Lii Song has sent me their new flagship drivers, the PT-10's which are quite the animals...  it shows a company who's passion for exceptionalism is over and above.

They asked if I would design an enclosure for these drivers. When I received the drivers I had no idea what to expect. I measured the Thiel Small Parameters and was stunned to find the impedance at resonance at 500 ohms. It actually created a 180 degree phase shift at that frequency of 30 Hz. This got me a bit panicky. I spent the rest of the evening making a transformer to largely eliminate the phase shift just in case it proves to be a problem and how couldn't it, right?



Well, we still don't know the answers to any of this, it is too soon.  I just want an ace in my pocket to delete the phase shift just in case I need it. I then moved on to model the perfect box based on the Thiel Small parameters I had measured.  This was depressing because nothing was really modeling correctly.  The driver wanted to roll of at 300 Hz in most box types.  With some trickery it can go flat to 100 Hz, and if really stretched you might get it to hit 60Hz.  Or so I was being told by the computer models...




Finally I got frustrated and just went and got a sealed box of around 3 cubic feet and shoved one of the drivers over the hole since it was too big to fit a normal 10 inch cut out.  I just needed to see if this thing was going to make any bass...  Sure as shit it did.  Not a lot but I could hear the potential and an uncanny speed. It was special despite being only from the back side of the cone. 



This is when I knew I was going forward.  The Audio Gods told me it's not modeling well because it wants a real horn.  I got right on it.   When I finished the plans about 4 weeks later I started to build a pair.  This is when I found out my plans would have made my phone ring and clogged up my email...  so time to make some revisions.

ohhhh yeah- a spark of excitement just ran through my veins. Looking good and can't wait to see the final results. I will pace an order as soon they are available. Thank you for posting!

I think I’m gonna need to pick up a few more jigsaw blades.

If these can produce something similar to the bass you get from those corner cabinets (imperial?) then this is an exciting build.

I almost wish I'd waited now as I'm sure Steve's backloaded horms will sound absolutely spectacular.... Then again, my MLTL Platinum-10 speakers should sound fantastic also. I'm rather hoping it's pretty hard to get a Platinum-10 based speaker wrong.  

I'll take delivery of mine this coming Sunday  

Will you be looking to get a pair of your PT-10 BLH into the hands of Stereophile magazing Steve? I'd really love to read up on that  

Drew,

They are certainly gorgeous! I saw them on Facebook.

I’ve been wondering myself, why he hasn’t posted pics on this forum yet. Prolly too busy listening 😎

Well done

Hi Matty,

Great looking speakers!

It will be interesting to see how these sound in open baffle.  I think I can shoehorn them into to my existing C10 baffles with just a little trimming of the baffle.  My C10s are rear mounted and the mounting area is flared.

Once I get a ship date, I will pull everything out of the existing baffles and start working on them.

If they sound promising, I'll probably build new baffles.  Of course that's what I said about my current C10 baffles and here I am four or so years ago.

As I mentioned, I have the bottom end well covered so I just need these from around 160-200Hz and up.

Matty, those look great!  Interestingly they are about the same size!

The horns are nearly finished now.. just waiting for paint.  We scheduled a group listening session with Bob, Randy and several extended members of the Decware family this past weekend and all agree the project is a hit.  Actually the comments were so over the top you wouldn't believe me if I told you.  Some refused to go back in for fear of ruining their audio hobby for life.

Here is a short video of them playing in my wood shop.  

https://drive.google.com/file/d/1uFy5O9XQ2jZD6WHd4Tna_YWTt-WAVCds/view?usp=shari...

Recommend you download it and then play it to hear the actual recording rather than use google video player that pops up which will compress it.


The plans are in revision 5 and should be available soon.

Steve

Galaxy S9 phone.  It is what I use for 99% of all the videos on this channel.  That way the viewers have somewhat of a common frame of reference since they can record their own stereo playing the same tracks and upload it to YouTube for a direct comparison.

Steve

It would be interesting to know how it compares with the Silver-10 based Origin speakers as a baseline as that’s arguably Lii’s best known ready made speaker.  :)

The braces are curved with holes to break up the standing waves that otherwise occur between parallel surfaces.









The slotted things are diffusers, they deal with high frequencies but also stabilize bass frequencies by keeping the air pressure from sliding up or down on the rear panel.  The size diffusers carry the highest amount of energy.

Pre-drilling the holes for the wings so I can make it hard with the white paint.  The interior panels are all sealed with two coats of clear sanding sealer.



This is the wing.




Two for each speaker.



The removable baffle is made from cabinet grade plywood.  The plans under the baffle are showing the blade angles on your table saw to cut each panel.

Yes, I got Bob Ziegler involved!  We spent a good hour just getting the threaded inserts aligned.  It's a heavy driver all bolted into the 12 inch baffle so it was nice to have an extra set of hands holding the bottom as it was being tipped into place.


Now here is a story about what happened with the Audio Gods...   It starts with a round pillow!



I have at least four of these in my wood shop because the wind keeps blowing them out of the grandkids treehouse into the yard where they kill circles in the grass.  I found they are great in the shop because they are soft and level and firm enough to hold projects on without scratching anything.



Inside this horn is a pie shape just below the driver that when chanted into makes a horrible droning sound, and at resonance the sound continues for a few dozen milliseconds after you stop chanting.  The first time I heard this I felt panic.  Did I just make something for the bond fire?  You can't have sound like that inside the box with a cone this thin!  Crap.

I started having visions of stuffing the box with wool, and worried that the sound might be the horn flare itself!  Dread...

The the Audio Gods showed up and made sure that when I looked around for something to shove in that cavity that the pillow would be right there.  A perfect fit, and by itself it MORE than fixed it.  I seemed miraculous at the time, and my brain wasn't even processing it fully yet.  So simple... yet a wide band linear diaphragmatic absorber was just created and I missed it.

I'm sure it bummed them out when I ordered $187 worth of 1/2 inch wool to line the inside of the box with.  Also some foam that would be slicker to put near the throat of the horn.

While Bob was there I installed the felt in one of the horns and the foam and stuck my head in the cabinet and was satisfied that it was working, but I also remember the sound with the pillow days earlier.  So the little voice suggested an A/B test.  I relayed their wishes to Bob.  We agreed and put the Pillow in one cabinet and the fancy felt/foam job in the other and then tested the cabinets with the drivers installed on music.

The 1/2 inch thick ultra dense wool was removed as it was found to distort the sound at all volumes.  By comparison it sounded garbled.  It was hard to keep your ear 6 inches away from the cone, while the pillow side was crystal clear and it was easy to stand there indefinitely at that same distance.

During the process of getting the threaded fasteners aligned I realized that it was not fun taking the drivers in and out and thought we should just add the felt to the other cabinet and skip the A/B tests, because obviously the felt would win anyway.  I thought it, but I never spoke it.  Then I realized it was father Murphy trying to trip me up using laziness and pressure to win a bet with the Audio Gods.

I'm going to admit it wasn't easy to resist but I did, and thankfully so because the sound of this speaker would have been ruined and we would have never known.

The Felt was absorbing some frequencies and not others.  As well it was deaccelerating the air slowing down the reflex and doing it differently at different frequencies.  This was causing what I would have to call 'dynamic smearing' where the timing was off.





Here you can see the pillow installed. It sets at an angle just below the 10 inch driver.  The four corners allow instantaneous air movement between the two spaces created by the pillow.  This keeps the reflex speed at max, unlike the heavy wool that was simply lining all the walls.

The fleece on top of the 3 inch foam pillow creates just the right surface for voice, way better than just bare foam.  The heavy wool now gone allowed me to place some ultra thin green crafting felt in critical places.  It won't create too much drag on the air, but will delete the sound of MDF in the midrange.

Looking up instead of down at the pillow, we see the top of the interior chamber and the horn throat which is the slot on the left side of the image.




Since the closer we get to the slot, the faster the air flow / higher the air pressure and this is what feeds the horn flare.  We do not want to slow it down, but this is what the speaker cone sees, so we installed two pieces of thin craft foam, which is slicker than craft felt, to kill the MDF sound that would otherwise affect the midrange.  This stops before the slot.

I have to say this is a real achievement for me when it comes to interior box design / tuning.  Even the HDT wasn't this good.  By that I mean it is very satisfying to have no echo, no speed reduction and nearly perfect intelligibility inside a speaker box.  Usually the best you can hope for is a muffled sound without sharp reflections.

I know this is the most boring part of the speaker design, and if I put it in the plans most will ignore, but this is next to getting the angles right, the most important part.

Installing binding posts



The drivers



Yes, you can have them come out the rear, but I'm a purist and the internal wire is shorter this way.  

. Actually my heads been wrecked for a long time.  The closest I ever got to this sound was from my Acoustat Monitors.  They are full range electrostats with the "cone" area equal to eight 15 inch drivers per side with the mass of a few tweeters.  The panels are directly driven by servo charged tube amps where the plates of the high voltage tubes put 5KV directly on the panel without an interface making them unlike every other popular electrostatic speaker.  These are 20Hz to 20kHz panels that are 4 feet wide and 5 feet tall with four 5 degree facets but they were still real head vise speakers and even after weeks of placement adjustments they never sounded perfect because the amplifiers weren't good enough.  Well, not really but kinda really.  I figured some day I would build some tube amps for these electrostatics and use them again.  Now I have the speed, but also the range and the sound is way better because the amp is way better.  The dynamics are more visceral and the bass depth is more tangible, less oversized and diffused.  And I'm doing it with a single amp that is only 2 watts / channel and it gets to the same volume as the Acoustats.  Best of all the head vise effect is by comparison -- gone.  These cabinets completely disappear and I am only sitting less than 8 feet away from them.

It's hard to believe what I am hearing right now compared to this time last night...  Proof that miracles can happen because I laid awake all night thinking it would take one to get the sound I wanted and now I sit here easily able to say I've not heard better, and this is still only from a 2 watt amplifier.  I'm playing disco music, jazz, classical, vocals, electronica, trance, classic rock.  The pin point dynamics and the way everything is separated out is at a new level for me in all the things I've heard in my 50 years of hifi.

Even at normal listen levels I can feel the bass in the concrete everywhere in the building.  Also the lowest and the fastest bass I've ever heard.  It can start moving the whole building and then just stop and the building itself freezes until it is released and OK'd to finish moving.  It's freaky frikin fast bass and it moves from top to bottom with zero bloat.  There is zero mid bass bloat.  It's like listening the Zen Master Series larger baffle (model ZF15L) with an octave lower bass, and even great speed and way more neutrality.  The sound is perfectly neutral.  It energized the room in a way only large horns can.  This is even better than the full size imperial horns because it's faster and at 1/3 the width the standing waves in the room are reduced by 2/3rds and the bass is increased by the same amount.

Steve

Steve…thanks for the detailed update on this project. Congratulations….this is one badass speaker!!  Intimidating is an understatement!!  I think I’m going to need to coax the wife to allow me to burn some vacation time to attend this years Decfest.  

At my last Decfest…I can still remember listening to Yello’s Takla Makan through the Imperials sitting in the main chair and it blew my doors off!!  I can only imagine what this song would sound like through the new Headwreckers!!  Please post some video clips soon.

Dom

Maybe you will feel better this morning after some sleep Steve. We seem to share the same problem with anxiety when things are not right and/or very perplexing in our world. Valium works for me in the times of sleeplessness. Don't really like the side effects but it is better than the hopelessness feeling that develops with lack of sleep.

The Headwreckers will fit in my scheme Maybe? The width is perfect but the depth might interfere with the theater sound and view. Height will tower impressively in the Charoit for sure.

Nice work!

John

Are you going to sell them with the pillows in ?  :D

The phase shift at 30 Hz was measured with the speaker in free air.  I don't know what it measures in the cabinet yet.   I wouldn't waste my time on a speaker with a hole in the resulting frequency response which is why I designed a transformer for the driver just in case. So far am not hearing any holes in the bass response.


The wings were designed at the same time as the speaker.  They are optional.  The purpose is to project sound similar to the way the larger open baffles do.  It adds density to the midrange.  

Yes, the pillows are part of the speaker.  They are not optional.


I stayed up most of the night listening to these.  I had to take today off and sleep.

Quote:


That speaks volumes (no pun intended).

With the wings it reminds me of the Voigt pipe Speakers but the horn is folded so it isn't as tall.  

https://fredt300b.smugmug.com/Hobbies/Building-the-Voigt-Pipes/

Today I got up and wrestled with the pool liner.  After I finally got it out I had to put a new bottom in the pool.  Several trips to town for stuff, rain, brutal.  The only thing that doesn't hurt right now is my eyeballs. So I'm having a couple beers to kill the pain and taking the opportunity to listen more to these speakers.

So far all I have heard them on in this room is my UFO25, and only turned up to 1:30 on the dial. That's plenty loud, in fact 10:30 would be the normal listening level with these speakers in my largish room.

Tonight I decided to hear some of my reference tracks for slam that I used in the wood shop which is when the name 'Headwrecker' was coined.

I wanted to see what these things sounded like turned up, like we played them in the wood shop, but that was a push-pull amp with 3 to 5 times the power...  Anyway I decided to do what any normal man would do in this situation and turned up the dial until the VR tubes in the back and or the meters started to flinch. I got to 3:00 on the dial and it was so loud I stopped.  The amp was not clipping, I could not believe it.  It was as loud or louder than I remember in the wood shop, and this room is much larger and a lot deader...

So I listened to this particular track and had a brand new thought that I've never had before...



The slam and the speed at which the notes stop is so over the top, I've never heard anything do it this well before. It actually made me realize with amazement that air is really fast! That those notes could leave that cone and hit my chest that fast without any softening or spongy effect from the 9 foot air cushion was really just astounding.

The uncanny thing about these speakers, and this was true in the wood shop too, is that at high SPL, the clarity is unheard of. This goes back to the felt thing and the discord that came with it. The clarity from top the bottom on this is so unreal that you can play music 10dB (twice as loud) without shorting out your brain because your ears actually like it. No other speaker has this insane density throughout the midrange and top end.  It makes tweeters sound silly, like BB's. The highs on these speakers are like 50 caliber rounds compared to BB's.

These speakers, if you could record it, could easily reproduce a 50 caliber round shot inside a building. After it went off, you would look at your chest to make sure you weren't hit. That is the kind of realism from a density and dynamics and speed perspective that these speakers are achieving.

So yea, they actually made me ponder how fast air actually is. It was faster than I thought. That was the conclusion, after listening to sounds for 62 years., most of it audiophile grade.  Also the fact that what I am experiencing is through a 2.3 watt Zen Triode Amplifier is just about impossible to believe.  The Zen TORII mono's on the house speakers only graze the boundary of what these speakers are doing with 30 times less power.

Never before has my bell been ringed this hard or my chest thumped this crisply --  and please understand that Decware started out life in the 1990's as a pro audio company that designed, built and installed sound systems in night clubs.  We used Imperial horns, several of them in each club.  We could make you car vibrate just driving by the club on main street.  

With all that, and hundreds of IASCA winning car audio systems that I designed prior to the pro audio business, and the 30 years of DECWARE that you know of -- making low power amplification... I have a reputation for serious bass which means good bass and I can safely say that I have never heard anything hit like this. It's ear candy. You might think with millions of watts and a line array of woofers and subs that you can achieve similar results, but that's because you've not heard this, so we'll give you benefit of the doubt until you come over and listen to it in person.  You can't make that many voice coils work together with this kind of resolution, it's impossible.

So again, with all this experience and bass reference it was never anywhere near this fast. And speed was its hallmark. But speed is relative. The speed is the key.  These speakers are a lesson from the Audio Gods.  It will be a real thrill to share them with audio community.  

Steve  

Sorry I know this is droning on and on, but I have to capture it as it happens.  I am listening to 'Send me an Angel' on this same album and this is really the epitome of heavy / hard metal music.  It is so dense with stuff that 99% of the time when I hear music like this I bail out and in a damn hurry because the horizontal headroom disappears.

Tonight I am listening to this through the UFO25 which has been processed by Cryotone, and connected directly the HOLO Audio MAY dac and I have never heard music this 'busy' sound this clear.  I did not know it was possible.  Until right now, I was bias against this music because I am allergic to homogenization.  I am so stunned that I feel like I just uncovered a whole new universe of sound.  It's like going from the Hubble to the James Web and finding out you live inside a black hole.

God I love this hobby and being able to share it with all of you is my Re: New DECWARE Folded Horn