[gooberdude]

Pics of my recent project.   i decided to clone the Duet frames that Darrell Hawthorne makes but tweak the design a bit.   OB baffle projects are fun even with limited woodshop resources...















3/4" Birch plywood was used for all the pieces.   I had Hawthorne Audio make the wooden driver mounts in the 3rd picture.  In order to isolate the drivers from the main baffles even more i used Neoprene washers on both sides rather than bolt the driver mounts to the front bafle with T-nuts.   these are below the large washers you see in the pics...8 on each baffle front.

Trimming the side wings to 45 degree angles and routing around the driver holes made a huge change away from a driver-centric sound...after i trimmed the fat the baffles really began to 'disappear'.   I think its important to let all aspects of an OB baffle get out of the way, assuming the basics of keeping the out-of-phase sound waves apart from one another have been met.    round all edges and let each baffle do no harm.

I included a pic of the center of the Silver Iris driver, i've removed the bug screen inside the tweeter throat, and also the cloth dustcap on the Silver Iris woofer.   the improvement is wild.  total clarity was the result, along with throwing the Warranty out the window.  The baffles will be covered in grill cloth keeping dust out of the sensitive area though.   it was a gutsy tweak but more than worth it to me.   1 gram of very stiff cloth was removed from each woofer.

The other change i made to the baffle, at the last minute no less, was to slice the front baffle in half....isolating the Auggie from the Si.   The Auggie vibrates a lot.    This created a really intense & emotional improvement, loads more midrange lushness & palpable 3-D musicians on stage.  The frames are held together by the glued-on side wings, and these wings do not touch the base.     

Unless the recording is sub par, all musicians have their own 'space' on stage...noone is crowded or centered.  Often drum kits are off in the corners even, 5' - 7' back, quite cool.    Prior to slicing each front baffle, the baffles were only held together with Titebond II wood glue.  after the slice i had to insert some woodscrews to make sure it all held.   In all ther's probably 3 pounds of metal hardware in each.

the vibe transmission from Auggie to Si is several orders of magnitude lower than in the original form, however the music doesn't sound isolated or muffled or dull.      I installed small neoprene washers on all the driver mount hardware during testing also, but they really killed the sound.  having the drivers mounted right into wood, plus proper speaker gaskets, sounded best by a wide margin.   

I don't have pics yet, but the front, sides and the rear wings are now covered in felt.  Having a large baffle like this  (38" tall x 22" wide)  requires some sort of absorptive covering.   the disappearing act gets much more severe and imparts an ease to the sound that's inviting.   bare wood baffles this size have a  flaw IMO & IME.  they do look cooler though...

so far no genre of music is bad...these really are transparent drivers with this baffle arrangement, and the bass is astounding.   

The gist of the design is that the drivers themselves are only touching the 3/4" birch driver mounts, and nothing else.   I like this arrangement for the obvious benefits, but also since i can take the mounts & use 'em on any future baffle designs.    Removing the drivers from the baffles takes less than 5 minutes in total...pretty sweet.   Right now the driver mounts are secured tight with wing nuts...at some point Nylocks will be used.    All driver mounting hardware is secured with Nylocks...  very cool to use nylon to damp ringing in the bolts.

If any OB fanatics are still using boxed subs...its time to get on board & let Auggie's bring big, big smiles.  The fact that they work in mono is just icing on the cake. 


Of all the systems i've heard, only a few have that 'i can walk around each musician' quality of imaging.  This set-up has it, in spades.  the imaging is just insane, and when combined with the Auggie bass the whole package is awesome.    From all i've read, even the Jamp 909 review at 6Moons, OB set-ups 'supposedly' have diffuse imaging.   I do not find this to be the case whatsoever, but, i had to work to get here.

One aspect that sticks out in my brain of the change in performance between a 1 piece baffle and the semi 2 piece that i ended up with is that before the Auggie really stood out sonically.  After the slice each baffle sounds as if it contains 1 massive & bad-ass single driver.   both woofers in each baffle have melted into 1 congruent, forceful & sublime mixture.  There isn't any less of anything, just a lot more synergy. this is the effect i wanted but wasn't sure could be achieved given my experience and woodworking resources.


sidenote:  during experiments i used the Premium T-nuts from Parts Express...i highly recomend these though i didn't use them in the final design.  they are aggressive, won't pop out and cost 50 cents more per bag of 50.    no affiliation.


matt

[mcgsxr]

Thanks for taking the time to share with us Matt, I appreciate the hard work (I have been through baffle revisions a number of times myself), and it is great that you would give us insight into what you do on that balcony of yours!

[Jumpin]

Has anyone tried a granite baffle?

Since all you need is a flat piece with one or two cutouts, granite may be easier than wood with the associated resonance benefits.

 

[kyrill]

hi creative creator

As English is not my native speaker i dont understand 2 things actually 3

1) Trimming the side wings to 45 degree angles and routing around the driver holes
I dont see any side wings on yr picture, you mean side baffles? And what means "routing around the driver holes" what do you route?
2) how did you decouple the woofers mechanically from the front baffle? or in other words how is the "2nd" baffle of the woofers connected to the front baffle? And if they do not touch or "see" the front baffle at all, what keeps it in its place?
3) is the tweeter an integral part of the woofer? originally out of sight as it was covered by a kind of dome? The picture of the silver irish driver ( the tweeter) looks as if it is in the centre of the woofer
and if so how is this possible? : " the last minute no less, was to slice the front baffle in half....isolating the Auggie from the Si"
Or is the si just as big as the Auggie albeit a tweeter? On the picture i see two almost identical big speakers. Or is "woofer" with the integrated tweeter and called the irish? Or if it is decoupled from the other woofer, it still is very coupled to its own woofer? Or frequency wise , although the speaker is just as bif as the lower speaker, it gets mid bass, mid  frequencies?
i wonder does the side panel not transfer vibration from and to the 2 apart speaker panels?

challenging design nice thinking

[gooberdude]

hey guys, thanks for the kind words.    this is my 1st real attempt at an OB baffle, so i don't mind being peppered with questions.   



Kyrill, the wings i mentioned are just the sides of the baffles.   Initially my baffle was a perfect rectangle w/ all 90 degree angles and sharp corners.   slicing down the 2 sides (left and right) made a big, positive change towards having the speakers disappear, meaning no sound seems to eminate from the drivers themselves.   I call them wings since they are built up wwith 3 layers of 3/4" Birch.    Once i do the final design, there will be small wings on the back...same as hawthorne's actual Duet frames.

The top 15" woofer is actually a co-axial driver.  These are most common in cars..


The woofers are bolted to 16.5" x 16.5" Birch boards.   these boards are then bolted to the front baffle, but i through-bolted them and on both sides of the baffles used thick neoprene washers so that the vibes from the drivers don't transmit to the main baffles.


I like wood for speakers, and for stereo systems in general.  But, the way this baffle works out most any baffle material could be attempted...there are very few vibrations entering the main baffle.  However, i do think granite might be too dead, or ring too much, to be a great baffle material.   that's just my opinion though, based off nothing but speculation. 

[richidoo]

Nice job Matt!! Very creative solutions there. You obviously have a good grip on what to try to fix a problem. Very impressive!! Ive been reading the Hawthorne site and forum, I might give it a try too. Easier than building Orion, and with normal simple crossover it might sound better too. Thanks!
Rich

[gooberdude]

Hey Richidoo, are there several Orion speaker designs or just the mega buck ones on their website?     i was at that site a few weeks ago, very interesting stuff and, essentially, the beginning of OB if i read it right.

$8K - $10K is a bit rich for my blood though!  8 channel amp?    sounds complex to say the least.


In all i've spent about $1000, not including my time, on the baffles, speaker cables and plate amp that you see.

[Bob in St. Louis]

Nice job Matt. I've done surgery on a pair of Duets, and yours are very close. Well done.

Bob

[richidoo]

There's one Orion, with a couple options. You can build one from plans for about 2500 plus amps. It is a very complex design, but very dialed in. IMO the crossover dulls the signal with lots of non high end parts doing lots of jobs, it has two dozen opamps that are not state of the art quality. The processing needed could be done digitally with no damage to signal. It uses drivers designed for box speakers so the crossover has to compensate with EQ. The orion forum users have experimented with updated opamps like LM4562 and dream of using tube amps to recover the magic, but not when you need 6-8 channels.

I like the Hawthorne because it is cheap and everyone says it sounds great. I have a Cary integrated that I think will work great with the duets for a second system. Maybe I can get off the mouse wheel.
Rich

[gooberdude]

Close but no cigar Bob - i'd like to hear a finished Duet for comparison.  


I have a feeling the tricks that Darrel incorporates to the backside of his speakers puts 'em in a league well above mine.  


Since i haven't yet found a location for the x-over they are sitting on monitor stands.   One set of stands i have (not pictured) has a triangular shape to the vertical part so i set them right behind the drivers to listen for an effect.   There certainly was a change, but not all good.  i'd like to play with waveguide's more.   On 1 hand a crazy smooothness was evident, but imaging was off.       I've seen a few prelim pics on hawthorne's site in the Member's gallery, but the actual waveguide used in the rear of the production DUET's is a secret.


One arrangement i might try is having the x-overs a few feet from my amp and run long cables from the x-over to drivers....   i might also try using the same cable from amp to drivers.     these cheap Rat Shack cables i'm using are great.    finding the x-overs a box to live in might be in the future too.


Bob, this may be a discussion for another time but what do you find is different when going from a Duet like arrangement to having the Si & Auggie's separated??

[Bob in St. Louis]

Bob, this may be a discussion for another time but what do you find is different when going from a Duet like arrangement to having the Si & Auggie's separated??

HMMM, The Duet has more bass. Mounted as separates the low/mids range on up the scale seem to be clearer. But I think (from what I've read) that I'm in the minority of those users that tend to like a thinner baffle. Remember, I had the Coaxials mounted baffleless for quite a while. Even now, I've only got a 2" ring around most of the driver.
I also have the freedom of placement. With (now) seven 15" drivers in a horizontal array, I can place the Coaxials where I want in the arrangement thereby expanding the imaging/soundstage. Something now possible with two individual speakers. It basically give me the ability to shuffle the deck so to speak by moving stuff around.

Different strokes for different folks.

Bob

EDIT: My version has a much lower WAF for most peoples rooms/taste. Not possible for the average living room. A pair of tasteful black speakers has a much higher WAF. My wife says my room now looks like a garage sale of speakers the way I have them all lined up. 

[tyee]

Gooberdude
  What plate amp are you using? I want to get the augies too but need a XO too! I am still thinking about getting an active XO also.

tyee

[gooberdude]

Hey Tyee,


I bought the remote control 240Watt plate amp from Parts Express...i don't think its avail now though.   Heck of a deal for $100 if you can find one.


What's wild about the Auggies is that they run perfect in mono...   get a plate amp that'll put out 300 watts or more into 4 ohms and wire up both Auggies to it.   If you are using the Silver Iris' they play low enough to put out ALL the directional cues for bass.   i've had stereo subs before, no need for the hassle with the Auggies though.


matt

[richidoo]

Does Augie need a low pass filter when used with SI coax like in duet type OB? Dpes it take signal from the SIs crossover? Or is it just played full range?

When is sterling coming out, and should I wait for that? Likely be fairly precious, huh?
Thanks
Rich

[Bob in St. Louis]

When is sterling coming out, and should I wait for that? Likely be fairly precious, huh?

They're very nice Richidoo. Hard to answer whether or not you should wait for the Sterlings though. Kind of a judgement call on your part. They ARE worth the wait if you decide to hold out. The 'Performance grade' is no slouch by any means.

Bob

[gooberdude]

Hey Rich,

The Silver Iris drivers come with their own 2-way x-over.   the Auggie is not involved with this though, you'll have to get a separate x-over for it...making the plate amp option economical & simple to implement.

[richidoo]

OK, I see, thanks Matt. Seems like the Duets are quite a value.
Thanks Bob, I am keeping my ears open for the announcement and first wave of early adopters, of which you are one, right? hehe

[Bob in St. Louis]

Thanks Bob, I am keeping my ears open for the announcement and first wave of early adopters, of which you are one, right? hehe

You're Welcome Rich.
By 'adoptors', I assume you mean like "adoption" of a child? Then ALMOST.
These are on loan (Beta test) my Mr. Hawthorne. Nobody owns any Sterling Augies yet.

Bob