Dual membrane high excursion planar magnetic bass driver Part 1 - Building
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- čas přidán 8. 09. 2024
- A thing i was thinking about for a long time, also tested it in small.
but to see what really happens down low :) lets make a bigger one.
Best outcome is better linearity with the same amount of magnets ! check the measurements for yourself :)
Who thought we'd see Isobaric planar bass? Fantastic stuff
Well its kind of different then isobaric , this shares the same magnets.
Dual drivers make sense for low bass. Very smart stuff.
thank you, not sure if it is but what i seen so far it might... then again its also more work. in any case its nice to take a look at :)
I believe drivers that , in use , have large excursion also have high intermodulation distortion with multiple frequencies . Larger is better for bass , IMO . Especially for open baffle and planar .
Hihi, I meant air passages not between the panels, on the main frame make some passages from center to outside like wave guides. You will lower the pressure between the panels, as well the resonance will be lower. In current configuration the speaker works like closed box, that is why you have higher resonance
Genious at work!
Nifty AF
very good idea to lower the distortion without using a push pull magnet arrangement....
at the expense of efficiency if the resonance frequency were reduced to the same value as the single membrane arrangement, I guess
for rising the sensitivity with same magnet and magnetstructure, there are the three known posibilities, ...reduce distance of foil to magnet...increase the resonance and... or...increasing the radiation resistance by increasing the radiation area of the foil...
a dipol with deep and loud bass has to be very huge...my dipols have 2 square meters radiation area per side and approach at 30 Hz the 100 dB range 😊
for higher sound pressure level or a pressing sound the use of a subbass box speaker under the 50 Hz range is neccessary....
well yeah these are small to begin with :) and i increased xmax from 3 to 6mm, both dont contribute to efficiency :) but the thing i wanted to test becomes more clear with 6mm xmax :) hence why i chose it. the res will always be higher then one membrane alone, but in this cae both foils needs to be lower so i end up at 40-45 Hz , that would be my goal for this tiny panel. see if i can hit xmax so i know what the limits are. and also might have a better idea of what 1 vs 2 foils do.. beneficial. or not at all :) since there never is a free lunch... well usually there aint :)
@@joppepeelen I belive that the air load (mass of the air) left and right side of the membran is more or less the same driven a single or push pull membran but the suspension rises with push pull so that the resonance rises also with push pull system....
but beside that I have to say... you make a very good job Joppe....a real sientist in this area 👍...
Awesome video again! Thanks for the upload, really appreciated.
Are you using regular ferrite magnets? Thanks!
So an isobaric speaker that sort of works like a magnet-to-cone config in that it cancels asymmetry. The distance is small so it should work rather well. The question that I have is what is the impedance of the slots between magnets. Microphones have quite elaborate hole matrix in the plates to dampen the diaphragms. I think I'd start with filling this area with felt.
yes it needs damping there ! thats for sure, i can play with open area as well, but top of my list is width of the foil to get res lower. while maintain tension. i am really pleeased with this idea, 2e order dropped insanely amount. there is a measurement between this tiny panel and the LRS... near res dropping 8%... thats well sick :)
@@joppepeelenNear res means?
@@allankvist6741 near resonance
whoaaaaaaaaaaaaaaaaaaa
this is cool...
Amazing work, probably you should make some air passages between the panels, that will lower the resonance and lesser distortions
Hihi i guess you did not see the frame in the beginning :) there are plenty of passages or there would not be any sound I'm afraid.
@@joppepeelen Hihi, I meant air passages not between the panels, on the main frame make some passages from center to outside like wave guides. You will lower the pressure between the panels, as well the resonance will be lower. In current configuration the speaker works like closed box, that is why you have higher resonance
Would you consiver selling such a bass panel (to someone in the Netherlands)? I don't have the equipment to make one and I am very interested!
well if i am content with them you sure can !, as for now this is the first version i made to check my idea. so far it works. but i bet there is more to fiddle with :)
Could you make a sub from them, panels on two faces of box?
planars magnetics in a box is not ideal, needs a huge box and normal drivers are better suited ! without box is nicer anyways, but will need big surface area etc :(
Where did you get the coils from?
did you ever build a planar with a Halbach array ?
What is the name of the material you use as a membrane?
where did you get the mylar and what foil are you using?
You should watch some of the very first video Joppe did about diy magnetoplanar spkrs; he also shared some links/addresses.
Is there such thing as a hard diaphragm planar? Instead of flexible membrane use something like cardboard idk. It'll have a separate suspension and possibly less distortion. I know it'll be heavy but you can put more thicker traces to keep the sensitivity. Just an idea I have in my head.
Finally someone that made a planar subwoofer!!!
well its not a sub by any means. its just a panel size that gave me enough info on whats going on in the low end without it been to big for my cnc :) but well making it stiff etc etc will end up been a woofer :) but i did add some 1mm foam to stiffen it up before , while been light. normally that dit not gave me what i was hoping for. changed some for the good and some for the worse. in the end not worth it :(
@@joppepeelen Have you expeimented with heavier/thicker foil? Is going for thin for thin and light actually beneficial? If so does this count for all aspects of performance and at all frequencies? Cheers!
@@allankvist6741 in the low end usual a bit thicker foil wont hurt all that much, in this case i used what i always use:) 12 micron. you can get away with heavier for sure. you can stretch it harder. but need to go wider to maintain low enough res.. like i did not :) i should have made the foil 2 or 3 cm wider and stretch it a little tighter. but hell its a good start.