[Vapor Audio]

It seems like every day I'm having discussions with people either on the phone or email, explaining things about how we build cabinets.  All the fine level details and performance benefits/reasons that go into the shape of cabinets, how we choose drivers, our philosophy in voicing and why we offer Black and White versions.  Inevitably those conversations turn into very long ones, because everything we do is for a reason, not just "oh that'll be cool". 

With the Perfect Storm the goal was very clear from the first day we began discussion, let's build the absolute best speaker we possibly can.  Let's not set a price point, just pursue the ultimate and after all the dust settles, figure out what we have in them and let that set the price.  For a true Flagship design, we believe performance not price must be the only design criteria. 

But there are a lot of real World consideration, the biggest of which turned out to be execution of cabinet designs.  We're not willing to give up things like diffraction elimination for example, and many cabinet design choices are led by the need to incorporate those elements.  Then there's simply the difficulties with executing very large, very complex, stacked Birch Ply cabinets.  Wood moves, wood has a mind of it's own, and sometimes it doesn't want to co-operate.  So learning ways to make the wood comply with OUR will and not the other way around was a big part of successful implementation of ideas as well. 

With that said, Pete is going to now share some of the thought process and evolution of ideas that went into decision of the final cabinet shape.  I wouldn't be exaggerating to say we had 500 hours of work into the cabinets before a single piece of wood was ever cut, and if you consider time spent on Joule design elements which then translated into the Perfect Storm, we'd easily be into the thousands of hours.  After Pete talks about the cabinet, I'm going to share info and data about the drivers used, which I think constitute the finest collection of drivers used in ANY commercial loudspeaker, and I think the data will show that as well. 

It's our uncompromising approach to all the elements that form a loudspeaker that make us different.  And we're going to try and illustrate that in the coming posts here.

[Pete Schumacher]

Perfect Storm . . . where to begin.  Why not the beginning?

When Ryan launched the business, he started with the best 2-way monitor he could think of, the best materials, the best drivers, and the best enclosure based on everything he had researched up to that point.  Audio Technology and RAAL were the final choices after evaluating dozens of each driver type.  I remember perusing the storage room looking at all the drool worthy components he spent time evaluating: Scanspeak, SEAS, Peerless, Usher, Raven, Aurum Cantus, Fountek, among many others.  He wasn't just evaluating on paper, but with his ears and in completed systems. 

Along with that, he set out to make the "ultimate" enclosure that featured many of the proven concepts that make for a great platform. an eclosure that doesn't contribute to the sound.  Among those features, large rounded edges to reduce and smooth the diffraction signature of the speaker.  Not incorporating that feature leads to not only a more erratic frequency response, but a speaker that loses pinpoint imaging.  Another feature is that of not transmitting sound through the walls, not just through panel flexing but direct transmission (think thin apartment walls allowing you to hear conversations in the next room).  And then there's the interior space behind the driver.  That space needs to be set up to diffuse and absorb the back wave of the midwoofer in order to keep the internal reflected sound from coming back through the cone in a correlated manner.  That keeps the response smooth and transients clear and clean.  To that end he employed finite element analysis to arrive at an internal structure that allows judicious use of damping material and scattering features to create a space that controls the back wave, not just kill it.

The result was Cirrus, a giant killer of a monitor that became the sound against all other builds would be judged.

As things progressed, we were tasked to create a more sensitive monitor that would be able to reach sound pressure levels well beyond that of a 7" 2-way.  The Arcus project resulted in just such a monitor.  That build taught us the limitations of trans-laminated construction which led to the eventual failure of the first set of cabinets.  After a redesign of the pieces, a much more robust and stable construction resulted.  But we still had to deal with movement, as Ryan mentioned, which causes the exterior finish to become stressed.  Only through many builds and attempts to properly seal the cabinets were we able to greatly improve the techniques and results.

Arcus sealed for us a love of higher sensitivity systems.  The main reason was that it enables us to utilize virtually any amplifier that comes our way, and at the time, that meant SET amplfiers.  While Arcus wowed, it still required low frequency augmentation for some music.  That led us to build Nimbus, our first full range high sensitivity design.  The use of a 15" woofer brought to us a new level of dynamic heft, punch, slam, and doing so with effortless ease giving us a sense of unlimited dynamic capacity.  Along with Nimbus we also developed a high sensitivity version of Cirrus by utilizing an Accuton midwoofer and accepting the absolute need for a dedicated, quality subwoofer to fill out the bottom octaves.  Cirrus White revealed the subtle differences that cone materials offer in the presentation of musical information.  The "spicey curry" of the White was a wonderful compliment to the "juicy steak" of the Black and we decided to stick with the option for future builds.

While this was going on, we were in the process of developing Joule, our first 3-way system that took what we knew from Cirrus and expanded upon it.  It started as a vented, pedestal mounted 8" based 3-way, but after the first few builds, we realized that it did not present quite the impact we were now quite fond of in both Nimbus and Arcus.  It's sensitivity was just too close to Cirrus to really offer that extra dynamic punch with low powered amplifiers.  We also wanted a little more extension to the lower frequencies that we just couldn't get with the size enclosure we were using.  The only real option we were willing to entertain was to upsize the woofer to a 10" model, and if we were doing that, a transmission line seemed the way to go.  This is about the time we were contacted by someone who was interested in something even more ambitious than Joule, and the quest for Perfect Storm was begun.

To be continued . . .

[MDolphin]

Pete we are all anxiously awaiting your promised sequel to the rest of this story.

[Tomy2Tone]

Yeah, come on Paul Harvey...

[Pete Schumacher]

Yeah, come on Paul Harvey...

And now, for the rest of the story . . .

As mentioned earlier, Nimbus gave us a new level of concussive bass that we hadn't heard before.  The use of the incredible 15" Acoustic Elegance woofer in that massive vented enclosure delivered ear-to-ear-grin levels of enjoyment.  When we had them in that Newport Beach hotel room, we took an in-room measurement to check for room modes and other issues.  As Steve Nugent queued up the signal, I stood looking at the display and was in disbelief at what I was seeing.  What I saw was a literally textbook optimum in-room response excepting for a couple of bass modes at 40 and 80Hz.  Otherwise, the response at the listening position was simply a straight line, flat top to bottom.  I called Steve over to look and he also echoed my surprise.  His comment to me was this was the first set of speakers he'd ever demoed with at a show that didn't need any EQ above 100Hz.  He'd used a number of very high end speakers too.  Needless to say, the Nimbus wowed listener after listener that weekend.

When we got back home, we were finishing up the first set of Joule featuring the transmission line bass bin.  Everything was set in place and we proceeded to queue up our first test tracks to audition what we had created.  With the first song, we looked at each other, stunned at what we were hearing.  As incredible as Nimbus was in the bass, Joule was producing what we could only describe as "transparent" bass.  There was a level of subtle detail and control that we'd never heard before.  Only two things could be responsible for this wonderful sound: the Audio Technology driver and the transmission line loading.  It became very clear that the use of stuffing between the driver and terminus was reducing the back wave sound from the woofer nearly completely and our measurements at the terminus confirmed that.   We had arrived at our approach for the ultimate system and the match of Audio Technology and transmission line loading was it.  The final design approach for Perfect Storm was beginning to coalesce.

The many iterations of conceptual drawings and approaches were finally winnowed down to simply using an upsized, proven Joule concept.  Many hours were spent finalizing the CAD drawings of the transmission line and new upper section based on the Derecho cabinet.  After a lengthy two years, we finally had all the pieces of the puzzle in place to begin the assembly of our massive flagship starting with the cutting of the many dozens of sheets of Baltic ply.  Just the act of cutting all the pieces for a pair of Perfect Storm takes a couple of weeks of uninterrupted time on the CNC, a machine we are blessed to have access to thanks to a very kind and understanding local cabinet maker.  So all that time needed to be coordinated with his primary need to cut wood for his projects. 

Between the time we started cutting and the end of April, a massive amount of work was done in a relatively short period of time and we brought the finished speakers to Chicago.  It was an Herculean effort for two guys to pull off something so massive, but the result was immensely satisfying to say the least. 

[Pete Schumacher]

Along the way to the final design based on the up-sized Joule, various iterations were conceptualized, all of which presented difficulties in fabrication that relegated them to the dust bin.

The first took the Cirrus shape and stood it on its face, stretched it an immediately told us that something with pieces that large would become a nightmare to construct.



This version also didn't allow for the inclusion of a tapering transmission line into the cross sectional pieces, something we wanted to incorporate as the design progressed.

This was followed by another few attempts at 2-piece construction using dual mids.





All these versions predated the final version of Joule which was our inspiration for the final iteration of Perfect Storm.  I kind of like the look of a couple of the later versions.  However, the construction process that they would entail was even more daunting upon further research.

[Vapor Audio]

Next I'll post data and discussion about the drivers used, without doubt the finest lineup of drivers available today.

[Vapor Audio]

The drivers!  No doubt, the #1 factor in setting the performance ceiling of a speaker is the drivers used.

[Vapor Audio]

First, the woofer. 

The Nimbus set the bar in dynamics, and the Joule for transparency.  The list of woofers that can combine the two is pretty short, Audio Technology and well ... Audio Technology.  In this case a 15F Sandwich Cone. 

Woofers are all about managing the specs to hit a desired result.  Motor force, moving mass, suspension compliance all determine together sensitivity and bass extension.  Our target was flat to 20hz and a 93db+ final system sensitivity.  Since it's the woofer that always sets the system sensitivity, that makes finding the right woofer critical.  We have been working with Per Skaaning at AT for years now, and he has never failed to exceed expectations.  We told him our targeted goals, and the woofer he put together for us is nothing short of incredible.  Yes they're expensive, like really really expensive.  But there are times where your confidence in the free market is restored and you receive what you pay for, and more.  AT has always been one of those cases. 

Attached is the distortion plot of the 15F Sandwich Cone unfiltered.  What you're looking at is distortion below 1% down to 20hz, and below .5% for most of it's range, fantastic!  And flat FR to 2000hz from a 15" woofer!  That's only possible with a cutting edge, ultra-low inductance motor and extremely well behaved cone/surround.  Put this woofer in our 10:1 tapering line, and you have the best bass reproduction available at any price.  As I've told many people, don't even think about pairing subwoofers with the Perfect Storm ... you'll just screw up the bass.

- a couple notes about the graph.  The dip at 150hz is floor bounce, a nearfield shows the woofer is smooth through that range.  And there is no port output shown in this graph, with it included they are indeed flat to 20hz.

[Eugene2]

Fantastic specs I wondered why you didn't go with two smaller woofers, to get the same surface area and low distortion, I see why with those specs.  On Sunday in Chicago you could really feel/hear the texture, speed and dynamics of the bottom end of the PS.  I'm sure now with the additional break-in time on the speakers it must be nothing short of breathtaking.

[roscoeiii]

Ryan or Pete,

Can y'all also speak to why you went with a transmission line design for the bass? This seems like an aspect of the build you haven't touched on yet in this very informative thread.

[Pete Schumacher]

Ryan or Pete,

Can y'all also speak to why you went with a transmission line design for the bass? This seems like an aspect of the build you haven't touched on yet in this very informative thread.

I'll quote myself from part 2 above.

With the first song, we looked at each other, stunned at what we were hearing.  As incredible as Nimbus was in the bass, Joule was producing what we could only describe as "transparent" bass.  There was a level of subtle detail and control that we'd never heard before.  Only two things could be responsible for this wonderful sound: the Audio Technology driver and the transmission line loading.  It became very clear that the use of stuffing between the driver and terminus was reducing the back wave sound from the woofer nearly completely and our measurements at the terminus confirmed that.

There is an audible tightness, clarity, definition to the sound below 500Hz that we don't get from almost any of our other builds.  T-lines do bass better because of the way the stuffing sits between the woofer and the port.  The back wave is handled much better.

[roscoeiii]

Thanks Pete!

[MDolphin]

On 7/10, Pete concluded an outstanding and very informative recap of the evolution and unique design of the Perfect Storm Dual cabs and transmission line enhancements for the Bass. 

On 7/7, we were then educated by Ryan about the stalwart Sandwich cone woofer selected for this transmission line design. 

The Vapor community at large is now anxiously awaiting the details and synergies of the other components.  Enlighten us......

IS THIS PERFECT STORM DEVELOPMENT SUBJECT NOW CLOSED???

We are now in September.  This topic began in June, so is the Perfect Storm still in the R & D phase?

[Pete Schumacher]

On 7/10, Pete concluded an outstanding and very informative recap of the evolution and unique design of the Perfect Storm Dual cabs and transmission line enhancements for the Bass. 

On 7/7, we were then educated by Ryan about the stalwart Sandwich cone woofer selected for this transmission line design. 

The Vapor community at large is now anxiously awaiting the details and synergies of the other components.  Enlighten us......

IS THIS PERFECT STORM DEVELOPMENT SUBJECT NOW CLOSED???

Ryan's been very busy finishing up a number of builds.  That takes priority.  It will be updated when Ryan gets a little free time.

[verdun47]

"After Pete talks about the cabinet, I'm going to share info and data about the drivers used."

Man alive, holy guacamole, how many times do I check (before giving up) to see if you've finished the driver write up.

You should have been realistic and written ........ share info and data about the drivers used THIS YEAR.

It's faster watching tortoises copulate.

[rascal]

So with Storm developed, has money been refunded  back to bassfeen?

[Vapor Audio]

After much ado, the continuation of the story:


Probably the most difficult part of the puzzle was the driver we wanted to handle the primary vocal range.  One of the things I've learned over the years, is for vocal reproduction, you want the largest cone area possible before the compromises of larger cones start impacting your desired frequency coverage area.  The Accuton C173-6-090 would have certainly done the job, and like the Joule White, is appropriate in a 3-way usage.  But we wanted larger, more power, more full and dynamic vocals.  That meant using a larger cone for the lower midrange. 

The pure ceramic (non-sandwich) Accuton C220 cone is a proven performer, very behaved and delivers exceptionally low distortion with class-leading energy storage characteristics through the desired 200-1000hz range.  And even the off-the-shelf Neo C220 would have probably been sensitive enough for us to meet our 94db sensitivity AND efficiency goal, but still we though we could do better.  Smartly realizing that there are many other smart people in the World, we teamed with Mark Warner and Warner Dynamics to develop the new driver for this purpose.  In his words, as he says "get your barf bags ready", lol. 

   One of the greatest challenges faced when creating hybrid loudspeakers featuring ribbon tweeters and dynamic cones, is somehow coming up with midrange and bass drivers that can keep pace with the sense of speed and clarity that ribbons are revered for. The experienced design team at Vapor Audio, in their quest to raise the bar yet again with their new flagship Perfect Storm system, knew well that there were no existing drivers that could accomplish this feat, as doing so required a driver developed with the singular focus to satisfy this need. Partnering with Accuton and Vapor Audio, we have succeeded in turning this requirement into reality.

     Using Accuton's superb C220 platform as a starting point, we have totally re-engineered the driver to accomplish this task like no other. The already powerful 120mm Neodymium underhung motor structure is further enhanced to achieve a mean saturation of 1.8 Tesla through the height of it's magnetic gap, which when coupled with it's newly optimized voice-coil and pure Titanium former gives the driver unparalleled control over the highly rigid Sapphire cone. To further reduce moving mass and thereby improve litheness, the heavy rubber surround has been exchanged for one made of lightweight, treated fabric.

     The revised motor and suspension system not only further reduces the incredibly low distortion Accuton products are legendary for, but increases the native sensitivity of the driver to an impressive 97db, causing less of the music to be converted into distortion-raising heat. Similarly developed is the brand-new 2 inch sapphire midrange above and custom 15 inch sandwich cone woofer below, all uniquely.

So while Mark put on his flowery prose hat for marketing speak, it is all true.  He and I talk about it and what needed to be done can be made to sound very simple:  take an ideal cone and attach it to as powerful a motor structure as the World has ever seen, fill it with copper to completely eliminate inductance, and give it a very linear and compliant suspension.  Simple in concept, more difficult in execution.  Mark and Accuton deserve the laurels, because all I did was say what I wanted.  Beyond that was standing back and letting smart people do their thing. 

So how did it turn out?  Well, beyond our expectations quite simply. 

Here is the distortion of our custom C220.  What you're seeing is quite simply the best 100-1000hz distortion on the planet, bar none.  Nothing else I've seen even comes close!



Expensive, very!  But best possible was the one and only goal.  This driver certainly delivered on that.

[Vapor Audio]

For much of the design phase, we envisioned the Perfect Storm as a 3-way design.  Easier to execute, less expense both in less drivers and less crossover components, and you can sit closer for proper summation between drivers.  But once the scale of the bass section cabinet came into view, we realized there was no point is making the Perfect Storm "smaller room friendly" speakers ... that ship had already sailed.  So transitioning into a 4-way design was the next step. 

There was one BIG problem with that however.  At the end of 2013 and early 2014, there was no driver anywhere at any price that could fill the gap between the top of the custom C220 lower midrange and the RAAL 140-15D tweeter with the sensitivity we needed that wouldn't be a huge compromise in accuracy, linearity, and ultra-low distortion that the other drivers delivered.  We could have used one of the many higher-sensitivity full-range drivers out there to bridge the gap, but any would have been massive steps down from the rest of the driver compliment.  We were at an impasse, honestly we didn't have any options. 

Just then it was Mark Warner again who while working with Accuton, had heard of a new driver they were developing.  It was first developed as the BD51 diamond midrange for Marten, but after the diamond version was released they considered doing a ceramic version.  At the time it was just a concept, nothing existed in the real World, but Accuton provided prelim spec sheets, and it seemed like it would be a perfect fit.  The early specs indicated 93db sensitive, ultra-low distortion, and flat response to a breakup at 17khz.  We contacted Accuton and said we need a few pair NOW, like yesterday!  And again Accuton came through, they bumped up their production schedule for the driver to fit our needs, and delivered the first sets off the line just in time. 

And what's more, the final version bettered the prelim specs in every way!  Sensitivity was 96-97db, and the cone breakup in fact doesn't happen until 26khz.  Just look for yourself at this distortion chart, I still think WOW to myself every time I look at it.  Again this is best in the World through it's range of 1000hz-5000hz, although we're using it to 3500hz.  Performance like this simply didn't exist before this speaker.  And other manufacturers may say "that's no big deal", but if they do, challenge them to show similar data for whatever they're using. 

[Vapor Audio]

And the tweeter, the big RAAL, the 140-15D. 

We've been asked many times why we didn't opt for the smaller RAAL that most others use.  Simple the big RAAL is just better in every way.  That's why we're slowly transitioning the entire upper end of the line over to the 140-15D.  It is more expensive, but like every other decision made for the Perfect Storm, cutting cost never figured into the equation.

As Aleks at RAAL told me once, put the best possible crossover components on an Amorphous Core 70-20XR, that performance is where the standard core 140-15D starts with pedestrian components.  And put good stuff and the AM core on the 140-15D and the performance just goes up from there.  The big RAAL is just more of what you love about the RAAL sound. 

At this point RAAL is a known commodity, no point of posting graphs.  They measure ruler flat, especially in our zero-diffraction cabinets, and have the best step-response of any tweeter made.  The 140-15D was known from day 1 that it would be the tweeter used in the Perfect Storm, because simply there isn't any other tweeter worth considering.