Hi More
Did you solve the mystery for matching top and sides ? Also, did your friend use a router for profiling the sides ?
BR
Jean-Louis
Did you solve the mystery for matching top and sides ? Also, did your friend use a router for profiling the sides ?
BR
Jean-Louis
Hi Jean-Louis
He didn´t have any more photos.
I believe he used a bandsaw to cut the sides, and then a belt sander to make them fit exactly.
I am planning to build something quite similar. I will use a template and a flush trim router bit to make 2 cm high side elements which I will join together after cutting.
He didn´t have any more photos.
I believe he used a bandsaw to cut the sides, and then a belt sander to make them fit exactly.
I am planning to build something quite similar. I will use a template and a flush trim router bit to make 2 cm high side elements which I will join together after cutting.
Great build, congrats more 10
Some pix on the build and the gig maybe ? Did you encounter some difficulties ?
Jean-Louis
Some pix on the build and the gig maybe ? Did you encounter some difficulties ?
Jean-Louis
JLOP. I am just putting Astos pictures here since he is not so good in English. Read the thread from start.
Of course I did, long ago (;-). Just thought you had build another pair for yourself. Thanks for posting
Horn measurements with beryllium diaphragm in Radian 475PB. Measuread at 0,15,30,45 and 60 degrees horizontally at 1 metre. 15uF in series with the driver.
The dip at 8 kHz is gone.
The dip at 8 kHz is gone.
Is he using subs to bring up the lower end? Did he design a crossover to knock down the peak at 2k and bring up the lower end?
The 8 kHz dip dissapeared "magically" when switching from alu to be diaphragms. Maybe the alu diaphragm wasn't mounted properly. Hopefully I will be able to talk to Asto on the phone later this week, I will have more information then
I believe he will use the measurements to make an active filter. The low end will be enhanced using Linkwitz transform.
This measurement is with both horn and 12 inch drivers at different angles. I believe the purpose of this measurement is to verify the filter.
The filter is active 48 db at 800 Hz.
The filter is active 48 db at 800 Hz.
I talked to Asto today. When mounting the Be diaphragm he used a 1 khz signal generator. The diaphragms are very sensitive to how much torque are used on each screw. The diaphragm frame is probably a bit too weak.
Asto is very happy with the horn. Very detailed indeed.
The horizontal wave shape is almost identical from the horn and the basses, integrating beatifully.
Tuning the box to start rolling off at 60 Hz makes drums sound very hard. Most probably there will be subs added later.
Asto is very happy with the horn. Very detailed indeed.
The horizontal wave shape is almost identical from the horn and the basses, integrating beatifully.
Tuning the box to start rolling off at 60 Hz makes drums sound very hard. Most probably there will be subs added later.
On this measurement Asto has inverted the horn in order to evaluate how well the units integrate at crossover frequency. He wants to reach a 30 dB dip, so he needs to change the delay somewhat. The measurement is made with 15 degree increase horizontally.
[Be] is Just Better
The notch in the frequency response is due to a primary breakup mode of the aluminum diaphragm. The following comparison of diaphragm materials will make clear why the notch disappeared.
Aquamarine and emerald are precious forms of the mineral beryl, [Be3Al2(SiO3)6] from which the element beryllium (Be) is extracted.
The acoustical superiority of beryllium as a diaphragm material can be clearly seen when its mechanical properties are compared to those of titanium (Ti) and aluminum (Al)
For a given diaphragm size and geometry:
a) Sound Velocity
(for longitudinal waves),
determines at what frequency the first breakup mode occurs.
[Be] 12,890 m/s
[Al] 6,420 m/s
[Ti] 6,070 m/s
b) Density
determines moving mass for a given diaphragm size
[Be] 1.85 g/(cm^3)
[Al] 2.70 g/(cm^3)
[Ti] 4.51 g/(cm^3)
c) Rigidity Modulus
determines how well the diaphragm resists deformation (stiffness)
[Be] 132 GPa
[Al] 26 GPa
[Ti] 44 Gpa
Regards,
WHG
The notch in the frequency response is due to a primary breakup mode of the aluminum diaphragm. The following comparison of diaphragm materials will make clear why the notch disappeared.
Aquamarine and emerald are precious forms of the mineral beryl, [Be3Al2(SiO3)6] from which the element beryllium (Be) is extracted.
The acoustical superiority of beryllium as a diaphragm material can be clearly seen when its mechanical properties are compared to those of titanium (Ti) and aluminum (Al)
For a given diaphragm size and geometry:
a) Sound Velocity
(for longitudinal waves),
determines at what frequency the first breakup mode occurs.
[Be] 12,890 m/s
[Al] 6,420 m/s
[Ti] 6,070 m/s
b) Density
determines moving mass for a given diaphragm size
[Be] 1.85 g/(cm^3)
[Al] 2.70 g/(cm^3)
[Ti] 4.51 g/(cm^3)
c) Rigidity Modulus
determines how well the diaphragm resists deformation (stiffness)
[Be] 132 GPa
[Al] 26 GPa
[Ti] 44 Gpa
Regards,
WHG
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Its a Gasket
This no different in concept than the bolting down the heads of an automobile engine which are sitting atop resilient gaskets. Like the engine, the issues are of warp and seal. If you have an air leak in the compression driver, output dies, If you warp the compression driver end cap or over compress the 'frame" (gasket), you change diaphragm clearances. The "frame" serves as a gasket and anchor of the diaphragm suspension and it gains "strength" when it is under uniformly distributed compressive force of an appropriate magnitude. Note also, that when bolting up the horn to the driver, us a similar torque-down procedure.
Regards
WHG
This no different in concept than the bolting down the heads of an automobile engine which are sitting atop resilient gaskets. Like the engine, the issues are of warp and seal. If you have an air leak in the compression driver, output dies, If you warp the compression driver end cap or over compress the 'frame" (gasket), you change diaphragm clearances. The "frame" serves as a gasket and anchor of the diaphragm suspension and it gains "strength" when it is under uniformly distributed compressive force of an appropriate magnitude. Note also, that when bolting up the horn to the driver, us a similar torque-down procedure.
Regards
WHG
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