[Kevin P]

We have a new prototype driver specifically designed for dipole use that will probably be in production within the next 12-16 weeks.

What makes a great dipole driver?   Low noise for starters.....  aerodynamic noise of moving components is one of the biggest concerns with a dipole driver.    All of the parts used were designed to minimize turbulance and cut extraneous noise to a minimum.  

Another requirement for dipole use is the ability to move massive amounts of air.   We use a massive 15" with plenty of cone area and an XBL^2 motor with 29mm of linear excursion to make sure we are not limited by the motor.   Combine the cone area by the usable excursion and these puppies outperform any driver on the market by a long shot for use in dipole applications.    Consider also that the cabinet dimensions for these puppies is a VERY livable 12"W x 24"H x 18"D and dipole bass becomes a very possible alternative for a number of applications.

 

Notice the large vents under the spider and the massive amounts of space around the spokes.

 

Also note the leads are designed special to prevent lead slap.   When you have over 2 inches of peak to peak displacement these details become much more important.

 

How about a pole vent you can drive a Voltswagon through?   Really... a golf ball will roll down that vent!  


 

A better look at the vents under the spider.   All of these details along with the incredible XBL^2 motor promise to delivery some tasty dipole expereinces.  

[JoshK]

Are we going to have to take out a second mortgage on our house to obtain one?

[Kevin P]

Probably...  


The driver itself should run around $450 or less.   We have a new amp that has the dipole equalization and a couple bands of parametric EQ to dial in the room.   It is going to cost $450-$550 and consider that most people will use these in stereo.   It won't be a low cost solution by any stretch but it will be the best dipole bass solution on the planet.

[JohnR]

Kevin, do you have estimated T/S parameters? Just curious

[Marbles]

Another requirement for dipole use is the ability to move massive amounts of air. We use a massive 15" with plenty of cone area and an XBL^2 motor with 29mm of linear excursion to make sure we are not limited by the motor. Combine the cone area by the usable excursion and these puppies outperform any driver on the market by a long shot for use in dipole applications. Consider also that the cabinet dimensions for these puppies is a VERY livable 12"W x 24"H x 18"D and dipole bass becomes a very possible alternative for a number of applications.  ...

Kevin, 12" W does not seem very wide for a 15" driver  

Would you explain what a dipole subwoofer is?  

Thanks

[Kevin P]

John R:   I'll measure them later this week and let you know exactly.   We will dial our production units in to whatever specs we want but I had these put together with parts on hand.


Marbles:   The driver sits in the enclosure facing sideways.   The opening is to the front & rear and if you look down at the top cutaway view it looks like an "S".   I'll take some pics of the prototype cabinet when we are done.

Dipole is when you run the driver without an enclosure.   You have both a front & back wave that create a figure eight or cartoid type polar respose.   The advantages are drastically reduced room interaction and very natural bass & midrange.  

The best reading is probably on Linkwitz's site but here is a good general link for more information.

http://www.diysubwoofers.org/dipole/

[Jack Gilvey]

Looks cool, Kevin. FWIW, dipole bass (in the form of Adire DPL12's on a U-frame) is easily the best I've heard, surpassing IB in my room (still monopole, of course).
 Since it's so difficult to get really deep bass from a dipole due to the great cancellation down low, what are your thoughts on running dipole down to 40Hz or so (where room modes usually end) and crossing over to a monopole at that point?

[Kevin P]

Looks cool, Kevin. FWIW, dipole bass (in the form of Adire DPL12's on a U-frame) is easily the best I've heard, surpassing IB in my room (still monopole, of course).
 Since it's so difficult to get really deep bass from a dipole due to the great cancellation down low, what are your thoughts on running dipole down to 40Hz or so (where room modes usually end) and crossing over to a monopole at that point?

I think it is a great idea as you don't rely upon the dipole set-up to try and reproduce those long wavelengths.   At 20-30HZ you need crazy excursion from even a monster driver in dipole use and your always better off not using all that excursion.   You get less noise related to the massive moving cone (aerodynamic related) and your going to have less power compression and driver induced distortion the more conservatively you run them.

As you say.... the room nodes are higher up and you can get away with a very simple monopole to cover the very last octave.   You will still get some room modes due to harmonics but with a parametric EQ you it would be much easier to deal with compared to a straight monopole set-up.  A lot will depend upon your room construction.

Linkwitz has arrived at something similiar with the Orion.   Our strong suite will be that the drivers are magnatudes better in terms of distortion covering the 2nd & 3rd octaves compared to those wimpy Peerless units.  

[nullspace]

Kevin -- Anything new on the DDR driver? Maybe some T/S for the hopefully quickly approaching production units? Thanks, John.

[Kevin P]

I'm afraid there isn't going to be a DDR in the first production run.   We had to get the most popular products in the first wave.   The DDR will probably follow in the future if we can esablish that there is going to be a real market for it.

[Carl V]

well, for those of us running a Tumult and the new Adire 1200
plate amp....how much differnt is this new driver?  How much
power are you planning for this new Dedicated DDR amp?

In other words can we use our Older Adire stuff in this new
application?

How many people have used the Tumult in an IB arrangement?

[Kevin P]

well, for those of us running a Tumult and the new Adire 1200
plate amp....how much differnt is this new driver?  How much
power are you planning for this new Dedicated DDR amp?

In other words can we use our Older Adire stuff in this new
application?

How many people have used the Tumult in an IB arrangement?

The driver has a larger pole vent than the Tumult but less excursion.   Typically aerodynamic noise from the driver under extreme excursion is what will limit your output rather than the full linear capability of the driver.   The Tumult will work awesome for dipole use and I wouldn't sweat the differeneces.  

I don't know how much power we will need.   Probably not much.... in free air you don't need near as much power as you do in a sealed cabinet.  Even with dipole EQ you don't ever use more power than needed to reach full excursion of the driver in free air.  Your limitations are based upon the linear throw of the driver and having more power than needed to reach it won't do a thing for you.   If I had to guess I'd say a couple hundred watts will be plenty.

The Tumult would certainly be usable in a dipole application but you would have to do the design work specifically for that driver in the intended application.  

IB is of course a different application than dipole..... I don't have any idea how many people are using them in IBs.   I've only sold a small portion of the total Tumults and most of the time people buy them and go on their way.   I don't know how about 50% of the people are using them.     I've not sold any into a IB application that I know of.    For IB applications you won't need anywhere near that much power either.   Even a driver like the Tumult doesn't require that much power running in either IB or dipole applications.   The EQ functions on the new Adire amps are awesome though.   They are easily the most flexible plate amp on the market.