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One of the most common questions is what size panel to use.....Some will say the bigger the better but that is not always the case as panel size will depend on the type of exciter and the amount of exciters used on each panel.....a very small 13mm 3 watt exciter can be used on a smaller thinner sized panel even as small as 8 inches while a 32mm 40watt rms exciter will be over kill on the same size panel. On the other hand a 13mm 3 watt exciter on a 2ft.X4ft. panel is not enough to vibrate such a large panel while the 32mm 40 watt exciter should be enough. So like I said panel size is predicated on the type and the amount of exciters used per panel.Bigger higher power exciters can be used on bigger and thicker panels.Smaller less power exciters can be used on smaller and thinner panels.Multiple exciters can be used on bigger panels.
I beg to have a different view, let me explain thisAbout ten years ago, when I started to cut & try with DML exciters, my opinion was exactly the same as yours. At this moment, my supposition based on what I ought to know from previous experimentations with line_array multi-drivers was, that in order to move a big panel, I would need a certain amount of Watts, and just because at this moment, only smalls exciters where available, I guesstimated that a minimim of 4 to 8 exciters was requested.How wrong I was, and why? because I had in mind piston loudspeakers, Distributed Modes loudspeakers are a different kind of beasts.A small motor will move any panel, tiny or huge the same way, and bass depend only of the radiation surface available (acoustic impedance). Obviously a bigger motor will move the panel deeper, but not lower in frequency.Conclusion, you can put a single 5w exciter on a huge panel, and reach quite low in bass range, and if you need 9dB more loudness, just pick a 40w model.But the important thing to keep in mind is that by putting a group of exciters on a panel , it's no more a DML system, it's a kind of hybrid monster.POL
Hi, Odal3....Like Ive stated above my DML Panels mimic Bertagni speakers. I am currently using a 5.1 system of ALL DML panels including the sub. A DML panel sub is just a DML panel utilizing a sub amp.
Got it. Thanks for clarifying. It's fun and very rewarding, isn't?
Basically any type of exciter will move/vibrate any size panel BUT the difference is in the out put of the vibrations of each type of exciter which can be due to size, design and power handling. More vibrations equals more loudness more loudness equals more audible bass at moderate volume levels....a 13mm 2-3 watt exciter bass out put is very low and will start to distort at moderate volume levels when ran full range due to bass restriction limits.I believe there is a certain OPTIMAL RATIO of exciter vibration out put and panel size like I mentioned in my above post.....From my experiments these 3 things come into play when determining bass output...1. Type of Exciter design/size/power handling...2. Type of panel material (EPS for me) 3. Panel size as well as panel thickness.
I see that you are still thinking in terms of plane pistons, where a bass loudspeaker should have great excursions to make low frequencies.Let me ask a simple question: Between a 1 meter square speaker with a 1 millimeter excursion and a 10cm speaker with a 10cm excursion, although they move the same volume of air, which is the more likely to reach low frequencies? and why?Only because of their acoustic impedance, that of the air and the radiation impedance of the transducers, as well as their mutual adaptation.with DMLs a small transducer will reach exactly the same bass frequency than a bigger one on the same panel, it will simply output less volume.but on the other side a big transducer wont get very high in frequency, because of his weight and the diameter of the voice coil.I am using 5 square meters of panels with tiny 5W transducers, & full range...
Looking at the bertagni speakers ,they are a heavily clamped panel with thinning in area's, the lower end below 500hz is handled by the larger clamped panel ,in the YouTube video it does seem to act as a clapped piston at low frequencies hence the large clamped frame and magnet .I would expect the sound to be similar to a standard cone type speaker ,and very different sounding from a free floating panel.Clamping a polystyrene panel does not sound good to me ,clamping something like 3mm plywood can improve the sound and output,they react differently to the same procedure.A single 10watt 25mm exciter freely mounted on a ,let's say 3ftx7ftx 1inch poly panel would fill a house let alone a room with a fullrange of sound from 20hz to 20k(as long as room and panel cancellations in the 100hz to 300hz have been taken care of) a 2x4ft panel does a good job too.Personally though I would use a low frequency driver to take the strain of the larger movements from the panels.Steve
BendingwaveI did look at the video link's you posted ,I could not view newbie,s video as it is unavailable ! I have problems with the other video as the sound did not match the movement of the camera so am unsure how this recording was made?The YouTube video you previously posted gave a much better idea of how the bertagni speakers sounded in a real room.Yes they do sound good ,but the drive units used are very similar to bmr units but larger,and as such will suffer the same problems as standard drive units.Steve
yawl can judge for yourselves which sound you prefer better.Bertagni speakers> https://www.youtube.com/watch?v=U-OQz_AuzB8&t=40sRich (aka OBNewbie) free floating panels with EQ> https://www.youtube.com/watch?v=To3IOYxTFKw
So,what you are saying is that free floating panels sound bad ,so we should all go out and buy bmr units and hey presto all problems solved ?The video's play on my computer but not my tablets, only trouble is i can't get much volume on my computer !I used headphones when listening to the YouTube video on the tablet and when he moved left to right the sound stayed dead center you would also expect the sound to change when moving over tweeters and midrange drivers,also when the music stopped so did all the sound,dead silence ,even though there were other people and a dog in the room ?Comparing newbie,s small panel (which would not be my first choice for best sounding panel) to a full range panel type speaker with open panel sub and tweeters is not a good match.You would have to add a sub plus tweeters and xo, playing a midrange unit only ,would sound odd !From experience if you clamp a poly type panel you might as well buy a bmr , as the sound is totally destroyed by over damping !Steve
The Bertagni video is clearly a sound / video remix with a soundtrack that does not match the actual recording of the microphone. If we run a vectorscope software in background we see that the separation of the channels and their position in the space does not change at all. Juste a small scamPOL
I do a lot of sound editing for my pleasure and for measurements and I can guarantee 100% that this track does not stick with the movements of the microphone. No phase changes between the left and right channels, no sound balance change, and at the end the sound stop one second after passing over the Bertagni because the guy awkwardly tried to make the end of the sound track coincide with The passage from the front to the rear being aware that there must be a sound attenuation at this moment. And last there is absolutely no back ground echoes from the room, A huge joke.
Yes, I have been to his Ebay page and have read his post"I did make a video, with them playing !! Go to YOUTUBE .......Search Bertagni Panel Speakers, you will see them playing with a warm rich sound. There is no rattles, bass is deep and sound amazing. In the video, ( taken from a cell phone, the color is not that great, but you can see, and hear them perfectly.) "I have yet to see a cellphone able to take such a great stereo recording, ICH LACHE MICH TOT !!!POL
I wont step in because I am not the sheriff of this planet , and I do not aim at paying 650$ for a couple of sound transducers half a century old.But I do know when I see a forgery.And because the sound track is a little scam, I am suspicious of the whole annonce, there is zero picture of the transducers and of the inside of the loudspeakers. You should guess why...POL
