Isobaric cabinet design benefits

[AsterL]

I'm looking at building my own small portable cabs. I've seen the SP series that orange do and I'm wondering about the benefits are from isobaric speaker design in cabs. What are the benefits. I'm looking at doing something similar to the old ashdown mini rig (4x8 +1x15) thought it would be pretty cool to do a 8x8/12x8 + a 2x15 in a tiny rig. Or is that a bit of a insane idea?

[Bill Fitzmaurice]

The benefit is that the net volume of the cab, not including the second driver and plenum between them, is halved. The downside is that the output remains the same as that of one driver, and the driver cost is doubled.

[lojo]

Id like to try and revive this thread

Im puzzled by these cabs after seeing the design

Anyone got any more info or can review compare to standard cabs that we can relate it too ?

Anyone gigging one in and around surrey ?

Edited March 29, 2011 by lojo

[Mr. Foxen]

Basically, with an isobaric 2x12 like the Orange one, you get all the volume of a 1x12, in a box 'twice' as big. Twice in quotes as only the box behind the rear speaker counts. Most bass cabs are undersized for their speaker loadout, so the perception it these boxes are very bottomy. But you could make a standard 2x12 at the same price, and eq in some more bottom, as you'd have twice as much useful power handling, and sensitivity, because you have twice as much speaker touching the air, but the box would be necessarily bigger.

Edit: Another way of picturing it: You are sticking together two speakers to make one speaker that is twice the weight, with twice the motor power, but with the same air moving ability as one speaker.

Edited March 29, 2011 by Mr. Foxen

[dan670844]

[quote name='Mr. Foxen' post='1181314' date='Mar 29 2011, 08:18 PM']Basically, with an isobaric 2x12 like the Orange one, you get all the volume of a 1x12, in a box 'twice' as big. Twice in quotes as only the box behind the rear speaker counts. Most bass cabs are undersized for their speaker loadout, so the perception it these boxes are very bottomy. But you could make a standard 2x12 at the same price, and eq in some more bottom, as you'd have twice as much useful power handling, and sensitivity, because you have twice as much speaker touching the air, but the box would be necessarily bigger.

Edit: Another way of picturing it: You are sticking together two speakers to make one speaker that is twice the weight, with twice the motor power, but with the same air moving ability as one speaker.[/quote]


Ha ha so what everyone is saying there are no advantages ha ha!!! I always thought it was something to do with weather........... wind!!!

[Mr. Foxen]

The significant advantage is Orange's favourite thing, it makes a fundamentally mundane item stand out as being different. I think in the days when speaker motor power was limited it was a fair advantage, but not so much now.

[Bill Fitzmaurice]

[quote name='Mr. Foxen' post='1181529' date='Mar 29 2011, 05:11 PM']I think in the days when speaker motor power was limited it was a fair advantage, but not so much now.[/quote]It was advantageous 30 years ago and more when driver technology made it necessary for cabs to be very large to reach very low. And then it was applied pretty much to hi-fi woofers and subs, not electric bass cabs, explaining why they weren't employed in them. Ampeg made one, and it was a commercial failure.

[Mr. Foxen]

[quote name='Bill Fitzmaurice' post='1181660' date='Mar 29 2011, 11:25 PM']It was advantageous 30 years ago and more when driver technology made it necessary for cabs to be very large to reach very low. And then it was applied pretty much to hi-fi woofers and subs, not electric bass cabs, explaining why they weren't employed in them. Ampeg made one, and it was a commercial failure.[/quote]

Any idea how the Ampeg thing measured up in practice? Commercial failure/success is more down to garish colour schemes and dubious marketing than anything practical.

[Bill Fitzmaurice]

[quote name='Mr. Foxen' post='1181761' date='Mar 29 2011, 07:56 PM']Any idea how the Ampeg thing measured up in practice? Commercial failure/success is more down to garish colour schemes and dubious marketing than anything practical.[/quote]
I've only seen them in pictures. The look was OK, the 134 pound weight a wee bit off-putting.

[Phil Starr]

Isobariks are borrowed from hi fi designs, 'Normal' speakers operating in a sealed cab change the air pressure as they move to and fro'. putting a second speaker behind with an air chamber means the radiating speaker is operating under constant pressure (hence the name) and promises more linear movement of the cone and higher fidelity. Linn made particularly successful speakers this way.

Even for hi fi there is little real advantage in isobariks and they remain a niche product. For bass it is just mad, twice the weight and twice the price for a very similar result. Just as Bill says. You'd get a better result by just using a better single driver.

[ShergoldSnickers]

[quote name='Bill Fitzmaurice' post='1181660' date='Mar 29 2011, 11:25 PM']It was advantageous 30 years ago and more when driver technology made it necessary for cabs to be very large to reach very low. And then it was applied pretty much to hi-fi woofers and subs, not electric bass cabs, explaining why they weren't employed in them. Ampeg made one, and it was a commercial failure.[/quote]
The first time I came across this loading method was in the Linn 'Isobarik' speaker design, dating from 1976. It was Linn that patented the isobaric principle according to several reports I've read. It used two KEF B139s in each cabinet, and the original idea was to reduce distortion levels in the bass. They were a notoriously difficult load for power amps of the time, requiring lots of power and an ability to happily dip to driving a nominal 3 Ohm load. They were also large, ludicrously expensive, but sounded incredible.

It does seem a bit anachronistic to use this loading in a bass cab design.



Edit: you must have posted whilst I was still preparing mine Phil.

Edited March 30, 2011 by ShergoldSnickers

[chris_b]

[quote name='Mr. Foxen' post='1181761' date='Mar 30 2011, 12:56 AM']....Commercial failure/success is more down to garish colour schemes and dubious marketing than anything practical....[/quote]
No it's not. It's also down to price, weight and effectiveness. Isobaric cabs for bass fail on all three.

[watchman]

[quote name='chris_b' post='1181862' date='Mar 30 2011, 09:28 AM']No it's not. It's also down to price, weight and effectiveness. Isobaric cabs for bass fail on all three.[/quote]

Has to be said that my tryout of the Orange Isobaric one with the 10" speakers left me wondering what all the fuss was about. I don't particularly like lugging my big cabinets around, but every time I fire them up I remember why they need to be so big. And the little Orange was pretty heavy too.

[Lozz196]

Have to say I wasn`t very impressed with the Orange Isobaric 210 when I tried it out.

[Bill Fitzmaurice]

[quote name='Phil Starr' post='1181809' date='Mar 30 2011, 03:00 AM']'Normal' speakers operating in a sealed cab change the air pressure as they move to and fro'. putting a second speaker behind with an air chamber means the radiating speaker is operating under constant pressure (hence the name) and promises more linear movement of the cone and higher fidelity. Linn made particularly successful speakers this way.[/quote]In those respects isobarics operate exactly the same as single driver systems. Some early designers may not have realized how they worked and made erroneous assumptions. Technically what happens with isobaric loading is that with two drivers Vas is halved, and along with it net cabinet volume. But Vd remains the same, as only the area of one cone is exposed to the air, so SPL remains the same as with one driver.

[Mr. Foxen]

[quote name='chris_b' post='1181862' date='Mar 30 2011, 09:28 AM']No it's not. It's also down to price, weight and effectiveness. Isobaric cabs for bass fail on all three.[/quote]

The fact Orange still exist as a large and generally successful company is the basis for my statement. They still make unbraced sealed bass cabs, and expensive valve amplifiers in the far east. How does that tick any of those boxes?

[lojo]

This all seems a shame, the best cabs I ever played through where the Orange OBCs, but there to heavy to take to gigs week in week out

Is everyone really saying, that those on here who rate these cabs would still do so even if the 210 was only a 1x10 ?

[Owen]

[quote name='Bill Fitzmaurice' post='1181786' date='Mar 30 2011, 03:18 AM']I've only seen them in pictures. The look was OK, the 134 pound weight a wee bit off-putting.[/quote]

I felt that pain. I sold it sharpish.

[Bill Fitzmaurice]

[quote name='owen' post='1183244' date='Mar 31 2011, 07:55 AM']I felt that pain. I sold it sharpish.[/quote]
+1. The appeal of isobarics is smaller size. But with heavy ceramic magnet drivers that size is arrived at via much higher weight. Neo drivers gets us around that, and the size benefit is real, so there is some method to the Orange price madness. You will get the low end output of a much larger cab. If size is a paramount consideration, as in you schlep your gear on the tube or have to carry the entire band in a mini, then the high cost may be worth it to you.

[aldude]

I used to have an Orange SP210.

In my experience, these cabs are very very small, and yet put out plenty of bottom end. However, they are not terribly loud. So, if you want one, just make sure that you can put enough power into it. I was using a Trace Elliot (recent) 500W head that put about 250W into the 8 ohm cab. It was [i]almost[/i] loud enough, but not quite, before the power amp started to clip (mind you, I am in a loud band!). So, make sure your amp can put more power into 8 ohm - the Orange Terror Bass I think will put the full 500W into it - or, get two! I must say, though, that the sound was absolutely brilliant.

So in short: these cabs are small, low, but not loud. They are also heavyish for their size, but not really that heavy overall, though they are easy to move around due to their size. But they sound bloody good.

If I did not have my barefaced I would definitely go for the isobaric SP cabs, maybe one or two of the 410s or perhaps two 212s.

Edited March 31, 2011 by aldude

[Lfalex v1.1]

[quote name='Bill Fitzmaurice' post='1183341' date='Mar 31 2011, 02:10 PM']+1. The appeal of isobarics is smaller size. But with heavy ceramic magnet drivers that size is arrived at via much higher weight. Neo drivers gets us around that, and the size benefit is real, so there is some method to the Orange price madness. You will get the low end output of a much larger cab. If size is a paramount consideration, as in you schlep your gear on the tube or have to carry the entire band in a mini, then the high cost may be worth it to you.[/quote]

Perhaps they're looking forward to the implementation of an EU concept that would ban combustion-engined vehicles from town centres, then we'll all be stuck with using public transport. As if gigging wasn't hard enough as it is. I sincerely hope it was an April Fools Day type prank, but the fact it's EU related means anything's possible...

[Bill Fitzmaurice]

[quote name='Lfalex v1.1' post='1185085' date='Apr 1 2011, 01:35 PM']Perhaps they're looking forward to the implementation of an EU concept that would ban combustion-engined vehicles from town centres..[/quote]
Which increases demand for hybrid and pure electric vehicles, which increases demand for neo, which results in neo price gouging, which doubles the price of said Orange cabs, leading to their ultimate demise. Just get a big cab, put wheels on it, don roller skates and push it to the gig.

[Mr. Foxen]

My policy is stash enough big cabs about that you won't need to move one far. Maybe we should organise a cab community project between bass players.

[Wooks79]

[quote name='Mr. Foxen' post='1185451' date='Apr 2 2011, 12:24 AM']My policy is stash enough big cabs about that you won't need to move one far. Maybe we should organise a cab community project between bass players.[/quote]

I actually think thats a really good idea!

[Mr. Foxen]

Well, I have a 18" folded horn cab, in the style of an Acoustic 360 stashed near the Croft in Bristol. My other bass cabs are kind of miles from anywhere useful, but it is a short van hop to get them to any other Bristol venue.