I m following this and needed to say, I looked into DAS drivers and although they have dealers in U.S but the ones I contacted only have PA equipment and not the drivers, they said they might be able to order the drivers as replacement part but i think it's more likely that it would be expensive since they are not selling speakers. So having both Faital and DAS options would be nice.
Summary post -- woofer selection
This is just a summary post to clean up the first post of the thread in order to make room for a list of sponsors that provided financial support to the Monkey Coffin project (here).
Below is the list of woofers that we considered so far. We concluded that the Faital 12PR320 and the D.A.S. Audio 12P would be the most suitable candidates.
12" woofer candidates:
10" woofer candidates:
This is just a summary post to clean up the first post of the thread in order to make room for a list of sponsors that provided financial support to the Monkey Coffin project (here).
Below is the list of woofers that we considered so far. We concluded that the Faital 12PR320 and the D.A.S. Audio 12P would be the most suitable candidates.
12" woofer candidates:
- Beyma SM-212 -- see also post 15
Qms=5.3, Xmax=±8.25 mm, Le=0.6 mH
AJ Horn: BR 70L/80cm²/110mm, f3=42 Hz, 97.5 dB/2.83V/1m/2pi - Beyma 12G40
Qms=11.6, Xmax=±5 mm, Le=2.1 mH
AJ Horn: BR 48L/80cm²/120mm, f3=49 Hz, 97 dB/2.83V/1m/2pi - Beyma 12LX60V2
Qms=15.3, Xmax=±9 mm, Le=2.1 mH
AJ Horn: BR 40L/80cm²/192mm, f3=44 Hz, 95.5 dB/2.83V/1m/2pi - D.A.S. Audio 12P -- see also post 46
Qms=10.13, Xmax=±6 mm, Le=1.6 mH @ 1 kHz
AJ Horn: BR 65L/80cm²/125mm, f3=42 Hz, 96.5 dB/2.83V/1m/2pi - Eighteen Sound 12NLW9300 ?
Qms=4.67, Xmax=±8 mm, Le=0.49 mH @ 1 kHz
AJ Horn: BR 28L/80cm²/190mm, f3=57 Hz, 97.5 dB/2.83V/1m/2pi - Eminence Impero 12-A -- see also post 42
Qms=13.8, Xmax=±6.2 mm, Le=1.64 mH
AJ Horn: BR 55L/100cm²/145mm, f3=46 Hz, 97 dB/2.83V/1m/2pi - Eminence Kappalite 3012LF Neo
Qms=6.94, Xmax=±9.1 mm, Le=0.98 mH
AJ Horn: BR 64L/100cm²/180mm, f3=41 Hz, 96.5 dB/2.83V/1m/2pi - Eminence LA12850
Qms=6.94, Xmax=±5 mm, Le=0.96 mH
AJ Horn: BR 43L/100cm²/163mm, f3=51 Hz, 97 dB/2.83V/1m/2pi - FaitalPRO 12PR320
Qms=7.8, Xmax=±7.37 mm, Le=0.67 mH
AJ Horn: BR 70L/80cm²/120mm, f3=41 Hz, 97 dB/2.83V/1m/2pi - FaitalPRO 12HP1010
Qms=9.4, Xmax=±9.25, Le=1.33 mH
AJ Horn: BR 42L/80cm²/145mm, f3=48 Hz, 96 dB/2.83V/1m/2pi - Fane SOVEREIGN PRO 12-300 -- DISCONTINUED!!!
Qms=5.2, Xmax=±4.5 mm, Le=1.64 mH - Fane SOVEREIGN PRO 12-500
Qms=3.04, Xmax=±6 mm, Le=1.6 mH
AJ Horn: BR 66L/100cm²/127mm, f3=44 Hz, 97.5 dB/2.83V/1m/2pi
10" woofer candidates:
- Beyma SM-110/N
Qms=7.88, Xmax=±4 mm, Le=1.7 mH
AJ Horn: BR 47L/50cm²/105mm, f3=41 Hz, 95 dB/2.83V/1m/2pi - Beyma 10G40
Qms=7.1, Xmax=±7 mm, Le=0.6 mH
AJ Horn: BR 24L/50cm²/160mm, f3=48 Hz, 94.5 dB/2.83V/1m/2pi - Beyma 10WR300
Qms=3.9, Xmax=±6 mm, Le=1 mH
AJ Horn: BR 32L/50cm²/125mm, f3=49 Hz, 95 dB/2.83V/1m/2pi - Ciare FXE 10-2.5
Qms=11.21, Xmax=±6 mm, Le=0.68 mH
AJ Horn: BR 30L/50cm²/170mm, f3=42.5 Hz, 94 dB/2.83V/1m/2pi - Fane SOVEREIGN PRO 10-300SC
Qms=10.13, Xmax=±4.75 mm, Le=1.27 mH
AJ Horn: BR 28L/50cm²/162mm, f3=45 Hz, 95 dB/2.83V/1m/2pi - Monacor SP-10/250PRO
Qms=6.16, Xmax=±7 mm, Le=0.83 mH
AJ Horn: BR 26L/50cm²/172mm, f3=49 Hz, 93.5 dB/2.83V/1m/2pi - Supravox 215 GMF (9")
Qms=6, Xmax=±5 mm (?), Le=1.4 mH @ 1 kHz
AJ Horn: BR 62L/50cm²/65mm, f3=48 Hz, 97 dB/2.83V/1m/2pi
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Just donated a bit, almost halfway now.
Hope we can get this thing together soon.
Thanks! The campaign is well under way, but we still need s bit more cash. Help us getting off the ground here!
I am a big fan of the VM752 dome, so I would really like to use it. All the Monkey Coffin simulations so far were done based on the VM752. Looking at the M5N8-80 specs I see a rather low Qms (high mechanical losses). This does not scream "I am good at low level detail resolution".
I have now ordered the woofers. D.A.S. 12P was in stock and I got a good price from the local distributor. Faital 12PR320 was indicated to be in stock, but turned out it wasn't. I hope I have them sometime soon after the holidays. The money should be enough to build an enclosure or two for them, but we'll need a bit more for the filter parts. Maybe it's good to measure the drivers in box first and have a second run of simulations with these data for the filters.
It should be a good thing to measure the drivers also on a large IEC baffle, if you should have the opportunity to do so. Together with the measured impedance, good infinite baffle models can be made for simulation. And the impact of the enclosure diffractions can be seen very well, by comparing the infinite baffle and the ‘in cabinet’ curves. I have installed a 225Hz IEC baffle and do it that way.
Important is to have accurate impedance measurements on baffle or in free air (almost the same) to obtain correct TSP values. Without the SPL measurement on IEC baffle, I can derive also the infinite baffle model out of the cabinet measurements and the TSP. It is not so accurate, but possible.
Important is to have accurate impedance measurements on baffle or in free air (almost the same) to obtain correct TSP values. Without the SPL measurement on IEC baffle, I can derive also the infinite baffle model out of the cabinet measurements and the TSP. It is not so accurate, but possible.
Would you need IEC measurements of the mid and woofers, or just the mid? At what angles?
Also, what about the tweeter? Any suggestions other than the Santori Be dome? The ScanSpeak Be 6640 will not work, because it is too low impedance and not efficient enough to add a series resistor. The only way out would be a waveguide, but my initial tests with the 6600 (same geometry) were not great. The diameter is too large, given resonances at the horn throat in the audible range (about 16 kHz).
Also, what about the tweeter? Any suggestions other than the Santori Be dome? The ScanSpeak Be 6640 will not work, because it is too low impedance and not efficient enough to add a series resistor. The only way out would be a waveguide, but my initial tests with the 6600 (same geometry) were not great. The diameter is too large, given resonances at the horn throat in the audible range (about 16 kHz).
If possible IEC measurements for the three drivers
. For the simulation I like to make an infinite baffle model for all. In the cabinet there is some cabinet impact visible in the SPL of all the drivers. SPL on axis at 1m and impedance on IEC is enough to make the model. Off axis measurements I don't really need for the simulation. The simulator has its own off axis driver model. Off axis measurements are useful to check the simulation, but I cannot use them in the model. If I measure it, I do it for 0, 15, 30, 45 and 60 horizontal for midrange and tweeter, at least 30 and 60 degrees. Off axis driver measurements in the cabinet are useful, because it is a check of the driver and the cabinet.
I have my doubts if a waveguide for the tweeter is indicated in this design with the 3 inch midrange. Now the power response of the speaker is flat in the simulation. Using the waveguide the power of the tweeter in the application will decrease, because the SPL boost, that the waveguide delivers, has to be filtered, so also the power. I think a waveguide is more recommended in combination with larger midranges, because they have less power above 1.5 - 2 kHz.
Anyway if there is some intention to use a waveguide, a good study is required IMO.
I see your point. However, how good is the LEAP model for the mid dome with its waveguide? I guess we will have to see once we have the drivers and their measured data.
I already mentioned the differences between the Leap model and measurements for the 3 inch midrange with waveguide, see post #88. At this moment, with Leap I have no solution to make a model with measured off axis responses. For off axis simulations a more powerful simulator is required with a better driver and waveguide modeling, like BEM Acoustics for example, something for later...
Edit: The simulated power response of the 3 inch midrange is correct now, but the way the power is radiated in space is not correct in the simulator now. So using a waveguide for the tweeter will affect the power flatness, I still think so. Remark also, that a power measurement is very complex. We have to try to calculate/simulate it in the best way. Comparing off axis measurements of tweeter and midrange is already a good indication for constant power.
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I really like the looks of this ATC EL 150 ! This kind of curved cabinet is not easy to make, but many of us are very talented woodworkers... Should be easy to scale to this project, just keep width approximately same.
ps. I hate those legs...
ps. I hate those legs...
The Sica LP90.28/N92TW is one of very few conventional dome tweeters which is able to keep up with the maximum SPL of the other drivers in the Monkey Box. Bl ~ 4.5 N/A, efficiency ~ 0.6 % and probably no ferrofluid.
diBirama: Sica LP90.28/N92TW
HiFi-Selbstbau:Sica LP90.28/N92TW
That's an interesting driver. However, a quick look at those measurements shows a few suspicious peaks in the impedance curves. SPL response is not as linear as with other tweeters, and the CSD shows a number of resonances. I'll have a closer look when I am back from holidays (reading the tests on my phone is a PITA).
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We already had this discussion in the previous thread(s). The box must be easy to make on everyones kitchen table. Easy peasy rectangular box it is.
My experience with the 3" TangBand dome in a quasi-waveguide much like the VOLT is that they are more directive than you would expect at lower frequency than you would expect. I wouldn't cross the TB above 2.5khz IIRC. OTOH they do have a similar diaphragm diameter to a 12cm woofer, so the directivity shouldn't be unexpected. I think the height of the dome also contributes. Anyway, for smoothest power response you actually have to cross rather low, or use a waveguide on the tweeter.
^A dome, cone and plate all have different radiation characteristics (off-axis). Recession /waveguide makes it's own diffractions to be added...
About box, I just wanted to remind, that box shape/geometry plans can be modified. Changes have some effect to response, mostly to baffle step and diffractions. The constructor must have some understanding and be ready to make changes to xo filters too.
About box, I just wanted to remind, that box shape/geometry plans can be modified. Changes have some effect to response, mostly to baffle step and diffractions. The constructor must have some understanding and be ready to make changes to xo filters too.
For those who are able to make such kind of curved cabinet, it has very good horizontal dispersion characteristics. I did some simulation on it in the past. A classical cabinet like the monkey box has a bafflestep SPL boost which is higher on axis than off axis, in a way the horizontal dispersion is less uniform. A curved front, on the other hand, is much more uniform, the baffle step boost is less and the on and off axis responses are more equal. In other words, the transition between half space and full space is smoother. So, technically the curved cabinet is much better.
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