DIY Push Pull Ferrite Bass Planar speaker - Part 3 tune and measurements
Vložit
- čas přidán 8. 09. 2024
- Well made my first measurements , while playing a tune. only listen to the left side speaker/channel :) PLEASE KEEP IN MIND MEASUREMENTS WHERE TAKEN CLOSE TO THE SPEAKER JUST TO SEE THE DIFFERENCES BETWEEN THE DUAL FOIL AND THIS ONE, SO SPL IS NOT CORRECT. it was stated in the video, but somehow people are amazed by these distortion numbers. @98dB @50 hz . and i would be too... but thats not the case ! the one at 1 meter is calibrated. correct since i wanted to know the SPL. the rest are comparisons, to the older panel.
directly to tune without me rambling go here : • DIY Push Pull Ferrite ...
Wonderful realism Joppe. I just love it.
Phenomenal!
Wow, what a tune! I got taken back for a minute there.
That sounds awesome
Tell me if you have already thought of this, but I've just thought of a way to find tune the tension very easily.
First, design the frame with a front and back as you have done here. The idea is to stretch the film between the frames, like a sandwich. The frames are simply rectangles, with rectangular holes, the same as what you've done here, but make one have a smaller hole then the other. Maybe by 10mm or so. So when they are together, there is a 10mm lip because the one with the smaller hole will overlap. To the one with the lip, apply a 20mm wide weather strip made of closed cell foam to the lip.
tension the film onto one of the frame with the larger hole. The one without the foam, ensuring no wrinkles, and even tension and secure it. As you clamp the second frame onto this frame, the foam will press into the film. This will add tension. The more clamp pressure, the more tension. They can be clamped with screws or bolts. This could be used to create both uniform or non uniform tension. Because the weather strip is also being sandwiched sure to it being 10mm wider then the lip, as tension is applied, the down is compressed. This keeps the two frames apart and prevented vibration.
Magnets would be attached to the lip frame. I this way, the gap distance between the film and the members would be roughly the same, regardless of compression. The first will of course compress the foam a little, but hopefully not much. So yeah, push only arrangement. Or perhaps, if magnets where in push pull, the foam would compress from the film at half the rate of the movement between frames,meaning the film would remain centered?
The foam may also absorb excessive energy, leading to better dampening, which may be good for lower frequencies.
Just an idea
Thanks m8 ! i think i do not understand 100%, when pushing the mylar with a weather strip resonance goes up but also the distance to magnets will change towards the back or front magnets., the use of weather strips on all edges of the rectangular frame is something done before (like apogee) but tension i think should cone from sideways movement so either an extra bar or like i did rather crude, is forcing it sideways to stretch the foil by using the metal and a screw to pull the mylar holding frame outwards, and lock it with the regular bolts, i should be able to remove the wood screws after if...... i tensioned the bolts hard enough :0
@@joppepeelen Fair enough. I'm sure there are so many ways to do this. Perhaps even using a fly screen door 😂 I dunno.. Anyway, thank you for all your videos. I really love them!
@@ubza1234 Thank you for your input !!! much appreciated !! and i am glad you like the videos ! multiple people know more then one! or come up with something new more easy :)
Those low distortion measurement values are very impressive!
well cant say they where playing loud. (they where measured real close so the SPL in that measurement does not say much i am afraid :( ) at all. i was measuring the differences. and i did not wanted to change the output volume since it was still on 2.85 volt. so i thought
Happy Birthday to Puss 😼😼
JEEEEJ ill give her a pet !
I am amazed how close the two measurements are. Foil tension seems to be under control!
Qes is so high... I guess that makes sense. It is a lot of magnetic flux over a large area.
Yep it's not dynamic driver :)
Open my world
very nice, huge gain in output! is it possible to have too much magnet strength that it will detract from low bass output? (qms?) i recall that smaller magnets on traditional woofers was actually better for acoustic suspension bass design.
hmm i think its because low magnet designs have higher QTS, or a High Q so they go nuts on there own at resonance. (less controlled) just like many planar magnetic bass drivers, and most certainly like the dual membrane drivers, they have a really high QTS.
Мне нравится! Классно!
it looks pretty good between 40-80hz drops off above that... lol maybe a lo-mid driver coming soon?
The up close measurement suppose to drop :) it's the open baffle compensation. I only made those to see the difference in efficiency
@@joppepeelen that was like 9db gain. yeah. Hella better efficiency
Much more adept than the dual foil version. What are the dimensions of the bass planar?
Foil size is around 26 cm x 51cm. pretty small, overal size 32 cm x 59 cm
Why not build the frame with hollow steel tube? Or aluminium? My original Magnepan Typani back in the early 70s had steel tube frames.
Brown : 20 hz , 79 db : 30 hz , 88 db.
Blue : 20 hz , 88 db : 30 hz , 98 db .
Looks good .
Well ignore the spl it was measured up close. I'm only looking for the differences in volume
so.. next would be cylindrical same pole opposing magnets in checkered pattern and hyperelipse shaped coils in the foils?
pardon me ?
@@joppepeelen Just a lame attempt on a joke. Keep doin what you are doing :-)
@@tobiaslindblom2187 oh haha , i was like wtf ? am i missing something :) haha thanks m8 will do !
What is dimension of magnets?
100mm x 20 x 12
MiniDSP crossover is cheap and good!
well i got a minidsp 4x10 :) cant say it was cheap though. best cheapest minidsp is still the 2x4 had much fun with those for the price !