# Inexpensive and easy subwoofer tube enclosures



## tdgesq

I've had a few members request that I post a quick tutorial showing the build process for the tube enclosures that I used for my review of the diyma 12. Some disclaimers up front.

1) I used these as test enclosures, not for long term listening use. I do not know how well they will hold up with prolonged use.

2) They are ugly. I know that, so don't tell me that they are. They are a cheap and easy way to test different enclosure sizes and designs without having to build a box.

3) Use power tools at your own risk. Also, breath mdf dust at your own risk.

Here we go:

I bought all of the products for this project from Home Depot. You will need a 12" concrete construction tube, a sheet of 3/4 mdf (they sell these in little handy panels in case you don't have rig to haul a whole sheet in), and some Gorilla Glue or Elmer's Ultimate Glue. You will of course need speaker wire and a terminal plate. You can order these from Parts Express or (God forbid) pick them up from Radio Shack.

Step #1. Decide what you want for internal volume. Then go to this website http://www.freeonlinecalculator.net/calculators/geometry-solids/cylinder.php to calculate the length of the tube to attain that volume. Just enter the desired volume (remember to add the displacement of the driver) in cubic feet and the radius of the tube. Then hit the calculate button and it will give you the needed length. Then - well - cut the tube to the correct length:










I found it helpful to mark the tube at several places where it needed to be cut and then to have someone hold a tape measure taut between each of the marks while I ran a pencil along the edge to mark a complete circle around the tube where it needs to be cut.

Step #2. Cut two squares of 3/4" mdf large enough so they will cover the holes on each side of the tube. Each square needs to be of the same dimensions or else the tube will be unstable when you set it on its side.










Then cut out a hole on one of the squares where the sub will be seated. I didn't take a picture of this one because I did such a miserable job with the jigsaw the first time around. :blush:

Step #3. Take the mdf square where you cut out the circle for the sub and glue it to the tube. For Ultimate Glue at least you need to follow the directions and wet both the end of the tube and the mdf before applying. Wait until glue dries before doing anything else.










Step #4. Take other mdf square and cut out a hole for the terminal plate. If plate doesn't have a gasket use some caulk to seal from air leaks. Screw it on and solder the speaker wire to it. If you don't have a soldering iron, you can buy the cheap crimp connectors to attach the speaker wire, although I don't recommend it.










Step #5. Glue the other mdf square to the bottom of the tube. Make sure the squares are roughly parallel to each other. Let it completely dry.










Step #6. Drill the screw holes for your subwoofer, drop the sub in, and put in the screws and you have . . .


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## demon2091tb

Awesome, now you wanna tutorial some 18-21" tubes...... 

Will definently be using this tutorial when i do my Sonotubes for my Pair of Tempests 

Just gotta make ports......And hope the neighborhood dosent hear me.


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## Whiterabbit

got a question

you took the time to solder the connections to a terminal plate, cut a hole for a terminal plate, and seal everything up. As opposed to drilling a hole and siliconing or hot gluing the wires coming out.

Even if you were of the (incorrect) opinion that terminal plates are required hardware for all subwoofer boxes, you admitted these are just test boxes, designed for temporary use.

So why so much effort spent with the wiring? even so far as to suggest the use of spades (at a fraction of the time spent) is unrecommended?


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## tdgesq

Whiterabbit said:


> got a question
> 
> you took the time to solder the connections to a terminal plate, cut a hole for a terminal plate, and seal everything up. As opposed to drilling a hole and siliconing or hot gluing the wires coming out.


I've had bad luck in the past effectively sealing a drill hole with wiring coming out of a piece of mdf. I just didn't trust it with a 0.30 cft enclosure running 880 wrms. 



> Even if you were of the (incorrect) opinion that terminal plates are required hardware for all subwoofer boxes, you admitted these are just test boxes, designed for temporary use.


If you can effectively seal the wiring hole, then that's all that's needed.



> So why so much effort spent with the wiring? even so far as to suggest the use of spades (at a fraction of the time spent) is unrecommended?


Again, very bad experiences with using crimp connectors in a subbox. Have protected amps a couple of times doing that. If you've got an iron it takes about two minutes to do the actual soldering work.

I assume that people will want to modify enclosure size and design several different times as I did with the six feet of tube they have. The method I used was the minimum I felt comfortable with to prevent air leaks and wiring connection failure.


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## bobditts

terminal posts FTW!!! Ive seen people use the cheap terminal cups that dont screw in on a sealed enclosure using a high wattage sub (also high excursion). once that sub starts going the cups just pop right out. too much pressure inside. Even before the cup popped out, I could see the plastic in it actually bending and flexing. POS IMO


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## 00poop6x

Nothing like one of my customers did...











Believe it...




























One of those 5 gallon buckets.


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## kappa546

so the tube is concrete? because it looks pretty thin. any flexing at all?


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## ca90ss

kappa546 said:


> so the tube is concrete?


Cardboard.


I got bored today and decided to make one for myself. It took about 30 minutes and under $20 in materials.




























1.25cu. ft. tuned to 33hz for a JBL Gto 1002d


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## tdgesq

Cool. You did it like the guys who have the home theater sonotubes do it. My wood working skills aren't good enough to get those circles right.

As for flexing, my tube is designed to hold 104 lbs of concrete per foot of tube. I held my hands tight around the tube at several places while the sub was working at fairly high excursion and could not detect flexing per se. It's a little bit hard to tell though because of the vibration. It did sound good.


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## ca90ss

tdgesq said:


> Cool. You did it like the guys who have the home theater sonotubes do it. My wood working skills aren't good enough to get those circles right.


Router and circle jig


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## Whiterabbit

and flush cut trim bit.

whats REALLY neat is you can use two circles, say a 10" tube and a 12" tube for a 10" subwoofer, then use four pieces of 1x1" wood to suspend the 10" tube inside the 12" tube. makes a ported box with four ports that are "coincidental" if you will with the driver. prevents any combing effect youll never hear anyways. and looks cool too.


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## ryan s

how close is the sound relative to a standard box? i mean, can you tell a difference between the .5ft^3 tube and a .5ft^3 MDF box?


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## chad

Whiterabbit said:


> and flush cut trim bit.
> 
> whats REALLY neat is you can use two circles, say a 10" tube and a 12" tube for a 10" subwoofer, then use four pieces of 1x1" wood to suspend the 10" tube inside the 12" tube. makes a ported box with four ports that are "coincidental" if you will with the driver. prevents any combing effect youll never hear anyways. and looks cool too.


Although that sounds like a nightmare to calculate at first I am REALLY thinking about that now. Very cool idea assuming that the port length does not exceed the inner cavity length.

Chad


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## couchflambeau

hmmm.... side walls seem way too thin and that ain't MDF you're using, looks like the regular particle board.... 

You can buy full sheets of 1/2 and 3/4" MDF at Home depot, and if you have issues transporting it, have the guys working there rip it down into 4x4 or 2x4 foot sheets... its cheaper to buy the full sheet than handipanels, it's the right material, and the cuts are FREE!!! 

If it was something you intend to use long term here's what I'd do....

Cut multiple ribs (using the same circle template) and space them every 6-8 inches, glue em in place with a good construction adhesive. Then I'd lay a little fiberglass/chopmat from the inside, couple of layers. That should help with rigidity issues....

Sorry guys, I'm just not into doing things half-way.... as my HS math teacher used to say, do it right or it's wrong


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## chad

couchflambeau said:


> hmmm.... side walls seem way too thin and that ain't MDF you're using, looks like the regular particle board....
> 
> You can buy full sheets of 1/2 and 3/4" MDF at Home depot, and if you have issues transporting it, have the guys working there rip it down into 4x4 or 2x4 foot sheets... its cheaper to buy the full sheet than handipanels, it's the right material, and the cuts are FREE!!!
> 
> If it was something you intend to use long term here's what I'd do....
> 
> Cut multiple ribs (using the same circle template) and space them every 6-8 inches, glue em in place with a good construction adhesive. Then I'd lay a little fiberglass/chopmat from the inside, couple of layers. That should help with rigidity issues....
> 
> Sorry guys, I'm just not into doing things half-way.... as my HS math teacher used to say, do it right or it's wrong


But your HS math teacher would also note that since it's a cylinder then it's a very rigid structure. This stuff is designed to hold assloads of concrete in place, it ain't going anywhere, it's tuff stuff! it will probably flex less than MDF....because of it's shape.

Chad


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## couchflambeau

call me paranoid... I always overbuild....


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## chad

But it kind of IS overbuilding in that if you put the same amount of concrete in a square box it MAY just not hold it whareas the tube would easily, these are the same type of pressures we will be dealing with in the expansion and contraction of air.

Chad


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## tdgesq

couchflambeau said:


> hmmm.... side walls seem way too thin and that ain't MDF you're using, looks like the regular particle board....
> 
> You can buy full sheets of 1/2 and 3/4" MDF at Home depot, and if you have issues transporting it, have the guys working there rip it down into 4x4 or 2x4 foot sheets... its cheaper to buy the full sheet than handipanels, it's the right material, and the cuts are FREE!!!


You are correct that I did initially use particle board I had laying around for that enclosure. I later built another one with 3/4" mdf, and frankly, I believe I heard a difference. Point well taken. I didn't know Home depot would rip a full sheet for you. Since I have a pickup I just bought a full sheet. Would have been much easier to have them cut it in half first.


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## yermolovd

I am going to try this as my temp box for a 10" w7.


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## MiniVanMan

If you want to overbuild then you can always brace with MDF rings along the inside of the tube.


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## DS-21

Whiterabbit said:


> and flush cut trim bit.
> 
> whats REALLY neat is you can use two circles, say a 10" tube and a 12" tube for a 10" subwoofer, then use four pieces of 1x1" wood to suspend the 10" tube inside the 12" tube. makes a ported box with four ports that are "coincidental" if you will with the driver. prevents any combing effect youll never hear anyways. and looks cool too.


That's a really great idea. A commercial product that was the first and only application of it I've seen was the Adire Sadhara. The math isn't really that intimidating, either, in that you can do it without having to integrate anything. Just take the area of the big tube minus the small one, subtract the area of the support struts, round down a smidgen to account for the area under the curve between strut and wall, and you've got port area to plug into your modeling program of choice. The only thing tricky is then finding a woofer that will do well in an enclosure with a port of that area and the length of the enclosure.


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## Pseudonym

yeah ive got a sadhara and i always thought that enclosure was pretty neat.


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## RedMed427

Allright guys its about time the whole sontube idea came over here...(im more at home in a ht environment ) Ive been to a guys house that has a 7 foot tall sontube ported to i think 14 or 12 hz. Oh BTW its a soundslplinter 18". It will blow your balls off  And its the tightest most musical darn thing ive ever heard. If any of you want to see some examples of sonotubes go to the diy forum at avsforum.com . There a great bunch of knowledgeable people over there.


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## fej

I have always been tempted to do the tube thing since I first read about them about 2 years ago or so I think. I built a "to spec" box from Adire for the tempest that I have on a 1000w dayton amp and it shakes the house quite nicely  Good low extension .. but a tube tuned to 14hz sounds crazy .. makes me want one heh


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## johnson

Ive got plans for my RL-P15 D2 build. I dont have an amp so im lazy to get started on it.


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## yermolovd

I made one two weeks ago. Sounds as good as sealed box at normal listening levels. When I crank it up though, I hear funny rattles, either coming from my car or a box.  
This enclosure really helped me to whip something up quick and listen to it for two weeks already. I just got tablesaw and brad nailer, so I can make a normal box. This idea is awesome for temp trials!


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## scratchy

couchflambeau said:


> hmmm.... side walls seem way too thin and that ain't MDF you're using, looks like the regular particle board....
> 
> Cut multiple ribs (using the same circle template) and space them every 6-8 inches, glue em in place with a good construction adhesive. Then I'd lay a little fiberglass/chopmat from the inside, couple of layers. That should help with rigidity issues....
> 
> Sorry guys, I'm just not into doing things half-way.... as my HS math teacher used to say, do it right or it's wrong


I guess you must've missed the HS Science/Physics class where the teacher explained that next to a sphere, a cylinder is the strongest shape for containing pressure. That's why air tanks, & submarines are cylindrical in shape.

Internal pressure acts equally on all surfaces. The only place you can have flexing/bulging is on the end plates, since they are flat (this is what causes boominess in poorly built speaker boxes).

However, if you are really obsessed with strength & building a really heavy box, then you might want to build one like I did


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## Mirage_Man

Hehe. Here's mine. Albeit for home. It houses two Adire Shivas ported. Click on the picture to go to my outdated website for how it was built. Lot of pictures there.


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## WrenchGuy

Sweet! you have just given me more reason to redo my auto tubes. And inspired an idea for my Home Theatre. Great work Im just getting into making these and its bad ass they are definitely different. Where do you get stuff for the piano finish? Colors?


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## Mirage_Man

WrenchGuy said:


> Sweet! you have just given me more reason to redo my auto tubes. And inspired an idea for my Home Theatre. Great work Im just getting into making these and its bad ass they are definitely different. Where do you get stuff for the piano finish? Colors?


The finish is described on page 4 of the build on my website. It is a very time consuming process and one which I won't likely do again. If I were after that type of finish in the future I would take my parts to an automotive body shop and let them spray them for me.


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## WrenchGuy

Mirage_Man said:


> The finish is described on page 4 of the build on my website. It is a very time consuming process and one which I won't likely do again. If I were after that type of finish in the future I would take my parts to an automotive body shop and let them spray them for me.


Yeah that was the alternative I was looking toward but could get great value out of it with that Piano finish. My auto tubes are in the threads. First try! cutting them sucks man! I just have to do more finish work then I want to. If I start over It will be perfect. Mine arent bad but not what I want.


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## dirthog

ryan s said:


> how close is the sound relative to a standard box? i mean, can you tell a difference between the .5ft^3 tube and a .5ft^3 MDF box?


x2


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## Mirage_Man

dirthog said:


> x2


Not that I could tell.


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## WrenchGuy

You can build these things in an hour! Im makin more! They sound great too. No MDF vibe.


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## theRESONANCE

Revived from the dead.


Just thought i'd share with you all;
Was inspired from this tutorial to create something of my own...
Actually.- my first enclosure :]
Tomorrow will be the official Listening day.


Raw materials.











Didn't get a chance to go pic by pic during the install..
But just an idea -- Pretty much self explanatory
Gluing


















Speaker terminal plates on opposite ends.









final product :




























I'm not going to lie.. I did put a bit of work into these boxes. Amazingly enough, i didn't have to measure much out besides the volume and initial cuts.
Much of the box was done by eyeballing...Seeing how it was intended for a 'quick' temporary test box.

-I wasn't so fortunate with 30 minute procedures like the some of the skilled woodworkers on here. But--Overall it was pretty straight forward. And i'm proud of what i got :].
It's very solid.. i'm quite suprised. I could probably hop on my box and not have it show any signs of torment whatsoever.
Cost : 8$ tube + 6$ gorilla glue homedepot, 1$ screws, ~12$ 3/4 Mdf. (i forgot exact cost...). 
Cheap and affordable.. I'm happy, and thats all that counts.


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## Chris_Harper

That looks sweet. I could see 'glassing it to look like a box enclosure from the outside.


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## theRESONANCE

haha. Yeah, totally. I was going to go all out crazy with the box.
But realized..-- it would totally defeat the purpose of 'inexpensive and easy subwoofer enclosure' lol.

I was going to vinyl the box and add some designs to it. In the end result however-- i decided that it would be far more interesting seeing the box design raw. Gives it a sense of character. (i know, lame)

I'm a little excited to see how it goes. Kind of want people to go:
"No way, you can't be running 8's "--" And what, that's your box ? --! "

I'd be a true DIY'er at my heart's content.


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## chithead

Schweet... I have got to try this!


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## Pseudonym

what would happen if one were to place a sub on both ends of the tube?


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## chad

Pseudonym said:


> what would happen if one were to place a sub on both ends of the tube?


One would have to make the tube twice as long


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## Pseudonym

it would be no different than 2 subs sharing a common chamber in a typical box right?


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## chad

Pseudonym said:


> it would be no different than 2 subs sharing a common chamber in a typical box right?


correct, but you need to compensate for the added airspace needed obviously.


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## Doctor B0MBay

Alright so I want to make one of these ported. I heard from somewhere I dont remember that if I put the port (im going to use a tube port) directly across from the driver it would be bad. Is this true or should I go for it?


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## littlejuanito

I wonder how these tubes held up.


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## LEN671

I am thinking of doing this just for the hell of it. It looks like a lot of fun. But I am going to try a ported design though and see how that works out for me.


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## theRESONANCE

Wow it's been a while!
I ended up selling the enclosure with the pair of 8w7's a month after i made the box. The month that i had with it was intense, i was so sad that i had to sell it. (Needed money for school at the time). The only downside with the pair was its lack of 'fullness' and extension to the bottom range. I'm not sure if it was because of the enclosure or the fact that they were 8's. They played loud though, and were quick and punchy...gave that "thump to the throat" sort of deal.

I don't know how its doing now, just thought i would chime in for whatever its worth.
If you guy's are debating whether or not to make it, definitely do it. Not only is it super cheap, but I bet you the output will surprise the hell out of you.


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## SHOToonz

hmmmm...this might be a nice, viable option for my Earthquake until i can get my **** together (not to mention funds) to build my 4th order bandpass...


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## kwalsh24

Seen this posting via a google search. Signed up and now I am posting my question haha

I have 1 Boston Acoustic G2 sub, that i wish to install in a very limited air location. I can only manage to get .7ft of volume for my tubed sealed compartment. The specs call for 1.0ft (from a typical box) Now with these measurements does this include the sub or not include the sub. My .7ft would include the sub... Would this be safe or would it kill my sub?


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## spystyle

Hello from Maine USA 

Thanks Tdgesq, I read your first post and ran off to Home Depot.

Here is what I came up with :

h t t p : //postimage.org/image/rwjqyqhjb/

(I don't have a high enough post count to post pics LOL)

I routed a shallow circle for the tube to fit into, and I used caulking rather than glue. 

And theRESONANCE, nice dual tubes 

Cheers!
Craig


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## CaptEditor

theRESONANCE said:


> Wow it's been a while!
> I ended up selling the enclosure with the pair of 8w7's a month after i made the box. The month that i had with it was intense, i was so sad that i had to sell it. (Needed money for school at the time). The only downside with the pair was its lack of 'fullness' and extension to the bottom range. I'm not sure if it was because of the enclosure or the fact that they were 8's. They played loud though, and were quick and punchy...gave that "thump to the throat" sort of deal.
> 
> I don't know how its doing now, just thought i would chime in for whatever its worth.
> If you guy's are debating whether or not to make it, definitely do it. Not only is it super cheap, but I bet you the output will surprise the hell out of you.


I would be curious to try a single box with a set of 8" or smaller drivers set in an isobaric configuration. :idea2: Perhaps there would be a gain on the low end significant enough to sacrifice the efficiency of the driver.


-Kevin


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## Quinn

> I would be curious to try a single box with a set of 8" or smaller drivers set in an isobaric configuration. Perhaps there would be a gain on the low end significant enough to sacrifice the efficiency of the driver.


I did this exact thing back in the early 90's in a 1980 Toyota P/U. Zero room really behind the seats. Picked up some 8" sonotube, installed two Kicker 8" comp face to face with a piece of 3/4 mdf to make sure the cones didn't hit in isobaric configuration. Ported them to 36hz, with a 3 inch pvc. The first one turned out pretty good so I made another one for behind the drivers seat. I ran them off a PPI2300m amp. It hit crazy hard.. 

I'm in the works of building a 4th order bandpass (sealed drivers (est .7cuft into each side of a chamber 1.4cuft ported with 6" aero tube.) Vented right into the factory sub location on my Lexus Ls400.


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## subwoofery

CaptEditor said:


> I would be curious to try a single box with a set of 8" or smaller drivers set in an isobaric configuration. :idea2: Perhaps there would be a gain on the low end significant enough to sacrifice the efficiency of the driver.
> 
> 
> -Kevin


Gains from isobaric = smaller enclosure 

Since you're going with 8" or smaller, enclosure size shouldn't be an issue... 

In an isobaric enclosure with 2 drivers (let's assume 0.5cuft is optimal for 1 driver): 
- if you cut the enclosure in half (0.5cuft times 2 drivers cut in half = 0.5cuft), you'll have the same low end as 1 driver in 0.5cuft 
- if you keep the enclosure in its optimal size for 2 drivers, you'll have the same low end as if 1 driver was in a bigger enclosure (1cuft) - meaning the power handling goes down too due to excursion... 

If you were using a 15" or bigger, I'd see the advantage of using isobaric in a car but not with 8" or smaller - my opinion. 

Kelvin


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## Quinn

> - meaning the power handling goes down too due to excursion...


Not exactly... In an isobaric config the power handling actually goes up. Remember you are now using 2 speakers as a unit. Efficiency is down by half in isobaric loading. The gain is you are now utilizing 2 speakers to control the same airspace.


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## subwoofery

Quinn said:


> Not exactly... In an isobaric config the power handling actually goes up. Remember you are now using 2 speakers as a unit. Efficiency is down by half in isobaric loading. The gain is you are now utilizing 2 speakers to control the same airspace.


I've described 2 examples - a 0.5cuft box and a 1cuft box - the power handling is lower in the 1cuft one so my statement is correct. 
I know what you mean but I assumed that _CaptEditor_ knows about the lower efficiency. 

Kelvin


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## CaptEditor

thanks for your input! I guess in a way it's like an IB subwoofer where you want maximum cone area because excursion limits your power handling. I need to pull my speaker book out of storage and read up on it.


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## subwoofery

CaptEditor said:


> thanks for your input! I guess in a way it's like an IB subwoofer where you want maximum cone area because excursion limits your power handling. I need to pull my speaker book out of storage and read up on it.


^ correct  

Kelvin


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