2011 LAB / SFN EXPO / SMAART 2-day May 16-19 in MA

Re: 2011 LAB / SFN EXPO / SMAART 2-day May 16-19 in MA

21 inch passive radiator in a Bandpass box? Enquiring minds want to know.
 
Re: 2011 LAB / SFN EXPO / SMAART 2-day May 16-19 in MA

Hey guys,

Ales calls it "Isobaric", but of course with the different driver sizes and quantity front to rear it is unlike anything else I am aware of. You would have to ask him what he discovered on the three year long road between this sub and his last isobaric design, but the power density is pretty incredible and having a true -3dB point below 30Hz is a lot of fun.
 

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Re: 2011 LAB / SFN EXPO / SMAART 2-day May 16-19 in MA

All drivers are 'real' drivers, each separatelly powered by dedicated 3.3HP power amplifier (almost 10HP total).
There is nothing 'bandpass' about it. It's almost a textbook isobaric design.
To simplify even further : From listeners and system designer's perspective it is plane ol' front loaded, ported sub.

Magic is, that this particular configuration DRAMATICALY reduces t.h.d. @ higher SPL, especially @ very low frequencies.
JD21 'corners' well below 30Hz (-3dB) and reaches the neighborhood of 140dB SPL, so lower t.h.d. is a must (if you ask me).
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Main reason for the design is me being an old fart now and I refuse to drag heavy stuff around. I needed a 'power dense' SUB.

I emphasized 'sub' since I firmly believe that flat response down to 30Hz is a must. All ADRaudio subwoofer designs meet this criteria.
 
Re: 2011 LAB / SFN EXPO / SMAART 2-day May 16-19 in MA

Hey guys,

Ales calls it "Isobaric", but of course with the different driver sizes and quantity front to rear it is unlike anything else I am aware of. You would have to ask him what he discovered on the three year long road between this sub and his last isobaric design, but the power density is pretty incredible and having a true -3dB point below 30Hz is a lot of fun.
I would say the mass density is pretty incredible too - 200lbs in a 24 X 36 X 30 box, though that includes amps. Not a negative - just an observation.
 
Re: 2011 LAB / SFN EXPO / SMAART 2-day May 16-19 in MA

TJ,

I did the conversion myself just before posting the spec sheet and was surprised to see that it specs so heavy. Bill Hanley and I unstacked two onto the ground at the SFN Expo monday night, so it's an easy two person lift. Been moving these things for a while now, had thought they were 50 lbs lighter.
 
Re: 2011 LAB / SFN EXPO / SMAART 2-day May 16-19 in MA

That is a bit more than I suspected also.
In my observation the weight is balanced from front to back, so they "seem" lighter.
 
Re: 2011 LAB / SFN EXPO / SMAART 2-day May 16-19 in MA

Those things are like ground zero in a combined arms exercise. And they sound great doing it. Amazing combination of engineering and manufacturing.
 
Re: 2011 SoundForums.net Expo

At least Bennett Dave Rat and a few others now know what the resonant frequency of their heads are!! The SMAART class was very interesting and really made the trip over for me, I also must apologise to some people for the Scotch induced hangovers but I did warn you, Karen Jamie, Rich Dave etc etc G
 
Re: 2011 SoundForums.net Expo

Sorry for the late chime-in. Dave Gunness and I have been on the road nearly non-stop since the Expo. I want to profusely thank Bennett for so capably organizing the event (once again). Dave and I had a great time, and we certainly appreciate everyone taking a few moments to listen and comment on our latest designs. We cannot wait for next year's get together.

Next time we will know to stay clear of any brown fire water Gordon may be offering -- delicious though it may be!
 
Re: 2011 SoundForums.net Expo

For those who couldn't attend, and perhaps even those who did, some of the photos off my phone:

IMG_0015.jpgFOH Magazines all laid out for the start of the first day.

IMG_0043.jpgThanks Midas for sending a Pro6 for us to play with, we ran the whole event off it and it got a lot of hands on it. I really liked mixing the band on it Day 1, easy to get the sound I wanted.

IMG_0036.jpgThe whisky that Gordon brought, which caused day two to start half an hour late.

IMG_0032.jpgAdam: Frequency binning is the hardest thing I do.

IMG_0016.jpgThe McCauley M421s ready for the band on the evening of day 1.

IMG_0024.jpgDavid poses with one of the M421 drivers, sitting on an M421. It is that big.

IMG_0035.jpgBill Hanley inspects the interior of the M421.

IMG_0023.jpgDave Gunness gives his talk.
 
Re: 2011 SoundForums.net Expo

Better known as "The Gates of Hell" by Rodin

Those aren't "The Gates of Hell"...although there IS a resemblance :-).

THESE are the Gates of Hell At least one of the six bronze castings. This one's at Stanford University and I've mixed the same band set up in front of them twice. Once was a wedding and the second was five years later for the same couple. They made us "Return to The Gates of Hell" t shirts for that one
 

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Re: 2011 SoundForums.net Expo

Lee,

I got to see the original on tour at the Smithsonian back in the 80's.

You can put down any confusion on my part to the shakiness of my vision at the time.

Yeah, thats my story and I am sticking to it.