Orange

[Paul K]

I clicked onto this after seeing the ad in BP. There's no details, and these cats can't spell. But assuming it really is light, I want one. Or two. It's orange, and it's isobaric. Rochester's House of Guitars is a dealer; might be a good enough reason to visit the in-laws....

 

http://www.orangeamps.com/products.asp?Action=View&ID=116

[jeremy c]

What exactly is an isobaric cabinet?

 

The word "isobaric" means something about keeping the air pressure constant. Is this the air pressure behind the speaker? How would they do that?

[DanYmaL X]

This kind of explains it...

Looks like they mount the speakers in line, front to back, instead of side by side... interesting.

 

DX

[davio]

I've read a bit about this and IIRC, there are some definite trade-offs. First, the "breakthrough/revolutionary technology" line is a load of whatever foul substance you'd like to use for the statement. This method of loading speakers has been around for decades. Anybody who says anything they're doing with a bass cab is breakthrough or revolutionary is full of it because it's been done with other equipment...just maybe not with commercially available bass cabs. Second, while it allows a 210 (for example) to be smaller and go lower, it's in the neighborhood of -6 dB below a traditional 210 if I understand correctly. So you'd need twice as much power to get the same volume...assuming the speakers wouldn't reach any of their limits before that point.

 

Bill Fitzmaurice (owner of Bill Fitzmaurice Loudspeaker Design and general cab guru) said on TB a while back:

 

If your priority is maximum extension and output from minimum box size and you don't care about price then there's something to be said for isobaric, but only then.

I'm pretty sure he was refering to price of amp as well as cab.

 

Maybe Alex will chime in on this one.

[davio]

Also, iso boxes aren't uncommon in car subs and home theaters.

[The Geoff]

Try here:

 

http://basschat.co.uk/index.php?showtopic=55974

 

and scroll down till you get the posts from alexclaber

 

Alex is sort of our british equivalent to Bill Fitzmaurice.

 

G.

[DavidMPires]

I've learned that on a sealed cab, you can use weaker drives as the air presure will help pushing the speaker forward, the same thing doesn't happen with ported cabs.

 

But like geoff said, Alex should be coming around shortly.

[fingertalkin]

I used to build custom car sub boxes....makes me wonder why I haven't dabbled into my own bass cabs. Anyway, I built myself an isobaric box and it slammed. I particularly found it to be more efficient than conventional boxes. Could have been any number of factors or strictly pure dumb luck.

[jcadmus]

You're Isobaric.

[davio]

I used to build custom car sub boxes....makes me wonder why I haven't dabbled into my own bass cabs. Anyway, I built myself an isobaric box and it slammed. I particularly found it to be more efficient than conventional boxes. Could have been any number of factors or strictly pure dumb luck.

I'm just guessing here, but I would think that because it's a sub enclosure, the iso setup allows for a more extended low end, thus making it seem more efficient because you don't need as much power to push out the really low frequencies. However, a speaker pulling fullrange duty wouldn't share that benefit.

[fingertalkin]

I'll buy that. But after re-reading the "specs" on the website that DanYmal X put about the speakers being front facing rear of the other speaker, I am not sure that I built an iso box. I thought iso was the two speakers facing each other. IIRC, I had one 12" sub in about a .5 cubic foot space and the other 12 facing that one in a 1.5 cubic ft space. Both speakers were completely inside the box....you couldn't see them. I had both compartments of the box ported. I also through on a separate enclosure on the top with another 12 in a sealed cab. Like I said, that thing kicked. It was a competition car. Come to think of it, I am not suprised that I go through so much gear. It is just in a different avenue...sort of!

[davio]

Both yours and the Orange are iso boxes. They're just different configurations for different results.

[calypsocoral]

I would still love to try their 200 watt all-valve head. They now have an 8x10 cab to pair it up with!

[picker]

I was house sound man for a coffeehouse here in KC that had two isobaric subs for the PA, EVs I think. They really kicked the low end out. Very smooth sounding too.

[Paul K]

From the Wikipedia page on isobaric speakers:

 

The result is that the coupled driver pair (iso-group) can now produce the same frequency response in half the box volume that a single driver of the same type would require. .....(snip)....Stated alternatively, an isobaric array mounted in a box of the same volume as a single driver will produce half an octave more of bass extension. The aforementioned volumes exclude the isobaric chamber. (which another section of the wiki page states is typically as small as possible)

 

My thoughts is that with ceramic magnets, that would make a stinking heavy cabinet that is not worth schlepping around. Perhaps neo magnets now make is worth the added cost and complexity. 'Cause I'd take either half the cab size or half an octave if it doesn't weigh as much as a Peavey Hernia. I'm also thinking that a major problem is that since the chamber between the woofers is sealed, there's no place for the heat generated in the front speaker to go, and that heat is not desirable.

 

Of course, it's still orange. Maybe they'd make J.C. a blue one?

[davio]

It's similar to having a better single woofer cab at twice the weight, cost and required power.

 

I'm also thinking that a major problem is that since the chamber between the woofers is sealed, there's no place for the heat generated in the front speaker to go, and that heat is not desirable.

That's an interesting conclusion. Are other sealed cabinets not desirable as well? Once again, this is a practice that's been around for decades.

[Paul K]

Are other sealed cabinets not desirable as well?

 

Good point. I hadn't considered that. But with my limited seat of the pants engineering skills, I still wonder if the considerably smaller area of the isobaric chamber might create an issue. How much heat do speakers create, and how much heat is tolerated before the system farts out? I'm fascinated by the isobaric concept, but not interested enough to buy one and stick a remote thermometer into the cab! .....unless they have one in Rochester and that gets me a ticket for an early exit from one of my many nieces' birthday parties. I'd pay big time for that.

 

And it's orange, fer chrissakes! How cool is that!

 

[davio]

Speakers do create heat and the have thermal power ratings (how much heat they'll withstand before crapping out) but it's exceedingly rare that that becomes an issue.