I sounds like you’ve gotten results far beyond my massive bass reflex cabs Steve. Congratulations on your build.

Given the incredible results you've achieved with these speakers Steve, will you be looking to see if Stereophile are interested in reviewing these? It really sounds like these can compete with the best sounding speakers on the planet and their high efficiency makes them perfect for your amps, or Nelson Pass' First Watt amps for those who prefer solid state.  :D

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My initial intension with these speakers is to provide Lii Song with a great cabinet for their new PT-10 driver, and to make the plans available to the DIY market.  Additionally, for those who want them in high performance black and are willing to drive to Decware to pick them up, we will gladly build them for you to match my pair exactly.

If we had a loading dock we could palletize and fright them to customers, but right now it is not an option so sending a pair out for review can't happen.  

The size of these are 14 x 28 x 60 inches and 140lbs each.  A pickup truck or a van is likely the only option as far as vehicle types go.

Steve,

When something hits you right and then you can just sit back and listen,,, at least until you want to hear how some other stuff sounds on it. We are not running in circles with this love, we just make sharp turns every so often.
Been doing that with the DNA2 and it is a blast.

I don’t think I’m worrying too hard now. I’m betting the development process will continue until you get the “mother-in-laws”(how’s that for nickname) singing as sweetly at 1/8th watt as 2.3 where they kick serious asparagus! And of course make nice- nice with the SEWE300B.
Plus ultra dude, plus ultra

So lets talk about the network...  




It uses a transformer in parallel with the driver so it is not in the direct signal path. The impedance is such that you can't hear anything happen when you insert it... not until you install the 10K 5W resistor on the high voltage side of the transformer.  Even then it is a barely detectable change.  The idea here is that we don't want to molest the sound with some overcomplicated crossover that is going to tank the transparency.

This is an air-gapped wide bandwidth SET transformer for those DIY readers.  And for what it's worth the 10K resistor could be made adjustable. On/off/variable from 10K to maybe 5K.  What would happen is the top end would begin to drop as well as the efficiency and the effect will also depend on the amplifier used.  It drops to around 2 ohms or so at 20Hz, but music doesn't live there so unless you're playing 20Hz test tones and your amp can't handle that...

I usually like to put the 10K on a switch at a minimum so I can hear what it does.

This is what happens with above network installed.  The impedance peak drops to 15 ohms and the phase shift is basically eliminated.

Here is the room at 60Hz.

Here is the room at 40Hz.



I didn't save 30Hz because while it was even around the entire boarder of the room there wasn't enough of it anywhere near the center to really contribute to the music.  This is typical of low bass from large horns in smaller rooms.

CONCLUSIONS SO FAR:

As far as the the bass response from a listening standpoint, I have found it to be completely linear sounding from top to bottom and ultra clean with unrelentless amounts of it outside the listening room in the adjacent spaces.  In that space outside the room we would have to double the size of the purple stars.  This is exactly how the Imperial horns behave -- they like large rooms.  If you have a small room and like really low bass get smaller speakers and a tiny sub.

Anyway, as suspected getting below 30Hz from giant horns at distance of 10 feet away is a pipe dream, but 40Hz really kicks some serious ass and I just have to remember to position my chair a tad closer rather than farther when listening to these speakers.

THE DIFFERENCE IN AMPS

I wish I had my Cryotone 300B tubes, or the Western Electric to really see what the bass is like on the Sarah 300B.  No worries, there is no shortage of it with the Chinese tubes we selected, but they aren't as fast and with this speaker it becomes obvious whereas with basically every other speaker in the room it is easily missed.  So far with hearing these tubes the UFO25 was faster and cleaner and tighter but the Sarah had more body and weight with some goosebump timbers and trails that make it hard to choose.

SOUND STAGE

By turning off the 10K load and leaving the high voltage secondary as an unresolved potential, it seems like something magical is happening to the sound compared to removing the network completely.  I noticed using the Sarah 300B that I got sound to come closer to my face than any other speaker ever dare go.  It felt like about 3 feet.  The fascinating part is that the depth of the stage went back at least that much or more at the same time.  This is unusual.  Typically when a speaker gets in your face, there is little or no depth.  This would have to be technically more accurate than most of the speakers I've heard including our own when it comes to a life size sound stage.

So despite sitting the same 8 feet or so as I do from all my speakers on this arc, these sounded like they were twice as big as they are and twice as high and twice as close and twice as far.

SPEED

Dynamically speaking it's like very high end headphones for your entire room except you have a deep sound stage and feel the music coming out of the floor into your body.

Go team Decware! It seems to me that with continued R&D, the “Mother-in-laws” WILL have have some of the presence & total awesomeness of Lois F. Maybe my comparison is a stretch because she didn’t scale 140lbs. & her bass was on the weak side, but otherwise somebody that would enrich the life of those in “earshot”.  After these are fully sussed out I don’t see how I won’t be traveling to East Peoria to darken your listening room for a demo.  Maybe I’ll have scored a pair of ER300B-MO’s by then to roll into a SEWE300B along with some Wathen & WE’s if you don’t have any laying around. This development is making my extended wait for your SEWE300B seem so much more satisfying. Again, go team Decware go!!

IMPORTANT UPDATE

I have decided the original network to deal with the phase shift makes such a small difference it probably isn't worth messing with.  Since I am not worried about the extra bass on the rear wall it has no effect on my room.  It does take a tiny edge off the upper midrange, I would call it glare, but again it's so subtle.

I have decided to change how the network functions and make it like our original Gizmo that I used with Lowther and similar full-range drivers. Why not use it to improve the sound instead of fix something you can't hear.  This way it would be possible to just dial in the presence you want without having crossover parts / notch filters in the signal path.

As I get more serious listening time on these speakers there is just a touch of something in the upper midrange I don't always like.  I want to figure it out organically vs. measure the driver's response.  Measuring the response will instantly poison my ears and lead me down the wrong paths to notch filters or who knows what. It is important to fall in love with the speaker before I measure it.  

On the PT-10 driver construction the metal is so thick that its resonance is like a big tweeter.  When I first tested this driver face down into a sealed box, there were highs up to 5K standing on the magnet and you could hear it everywhere in the room.  It was like our Radial driver.  So I think it should have a thick sock of 1/2 inch felt to damp it out.  I will try it to see if it works.  Meanwhile I want to chase the problem from another more esoteric angle, which is the following take on the previous network.





This is very similar to a device I made and sold for crossoverless single drivers called the 'Gizmo'. This model is actually better in that it has less loss and a wider more linear range of adjustment.

The initial listing results are very promising.

For those wondering how this works, the "coil" between the positive post of the driver and the amplifier is only there as much as you want it to be. The primary windings when shorted causes that secondary coil to disappear until such a point where it acts nearly like a wire.  The magnetic coupling of the air-gapped transformer is what makes this work and the 10K 2W linear pot is what makes it adjustable.

The beauty of this approach is that it can have a profound effect on the balance without affecting the speed or dynamics. It's all done with magnetism rather than capacitors, resistors and coils.  When the primary is opened completely the secondary drops the output of the speaker to just a bass heavy whisper.  As soon as you short the primary the magnetic field created acts like a switch that turns the speaker back on.  When you make it adjustable via the 10K control, you are adjusting the magnetic field which is responsible for conducting the music you hear.  You really can't buy expensive enough crossover parts to have this kind of transparency and super low loss.

In all actuality one of the big reasons vinyl and tape sound they way they do is the magnetic coupling happening inside the cartridge or tape head.  Listening to these speakers using this gizmo I would say it has removed all the glare, sharpness, ringing and given it an analogue feel with far bolder dynamics and superior overall balance not to mention imaging and sound stage.  Coincidence?

You already have over 3k views on your Youtube video. Amazing. Can't wait to get my drivers installed in these cabinets. I'll be dreaming about it until I do,

+1 on buying a Gizmo. I would place my order today.  

It's all silver/teflon wired.  The bypass switch will be optional.  When the control is fully clockwise it is at 1% effect and when fully counter-clockwise is at 10% effect.  Many will find it hard to hear the difference between 1% and 0%, so this is why the bypass switch will be optional.

Any further impressions Steve? Although lacking the massive impact of your speakers the PT-10 in big bass reflex cabs continues to impress me with the bass now becoming more detailed and extended. The sound has a physical presence I've never experienced prior to these speakers. I can only imagine how things would sound with all the added impact of your BLH cabinets.

EDIT: Ah, there was a whole lot more to read which didn't show until I posted. It sounds very much like I'm going to have to purchase a GIZMO2 to go with my speakers. They definitely far better at higher volume than low and I'd like to add that extra presence without having to crank the sound up..... A necessity for me actually as my wife makes me play my system as low as it will go unless she's not home.

So we listened to the speakers with the Gizmo2 all day without any sound issues, like skipping tracks because something doesn't sound good.  Last night we listened to them on a wide range of music, mostly acoustic, song writer, jazz, blues,  classical and some electronic.  It was flawless for over 6 hours. None of us could hear anything we didn't like.

I have concluded that because the driver has such a strong magnetic flux -- the back EMF is stronger than other drivers which may be why the sound changes quite a bit from amp to amp and where to occasional glare or sharpness comes from.  I believe the Gizmo2 has a large effect on the back EMF from the voice coil reducing it's effect on the sound.  This means that the driver doesn't actually do anything wrong from a frequency balance perspective that needs fixed.

I will give things another week or so and if I still am 100% happy with the sound, I'll measure the frequency response to see what it actually is in my room.

Steve

So far I would say none of them that I have listened to actually need it...  It depends on the enclosure and how much bass you can get from it at a low volume.  I will try it on the Fast-15's in leu of the network when I get time, as I expect it might be an expensive alternative.

It's really very simple, you just listen to your single-driver speaker and if there is glare or sharpness in the midrange or top end that you want to reduce or eliminate, your speaker needs it.

Steve

Hi Steve, do you have a rough idea of the price you’ll be selling the Gizmo2 for? I’d love to source one minus bypass switch and binding posts as I’d like to install EIZZ EZ-301 low mass gold plated copper binding posts….. Unless of course you can pre-install them?

The silver wiring internally, is that included to tweak the soundstage a little?

Cheers

Matt

I think I can swing that... The only downside is my needing to source more FoilFlex speaker cables. Blows the price out a bit. I'll keep an eye out for its release and bookmark it for a future system upgrade  :)

How are the “wings” affixed? Located with dual pins & glued into place?

Ok, I was going to admit to my mistake, but first I’m still wondering about the wing attachment? If removable I guessing no glue, maybe 3 dowels?
But I stand by my statement, not to be a malcontent (I guess I can’t help myself) but I can buy nitromethane even with the legal restrictions a lot easier than your FINE products. If you buy too much “out of the blue” so to speak, the feds WILL be talking to you. Better not buy to much diesel fuel & nitrogen based fertilizer either. Ok, enough joking around, I’m happily in for the long haul.

 Ok, took a CLOSE look at the build photos, and the wings attach/detach using 3 screws. Not going to explain more because the photos are worth more than my explanation. Go through them one by one, or you will miss it.

BlackBess,

I had pretty much the same question. Guys like you and me probably are thinking how to make it a snap on-snap off type of process. The dowel idea would be a start. Then again, I am sure that the screws hold tight, and there is that perpendicular brace that gets me to wondering about its contact with the cabinet without marring the cabinet. Could we get away with using the thinnest strip of felt backing for the wings? Uh oh, starting to think out loud again.

After noticing the 3 locations for fasteners along the vertical edge of the mounting hole for the removable driver baffle, I am now wondering if there is a 4th (or more) positioned mid-cabinet to align with the horizontal brace of the wing? Is this the case, strengthening the structure with some external triangulation?

UPDATE 6/5/23





Just logging the hours, and experimenting with speaker placement and amps/preamps.

For starters let's open with the following statement:

Lii Headwrecker Horns are like a high strung race car that that makes street cars look like turds stuck to the pavement. That might sound like fun, but it comes at a price.

When you have a speaker that is this dynamic and this fast combined with the giant bass wavefront that comes out of each cabinet you have a recipe for trouble.

The fastness will let you hear everything that is less than perfect.  I have found it a little challenging to settle on amp/preamp combinations because I am always trying to find something to make it street-able.  You know, warm, smooth, friendly, lots of bass, forgiving... but that is not its nature. Interestingly that is exactly what it will sound like if you get everything right, but that is not always easy.

I am convinced so far that the 2.3 watt Zen Triode is the better amp for these speakers because it just sounds better. This is counter intuitive since the Sarah 300B is a fuller sounding amp most of the time.  In fairness, I am using a Cryo treated SE84UFO25 with Cryotone tubes that is fully burned in vs. new Sarah amps with the Chinese 300B tubes and no burn-in.  It has been making me think the Sarah 300B really doesn't like these speakers all that much.

Of course it's an illusion brought on by the the hyper resolution of these speakers. Normally this difference wouldn't have so much magnification and be easily tolerated or ignored.

It can steer you into the wall before you realize what happened.  Example; I decided to try a Zen Ultra preamp in front of my UFO25.  The Ultra is the warmest and slowest voicing I have. It features a tube regulated gain stage into a cathode follower and uses large 5uf film caps.  It is masterful at making a decent quality bluray player sound like a reference dac during movies. Anyway I put it in with it's inferior film caps and 6N1P tubes and was stunned! Everything was fixed.  The difference wasn't subtle. I had never heard the speakers sound this good.  I listened to it this way for almost a week. By the end of the week I was falling out of love with the speakers. Actually had visions of getting them out of the room, maybe putting them back in my wood shop. This is what happens with weak links.  Yes, the preamp masked the problems of upper midrange aggression but the speed was gone and the detail that comes with it. Sounded like normal speakers.

The wavefront.

It's big. Because of this there are fewer nodes in the room which is to say the standing waves are larger and harder to deal with. The common problem that results is lots of bass outside the room in other parts of the house but pretty lean in the center of the room where you tend to listen.

Very large bass traps will help this issue to some degree, but when it comes to large horns in a space this size it's about damage control from 80Hz on down.

The measurements I published are misleading because there is more bass than the single microphone is indicating but the large null is typical. This lead me to stop looking at room modes for once and start looking at Speaker Boundary Interference (SBIR) and how the four walls are affecting this bass null. This is why I was pulling the speakers out into the room more, to create some delay between the speaker and the front wall.

I have had the speakers starting at 4 inches from the wall, and slowly put them at 24 inches from the wall. This is the distance from wall to rear of the cabinet. Nothing really changed enough to make a real difference, I was still wanting more bass and at lower volumes.  Bass and mid-bass aka weight / density.

After measuring for a day I figured out that several boundaries were stacking up to create this null. So I thought the only way to fix it is to pull them even further into the room, but then realized that if I could get the back of the speaker to actually touch the wall, there would be 25% less boundaries working against me and the wall being insulated would become a low frequency absorber so long as there is contact with the wall and the cabinet. Once the proximity is lost the absorption jumps to a higher mid-bass frequency.

So I put them back where I started as shown in the picture above and then pushed them back 4 inches until they touched the wall.  Remember the face of the speaker is 28 inches away from the back, so even touching the wall they are effectively 28 inches out into the room from an imaging standpoint.

Magic happened. The bass at the listening chair improved by at least 25% (I think more like 50%) which was huge.  Also the speakers are playing the room now -- the way the large open baffles do. Imaging and the disappearing act is massively improved. If you were blind folded you wouldn't know what happened. It would just sound real. The impact now that it is loading the room with one less boundary wrecking things, these speakers are more than everything I'd hoped they would be in the bass department and overall frequency balance.

It's so good now we need to find the magic preamp. Used a ZROCK2 set flat where I always put it and it was one of those holy crap moments when you hear everything get instantly fixed and several things get fixed you didn't realize were broken.

So in my opinion anyone serious enough to buy these drivers and build these horns should have both the GIZMO2 and the ZROCK2. They are like the parachute and the seatbelts. You'll want them, need them, and cherish them.

Probably not what some of you want to hear, but I'm just reporting what I discover as it happens.

I have made a dozen youtube video sound demos of these speakers, all before I figured out about putting them against the wall and using a ZROCK2. Almost doesn't sound like the same speakers to be honest, so I will have to make more videos of this new configuration as time allows.

To me this is really an astonishing discovery because everything has been transformed by moving the cabinets only 4 inches until they touched the wall. I have always been so concerned about dimensional room modes that I downplayed if not ignored SBIR. I now realize how important this can be and it certainly explains why speaker placement is so important. In my case it was more important than anything else I could do to treat the room and made a much larger effect. One you can hear everywhere in the building.

I always used to think that the null in bass response was occurring at the listening position because I largely focused on room modes, but in actuality the null is happening directly in front of the driver itself and it is from the SBIR effects. You can measure this null anywhere in the room which would be impossible if it were a room mode.

I would say unless you have a larger size room, you will have to place these touching the wall.

BTW, I have been using my prototype Sarah 300B amplifier and with both the Zen Ultra and no preamp at all I didn't hear a real synergy with the speakers as I think I mentioned.  Insert the ZROCK2 and move the speakers 4 inches to the wall and now I can't imagine using a different amplifier.  Yes, I am surprised by that.  When I get it all figured out to where nothing surprises me my passion will certainly mellow some.  No worries about that actually happening because I learn too slow ; )

Steve