All About ISOBARIC Loading

What is isobaric loading, and what happens when you mount woofers in series vs. parallel? Give me 7 minutes to explain.
12V Talk Video Podcast: • 12V Talk - Episode 35 ...
BigDWiz of 12V Talk: / bigdwiz
HiFiVega of 12V Talk: / hifivega
Homepage hexibase.com/
Facebook / hexibase
SoundCloud / hexibase
Instagram / hexibase
Products featured throughout my videos can also be found in my Amazon Storefront: www.amazon.com/shop/hexibase
If you'd like to support this channel directly:
www.paypal.me/hexibase
/ hexibase
Endless by Psykick (c) copyright 2015 Licensed under a Creative Commons Attribution Noncommercial (3.0) license. dig.ccmixter.org/files/Psykick...
Along the Lakeside by @nop (c) copyright 2017 Licensed under a Creative Commons Noncommercial Sampling Plus license. dig.ccmixter.org/files/Lancefi...

[@TheMushmul]

How is it possible that you get into such complicated stuff on your channel, explain it so in depth and professional , and the views are so low ? This channel should be on top of the youtube audio channels pyramid !

[@TheMushmul]

@@HexiBase I'm certain that your channel will grow tremendously. I've seen information and box designs on your channel which can't be seen ANYWHERE else on youtube! Keep up the quality work! Cheers !

[@islander959]

Too complex maybe? 🤷‍♂️

[@R3l3ntl3sss]

I mean 300k views is a decent amount

[@SoLowAudio]

@@HexiBase where do you learn this information? Is there a major you can study at universities

[@shaunhintz1570]

It's because these videos invoke thought process and the masses are used to having the thinking done for them.

[@drdyna]

I've been building speakers for 30+ years now, and this is the easiest, most concise explanation I've ever seen.

[@AraceaeFanatics]

I spent 30+ years in mobile audio and I've never heard anyone speak audio from a design engineer perspective. I could listen to you explain this tupe of stuff for hours.

[@Halomaster4ever]

The presentation level on this is insane. When you darkened some fs parameters to show off how other ones are linked and when you overlayed the frequency response of the single sub with the series/parallel subs by using a dotted line for the contrasting subs. Good stuff, really appreciated.

[@jrap97]

I know some of those words

[@britwint9r]

Your graphics are some of the best I've seen. Super clean and informative.

[@TheSeabeeMan]

If I recall correctly, when I had *FOUR 12's* in an isobaric box (i.e., clam shell setup)... ...I hooked up both subwoofers inside the box with reverse polarity (i.e., positive to negative, and negative to positive) and the two subwoofers outside the box with normal polarity (i.e., positive to positive, and negative to negative) when bolting the subwoofers face to face (with a 3/4" wood ring in between the subs that I prefabbed myself) . In this configuration, they all worked together as a team and had a lot higher dB gain from 20Hz-60Hz running at 2ft³ per chamber for each pair (as it had a divider in the Dual 12" 4ft³ net volume box).

[@Hilde_von_Derp]

Holy crap, this just cleared up years of 'wtf?' about iso loadings. You drop such tight videos full of solid, practical knowledge for anybody messing with speaker design. Thanks for all the work!

[@anthonylee7263]

You have the best explanation on isobaric enclosure, nobody do isobaric enclosure anymore after the 80's.

[@JaMarvelousjmar]

Always appreciate you for taking the time to break things down. Keep up the good work

[@thatspsychotic]

Just earlier today I was wondering about isobaric loadings, what impeccable timing!

[@bishopdante]

Good to see you getting back onto the acoustics subject, it's quality content, and your grasp of the subject is genuine.

[@DISOPtv]

Thanks Peter for your videos and talent! You got me back into stereos after 20 years!

[@Yagba09]

It is so refreshing to hear such useful knowledge. Thanks!

[@johnnycorn7225]

Man you're English is better than most native English speakers where I am for real!!!!! Best video I've seen yet and makes me want to build another ISO group ✅

[@kellypg]

I know this is an old video but I don't care. I just wanted to say that I didn't understand anything you said. Not because of you, but because of my lack of knowledge in this field. I think I may have a new hobby thanks to you.

[@robf4013]

The technical level of this video is off the charts! Thank you!

[@pvanb291]

Great delivery of very complex audio and electrical facts! Have recommended your channel to many audio engineering students. Keep up the good work :)

[@tylermedley4911]

12 volt guys got me over here and I'm glad they did keep up the good work brother.

[@twotonebtw5448]

Sooooo much detailed information! Also so glad to see you collaborate with Wilston Audio & Hifi Vega!!!

[@VEC7ORlt]

Excellent explanation! The bit about TL was quite unexpected! Really looking forward to that isogroup video!

[@ArztvomDienst]

Everything is interesting if you get into it deeply enough. - Feynman Sub!

[@letslearnsometech9296]

Huge respect man! The things that you know about sound and how to engineer everything from scratch... I guess you dedicated your teenage to go through the nooks and cranys of how things work... Aaand, here we are! Learning things everyday!

[@hardcorecap]

The best speaker channel on KZbin, hands down.

[@joshcavanaugh7864]

Your amount of knowledge is awesome. Thanks for sharing it with us with these videos.

[@mwahlert]

Just noticing... how does Pete not have well north of 100K subs? This guy is brilliant and his videos are pro grade.

[@JViello]

Same for the guys over at Tech Ingredients - AMAZING content low sub count. Then I thought about it and...well, it's useful information presented in a clear manner with professional grade production quality. There is no clickbait, no gimmicks, no drama, no anime goofy faced thumbnails, no silly mindless crap like "what happens if we plug this driver into the wall socket?!!! Lets find out!" so low subs. It's why we pay people who play with a ball 10's of millions of dollars and someone devoting their life finding a cure for cancer maybe...MAYBE a hundred grand a year. Unfortunately people like us are in the minority. Most want someone jumping up and down like a gorilla around a rented Lambo chanting mindless words like "It's everyday bro...it's everyday bro" Also, while he has low sub count, he's getting a decent view counts and that's what matters in the end for $$$.

[@Xenro66]

@@JViello Damn, well said.

[@noahrodeghiero9640]

I started watching this channel a couple weeks ago; and i can say i am happy i subscribed.

[@joshholden8561]

This man is extremely great at what he does . Such a privilege to be a huge fan of yours. Great work very professional very educational.

[@foxcob]

Just found your channel today. So much great information that no one else seems to cover. Would love to see you do a video where you go through the design process for a scenario(or two!). From driver selection to enclosure design (like what order and the process of making that decision). Something like a home theater subwoofer, music subwoofer, or car audio subwoofer with of course some specific design criteria like space, extension, output, etc. Keep it coming!

[@phillipbartlett1819]

Back in the 90's I had a Thunderbird with 8 kicker 8" iso. It had the low end of a 12" with the tightness of a 6" or 8" with plenty of volume. I was running 8 ohm subs all parallel off of a PPI pro mos 12. The box total was only 2.4 cf. Back then that was small and loud!! I loved building new boxes to try out. Learned a lot and if this channel was around then I would have saved a lot of headaches. Awesome job and thanks.

[@RAMON20IES]

Once again Mr. Wizard has blown my mind. 🤯. Great video! Keep up the good work!!!! 👍

[@roccocroce]

idk how i stumbled on this but i'm sure i'm glad i did. fantastic.

[@stephenweller56]

Thank you for a very clear and informative video. I've been curious about the physics involved in isobarics for a long time. In this short presentation, you accelerated my learning curve to near vertical.

[@sfsgcsvxcv]

Finally! Someone explaining the good stuff!

[@juststuff5216]

If he's not the best at explaining .. he's certainly up their in my esteem as an acoustician!

[@sittdogg]

Great stuff. Always looking for the next video. Wish some of the old guess the size vids were still there.

[@w00tah1]

Very well done Pete. Learned some things I didnt know. Cheers!

[@bryanCLXT]

I wish I had people like you thru out my schooling clean crisp clear

[@gerald8289]

This channel deserves way more views

[@riddempestcontrol8601]

Thank you so much for this video. This mostly helped me work with parameters when you have two woofers in series. I couldn’t figure out the formula to change the parameters and this is laid out very easily.

[@d3tach3d]

I freakin love this channel. I became a fan when youtube suggested the 3" 3D printed subwoofer enclosure video and have been watching and liking ever since. Cheers!

[@johnwanamaker358]

Always been a big fan of isobaric, great presentation!

[@KhawChing]

I don't know if I posted yet but I didn't need the mention on 12 Volt Talk to find your video's. I watched 1 video a bit ago and subbed then. I've linked your video's on FB in car audio groups, most recently a couple days ago on the "Counting Orders". Love the channel and look forward to whatever topic you bring up next!

[@ryanthomastew]

Keep up the awesome videos! Can't wait for that 4+ driver isobaric loading thing. I'm not building a damn thing but I love learning about it all. Maybe one day I'm gonna have to break out the power tools!

[@arsonist63086]

I like you videos because of how informative they are. Even tho I might not understand all those numbers it's good to know how those numbers work and what they are .

[@yvesinformel221]

good explaination and I like the fact that you don't do like most utuber and take 20 minutes to explain stuf that can be done in 7 minutes. good job

[@scottinWV]

I love how you explain everything.

[@ostelo84]

Holy crap you just blew my mind for how to do my next transmission line for my home theater!

[@coco805]

This was a fantastic tutorial! Very well explained, this was a deeeep concept and you really nailed it in a very short video.

[@twinkyunouwantmycreamfilli8297]

Good stuff. And its cool to see a little bit about the ppl "behind hind the cones" at Audio Dynamics. Definitely is helping peak my interest in y'alls gear.

[@phoobar9640]

Such a good explanation that even I could understand it. The diagrams helped too. Nice job!

[@reactormovie1529]

I wach this guy for about over year. Grat teacher. Confirm, best visualisation.

[@jlg23us]

Amazing to finally see someone dig into the maths, usually we see theory and then finished product, great job

[@colonelk3000]

Great info. Makes me want to go Isobaric on my next build :) particularly fascinated by isobaric in a t-line, but that'll have to wait!

[@russellborrego1689]

I knew all of these results, but had no idea WHY the results actually happened the way they did. Awesome video, thanks!

[@schnecks2180]

This video saved my two 18s in a Fiesta project :-) Thanks!!!

[@wbishop1330]

Thx for breaking it all down, useful information.👍✌

[@paziipa]

The quality of your videos are amazing! Creation of these videos must take very long - i appreciate the effort!

[@gijoemolinaro]

Thanks again man you're a font of massively interesting audio knowledge keep up the good work 😊

[@adhanda2017]

fount

[@nbowling10trio]

Yes, back in 92 I set up four fosgate series 1 twelves in a ported box in an isobaric configuration. Punch 150HD in stereo mode at two ohm per channel. Vehicle was a 1988 ford escort. Very small box in the hatch. Mcm goldline doors, rears and tweets ran off a Kenwood 920or 921,can't remember. It was a very impressive sounding set up. LA sound crossover. Kenwood head unit.

[@ItisBigJ]

Always loved the quality of your videos.

[@MrDexaudio]

148 Dislike ?!?! WTF ?! WHY ?? Crazy people ! THIS IS THE KIND OF THE BEST EVER GUIDE for all of us ( beginners or experts ).

[@lamazver]

I'm so into your channel.. I'ma watch all of them videos. Keep up with the good work!

[@prepetually-exploding-mind]

That was perfect. Thank you very much for the explanation. I value your knowledge and time.

[@thomaslindroos1667]

Well presented and informative as always.. keep it up🤙

[@SomeGuyNamedPaul49]

Can we get a video from you on TS parameters? You're quite good an explaining things and I'd like your take on the various parameters from your perspective and in a practical sense.

[@juststuff5216]

The only two issues as far as I know (i'm still learning) are that T/S parameters are not a constant, and they change with different atmospheric conditions. Also, I don't know how solid a *Rule Of Thumb* of ... ported under 0.5 sealed 0.5 0 - whatever IB - over 0.7 ... is? This guy mounted his Dynaudio Esotar 1200 in an IB configuration, and they have a QTS of 0,34! www.diymobileaudio.com/forum/2064684-post523.html bit.ly/2U7Y3BA so ... Other than that, its a matter of; how accurate the manufactures published parameters are. Some are Ok, whilst other can be wildly off. worst example I saw was the JL Audio ZR800 CW 8" midbass (no longer in production) had/has a published QTS of 0.662, but yet the actual parameter was around than double that. www.diymobileaudio.com/forum/member-reviews-product-comparisons/173556-jl-audio-zr800-cw-8-midbass-objective-review.html With that being said, I think its important not to focus on a singular parameter like QTS or Xmax, at the expense of any and all other parameters. Anyway ... no doubt Pete will correct any false assertions 😭

[@dalesmth1]

kzbin.info/www/bejne/gJW0ZKCCipqteKc

[@NorwoodComputer]

@@juststuff5216 the rule of thumb is not standardized. i run ADS S10's IB (truck door cavity), Qts=.22 Fs

[@riddempestcontrol8601]

I second this!

[@rickgrimes4133]

Thanks for the vids, I'm learning a lot.

[@psementalist]

Could've explained it any better myself excellent good video topic of discussion you're one of the more knowledgeable basshead's I know 👍

[@juststuff5216]

There are some who focus on shiny expensive equipment rather than on acoustics. I think Pete does the latter rather well, and more importantly, he backs up his claims!

[@dinosoarskill17]

the12volt is an amazing tool. so glad its still around, i use to use them 10 years ago when i was into cars a lot!

[@cocosloan3748]

BigD. brought me here to this channel! Cool channel indeed!

[@maxfmfdm]

im sorry you had to start in that channel

[@rollinstromboli7393]

My enclosure was made because of this video ! 4 VFL 6.5 in isobaric 6th order on taramp 5000.1MD@2ohms

[@dennishill9873]

I learned about you through Wilson audio labs. You guys are amazing ,thank you for the great info!

[@goodconnection69]

you have very good speech, preach and teaching skills man! tnx for the knowledge, very well explained!

[@blech71]

I love Hexi’s vids... been watching since the early days of him in his shop way back making boxes for customers coming from all over... seeing the design, the build process and even the fit and sometimes listen/measuring session.... al’a that crazy 4/12 confit in that Escalade/Chevy style big SUV he did I liked so much. To some they would probably want some laymen low connotation explanation to go along with his technical explanation in these vids but I think it evokes those interested to learn more. Like diving into Thiel Small Parameters accordingly. If you haven’t had the chance of seeing his wild box builds from back in the PWK days... I highly suggest finding those and some of those designs and builds were way beyond anything of their time... meaning the tech was there but no one was really tackling what it took to design and make tapered waveguides, T-Lines and aperiodic chambered boxes for the time... I remember Hexi getting hammered by quite a bit of his viewers and people of industry to release what software he used back then and come to find out if I recall.... it was his own design and maybe if I recall it was one of his projects for engineering school though don’t quote me on that but I think that’s what I remember him saying way back when he addressed the issue in a small snippet of one of his vids. Either way he has definitely contributed to the audio community as a whole... both automotive and hi-end/hi-fi home audio. For that I am thankful he continues.

[@gavaets13]

Excellent explanation. Thanks!

[@juststuff5216]

Thanks for the t-line lesson Pete!

[@lvomotor]

love this! Turns out ill be doing an isobaric design on my next speaker build :D

[@brentb5303]

Really good video. Thanks for making this content.

[@3stagevtec]

Great explanation on isobaric loading!

[@greggarner4477]

I love your presentations!

[@MrButuz]

Brilliantly explained!

[@poopik3151]

man you giving great lessons over youtube ! thank to you i built much better projects my self. big thumbs up to you for that

[@adrianbass09]

Thank you for your knowledge sir. Very much appreciated.

[@souhailla10]

nice, this was (for me) the first one that explains it very clrean and properly ... congrationlations my fiend !! very great explenation. i wish you could do a compact version like this on your air-vents that you have. it will be a great help for many people ! (including myself)

[@DadsRCGaragePNW]

Another amazing video

[@cartruck1070]

I like the frequency curve on that graph of the isobaric set-up. Now to figure out how i can do this with two giant 18" woofers in my little car. I got it in my head, but achieving it in person is another story. 😄👍👍

[@stefanvontobel3558]

thanks so much for these videos.

[@envisionelectronics]

“Twice the (Moving) Mass, Half the Vas” was a term I coined as a teenager in the 1990s when Isobaric made sense because manufacturers weren’t making drivers for smaller enclosures.

[@staywhite6332]

I've done hundreds of iso setups from 80s to now. My girl's box is a pair of 12s in 1.8 cubes with a 3", 18" long flared port tuned to ~29. Moves the winshield of her suv a 1/4" or more at 32Hz on 500W.

[@JesusSaves86AB]

The old boys I've met over the years in my local car audio community always know far more than the young guys that just want bigger drivers and more power. It's what fascinates me enough to try to learn the science to build my own transmission lines and bandpasses.

[@alimahdavi2276]

Lol very creative!

[@vonantero9458]

You touched on something at 6:20 that I tried to search a while back when I started to design a smallish tapped horn. You stated: "...as long as the mounting depth of the drivers doesn't exceed the the internal clearance". One of the biggest concerns I had with my design was the lack of room the driver had around it. I wasn't able to find any info about how much is room is actually needed behind the driver, so I decided to change the design slightly to give it a tad more space. Most tapped horns I found online are huge and the driver sits almost at the mouth of the horn, many times in a steep angle and the mouth is huge as well, so it's hardly an issue. In my build, a 6,5" driver is around 50cm deep inside the horn. Width of the horn is pretty tight fit, at around 7" and there's not that much room between the magnet and the outer wall. Making it any smaller seemed ludicrous. I just got it finished (still need to paint it) and I have tested it briefly and it is quite something in a small flat :D Need to find the time to set it up properly. Anyways, I was wondering if you knew any limits or have ever come across issues with too tight clearance in a tapped horn? What would even happen if it was or can it be? I have hard time trying to thing what actually happens if it was. If you have any ideas, I'd love to hear them. Love the channel. Lot of really well laid out info!

[@acjjones2981]

You sir are a genius! I only wish you uploaded my often. 👍🏾

[@supercompooper]

This was very helpful thanks !

[@johnnyoost1144]

Incredibly informative.

[@SuperMcgenius]

Have used this with very tight musical effect, but never thought of doing this in a transmission line. Thanks.

[@juststuff5216]

^ x2 - i',m ashamed to say 🙄 😏 But Pete only talks about cross section. It doesn't seem to change the line length it would seem. That might have help for my lat4est project which is a revision of a failed attempt at a Sundown E10 v3 kzbin.info/www/bejne/gGqVq31_ebScZ7M

[@dariocamacho9871]

As always great video 👍

[@jeffsloane8628]

If you really care about audio and the science behind it. This guy's videos are the best I've seen.

[@markkalaj6822]

Hexibase - love your channel. I’ve learned more from you than nearly 30 years of DJing, Car Stereo & Home Hi-Fi. Really love your channel for years! Do you still do enclosure design based on specific vehicles? I’m buying a new vehicle and want you to design my sub enclosure and recommend drivers. Thanks!

[@oldbuddyben]

Now I have to figure out the math on if the two woofers mounted in series were wired in parallel. Thanks for the video!

[@HashDogg06]

Yes! my thought's are it would be the same as the iso setup given the enclosure volume was doubled & not 3db below as shown but it would be nice if Pete could revisit this.

[@travis4798]

Speaking of 4 drivers in a row, the Polk Audio C4 from back in the day comes to mind. Utilizing two ported chambers, a sealed portion, and two sets of isobaric 6x9's. It was an impressive subwoofer for it's time. I'd like to see a video on passive radiators, since it's kind of making a comback for "compact" subwoofer enclosures.

[@danwilcox7650]

I really enjoyed this and several others on your channel. Subscribed. I built a set of subwoofer cabinets for my classic rock cover band 8 or 9 years ago. They have served me well but recently I overpowered one and damaged the driver. I was able to replace the out of production woofer (an MCM 55-1875) so I now have a pair again. These were not my first diy speaker project (my first was at age 12, I'm 62) and have the ported 4.5 cu ft boxes tuned to very near the drivers Fs (30hz). This I believe was an error on my part (box to small too but these were for bar gigs/compromises were made)(should of tuned the boxes to around 50hz where the bulk of the signal is/to gain most usable spl?) after 8 years of trying to educate myself in live sound sub-woofer design as up til then most of my designs were for high power home stereo application and a few guitar and monitor wedge cabs. I am now considering building a new set of cabinets for these drivers and since they must cover only a narrow band from 30 to 100 hz I would like to learn how to design an isobaric cabinet for a given driver's T/S parameters and the required pass band of the finished speaker cabinet. Is this an idea for a future video?

[@MrMan-ol4ic]

Was at a car show.....when ORIAN was on there top game. About 20yrs ago....lol. there was an ORIAN booth with a 90 something Toyota pickup with the extra cab and it had 10 10's in an isobaric configuration. That shit banged so dam hard. Never forget that build!!

[@claysonwebster1622]

Awesome vid keep up the good work

[@BUZDRIFT]

Nothing is to be said, another crisp video by HB!