DIY Flat Panel Speaker Love

[LOUT]

I finally got around to trying a BST-2 BassShaker attached to a large remnant of XPS (nearly 4ftX6ft, 1/2inch). It was attached off-center around 2feet from one end and maybe 1.5feet from the adjacent side. I tried holding it up by the driver (which seemed to work decently), holding it up by an edge of the XPS (which also worked alright but could be finicky, likely due to the tenuous attachement of the driver to the panel) and tried setting it down resting against surfaces while trying to avoid rattles a couple of different ways (which still tended to rattle at higher volume).

I didn't take the time to hang it from the ceiling nor did I take the time to glue/tape the shaker's face to the panel, I just used some course threaded screws and gentle tightening. I'm pretty sure some double-sided adhesive along with bolts+washers or similar backing/support material for the screws to hold more firmly and a proper method of suspension would allow the amp/driver to push harder without rattling or otherwise misbehaving...but I wasn't really prepared for anything long-term and this was more just a quick curiosity.

Soundwise, it seemed to push a lot deeper/lower and louder bass than any fullrange transducers I've tried, so I think a BassShaker (like the BST-2) could be a viable way to add lows to a DML-only setup. The bass seemed more directional than I'm used to experiencing, where facing the panel from the sides instead of the front/back was noticeably quieter...maybe a positive or a negative depending on the situation.
Overall though, I think a small-ish conventional subwoofer still reaches noticeably deeper and louder while taking up less space...at least compared to the BST-2 and XPS. Considering the price similarity between a 1/2" 4x4sheet of cheap plywood and a $35 SD215-88 VS a 4x8sheet of material and a $25-50 shaker, I feel like the shaker+panel route probably only makes sense in a few niche situations or when aiming specifically for a DML-only setup. I could easily be wrong though, particularly if a different material and/or BassShaker performs significantly better without getting super expensive nor huge.


Bit of a sidenote that was probably obvious to others but not to me; although the BST-2 gives a surprisingly balanced volume of fullrange sound in free air, attaching it to a panel does NOT seem to increase its mid/high-frequency output by much (unlike fullrange transducers which get a fairly fullrange boost when attached VS free-air)...I'm assuming the mids/highs from the BST-2 are mostly the bits that escape the internal driver's attachment to the metal shell without causing enough vibration to move the shell or an attached panel enough to act like a fullrange DML?
In short, the BassShaker doesn't seem to give a full-range sound and instead focuses on lows..."Duh", I know, but probably doesn't hurt to mention.

[badfish]

Tech Ingredients videos are beginner intro entry level design into DML technology. T.I. polk speakers sound better then his panels. lol Dont get me wrong though as DML's have a lot of hidden POTENTIAL.

Sound quality is based on ones design as DML's are heavily design dependent. Better the design the better it will sound.

DSP and EQ wont make a bad sounding panel into a good sounding panel. You're panel needs to sound good to begin with as EQ and DSP are only to fine tune a good sounding panel.

Weakest point of DML is the lower frequencies due to limited pistonic motion and exciter design. This is why most people use a conventional cone powered sub for the lower frequencies and or use the Layered Sound technique that I have mentioned above in my other post.

EPS has a warmer tone then XPS. Things to take into consideration are Density of EPS as there are different grades of density.

All exciters are not created equal. IMO you should get the Thruster exciter instead of the DAEX-32Q.

Most people use this exciter transducer as a fun novelty project but dont take it serious enough as they dont recognize its true potential.

There are a few high end commercial brands that use DML/BMR bending wave technology.

High End 2016 Munich: Göbel High End Loudspeakers - "Tin Pan Alley" - YouTube One of the most expensive speakers utilizing DML bending wave technology.

Thanks for the great feedback and all the info you've posted in the past. Taking notes!

So the DAEX32-EP would be better than the 32EXU (the ultra) in this case? I'll have to read up on what a thruster exciter is. I have the 32U on order, but it's back ordered and the thruster is the same price.

I have a sub incoming too to help on the low end side.

Was sitting around last night probably reading this forum and radioparadise played some live acoustics including Over Now by Alice in Chains which sounded very good on my presently not top tier panels. Was pretty inspired - they seem as many have stated to really shine when you have lots of textured guitars / strings and vocals and when I considered they cost me 35 CAD each, that added another layer.

Cheers

[Unbiasedsound]

Hi All,

New here and just authorized but have been reading this forum with focus of late. Like many, sucked into this DML speaker fun thought the world's best youtube.

I built a couple quick panels using the home depot 2x2 project panel (which I think is XPS?) and post rounding the corners and sanding them, attached a couple DAEX-25's (the spider looking ones) to the back and hung them in my garage.

Connected to a basic 50W amp, the sound was crazy harsh - the 4k band was especially ear grating. Using eqMAC and my mac as a source, I was able to deal with the highs and get to a better overall sound.

I am about to order a mini-DSP-HD and a mic (a bit for this project, and just seems like cool kit in general) and will run some REW tests to see what my overall response is. (nothing like spending 500 bucks to fix your 35 dollar speakers)

That said, reading here these panel's don't appear ideal and certainly while when EQ'ed my sound is interesting and there are definitely some qualities that intrigue me, they aren't really in the "good" category even by non audiophile standards - ear fatigue is quick.

On that front, my lows are nearing non existent (will add a small sub, but even lower midrange not ideal). Did see a tool that suggested getting much under 240hz would be tricky with a 2x2 panel.

I am going to coat these ones in glue/water and see if that helps with overall clarity but probably keen to build some cheap new panels.

That said, wondering about building a newer panel on EPS, maybe toward the 6mm to 10mm thickness, and debating on smaller (12x12 ish) or something larger 1:618 ratio style, like 24x38 etc (trying to get a bit more lows).

Also wondering if changing out the 5W DAEX-25 to a more robust DAEX-32U @ 20W would be a noticeable upgrade? They are so cheap ;-)

Cheers and thanks all for the wealth of info here.

Tech Ingredients videos are beginner intro entry level design into DML technology. T.I. polk speakers sound better then his panels. lol Dont get me wrong though as DML's have a lot of hidden POTENTIAL.

Sound quality is based on ones design as DML's are heavily design dependent. Better the design the better it will sound.

DSP and EQ wont make a bad sounding panel into a good sounding panel. You're panel needs to sound good to begin with as EQ and DSP are only to fine tune a good sounding panel.

Weakest point of DML is the lower frequencies due to limited pistonic motion and exciter design. This is why most people use a conventional cone powered sub for the lower frequencies and or use the Layered Sound technique that I have mentioned above in my other post.

EPS has a warmer tone then XPS. Things to take into consideration are Density of EPS as there are different grades of density.

All exciters are not created equal. IMO you should get the Thruster exciter instead of the DAEX-32Q.

Most people use this exciter transducer as a fun novelty project but dont take it serious enough as they dont recognize its true potential.

There are a few high end commercial brands that use DML/BMR bending wave technology.

High End 2016 Munich: Göbel High End Loudspeakers - "Tin Pan Alley" - YouTube One of the most expensive speakers utilizing DML bending wave technology.

[Kornbread]

I agree. The panels are ok, not great, unless the only thing you ever heard were WalMart specials, then they might be considered great.
My next panels were going to be tufftrax, similar to plexiglass but more durable.
The blue foamboard had a 'skin' or 'nasal' kind of sound I could never get rid of. Not necessarily overly harsh, just could not get rid of that annoyance. Don't think you will hear much difference sanding and adding glue to the surface, but who knows.
Plain single layer cardboard panels treated with lacquer sounded more natural.
If space is no issue, I've gestured about adding a full 4x8 sheet of 1/8 ply and a bass shaker for the low end.
Lows ... my experience was that the exciters (don't remember the model#) were very fragile when trying to reproduce bass. Be warned. I would not be surprised to find that a crossover and exciters made more for specific frequency ranges, aka similar to standard cone n dome 2 or 3-way speakers, to be the ticket to a fuller freq range of reproduction.

[badfish]

Hi All,

New here and just authorized but have been reading this forum with focus of late. Like many, sucked into this DML speaker fun thought the world's best youtube.

I built a couple quick panels using the home depot 2x2 project panel (which I think is XPS?) and post rounding the corners and sanding them, attached a couple DAEX-25's (the spider looking ones) to the back and hung them in my garage.

Connected to a basic 50W amp, the sound was crazy harsh - the 4k band was especially ear grating. Using eqMAC and my mac as a source, I was able to deal with the highs and get to a better overall sound.

I am about to order a mini-DSP-HD and a mic (a bit for this project, and just seems like cool kit in general) and will run some REW tests to see what my overall response is. (nothing like spending 500 bucks to fix your 35 dollar speakers)

That said, reading here these panel's don't appear ideal and certainly while when EQ'ed my sound is interesting and there are definitely some qualities that intrigue me, they aren't really in the "good" category even by non audiophile standards - ear fatigue is quick.

On that front, my lows are nearing non existent (will add a small sub, but even lower midrange not ideal). Did see a tool that suggested getting much under 240hz would be tricky with a 2x2 panel.

I am going to coat these ones in glue/water and see if that helps with overall clarity but probably keen to build some cheap new panels.

That said, wondering about building a newer panel on EPS, maybe toward the 6mm to 10mm thickness, and debating on smaller (12x12 ish) or something larger 1:618 ratio style, like 24x38 etc (trying to get a bit more lows).

Also wondering if changing out the 5W DAEX-25 to a more robust DAEX-32U @ 20W would be a noticeable upgrade? They are so cheap ;-)

Cheers and thanks all for the wealth of info here.

[Unbiasedsound]

On the DIY audio forum on the topic of "a study of DML as a full range speaker", the most recent post one mentions using mineral spirits to dilute the oil based paint. Whats wrong with that? Well on certain materials especially EPS and XPS they are very susceptible to corrosive substances so one has to be very careful as it will eat through the panels.

I cant warn him because I am banned from that site....I guess he will have to learn the hard way. lol

[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.