Virage

Let's class the joint up here a bit, shall we?  

When the Purifi woofers arrived on the scene a few years ago, I honestly didn't think much about them.  I mean, they were "interesting," in the same way it's "interesting" when Aston Martin releases a new car.  "Oh, that's nice.  Very expensive. Very high-tech.  Now, what was it I needed to get at the grocery store?"

However a year or so ago I was approached by someone to do a custom 2-way bookshelf with the 6.5" 4 Ohm midwoofer, and I figured I couldn't say no to that!

As I was working on this one-off design, I found myself floored by these Purifi woofers.  Not long after I finished that one-off design, I called up Meniscus and said we really ought to do a 2-way kit with these woofers.  Mark was very enthusiastic, and whipped up some really nice test boxes for me.  


After several months of playing with the drivers in a variety of crossover configurations (more on that later), I finally arrived at a high-end design that really showcases what is possible with some of the best-performing, low-distortion drivers on the market today.  

The Virage can be built as a medium/large-ish bookshelf or a floorstanding TM tower (a la Amiga).  

It is available as a kit from Meniscus audio.  

Driver CHoices

Purifi PTT6.5X04

The Purifi 6.5" midwoofers sound great in the mids, as one would expect with all their low-distortion trickery.  However, what really strikes me about them is the massive, delicious bass they are able to put out.  These are 6.5" woofers, but they SOUND like they are 8" or larger.  The bass digs so fantastically deep, and is able to resolve individual instruments with the kind of clarity I have never been able to get from a 2-way speaker.  I opted for the 4 Ohm version of the woofer to squeeze as much sensitivity out of them as I could. 

Satori TW29R-B

To complement what is possibly the most advanced woofer currently on the planet, I felt I had almost TOO MUCH freedom.  Should I go hog-wild, and use some exotic dome material?  Should I use a European or Asian manufacturer?  What shape of dome?  Should it be a dome at all?

Anyway, after a lot of thought I decided on the SB Satori tweeter family, which are also some of the most advanced drivers available.  I personally like the ring-dome one for its flat top end, and also think its look goes well with the Purifi woofer.

Cabinet Design

The Virage can be built in one of two cabinet shapes.  Which one you choose is probably going to be a matter of personal preference.  Both speakers have the same outstanding soundstage and bass that pressurizes the room so well.  The tower does reach a few Hz lower in bass extension than the bookshelf.  But beyond that, I think it's more a question of which speaker you think would look better in your space.  

TM Bookshelf

The bookshelf version is what I'd consider "medium-large."  At about 18 liters internally, it's slightly larger than, say, the Classix.  The port is 2" dia x 5" long, and is mounted behind the tweeter.  This tunes the box to 51 Hz, and you'll get an F3 of around 38 Hz.  You will want to tie the walls together with some proper bracing, and also use either damping material on the walls, or a medium fill of polyfil.  

TM Floorstanding Tower

The floorstanding version of the Virage is... well... it's the Amiga cabinet.  I mean, there's really nothing different about the dimensions and construction of this cabinet vs. the Amiga (although the Purifi frame is a few mm smaller than the Dayton RS180, so don't go using the Amiga baffles, or you'll be disappointed in the fit).  Other than that, you'll still want to tie the inner walls together with some bracing.  You'll still want to line the inside of the cabinet with some sort of damping material, and probably use a few light handfuls of polyfil near the bottom.  You can even use the same port length and tuning as the Amiga (2" dia x 3.5" long), and you'll get an insane F3 of 33 Hz.

Crossover Design

The challenge with designing a crossover for these drivers is that they are almost too good.  Let me explain.

You can slap a rough crossover on the Purifi woofer and Satori tweeter, and no matter what, it's going to sound pretty good.  (Which, in a very weird sense would make them good drivers for beginners?  But I digress)  See, normally when I design a crossover, I start with something in the ballpark of what I think will work, and then I add complexity, and then remove complexity, until I have chiseled away just the sound I like.  In the case of this speaker, no matter what complexity or topology I threw at it, it still sounded "good."  I ended up with a wide array of crossover designs, and they all sounded "good."  

So I had to actually kind of give myself a pep talk to push myself past that point of just "good."  "Self," I thought, "These are really damn expensive drivers.  You ought to be able to get something out of them that's better than just 'good.'  You know that 'holographic' imaging and soundstage you love?  You need to make these drivers do that."  And so I did.  And here we are!

The crossover is, essentially, a 2nd order filter with an L-Pad on the tweeter, and a 3rd order filter on the woofer.  As I said, getting those values dialed-in just right took a lot of patience and effort.  

I would recommend air-core inductors all-around.  15-18 AWG on the woofers, and 18-20 AWG on the tweeter.  You should probably use at least polypropylene caps--we'll skip the electrolytic capacitors here.  

Frequency Response

Impedance

Listening Impressions

Does the DIY world need another 2-way with a 7" woofer and a 1" dome tweeter?  No.  So why bother with something like this, when we could just have something like the Amiga, or the many other great designs out there by other DIYers and brands?  It has to bring something to the table the others can't.  

I mentioned this before, but to me, what the Purifi midwoofers do that others do not is put out gobs of luscious bass that defies their size.  And since the motors are so well-designed, that bass is also very low-distortion.  And since they have so much xmax, you can push them a lot harder than you can most other 7" midwoofers.  

Sitting atop that bass is a midrange you'd expect from a high-tech, leading-edge woofer.  And above that, the Satori ring dome tweeter does a beautiful job of integrating with the woofers, and provides fantastic imaging and soundstage, and otherwise disappearing from the picture, and not making itself known.  

The net result of all that is a pair of speakers that effortlessly do the "holographic" sound I love so much.  The soundstage is massive, and instruments and voices are clearly placed in front of the listener.  Several times while listening to these I had an experience of doing something else while mindlessly playing music in the background, and a singer or a sound would startle me because it actually sounded like someone/something was in the room with me.

I don't expect this is a project for everyone.  The prices of these drivers are outside what most DIYers are willing to spend on a fun little project.  But I also understand that other DIYers are willing to spend the extra money, either because they want to know they got the best, or because they know they're aiming to build something as-good-or-better than what they might spend thousands on from an audiophile brand.  I really hope those that do give this one a try will find it's a speaker they can really settle into and lose themselves for hours and hours of listening, and they get years of enjoyment from them.

by Paul Carmody | January 2023