DIY Flat Panel Speaker Love

[Unbiasedsound]

Another thing that is great about DML's is that you can custom tune your panels to your preference. You can make them sound bright, dark, forward sounding laid back sounding its all based on how one tunes there panel as the combinations are endless. One can even change the soundstage and imaging of a panel. These tuning changes can be done in as little as 30 seconds per speaker with very little cost and no tools required.

With conventional cone drivers the usual way to change the sound is to change the crossover and even then its very limited and time consuming, not to mention all the costly tools and parts needed to do so.

[Unbiasedsound]

It seems some people (on the other forum) dont understand about DML's and bass. Besides having very limited pistonic motion exciters are also not efficient in the bass region. When running full range a exciters mid to high frequencies efficiency will be way higher then the bass which will over power and drown out the bass frequencies. The way to fix it is to use the exciter as sub to only produce the low frequencies 100hz and below. A sub amp is needed as it will push the exciter to produce pistonic motion but wont have the higher frequencies to drown out the lower frequencies.


My DML sat/sub combo is my top preferred design as it has great high frequencies and well as the low frequencies down to 40hz.

[Unbiasedsound]

A controlled and predictable speaker cone is significantly more accurate than a random piece of wood/plastic/composite material vibrating. Isn’t the goal of speakers to accurately reproduce recordings?

Instruments are vibrating material. Whats more accurate then a panel vibrating like a instrument.

[Unbiasedsound]

DML's are great for mid to high frequencies as they are basically full range speakers being able to play from 60hz-20khz. Of course its all design dependent as the better the design the better they will sound. The low frequencies are not as good due to the limited pistonic excursion. Conventional cone drivers move more air to produce bass while DML's vibrate the panel (less air movement) which is why a larger sized panel is needed to produce lower frequencies because it needs to bend the panels hence the term bending wave transducers. EPS needs to be thin (5-10mm) 1/2-1/4 inch to flex enough to produce adequate bass. T.I. video uses 1inch XPS which is to thick. Also EPS is more flexible then XPS.

There are two types of damping. One is panel treatment damping usually done with a 50/50 water/glue mixture or even paint water based or oil based. The other type of damping is done with some type of foam damping material in which this is used to "TUNE" a panel to smooth out its frequency response. It can be applied directly on to the panel and or on to the panel frame. Shelly Katz Podium speakers gave me the idea to use this technique and it works. http://www.stereomojo.com/Podium%20....akerReview.htm

One of the best "ACCURATE", sounding DML's speakers are from a Russian company called Sheet Control.> https://www.youtube.com/watch?v=JheZ84QcZPw

https://www.youtube.com/watch?v=vBXQyR1EwSs

https://www.youtube.com/watch?v=PLweDrL4EDc


https://www.youtube.com/watch?v=MsEg7RjunhQ&t=96s This video compares DML to Dynaudio.

[viewcart]

While I love his YouTube channel, those speakers are going to be a complete mess for HF reproduction, and forget LF all together. For midrange they WILL work, but to get a smooth output the thing needs to be so damped you may as well forget any efficiency advantage from a radiator of that size. He states that these produce sound the same way a piano soundboard does, which IS true, but he goes on to say traditional cone speakers produce sound “artificially” while wooden resonances are “natural.” Sorry, sound is vibrating air and that’s it. It really doesn’t matter what makes it vibrate. A controlled and predictable speaker cone is significantly more accurate than a random piece of wood/plastic/composite material vibrating. Isn’t the goal of speakers to accurately reproduce recordings?

[Unbiasedsound]

What is the best shape for DML panels? Best most accurate shape is a square as it produces the most even sound because its shape is even. Next best shape is a rectangle but there is a limit to how long you can make it. A rectangles length should only be at most 8 inches greater then its width, preferably 5-6inches is ideal. The longer the rectangle the more exaggerated the sound becomes and it also becomes more uneven and weird sounding. This is the reason odd shape conventional cone speakers like 6X9's are not readily used in home speakers as the odd uneven shape makes the sound uneven and off sounding. Its no different for DML panels.

Once the corners are rounded though they are more of a hexagon shape.

[Unbiasedsound]

What is the proper or ideal exciter placement on a panel? When you look at P.E. exciter placement they use the 2/5 3/5 placement to off set the build up of standing waves. You can read up on there reasoning for using those placements in the P.E. buyers guide to exciters.

IMO those are not ideal placements. The ideal placement when using a single exciter per panel is dab smack in the middle/center of the panel. Has anyone ever seen a conventional cone driver with its voice coil off center from the diaphragm? NO right? DML's are similar to conventional cone drivers then most people realize as we are not trying to reinvent the wheel here. When any transducer is off center it will be less coherent. The most coherent sound is when the transducer is placed smack dab in the middle/center of the panel diaphragm.

[Unbiasedsound]

What is the right size panel? What is the right sized exciter? Smaller exciters can be used on smaller panels while larger exciter can be used on larger panels. Also when using more then one exciter per panel you can increase panel size.

Size's of exciters and recommended approximate panel sizes when used with a single exciter per panel.

9mm exciter.=8inch width panel square. if using a rectangle you can add more inches to length but width should be minimum 8 inches.

13mm exciter=10inch width. If using rectangle can add more inches to length but width should be minimum 10inches.

19mmexciter=14inch width. same as above

25mmexciter-16inch. width. same as above

30-32mmexciter-20-24inches width. same as above.

Also all the info given out is pertaining to high grade Expanded Polystyrene 1/2 inch (10mm) thick panels. Different materials will have different results.

[Unbiasedsound]

What is the best shape for DML panels? Best most accurate shape is a square as it produces the most even sound because its shape is even. Next best shape is a rectangle but there is a limit to how long you can make it. A rectangles length should only be at most 8 inches greater then its width, preferably 5-6inches is ideal. The longer the rectangle the more exaggerated the sound becomes and it also becomes more uneven and weird sounding. This is the reason odd shape conventional cone speakers like 6X9's are not readily used in home speakers as the odd uneven shape makes the sound uneven and off sounding. Its no different for DML panels.

[Unbiasedsound]

Ever since Tech ingredients vid on youtube a lot of people are hanging there panels to high. DML's do best closest to the ground. Why because like any conventional cone speaker ideal height placement is usually around ear level. DML's also have a very wide dispersion so if your panels are too tall and or placed to high the high frequencies will go over your head. Below ear level is best.

[Unbiasedsound]

I found out something new. When using a sub I have found that using the 180 degree phase switch blends well with DML panels. As to why it could be that DML panels are slightly out of phase.

[Unbiasedsound]

I see people build Rich's design and or Tech ingredients design and claim that they sound really good and or say they sound better then the average speaker which is not true. These people are most likely the average joe and not into hifi and or they are deaf. LOL

Even Andrew Jones cheap pioneer speakers will sound better then the average beginners DML design.

DML's do have great potential though one just needs to know how to bring it out.

[Unbiasedsound]

Ahh **** this topic has been dead for a while now. I bring it back up.

[Kornbread]

I'd start a bit cautious. Since you already have some decent bookshelves ...

For now, experiment with the exciter panels but keep them in a size that will fit into the drop ceiling. That way if you don't care for them as mains they can be hidden in the drop ceiling for rear surrounds (maybe height channels for the front/rear?) and take up zero room space or hung on the rear wall/side wall. Even though they are as thin as a sheet of styrofoam, from the front, visually, they can be quite intrusive. If you don't like the panels, use the existing bookshelves for mains.

Same for the sub/subs. If it's just a plain drop ceiling, build them into the ceiling and save considerable floor space. Since they are hidden out of the way, I'd consider multiples to help even out room response.

My av receiver is maybe 10+ years old so I have not a clue as to how far they have advanced in those years concerting eq and processing.

I don't recall ever making a .zma file for any of the exciters I played around with but can only guess that the impedance will vary greatly depending on the panel they are attached to. IIRC, they were a fairly easy load to drive ... but my memory could be wrong.

Just my $.02.

[troglodytes]

Hey everyone. I'm new to the forum and wanted to join because I've been digging through some of these long posts over the past week while I research the use of exciters and how they may be my perfect solution to our basement home theater. I just wanted to ask a few questions before I start really diving down the rabbit hole of purchasing and experimenting with materials and placements.

First off, the plan was always to have a 5.1 system, but I'm perfectly happy with a 2.1 system if the sound is enveloping. The room itself is open but half is used for watching TV/movies while the other half is an office space. Listening position is about 13 ft from the tv/speakers currently and the ceiling is 8ft with drop ceiling. I have a Sony STR DN1080 which provides 100W the LR Fronts / 150W to the Center / 80W to the rear surrounds. What I wanted to do was put DAEX25FHE-4 exciters in the drop ceilings panels on Left & Right fronts and run each of those in series to a XPS hanging panel on either side of the TV to bring the impedance on each channel to 8 ohms, which should play nicely with my AVR. I wanted to pair the entire thing with the Dayton Audio Sub-1000 10".

Now, I know that no one out there can tell me whether this will sound great or not because every room/panel/setup is different, but I wanted to ask if I'm going about this the right way, or is the configuration not what the exciters were intended for? I see a lot of talk of using crossover and EQ management, but I was hoping to use the AVRs crossover in my scenario, and for EQ management I was hooping to get away with the AVR calibration and built in equalizer as I'm trying to keep this a pretty budget setup.

I already have several speaker options to go in the room as an alternative (Aerial 5B bookshelves, B&W Matrix 1, KEF 203 Bookshelves and Energy Connoisseur C3), but the idea of super clean look flat panel (or hidden in ceiling) speakers along with the fun of a DIY project is really intriguing...and to be honest will allow me to maybe clean out some of my speakers because I'm running out of room. However, if my expectations are completely out of line with what the exciters can provide, please let me know.

Also, also if I were to attempt a 5.1 system it would probably look something like the following:

R/L: 2 DAEX25FHE-4 on two panels (4 exciters total)
Center: 2 DAEX25FHE-4 on one XPS panel (2 exciters total)
Rears: 1 DAEX13CT-8 on one panel( 2 exciters total)
Sub: DA Sub-1000

Is this a setup will experimenting with?