Dear All,
many thanks for the kind words! It was a lot of work...
Pico, your mention of rubberbands and exchanging body fluids does strange things with my phantasy...
In order to overcome this, just let me mention that the wires are from dyneema, high SWL and no stretch nor creeping. The arrangement weighs around 54 kg, and the adjustment of the wires had to be pretty precise.
But, as this is a gallery, I could open a thread with more details behind these speakers, should there be any interest.
All the best
Mattes
many thanks for the kind words! It was a lot of work...
Pico, your mention of rubberbands and exchanging body fluids does strange things with my phantasy...
In order to overcome this, just let me mention that the wires are from dyneema, high SWL and no stretch nor creeping. The arrangement weighs around 54 kg, and the adjustment of the wires had to be pretty precise.
But, as this is a gallery, I could open a thread with more details behind these speakers, should there be any interest.
All the best
Mattes
I assume the sheer mass eliminates noticeable swinging, when playing bass heavy recordings.
Other than a very high coolness factor, is there a benefit to doing the tweeters like this, too?
I ask, because I've done a no baffle with horns and 15" woofers.
I'm curious to try a mod suspending just the woofers, and fixing the horns to a frame/ speaker mast.
Other than a very high coolness factor, is there a benefit to doing the tweeters like this, too?
I ask, because I've done a no baffle with horns and 15" woofers.
I'm curious to try a mod suspending just the woofers, and fixing the horns to a frame/ speaker mast.
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Hi MIT,
that´s one point where I might not be 100 % with Michael, who has, by the way, a nice theory why that works. Without beeing in contrary to his approaches, I at one point decided to add a 22kg weight to the already 20 kg (with the double magnet) AE 18, this is the polished stainless steel part at the rear of the magnet. This made an astonishingly large difference, as the relation of masses has doubled.
Free swinging bass driver is a very interesting approach to try out, but nude driver simly produced not enough SPL for me, hence the "minimum" baffle (OK... it´s 93 cm largest diametre...). The baffle is decoupled from the driver with sorbothane, and material and 3-dimensional form was choosen to minimise all baffle effects. I have not sincerely measured it, but the difference was more than 10 dB in the lower registers, IIRC.
But why let only the bass driver swing? I think advantages are also to be gained with a "full swing".
The supertweeters are just there to correct the power response a little bit. The Fertin has - with correction - no problems to go to 16-18 kHz on axis, but of course not from behind. This is partly corrected by the wide dispersion rear tweeter (starting around 6 kHz), and position and upwards angle seemed to correspond best with my room and speaker position. These are easy experiments - the supertweeter was by far one of the cheapest elements in the design. First it was just incorporated to find out if it´s worth going in that direction, but then it simply stayed...
Looking forward to hear of your free-swinging impressions!
All the best
Mattes
that´s one point where I might not be 100 % with Michael, who has, by the way, a nice theory why that works. Without beeing in contrary to his approaches, I at one point decided to add a 22kg weight to the already 20 kg (with the double magnet) AE 18, this is the polished stainless steel part at the rear of the magnet. This made an astonishingly large difference, as the relation of masses has doubled.
Free swinging bass driver is a very interesting approach to try out, but nude driver simly produced not enough SPL for me, hence the "minimum" baffle (OK... it´s 93 cm largest diametre...). The baffle is decoupled from the driver with sorbothane, and material and 3-dimensional form was choosen to minimise all baffle effects. I have not sincerely measured it, but the difference was more than 10 dB in the lower registers, IIRC.
But why let only the bass driver swing? I think advantages are also to be gained with a "full swing".
The supertweeters are just there to correct the power response a little bit. The Fertin has - with correction - no problems to go to 16-18 kHz on axis, but of course not from behind. This is partly corrected by the wide dispersion rear tweeter (starting around 6 kHz), and position and upwards angle seemed to correspond best with my room and speaker position. These are easy experiments - the supertweeter was by far one of the cheapest elements in the design. First it was just incorporated to find out if it´s worth going in that direction, but then it simply stayed...
Looking forward to hear of your free-swinging impressions!
All the best
Mattes
Mattes
that's original, really impressive. who would have thought to combine flower with loudspeaker
my on progress OB, 4 way active dsp, i also had an idea on less vibration on the fullrange but not string, just separate the baffle
my design is not original, OB fans should have nown where i got te inspiration from, but i adopted the shape to my local culture
that's original, really impressive. who would have thought to combine flower with loudspeaker
my on progress OB, 4 way active dsp, i also had an idea on less vibration on the fullrange but not string, just separate the baffle
my design is not original, OB fans should have nown where i got te inspiration from, but i adopted the shape to my local culture
Attachments
-yes, this gets the oh-so-rare emoji:
..even more-so with this information:
https://www.diyaudio.com/forums/ful...v-aer-lowther-feastrex-etc-4.html#post5519254
Hi,
again, thanks to you all for the kind words.
Gadut, separation of baffles is a good thing. I did it before the full swing for evaluation, let´s see if I have some photos here... ok, this was a prototype for shape and separation trials, by that time with a TB 1808 (pretty good for the money). Separation was done with sorbothane pads. Another possibility is to fully disconnect the baffle from the drivers, given driver are magnet mounted on a backbone. A gap of a millimetre doesn´t do anything evil, the impact is very small. Also in the flower pictures you´ll see the gap between the suspensionless FERTIN and the baffle of about 1 mm.
Scott, thanks for linking that description of the FERTIN and your kind words. Sadly, that thread is now dead since a long time, never heard anything again from Dan´s experiments. I still stand to my words - the FERTIN 21M8EX is difficult to tame (look at the filter below...), very expensive, critical to anything upstream... but I still like it best. For a lot less money, an EMS 21LBII brings you almost there...
All the best
Mattes
again, thanks to you all for the kind words.
Gadut, separation of baffles is a good thing. I did it before the full swing for evaluation, let´s see if I have some photos here... ok, this was a prototype for shape and separation trials, by that time with a TB 1808 (pretty good for the money). Separation was done with sorbothane pads. Another possibility is to fully disconnect the baffle from the drivers, given driver are magnet mounted on a backbone. A gap of a millimetre doesn´t do anything evil, the impact is very small. Also in the flower pictures you´ll see the gap between the suspensionless FERTIN and the baffle of about 1 mm.
Scott, thanks for linking that description of the FERTIN and your kind words. Sadly, that thread is now dead since a long time, never heard anything again from Dan´s experiments. I still stand to my words - the FERTIN 21M8EX is difficult to tame (look at the filter below...), very expensive, critical to anything upstream... but I still like it best. For a lot less money, an EMS 21LBII brings you almost there...
All the best
Mattes
Attachments
That's a lot of crossover. Active and biamplification would be my choice.
Otherwise great looking speakers, congrats.
Otherwise great looking speakers, congrats.
Found right here at DIYAudio.
Look for XSim. Easy to understand and just by playing with parts, it will teach you how things work.
Hi Mattes,
your speakers really look terrific! Congrats!
And I'm very impressed about the level of detail on which you optimized them to your ideas.
However, I have some questions.
As you state, that it is a form-follows-function design with no gimmicks, I would really be interested in how exactly the very special shape of the baffles works. I think, I have a rough idea, but it would be great, if you could give as more insights in how you developed it to exactly what it is, which sources (of knowledge) you used and of cause, measurements would be great
2nd question: I've seen you already used the Acoustic Elegance Dipole 18 Woofer in your prototype speakers, so you seem to be happy with them.
What do you think about them? Did you compare them with alternative solutions? And have you always been satisfied with them in terms of max SPL at the lowest frequencies?
I'm short before buying them as well for my open baffle project, but I'm unsure if one per side is sufficient or if I need two of them.
Thanks and best regards
Matthias
Hi Carl,
Perceval has answered the program question already, but this is only a first step. You´ll clearly need measurements and therefore several handfuls of coils, caps and resistors...
and that´s how I do it. With a little experience it´s not that much guesswork, but I first need a good handful of crossover elements and a mic and REW. The finetuning of a crossover is a personal, subjective and questionable process incorporating, taste, room, synergy, mood, quality of red wine sipped... and I do it by ear. Just for me alone, without the need to sell or prove anything to anyone... now that´s a big relief after having it done for money as well in former years.
All the best
Mattes
Hi Adason,
I´ve tried several active approaches in history, and also with these speakers, using high-class DSPs and DACs. It was fine for 48 hours, then I returned to the passive filter. Don´t ask me why... active measures easily better, but somehow...
The filter used now looks more complicated than it is, due to the fact that it´s balanced.
All the best
Mattes
I´ve tried several active approaches in history, and also with these speakers, using high-class DSPs and DACs. It was fine for 48 hours, then I returned to the passive filter. Don´t ask me why... active measures easily better, but somehow...
The filter used now looks more complicated than it is, due to the fact that it´s balanced.
All the best
Mattes
Hi Matthias,
your questions will easily open up a longer discussion (not that I´m afraid of it...), and I think it´s better to split off same from here.
Anybody else interested?
The AE 18 is, in short, not perfect, but I haven´t found any alternatives giving 25 Hz in a reasonably sized baffle with a reasonable efficiency (around 85-87 dB in this case) with a passive filter and no DSP. If you sacrifice one octave in the bass, you gain 6 dB efficiency...
The AE 18 needs a lot of power. I found that the AD 1830 is a pretty good alternative, does (depending on baffle of course) around 90 dB and goes down to around 40 Hz. If that´s OK for you, you can save a lot of money (I even might have a pair to sell from experiments). If you want to go lower, you pay a lot more, or go active.
However, the AE 18 is a quite good driver. I pimped it with a second magnet to get the Qts to 0,66 instead of 0,81, prefer it that way.
To find out if it´s loud enough is difficult - room, amp, and how loud? I DO LOVE to listen to Jonas Hellborg´s Silent life. My SPL metre shows something between 100 dB and 107 dB peaks at listening position, amps full force, maybe 700 watts in 3 Ohms per side... it´s bloody loud!
All the best
Mattes
your questions will easily open up a longer discussion (not that I´m afraid of it...), and I think it´s better to split off same from here.
Anybody else interested?
The AE 18 is, in short, not perfect, but I haven´t found any alternatives giving 25 Hz in a reasonably sized baffle with a reasonable efficiency (around 85-87 dB in this case) with a passive filter and no DSP. If you sacrifice one octave in the bass, you gain 6 dB efficiency...
The AE 18 needs a lot of power. I found that the AD 1830 is a pretty good alternative, does (depending on baffle of course) around 90 dB and goes down to around 40 Hz. If that´s OK for you, you can save a lot of money (I even might have a pair to sell from experiments). If you want to go lower, you pay a lot more, or go active.
However, the AE 18 is a quite good driver. I pimped it with a second magnet to get the Qts to 0,66 instead of 0,81, prefer it that way.
To find out if it´s loud enough is difficult - room, amp, and how loud? I DO LOVE to listen to Jonas Hellborg´s Silent life. My SPL metre shows something between 100 dB and 107 dB peaks at listening position, amps full force, maybe 700 watts in 3 Ohms per side... it´s bloody loud!
All the best
Mattes