Waveguides and horns

[_Wim_]

Originally Posted by jzagaja

Respect

Thanks!

I will make all source code open source, and executables will also be posted. The pcb is very simple (see circuit attached). The only "difficult" thing for DIYers will be programming the PIC and finding a suitable motor cheaply.

I found a PITMANN motor on Ebay with a reduction of 63 and a 256 inc encoder for 30 €. Maxon motors with quadrature encoder show also up every now and then. For bearing I used one of these: Drehkranz Drehlager Drehteller Drehscheibe Ø 330 mm | eBay

remark: I have no affiliation with this seller. I just posted this because it’s ideal to make an automated rotary table.
This should allow many people there to build an automated rotary table.

[_Wim_]

Originally Posted by gedlee

Same here - nice job. Would you sell me one? What kinds of loads will it take? That usually ends up being the problem.

One suggestion. I do not test at equal intervals, its better to have more forward resolution than aft. But typing in the numbers would also be a pain. Could a numerical table be setup where one just clicks a button and it goes to the next value in the table? That coupled with HolmImpulse would be exceptional.

I may even make my polar mapping program available and for the first time in history we could all be looking at very high resolution and accurate polar data that is done the same way and hence comparable.

To avoid going to much of topic, I will create a new thread in the section "Equipment & Tools "

Please post any questions there, then all information will be grouped.

See DIY Automated rotary table for automatic polar measurements

[jzagaja]

Beyma 12BR100 close-ups.

[jzagaja]

Measured t/s:

Fs = 31 Hz
Re = 6.2 ohms[dc]
Le = 0.87 mH
Qt = 0.36
Qes = 0.37
Qms = 11.11
Mms = 80.5 grams
Rms = 1.4 kg/s
Cms = 334 um/N
Vas = 132 liters
Sd= 530 cm^2
Bl = 16.2 Tm
ETA = 0.99 %
Lp(2.83V/1m) = 93.2 dB

Added Mass Method:
Added mass = 32.00 grams
Diameter= 26.00 cm

[jzagaja]

This translates to 5Hz lower -3dB point against 12BR70. I will be making another Mummy (Ferrari Red) with 12BR100 and DE500 and compare with BMS 4524+12BR70.

[DJNUBZ]

Originally Posted by jzagaja

This translates to 5Hz lower -3dB point against 12BR70. I will be making another Mummy (Ferrari Red) with 12BR100 and DE500 and compare with BMS 4524+12BR70.

I am looking forward to this, these are the drives I want to try myself in these enclosure.

[jzagaja]

Distortion figures without taking care of mounting i.e. speaker lies on a carpet. Voltage is 2,87Vpp measured at 50Hz.

[Tytte71]

Originally Posted by jzagaja

Distortion figures without taking care of mounting i.e. speaker lies on a carpet. Voltage is 2,87Vpp measured at 50Hz.

Can you show measurements with the driver in a baffle raised clear of the carpet ... including off-axis behaviour?? . Also impedance and time domain measurements is interesting to see!

[jzagaja]

Will try. In the meantime impedance.

[jzagaja]

Compared to 12BR70.