruth7839]

They have plenty of free air subwoofers

[@trinithings5384]

Love all your videos

[@fakamean1208]

What sub enclosure for a HDC 3 15”...... not sure ..... what r u thoughts.....

[@BADASSBASSBOY69XXX]

Nothing really to comment about and the proof is in the pudding physics Don't Lie. Are you building t line for the peerless by tymphany stw-350f ? I read somewhere in your comments that you're going to build one or was it for the smaller driver,?

[@BudgetBassHead]

It is for the 4 inch Dayton TCP115. I'm building a T-Line for a dual set up of those guys.

[@BADASSBASSBOY69XXX]

@@BudgetBassHead that makes sense, i thought you wouldn't be able to fit it in the car, great video

[@BudgetBassHead]

😀

[@Rico702Vegas]

Since when is it pronounced "AQUSTIC"?