NXT.......rubbish??....THINK AGAIN!

emailtooaj · « **Reply #1880 on:** 17 May 2014, 06:35 pm »

Hey Mighty,

I have some pics in my photo gallery, if you would like to see a specific part/area let me know. I'll be more than happy to get it to you!

I have considered a tapped horn. But there's a few things that made me gravitate more towards the folded horn sub.

1. The looks... I like the look of the tapped horn, but I feel if I was looking at the speaker, as kinda what I drawn up, I think the Panel should be the main focus w/o any other speakers showing? I want that to be the lime light! Just me

2. With the sub enclosed I was able to get better specs and tuning (according to Hornresp). Also it gave me more flexibility to arrange the horn path and get closer to my original design, to incorporate the sub and Flat Panel together into one unit.
3. With the tapped horn design and the speaker on the outside of the enclosure, I'm also concerned with phasing issues more so than with the speaker enclosed.
4. And with a Horn sub setup I'd be able to design the cabinet to function as spine for exciter mounting (like my drawing) to help make the unit look more as a single unit and not have a "pieced together" look.

Just hoping some of my thoughts may help in your final design also

Peace!

zygadr · « **Reply #1881 on:** 27 May 2014, 07:45 am »

''The sound of a D.M.L''.................................coming soon

OB_Newbie · « **Reply #1882 on:** 27 May 2014, 06:13 pm »

Ziggy.... your such a tease!

I have everything but decent CC but should be getting 4 panel in the next day or 2.

Question on the CC. I did find some 2x6' panels with the flutes running the short length however they have creases in them across the entire short length that cause the panel to bend very easily (flops actually). Given this, my guess was that the exciters would not be able to fully/cleanly transfer the vibration through these creases causing some signal loss. Not sure how much loss but surely it would not be able to vibrate harmoniously with these creases as the panel is not ridged.

Is this assumption correct to some extent? Any experience first hand with this??

I ask because I have one set of panels with only 1 crease that is not all that bad and wondering if these panel are usable!?!?

Thoughts?

Thanks,
Rich

zygadr · « **Reply #1883 on:** 28 May 2014, 07:09 am »

Hi Rich.
Generally, the D.M.L. requires ''rigidity'' as a rule of thumb towards the ideal panel. If you have creases or a ''floppy'' panel, then the function of this kind of speaker system will be compromised to some extent..........maybe more than you think.

You mention that you have one set of panels that has on only one crease. if the panel stands up on it's own with bending backwards or forwards, then it might be o.k. as a start for experimenting. If there are problems in this area, you can brace the panel at it's weakest point with a rod(or two) of Balsa wood which hopefully will not affect the sound.

Anyhow, try it and good luck!!

zygadr · « **Reply #1884 on:** 1 Jun 2014, 04:22 am »

''The sound of a D.M.L.''

Having owned the following : Gale chrome and black dynamic loudspeakers, Kef Concertos, Polk Audio units, Celef loudspeakers, Maneplanar 2.3's, Magneplanar Tympani 1's, B&W hybrid electrostatics, huge Altec bass horns with Le Cleach 24 inch diameter mid/high horns run with 4 inch Selenium compression drivers, ..........I think that I have sampled a reasonable range of loudspeakers in my time?

So, what is the sound of a D.M.L.?.............most of you who have been following this massive thread will already have a good idea.

A ''Distributed Mode Loudspeaker'' for a start, sounds better than all the above...........bold statement?..........maybe, ...........but I have discovered that D.M.L.'s have a sound that none of the above can fully match. Amongst those is one VERY important factor that I will leave and highlight as the last in my list . Here we go:

1. FULL RANGE CROSSOVERLESS SOUND
2. INCREDIBLY FAST TRANSIENT RESPONSE
3. INCREDIBLY FAST AND TIGHT DRUM REPRODUCTION
4. OMINIDIRECTIONAL CHARACTERISTICS WITHOUT ''SIX FOOT WIDE MOUTHS OR PIANO KEYS''!!!
5. LARGE PANELS CAN PRODUCE STUNNING LOWS
6. TREATED CORRUGATED CARDBOARD PRODUCES VERY NATURAL HIGHS AND MIDS - NO METALLIC ''TIZZ'','' FIZZ'' OR ''SPLASH''
7. NO DEAD SPOT WHEN STANDING DIRECTLY BETWEEN PANELS
8. EXTREMELY WIDE SOUND STAGE WITHOUT LASER BEAM SWEET SPOTS
9. PANELS DISSAPEAR AND YOU FORGET YOU ARE LISTENING TO LOUDSPEAKERS.
10.D.M.L.'s ARE CAPABLE OF REPRODUCING ONE OF THE MOST REALISTIC SOUNDS OF A SYMPHONY ORCHESTRA, A JAZZ BAND OR A SOLO GUITARIST THAT IS TRULY SCARY AT TIMES!............I HAVE STILL NOT GOTTEN USED TO THIS PHENOMENON.

OK......................INCOMING!???????????????

Nickolay V · « **Reply #1885 on:** 14 Jun 2014, 09:50 pm »

Hi Guys !

Please explain (! after your deep explorations and experiments) , what optimal size and form factor shellac treated CC diapfragm for -3db at 35HZ sound ?
DML that mean exciters monacor placement or not ?

Many Thanks !

emailtooaj · « **Reply #1886 on:** 17 Jun 2014, 03:20 am »

Quote from: Nickolay V on 14 Jun 2014, 09:50 pm

Hi Guys !

Please explain (! after your deep explorations and experiments) , what optimal size and form factor shellac treated CC diapfragm for -3db at 35HZ sound ?
DML that mean exciters monacor placement or not ?

Many Thanks !

Hello Nickolay!

To answer your DML question... DML stands for Distributed Mode Loudspeaker. All flat panel speakers are classified by this name and it is not directly related to Monacor placement.
Monacor is a company that manufactures speakers and exciters. During their experimentation with DML technology and their exciters, they have come up with an "optimal" exciter mounting placement (arrangement) onto the flat panels.
This is why you'll read a lot on this thread regarding "Monacor Placement". Other people on this thread that have tried the "Monacor" placement while building their flat panel speakers, have concluded that it seems to be the most optimal exciter arrangement. As opposed to just mounting the exciters in a strait line down the flat panel.

As for the "optimal size" CC panel to get -3db @35Hz.... Well, Zygadr would probally be the best to ask that question to.
I'm not sure how much testing and chart results he's done with his CC panels to give you a concrete answer.

I can say this though. The larger the panel size, the more lower end Hz you'll be able to hear, but you'll also need more efficient and powerful exciters to accomplish this. Well, according to how big the room size is you need to fill

I hope this helps answer your questions?!!

Here is a pdf link so you can see how to use the "Monacor Placement". It's at the bottom of page 1.
http://www.monacor.de/de/FLE/EX1.pdf

Peace!

ttan98 · « **Reply #1887 on:** 18 Jun 2014, 03:24 am »

Quote from: zygadr on 27 May 2014, 07:45 am

''The sound of a D.M.L''.................................coming soon

I can't wait... when..when...when..

Really I am am interested in your design and if possible please include some details like x-over, spl, drivers used, etc....

FrankCA · « **Reply #1888 on:** 18 Jun 2014, 05:01 am »

Hello everyone... Started at p1, read to about 40, went to about 80, and read to the end.
At age 13, my best friend's parents owned a boat dealership. A vendor gave them a sample of a new product. Approx. 2" diameter, 1.5" high, cylindrical, housed in sealed beige plastic, two stud and nut terminals and a single wood screw protruding from the terminal end. It was meant to excite the fiberglass on a boat to turn some portion of the hull or deck into a speaker. Mount a small piece of plywood, screw to exciter into it, hook up speaker wires and presto, music in your boat. It worked pretty well considering the state of mobile sound in 1970! My friend and I spent many fun hours making speakers out of most everything we could stick it to.
Recently, my church has begun a sound system renovation, and I am going to create a panel (single and large, because this is a mono application) to be used as a backing track monitor in the choir loft.
Because of my youthful experience and the knowledge gained from this ever so helpful thread, I have some questions to ask and some "what ifs" to propose. Not necessarily looking for people to try this stuff out, but the most informed people I have come across on this subject are here. Any learned opinions are welcomed.

1. Has anyone tried to cosmetically beautify the shellacked cardboard? I was considering coating and then applying a faux woodgrain and then second coating with the shellac. Do you think this would cause significant sonic degradation?
2. I've noticed that exciting large (maybe heavy is a better term, 1/8th plywood comes to mind...) panels has proven to be tough. Might it be possible to take a page from my 70s experience and attach a plate of some kind to the exciter (plywood or metal, round or ?, slightly larger in coverage than the exciter itself and then to the panel to give the excitation point a little more mass?
3. Is there an optimum direction for the "ribs"... Longitudinal, perpendicular or possibly diagonal?
4. Has anyone hung one of these with fat monofilament, possibly a three point suspension, two at the top and one at the bottom?
RELATED: How about running the monofilament down a couple of the ribs (all the way through the panel) either near the center or edge, or possibly one of each with a "stop" at the far edge? Since we are DIYers, think pencil tied in the line as a stop...
5. Has anyone made measurements of the off axis attenuation when moving past the side of the panel... because these are flat panels, I would not think that this would be much of a problem... but if it is, I'm sure one of you is aware!
6. Has there been data that would indicate a somewhat optimal distance from a wall? Or is that frequency dependent?
7. Has anybody tried a corner placement? In some acoustic applications, this makes a significant difference, such as boundary mics, bass traps, etc.
8. Could a cardboard panel be stiffened by a strip made up from a couple of rows (cells) of coroplast glued to the edges. Or would the dampening be too much? If you could, this might relate to the second part of #4, a channel for the suspension.
9. Has anyone had experience with these:
http://www.parts-express.com/dayton-audio-daex25shf-4-steered-high-flux-25mm-exciter-20w-4-ohm--295-238

That's all for now folks... Looking forward to all opinions. I will be doing some experimentation, but if the best mouse trap already exists, that won't be where I'll put my time!
Thanks in advance, and I hope I've piqued your interest. My application does not need super bass nor super highs, neither does it need to be too loud. I just want good articulate sound to be able to wash over about 15 people in a tight group with a minimum of hot and cold spots. I think this technology is the ticket. FrankCA

FrankCA · « **Reply #1889 on:** 18 Jun 2014, 05:08 am »

Oh, and by the way... to source good cardboard, check with your local appliance store... refrigerator boxes, if you can get them to remove them carefully, are a great source!

FrankCA · « **Reply #1890 on:** 21 Jun 2014, 12:49 am »

Perusing the later posts a little more carefully, Zygadr says rib orientation- no effect. [Probably easier to get good shellacking with the ribs running the short direction, My comment].
Also from Zygadr, 3' minimum from wall. [Makes sense with speakers that act somewhat omni. As I recall from research on another project, bass frequencies can be made to "couple" and reinforce if the reflections are timed right. Naturally, you would need to seek a happy medium, as different frequencies would have different optimal distances. Someone with more experience could calculate possibly calc this out, I don't really need it for my project, but if done correctly, it could add some physical low end compensation for smaller panels... just musing].

GEE... I hope I'm not the last person to post on this thread! In the immortal words of Pink Floyd-
Is there anybody out there?!?!?

hblester3 · « **Reply #1891 on:** 22 Jun 2014, 01:34 am »

Since the thread was started a little under 5 years ago there has been about 1 post a day. Some of us check this thread often but have little to add. This thread is probability the reason PE has added new exciters to their line-up. Most will also wait for one of the masters of this tech to answer. Give it time and read all of it. Some of it I have read multiple times. Be cool and try some stuff then ask.

It will get better.

Hubert

FrankCA · « **Reply #1892 on:** 22 Jun 2014, 02:41 am »

Hi Hubert! My post was kinda tongue in cheek...
I have been using my time waiting for the masters to read the rest of the thread, and have been able to answer some of my own questions as a result. I now have amassed cardboard, shellac (plus dark brown colorant to try my faux woodgrain idea), exciters on order, etc.
To me, the most exciting thing is that I also have a real world application that, if my effort proves out, will solve a problem (in my church) that has been wrestled with unsuccessfully for a number of years. Since this installation will be in a public place, it will introduce this technology to people who would have never conceived such a thing exists. As I posted above, I have experienced this "special sound", and so even though the old stuff was pretty lo-fi, the spaciousness and absence of sharp directivity (my spell checker says that is not a word) were apparent to me even though I was "just a lad". While I expect some necessity for experimentation, I'm hoping that by distilling the lessons herein, I can come off the blocks strong on the first try. Thanks for the words of encouragement! Frank

zygadr · « **Reply #1893 on:** 22 Jun 2014, 04:12 am »

Hi all........................especially the new posters.................welcome to the craziest thread ever !!

There are a lot of questions that have been asked and all I can say is that the information you require is here on this thread already. Yes, there is a lot to read, but this kind of loudspeaker is not as complex as seems..........especially if you get confused by and put off by reading the numerous white papers and other technical articles on this technology.

I can confidently say that I have read a hell of a lot of information and tried many variations of materials, exciter placement, coatings etc.

There is no need to complicate or sophisticate your thoughts or operating procedures to the point that total confusion is the end result.
I have not had the opportunity to obtain access to measuring gear - simple or sophisticated..........I have just used my ears and listened to live music from a solo guitar, clarinet, saxophone, piano all the way up to large symphonic assemblies of 100 or more players.

Here is a short list of facts and tips that give best results:

1. use as large a panel as possible.
2. make sure it's thin and light and roughly rectangular in dimensions.
3. if you are using corrugated single cushion cardboard, Shellac coating inside and outside is a MUST for best sonics and moisture proofing.
4. the panel needs to be suspended at minimum points by some form of rubber like material between the frame and panel. The exciter needs to be held firm to the frame of the speaker, just so that it's ''foot'' can be adhered to the rear of the panel. This avoids any strain on the exciter's voice coil.
5.use the most powerful exciter you can afford (both in power rating and ''shove factor'').
6. thin plywood can provide some remarkable bass in a mid sized sheet if allowed to ''flop around'' with minimal support and damping, but you will experience some resonance problems as well as low efficiency.
7. all wiring must be carefully checked for multiple exciter total impedance and keeping the wires away from the vibrating panel (buzzing sounds).
8. the ''MONACOR PLACEMENT'' has so far worked the best for most of us, so I would recommend you try this.
9. rounding the corners of the panel can improve the sound according to some members.
10. placement of the panels in your listening area is not as critical as your average speaker - this is one of it's best attributes.
11. whatever anyone else may otherwise tell you, these unusual panels DO NEED A LENGTHY BREAK IN TIME. This may be due to the stiff suspension on the actual exciters and/or the panel's coating (in the case of shellac coated C.C. ).
12. do not use braces to strengthen low rigidity panels - these can cause more problems that are difficult to trouble shoot.

I hope this small bit of gained knowledge will assist in building what I still consider an ''AUDIOPHILE'S CHEAP D.I.Y. DREAM''!!!

FrankCA · « **Reply #1894 on:** 23 Jun 2014, 12:50 am »

Thank you for the summary Zygadr. I agree that the answers are in the thread, but there are a lot of posts touted as "the answer" that are superseded in later posts because some of the flaws were not immediately apparent, or a better "mouse trap" was developed. I'm not throwing stones here... what is found to be the best "today" is indeed the best until something new comes along and relegates it to a corner in the garage. Knowing that the folks that have nursed this idea and this thread have put so much time, resources and sweat into their discoveries, I'm looking to stand on the shoulders of giants in my design. This summary post is very helpful, although as any curious pseudo nerd, I will tread my own trail in the experimentation and implementation. As I progress, I'll try and get photos of the process for all to peruse. I just hope to avoid being one of those that throw up their hands and proclaim "This sucks"! FAILURE IS NOT AN OPTION!
Frank

zygadr · « **Reply #1895 on:** 23 Jun 2014, 03:48 am »

Hi Frank.
By all means experiment and try to improve on what we have here today - that's what it's all about and probably the reason why the thread became so long. Eventually we succeeded in making a great sounding panel speaker for next to nothing..............it was a long, hard slog but worth every minute!

Please keep us in the loop with your efforts as I am sure any future discoveries will be of interest to all!

Rob.

panomaniac · « **Reply #1896 on:** 24 Jun 2014, 08:36 pm »

I have heard the Holy Grail of NXT!! And it is good.

Last week in Las Vegas I got to hear a full fledged demo of professional NXT style panels, in a pro PA line array. Quite amazing! Even got a limo ride to and from the theater. That's Vegas, baby.

They are made by a new company in Seattle Washing called Tectonic Audio Labs. The panels are large, expensive and beautifully made. http://www.tectonicaudiolabs.com
Weigh about 90lbs each, and they were using 3 per side in a array. Each speaker contains 2 DML panels (Distributed Mode Loudspeaker) made of a Kevlar honeycomb covered with a carbon fiber skin - about 5mm thick. Definitely high tech. Each panel is driven by 4 neo motors IIRC. In between the two panels is a waveguide loaded ribbon tweeter.

The sound was certainly "Different". Very wide, very even, very clean. From "girl with guitar" music to EDM and Dubstep, they certainly delivered the goods. The system with 3 speakers per side and subs was said to be good for covering up to 3000 people. I would say yes, it probably could. There was a little bit of an edge to the sound, typical of loud PA speakers, that I thought was just the honeycomb panels. Found out the next day that they were running the ribbon tweeter too low, so that's probably what I heard.

Crossover was active and simple, no DSP, almost no EQ. Very clean and clear, and they didn't interact wit the room like conventional speakers. A plus for us pro sound guys is that they are very resistant to feedback. That's a big deal in live sound.

So, the future has arrived and it sounds good. I never thought the NXT panels could sound that good, or play that loud, but they do. If you have enough money.

EDIT: Typos

emailtooaj · « **Reply #1897 on:** 25 Jun 2014, 02:19 am »

Quote from: panomaniac on 24 Jun 2014, 08:36 pm

I have heard the Holy Grail of NXT!! And it is good.

Last week in Las Vegas I got to hear a full fledged demo of professional NXT style panels, in a pro PA line array. Quite amazing! Even got a limo ride to and from the theater. That's Vegas, baby.
They are made by a new company in Seattle Washing called Tectonic Audio Labs. The panels are large, expensive and beautifully made. http://www.tectonicaudiolabs.com
Weigh about 90lbs each, and they were using 3 per side in a array. Each speaker contains 2 DML panles (Distributed Mode Loudspeaker) made of a Kevlar honeycomb cover with a carbon fiber skin- about 5mm thick. Definitely high tech. Each panel is driven my 4 neo motors IIRC. In between the two is a waveguide loaded ribbon tweeter.

The sound was certainly "Different". Very wide, very even, very clean. From girl with guitar music to EDM and Dubstep, they certainly delivered the goods. The system with 3 speakers per side and subs was said to be good for covering up to 3000 people. I would say yes, it probably could. There was a little bit of an edge to the sound, typical of loud PA speakers, that I thought was just the honeycomb panels. Found out the next day that they were running the ribbon tweeter too low, so that's probably what I heard.

Crossover was active and simple, no DSP, almost no EQ. Very clean and clear, and they didn't interact wit the room like conventional speakers. A plus for us pro sound guys is that they are very resistant to feedback. That's a big deal in live sound.

So, the future has arrived and it sounds good. I never thought the NXT panels could sound that good, or play that loud, but they do. If you have enough money.

And I bet there wasn't one hint of "feedback" coming through the panels

FrankCA · « **Reply #1898 on:** 25 Jun 2014, 06:58 am »

Panomaniac! Thank you for posting that! http://www.tectonicaudiolabs.com/tectonic-photo-gallery/ Check out this gallery. I am a musician, and had wondered if this technology would be suited to pro sound. If it does what is purported, this is truly a new age. DML's acting in a line array! The death of directivity! This begs more scrutiny. Frank

panomaniac · « **Reply #1899 on:** 25 Jun 2014, 04:57 pm »

Quote from: emailtooaj on 25 Jun 2014, 02:19 am

And I bet there wasn't one hint of "feedback" coming through the panels

Not that I could tell, no. Couldn't hear the panels in the mic at all. Rather amazing. The real test will be lavaliere (clip on) and lectern mics, those are the tough ones.

Frank: Exactly. We will be scrutinizing them further this summer. I'm setting up a demo in a large hotel ballroom here in town. It's an acoustic nightmare of a room (200'x200') that we've been fighting for over 20 years - and losing. If these panels can come close to fixing the problem there, it will be a miracle.

I realize that this is not home use, not DIY, no where near cheap. But it's very informative to hear just how far this DML technology has come and can go.