I recently discovered DML panels through Tech Ingredients channel because I had an idea I want to play around with... I was originally considering turning a couple of cheap used drum kits off Gumtree (using the skins of both bass drums and different size toms & snares as drivers) into a tall pair of DIY planar floorstanding speakers by using adhesive sheets of aluminium to cut the trace and stick to the back of the skin and mount the magnet array on the inside, close enough to the skin to vibrate it. Then use an external active crossover to distribute the different frequency ranges to each of the different width drum skin drivers (the smaller the drum, the higher the frequency). But this would've probably taken a %@$%-ton of power and multiple amps to work, I don't know. Then by pure algorithmic chance I was recommended videos on DML panels using these exciters. I'd seen the bass shaker type transducers used before in gaming sim-rig setups. They're generally cheap, low wattage and pretty good for output so I thought "Why not try these instead!?". What do you think? I realise it probably wouldn't compete with proper floorstanding speakers like Magnepans and a sub or 2, but could it potentially be tuned to sound good enough for rock and metal music? I don't listen all that critically. Especially to music like classical, quiet vocal-focused music or jazz. I'm no audiophile and I have mild tinnitus anyway.
Good job! :) By adding a high-Q bandpass peak to the bass at 20-something Hz, you basically converted the subs into ported subs for all acoustical intents and purposes. You get all the group delay and phase shift just as you would by adding a port, you just use wattage and excursion to do it in stead of a Helmholz resonoance :D (the added distortion comes for free) It would be really interesting to see the separate bass/panel responses too, not just the combined response. I very much suspect you have a phase issue between 2-300 Hz where the bass still will play pretty strong with a 2nd order electric xo. The peak-and-trough response here might either be phase mismatching, or it might be already in the panel response? I'd go to a third order for the bass slope, and then play around with the delay between 1-4 ms to get maximum integration addition. Remember that ALL phase misalignments require an increase in driver power for both adjacent drivers, increasing distortion for both. On a totally different matter, when I played around with DML's I used the common foamcore boards that seemingly everyone uses. One very interesting (IMO) that I tried was to add 45mm rockwool to the entire backside of the panel inside the frames. This converted the polar response from almost perfect dipole to something more like a semi-cardioid. Not surpising when you think about what happens when you dampen the rear wave of a dipole. That was the best I ever managed to make that panel sound in-room.
Sounds like there is some cancellations going on like comb filtering. Also I hear some static noise just when you stood up? This is my DML>ruclips.net/video/00spcs18MeU/видео.html
Good stuff! You've made some significant progress here, I'm real curious now to see which way you go for room treatment. I documented my entire room treatment ordeal from beginning to end with measurements every step of the way proving state of change. Check it out if ya like: ruclips.net/video/2PTnZ7BU-X8/видео.html I'm really not a fan of the common multi panel approach, and I don't love the large panels that I built either, but they are very effective. So I'm really curious to see what you come up with. Cheers 🍻
What program did you use to add delay on the panels?
It's a feature of the Hypex Filter Design software.
good progress . .
the slap echo in that room seems horrendous . .
You do know you can get rew to autogenerate the filters for you and import direct to minidsp.
I recently discovered DML panels through Tech Ingredients channel because I had an idea I want to play around with... I was originally considering turning a couple of cheap used drum kits off Gumtree (using the skins of both bass drums and different size toms & snares as drivers) into a tall pair of DIY planar floorstanding speakers by using adhesive sheets of aluminium to cut the trace and stick to the back of the skin and mount the magnet array on the inside, close enough to the skin to vibrate it. Then use an external active crossover to distribute the different frequency ranges to each of the different width drum skin drivers (the smaller the drum, the higher the frequency). But this would've probably taken a %@$%-ton of power and multiple amps to work, I don't know. Then by pure algorithmic chance I was recommended videos on DML panels using these exciters. I'd seen the bass shaker type transducers used before in gaming sim-rig setups. They're generally cheap, low wattage and pretty good for output so I thought "Why not try these instead!?". What do you think? I realise it probably wouldn't compete with proper floorstanding speakers like Magnepans and a sub or 2, but could it potentially be tuned to sound good enough for rock and metal music? I don't listen all that critically. Especially to music like classical, quiet vocal-focused music or jazz. I'm no audiophile and I have mild tinnitus anyway.
Good job! :)
By adding a high-Q bandpass peak to the bass at 20-something Hz, you basically converted the subs into ported subs for all acoustical intents and purposes. You get all the group delay and phase shift just as you would by adding a port, you just use wattage and excursion to do it in stead of a Helmholz resonoance :D (the added distortion comes for free)
It would be really interesting to see the separate bass/panel responses too, not just the combined response. I very much suspect you have a phase issue between 2-300 Hz where the bass still will play pretty strong with a 2nd order electric xo. The peak-and-trough response here might either be phase mismatching, or it might be already in the panel response? I'd go to a third order for the bass slope, and then play around with the delay between 1-4 ms to get maximum integration addition. Remember that ALL phase misalignments require an increase in driver power for both adjacent drivers, increasing distortion for both.
On a totally different matter, when I played around with DML's I used the common foamcore boards that seemingly everyone uses. One very interesting (IMO) that I tried was to add 45mm rockwool to the entire backside of the panel inside the frames. This converted the polar response from almost perfect dipole to something more like a semi-cardioid. Not surpising when you think about what happens when you dampen the rear wave of a dipole. That was the best I ever managed to make that panel sound in-room.
Great job!
Great video!!
Sounds like there is some cancellations going on like comb filtering. Also I hear some static noise just when you stood up?
This is my DML>ruclips.net/video/00spcs18MeU/видео.html
👍
Unfortunately, I can see your measurements are not valid from upper midrange to higher frequencies, please investigate.
Are you refer to the rising HF response?
Yes, rising HF response.
Good stuff! You've made some significant progress here, I'm real curious now to see which way you go for room treatment. I documented my entire room treatment ordeal from beginning to end with measurements every step of the way proving state of change. Check it out if ya like: ruclips.net/video/2PTnZ7BU-X8/видео.html
I'm really not a fan of the common multi panel approach, and I don't love the large panels that I built either, but they are very effective. So I'm really curious to see what you come up with. Cheers 🍻
Thanks a lot! I’ll definitely take a look at your treatment vids.