Isobaric sub boxes

[NotDeafYet]

Anybody use one here? I still have my sapphire 12s in such a box, from 20some years ago. "Small" footprint. 2ohms/reversed parallel wired. All things considered, being in original owners car, my VW back then, and my various living room home theatre setups... And recently used it on a 2000km trip last summer... They can still give me a headache! They did 139db on an m50 back then. Still sound pretty good.

Just asking... As I might consider using my mk4 spare tire well for one.

Now considering subs might have gotten better since 2 decades ago, would a pair of recent 10s, in an isobaric box, be a viable/better comparison? Or doe sit really depend more on the actual grade of sub vs the size of it? The sapphires were the entry level subs back then I believe.. White steel basket... Matched the M amps and audio control gear nicely..

12s(newer) would be nuts... I have access to reasonably priced JL 12w6 subs(if anyone would want to purchase them... Pm me) ... But the power demand would be up there with everything I want to run off a 190amp alternator.

[Eric D]

With an isobaric setup, you run twice the power to twice the coils, because the dual motors have twice the force, so you can get by with half the box size. Well, audio manufacturers took note of this and started building subs with bigger coils, bigger magnets, and stronger overall parts. I would say that one reason modern subs work so well is they are really an isobaric design built into a single driver.

If you buy a good quality, long throw, modern sub, you don't need to go isobaric with it.

[NotDeafYet]

With an isobaric setup, you run twice the power to twice the coils, because the dual motors have twice the force, so you can get by with half the box size. Well, audio manufacturers took note of this and started building subs with bigger coils, bigger magnets, and stronger overall parts. I would say that one reason modern subs work so well is they are really an isobaric design built into a single driver.

If you buy a good quality, long throw, modern sub, you don't need to go isobaric with it.

So taking into account what you've stated, if one was to run 2 modern subs in an isobaric box like mine.. it would be nuttier? hehehe

[wooferdog]

139db from a m50! That must be one bad ass m50,sign me up for one or two!

[NotDeafYet]

In a vw rabbit. Port would shoot right up at the 45 degree hatch windows. Small interior. Fresh subs. Epicenter. Audio control line driver, eqx. Sounded pretty good. Used to cook my alternators very 4-5 months.. 12mins to change it, down pat. Then the tree got in the way...

I doubt they would do that number again!

[Mr. Wild]

Isobaric sub arrangements and many modern subs are suitable for very small enclosures. Thats their advantage over traditional subs. But this comes at the cost of efficiency and more weight.

Best way to go is build as large an enclosure as you can fit, and then choose a suitable sub. The bigger the enclosure, the more efficient sub you can choose.
Loudest sub I have is a JBL 1200GTI in 2 qu ft ported. Its almost nuts with an MS275, considering its just 200W++

Here's a great read on the topic if you're interested:

http://sound.westhost.com/articles/pwr-vs-eff.htm

[NotDeafYet]

I just got up, and reading the first couple pages.. I want to go back to bed lol. It would be awesome of Larry Frederick could explain this article to me, with curse words.. that would be fun. I'll give it a wack later.

So from what you've said, it would be 'advantageous' of me to say, use the entire volume of my spare tire area, figure out the volume, and chose a sub for that volume available. Ok.

That's what I kind of did.. I chose my enclosure for my little hatch cubby hole area, it had .3 cu ft of volume, and I chose the RF 8in that I have in there. I was limited in my choices due to mounting depth, and sealed box volume. Works great. So in theory, I did what you suggested, before you did.

The idea for the isobaric box design choice, from the original owner, is that this isobaric box design, was the smallest volume'd box that would make those 2 12s work. If the subs were in a standard ported, or sealed box, the overall size of the box would of been larger and he didn't want that. He wanted compact.

I've said it again, Ill say it again, I like this small phorum.. it's got a bunch of you knowledgeable guys. There's no childish stuff going on here.. well.. within reason hehehe. The grammar on some sites drives me nuts too, not here.