I am sure this is the best way to mount a woofer and a midrange. I attach three tech. papers written by Siegfried Linkwitz, Andrew Jones and Michael Gerstgrasser. I'm applying this concept with my Dipole-18.
I would expect the bass drivers to be moving around quite a bit. Even in a box, they move, and in a subwoofer you really need to go to push-push (active reactive force cancellation) to (mostly) eliminate it.
If the bass driver moves at all you are probably losing low level detail (DDR).
dave
I use duct seal for the same purpose, and for smoothing the shape of the basket/magnet.
dave
Those are some of the most incredible open baffle speakers ever made. I had pleasure to hear them in a few high end studios, at NYC AES 2019. The bass is extremely clean, fast, precise, and dynamic. Controlled and tuned to any room by DSP. Also, at NAMM 2020 heard those with an open baffle subwoofer (4x18" drivers). The amount, depth, and quality of bass is gut shuttering:
www.http://reflector.audio/
www.http://reflector.audio/
Fixed link:
Reflector audio
From their homepage:
Arguably the best two-way speakers ever made
I would probably add:
Arguably the least WAF friendly speakers ever made.
😀
Reflector audio
From their homepage:
Arguably the best two-way speakers ever made
I would probably add:
Arguably the least WAF friendly speakers ever made.
😀
AndrewJones: "...If however the magnet is freely suspended then it will accelerate in a direction opposite to the diaphragm, and with a magnitude in inverse proportion to the mass ratio."
Yup. There you have the effect of Newton's Third Law as Variac and I suspected.
Yup. There you have the effect of Newton's Third Law as Variac and I suspected.
Hi,
of course Mr. Newton´s invention is still valid... and can easily be calculated by ratio of masses. The difference between suspended mounting and rigid mounting of large bass drivers is that in the first case you´re loosing a little bit of efficiency - Mr. Jones has shown how little - and in the second case you´re stimulating all sort of resonances, which are realistically hardly controllable, even with a very heavy box or baffle.
Therefore, flying the bass driver as proposed by Michael is a very nice alternative - of course push-push is also a valid way to reduce resonances.
I´m also flying my dipole 18 since some time, but have - in order to reduce the efficiency loss - added a "counterweight" to the double magnet. The magnet/basket structure now weighs 44 kg, against app. 180 gr moving mass, which is a ratio of 1/244, more than double the ratio of Mr. Jones experiments linked above.
I´m very happy with the results and have stopped here - after many many years - for now with any attempts for more or better bass...
All the best
Mattes
Attachments
https://www.diyaudio.com/forums/multi-way/123512-ultimate-baffle-gallery-192.html#post4676264
re approached onda ligera, wonder if these bankrupt reflector audio too?
Hi Mattes,
In addition to your moving mass/44 kg ratio, I see that you also have a substantial wiring harness coming out of your floor that I would think adds stability to the system.
After reading this whole thread, when judging "Ultimate" OBs I would put yours is in the top 3! My judging criteria gives high marks for originality, aesthetics and execution. I'd like to hear them some day.
All the best!
Hi WBS,
have you really read the whole thread.... respect! And many thanks for your kind words, I´ve put lot of efforts into the design and execution, and I must stress again that the black flowers are a true form-follows-function design, there´s nothing fancy about it (apart from polishing some parts of course, like the counterweight and the Dipole 18 phaseplug…).
A gainst the possible visual impression, the wiring harness contains of very light copper foil cables in cotton insulation for the signals and a light 1mm² silicon cable for the fieldcoil, and is arranged in such way not to add any damping or stability to the system. The baffles are free to move - and do so for some time if touched. Of course some damping still exists, but I would think that the very small movements injected by cone movement are pretty unrestricted, we´re talking much less than a millimetre here.
Of course the system has looked much better without the cables...
The ratio of the fieldcoil fullrange is a lot better than for the bass driver; app. 11gr moving mass against 8,5kg of driver mass, 1/770, app. 3 times better than the bass driver, but adding more than 100kg of additional weight to the bass driver seemed a bit unpractical.
An even better approach would have been to let go the baffles, and I have of course tried this as well, but this has reduced efficiency too much. The compromise was to have the baffles in the least restrictive form - the flowers - and in the least restrictive material, EVA foam of 100kg/m³, as this stuff doesn´t resonate and has a non-reflective surface (feels like suede).
Of course you´re invited to hear them, but sadly, the world has turned very large since a few weeks. I was used to work worldwide, now I´m sitting here... let´s see what the future brings.
All the best
Mattes
have you really read the whole thread.... respect! And many thanks for your kind words, I´ve put lot of efforts into the design and execution, and I must stress again that the black flowers are a true form-follows-function design, there´s nothing fancy about it (apart from polishing some parts of course, like the counterweight and the Dipole 18 phaseplug…).
A gainst the possible visual impression, the wiring harness contains of very light copper foil cables in cotton insulation for the signals and a light 1mm² silicon cable for the fieldcoil, and is arranged in such way not to add any damping or stability to the system. The baffles are free to move - and do so for some time if touched. Of course some damping still exists, but I would think that the very small movements injected by cone movement are pretty unrestricted, we´re talking much less than a millimetre here.
Of course the system has looked much better without the cables...
The ratio of the fieldcoil fullrange is a lot better than for the bass driver; app. 11gr moving mass against 8,5kg of driver mass, 1/770, app. 3 times better than the bass driver, but adding more than 100kg of additional weight to the bass driver seemed a bit unpractical.
An even better approach would have been to let go the baffles, and I have of course tried this as well, but this has reduced efficiency too much. The compromise was to have the baffles in the least restrictive form - the flowers - and in the least restrictive material, EVA foam of 100kg/m³, as this stuff doesn´t resonate and has a non-reflective surface (feels like suede).
Of course you´re invited to hear them, but sadly, the world has turned very large since a few weeks. I was used to work worldwide, now I´m sitting here... let´s see what the future brings.
All the best
Mattes
It depends if you want good dipole behaviour or not
I was expecting something more elaborated : Manichaeism - Wikipedia
To be honest, I didn't read every word. I did however look at all the pictures! 😀
I didn't see a thread documenting your build. Did you start one? I'm especially interested in knowing how the EVA foam is cut and formed and where to source blocks large enough for an 18" woofer.
Hmm, I wonder if my grandson would notice if his EVA foam building blocks went missing.
Indeed, stay safe.
All the best!
Strange case of vanishing posts.....OB and dipole aren't necessarily synonymous, but you probably knew that already 😉
Take that as a warning to not post inflammatory stuff, and only because you make a solid point, that your last post with a comment on moderation has you not cooling your heels again in the doghouse.
dave
For a large driving area, high SPL on low end, and low distortion in medium to large spaces. For smaller spaces they have two woofer version, which BTW, is much more WFA friendly.
My understanding the reflector audio split with onda ligera. They are doing pretty well. Some highest end studios use them as mastering monitors. Because of exceptional linearity and phase integrity they immediately reveal any mix flaws.
I can't be more agree, my one woofer version gives me a flat frequency response at the listening point without any EQ in a tiny bedroom and the THD is impressively low, it is clearly the next step in audio... 🙂faint🙂
ok, modern low dynamic stuff heard from radio can be mixed with what ever.
But yeah, cool speakers. no interest to copy those