DIY Flat Panel Speaker Love

[Unbiasedsound]

It sounds like you're saying with all other things roughly equal, a smaller but significantly more bendable material will typically reach lower bass than a taller+wider significantly less bendable material.
Then again, you didn't mention whether it was the more bendable or less bendable material that can reach lower, so maybe I have that switched around?

It also sounds like (at least in a roundabout way) you're saying the material height/width doesn't necessarily need to meet a minimum size in relation to the wavelength of the low frequency it's trying to reach.

This isn't what I was expecting to hear, but I also know next-to-nothing about DML speakers so I should've gone without any internal guesses in the first place. I thought material rigidity had more of an influence on SPL (sensitivity?).

You have it switched around. Larger size panel equals more lower frequency response while a smaller panel equals less. A material that can bend more will produce more lower frequencies.

The physics for low frequencies in DML's is similar to conventional cone drivers in where size does matter. A 2inch driver will not produce the same amount of low frequencies as a 12inch driver....the same way a small DML panel will not produce low frequencies of a larger DML panel.

Larger the panel the more it will bend which equals more bass...smaller the panel the less it will bend means less bass.

No, actually less rigid materials have better sensitivity. The main reason why most do not use wood as a DML material is because its main down fall is very low sensitivity when compared to EPS/XPS because wood is way more rigid then EPS/XPS. There are compromises to each different type of materials used.

[LOUT]

Its the point of bendability that determines how low you can go. Oh and of course one other factor is the transducer used as not all are created equal. A bass shaker will play lower then any exciter listed on P.E.

It sounds like you're saying with all other things roughly equal, a smaller but significantly more bendable material will typically reach lower bass than a taller+wider significantly less bendable material.
Then again, you didn't mention whether it was the more bendable or less bendable material that can reach lower, so maybe I have that switched around?

It also sounds like (at least in a roundabout way) you're saying the material height/width doesn't necessarily need to meet a minimum size in relation to the wavelength of the low frequency it's trying to reach.

This isn't what I was expecting to hear, but I also know next-to-nothing about DML speakers so I should've gone without any internal guesses in the first place. I thought material rigidity had more of an influence on SPL (sensitivity?).

[Unbiasedsound]

Does the panel need to be a particular height and/or width to reach lower frequencies; like a quarter/half/full wavelength of the frequency it's trying to reach?

If so, does it need a minimum height, width, or both?

Sorry if this was already answered, the forum's search is less than ideal.

With DML's it will depend on the material used as there are many factors taken into account like 1. Density of material (stiffness) as less dense materials will bend more 2. Thickness of material as thinner materials bend more then thicker materials. 3. Size of the material as larger panels will bend more then smaller sizes. 4. Last but not least shape as certain shapes like rectangles will bend/flex more then a square. for example lets take EPS material if you have 2 pieces of EPS both with the same width of 1ft. and one is 2ft.in length and the other is 3ft which one would bend more when holding each panel up in each hand? Yes the 3ft. panel will bend more due to its longer length. Its the point of bendability that determines how low you can go. Oh and of course one other factor is the transducer used as not all are created equal. A bass shaker will play lower then any exciter listed on P.E.

[LOUT]

Does the panel need to be a particular height and/or width to reach lower frequencies; like a quarter/half/full wavelength of the frequency it's trying to reach?

If so, does it need a minimum height, width, or both?

Sorry if this was already answered, the forum's search is less than ideal.

[Unbiasedsound]

For whatever it's worth, the newer Dayton BST-2 bass shakers seem to work okay as a DML-bass device. They can get the furnature and floor moving enough at higher wattage to make hearable bass around 35hz and up (though I haven't yet tried mounting to a flat/loose panel.
They also play full-range if left to do so, which I'd expect should help them to cross-over whereever you want OR maybe simply use them full-range with some EQ if they happen to be good enough (I'm not sure if their full-range output is loud enough since I've not used them with a loose panel yet).

Mostly, I think their current new/sale price around $25 on PE makes them a lot more tempting to experiment with compared to their $50-80 cousins, while they still keep a lot of the claimed handling and force of those models...at least that was my thoughts when grabbing them. A lot of fun so far (though their supposed response down to 10hz seems a dubious claim to me right now; more like 25-35hz unless they have a reeeeally long breakin period).

Bass shakers are not designed to be used as full range as they are specifically designed to be used for low frequency hence the name "BASS SHAKERS". The difference between the Dayton bass shakers and a Dayton exciter is that the bass shakers are FULLY ENCLOSED so they vibrate from both sides while a exciter (is NOT fully enclosed) only vibrates on one side with the plastic attached to the voice coil.

Bass shakers are designed to actually be felt more then heard but can be used to produce low frequencies depending on the type of material its attached to. Hard/stiff surfaces will produce less sound but the vibrations can be felt. You wont hear a 10 hz response but you will be able to feel it through the vibrations of certain material its attached to. On softer materials like EPS/XPS you will be able to hear the low frequency sound probably down to 20hz. depending on the size of the EPS panel. Larger EPS panels will produce more bass because larger (also THINNER) panels will BEND/FLEX more then smaller EPS panels which is how DML's produce bass by bending (vibrating) hence the term bending waves. A conventional cone driver produces bass by moving lots of air.

Most people dont have enough room to accommodate (over 2ft. width 3ft. height) huge DML panels and or because of aesthetics that one's significant other wont approve. This is why most just use a conventional cone powered sub that they can hide or tuck in the corner. This is one technique of "LAYERED SOUND", in which I mentioned in my other post where one combines conventional cone waves with DML bending waves just by using a conventional cone powered sub to fill out the low frequencies.

[Unbiasedsound]

is it ok or even helpful to put some foam between panel and frame?

Yup that is how the EPS is suppose to be mounted to the frame using the rubber foam. I was going to mentioned it but I just figured you already read up on it.

Here are beginner steps to prepping DML panel.

1. Iightly sand both sides of EPS with 100 grit sandpaper and then 220 grit to smooth it out.

2. Coat both sides of the EPS with around 70/30 water/glue mixture. Let dry for 3 days.

3. Paint the front side with oil based gloss paint any color that matches your decor.

4. To attach EPS panel to frame use Frost King rubber foam.

5. For temporary attachment of exciter to the EPS panel use the sticky tape that comes with the exciter. If you want permanent use 5min. 2 part epoxy adhesive.

[bilidru]

If you are using a frame it should be ok since the frame helps support the EPS.

is it ok or even helpful to put some foam between panel and frame?

[LOUT]

For whatever it's worth, the newer Dayton BST-2 bass shakers seem to work okay as a DML-bass device. They can get the furnature and floor moving enough at higher wattage to make hearable bass around 35hz and up (though I haven't yet tried mounting to a flat/loose panel.
They also play full-range if left to do so, which I'd expect should help them to cross-over whereever you want OR maybe simply use them full-range with some EQ if they happen to be good enough (I'm not sure if their full-range output is loud enough since I've not used them with a loose panel yet).

Mostly, I think their current new/sale price around $25 on PE makes them a lot more tempting to experiment with compared to their $50-80 cousins, while they still keep a lot of the claimed handling and force of those models...at least that was my thoughts when grabbing them. A lot of fun so far (though their supposed response down to 10hz seems a dubious claim to me right now; more like 25-35hz unless they have a reeeeally long breakin period).

[Unbiasedsound]

If you are using a frame it should be ok since the frame helps support the EPS.

[bilidru]

You can use any picture or art canvas wooden frames....Depending on how much your DML panels weigh you can use galvanized 20 gauge wire on the frame and just hang them on a dry wall screw. Also there should be at least a 1 inch gap from the panel to the back wall as these are bipolar type of speakers where sound also radiates from the back. You can use some type of soft rubber/foam like this on the back of the picture frame. Cut 8 pieces about 1 inch and place them evenly on back of frame. This rubber foam will also prevent the wooden frame from rattling when touching the wall.

Oh, perfect. That sounds great. Thank you for your immediate response.
I've found 50cm square eps panels 10 and 6 mm thick. Are these measures ok for a 25mm exciter? They seem so thin...

[Unbiasedsound]

Hi, I'm new to this forum and to DML speakers. I read the first five pages and the last ten and have got some open questions also due to the fact that I don't understand every technical aspect in English, which is not my mothertongue. I'm not a hifi enthusiast. So it's not about building the best speakers.
Page 87 was helpful, as Unbiasedsound answered basic questions.
So I'm going to use two eps polysterene, 10mm thick and one 6 mm for a "bass" Panel. All powered by a fosi audio 2.1 amp.
My question is about how to hang them on the wall? In a wooden frame? Or using some wood construction, but 6 or 10mm don't seem to be much to use cotter pins. So I'm lost here and appreciate any uncomplicated solutions.
Thank you for any answer.

You can use any picture or art canvas wooden frames....Depending on how much your DML panels weigh you can use galvanized 20 gauge wire on the frame and just hang them on a dry wall screw. Also there should be at least a 1 inch gap from the panel to the back wall as these are bipolar type of speakers where sound also radiates from the back. You can use some type of soft rubber/foam like this on the back of the picture frame. Cut 8 pieces about 1 inch and place them evenly on back of frame. This rubber foam will also prevent the wooden frame from rattling when touching the wall.

[bilidru]

Hi, I'm new to this forum and to DML speakers. I read the first five pages and the last ten and have got some open questions also due to the fact that I don't understand every technical aspect in English, which is not my mothertongue. I'm not a hifi enthusiast. So it's not about building the best speakers.
Page 87 was helpful, as Unbiasedsound answered basic questions.
So I'm going to use two eps polysterene, 10mm thick and one 6 mm for a "bass" Panel. All powered by a fosi audio 2.1 amp.
My question is about how to hang them on the wall? In a wooden frame? Or using some wood construction, but 6 or 10mm don't seem to be much to use cotter pins. So I'm lost here and appreciate any uncomplicated solutions.
Thank you for any answer.

[Unbiasedsound]

My design will be similar to the Cambridge audio Aero speakers that use a conventional cone driver for the woofer and a BMR driver for the tweeter. Only difference is instead of the BMR driver I will be using DML panel.

[Unbiasedsound]

I am going to experiment with Shelly Katz "Layered Sound", technique of combining a conventional cone driver with a DML panel. I just placed an order for a pair of Visaton WS-17E 6.5" woofers.

The challenge is to get the correct configurations of a dml and conventional cone driver to blend together perfectly as Katz does not explain exactly how to do it.

[Unbiasedsound]

Using a Dayton DAEX 25FHE -4 exciter speaker on Foamular XPS panel ( 1" x 2' x2' ) . To block the frequency below 100hz would i use a 100uf capacitor ?

4 ohm=400uf cap at 99.38 hertz. The only cap at P.E. at 400uf is NPE caps. They are cheap but they can degrade the sound of the exciter....The Dayton caps is better but they only have a 100 uf cap which is very expensive compared to the NPE caps. The caps alone could cost more then your whole DML build.