Afterrmarket diaphragm for 2420? Radian? [Archive]

Don C

09-27-2016, 10:33 AM

Google translate says:

Compression driver Comparison Test on JBL 2342 Horn
JBL 2426H vs JBL 2426H / RadianAlu vs Radian 475BePB
www.behringer-electric.de
Phone +49 09305 495
1 of 14

Radian Audio 475BePB vs JBL 2426H vs JBL 2426H / Radian 1225-8
Again and again we are asked to "measurements" of our Radian 475BePB driver.
Therefore and because AS is not fully spread good of Radian
475BePB really is, we decided to make some "measurements" times.
In the following test we have the Radian 475BePB with probably the best-selling
Premium 1 inch driver ever, the JBL 2426H compared.
Next, compared with a JBL2426H Radian 1225 aluminum membrane. Alu sounds
known better than titanium.
Measurements were made at a JBL 2342 horn, a Bi-Radial horn with 100x100 °
Radiation and the "little" brother of the JBL 2344th
Why this Horn? We have a couple of them here and it's a good horn.
..... We tried the measurements -wertfrei- commenting .....

1. RADIAN 475BEPB WITH BERYLLIUM REED 2
2. JBL 2426H 3
3. JBL 2426H WITH RADIAN 1225 ALUMINUM DIAPHRAGM 4
4. HORN 5
5. MEASURING FREQUENCY RESPONSE 6
6. MEASURING IMPEDANCE 8
7. MEASURING DISTORTION AT 90DB (THD, K2, K3 AND K5) 10
8. MEASURING WATERFALL 12
9. CONCLUSION 14

1. Radian 475BePB with beryllium membrane
- 1.75 inch beryllium diaphragm with polymer suspension
- Ferrite magnet system
- Weight 2.9kg
- Field strength 1.88 Tesla
- 3 slit phase plug
- 1 inch exit
- Price 550 € / piece (as of 08/2015)
Particularities:
Copper shorting ring on the pole resulting in a higher frequencies hardly
increasing impedance results.

2. JBL 2426H
- 1.75 inch titanium diaphragm with patented diamond pattern suspension
- Ferrite magnet system
- Weight 4.3 kg
- Field strength of 1.8 Tesla
- 3 slit phase plug
- 1 inch exit
- Price € 549 / piece (as of 08/2015)
Particularities:
Pole with copper coated which is hardly growing at a higher frequencies
Impedance results.

3. JBL 2426H with Radian 1225 aluminum membrane
- 1.75 inches inches Radian aluminum membrane with polymer suspension
- Ferrite magnet system
- Weight 4.3 kg
- Field strength of 1.8 Tesla
- 3 slit phase plug
- 1 inch exit
- Price € 549 / piece (as of 08/2015) + Radian membrane
Particularities:
Pole with copper coated which is hardly growing at a higher frequencies
Impedance results.

4. Horn
JBL 2342 Horn
- Material structural foam injection molding
- Bi-Radial horn with 100 ° x 100 ° beam (HxV)
- Discontinued

5. Measurement Frequency Response
Red = JBL2426 with titanium diaphragm Brown = JBL2426 with aluminum membrane Blue = 475BePB
All drivers same smoothing = 1/24 octave !!
The JBL is slightly deeper coupled with titanium and aluminum membrane. At least from
Frequency response starting.
It is striking that the 475 and the 2426 / aluminum one over the entire frequency band
show much quieter than the course 2426 / titanium.
The 475 has the high range up to 10dB more level, but is expected to slightly heavier
be equalized.
The excess titanium membrane in the range 15kHz - 20kHz is a (harmful)
Resonance of the diamond pattern suspension which is then also in the waterfall and THD
Diagram looks.
Here, the frequency response in detail from 1.5kHz (same smoothing):

Yet clear here, the frequency response in detail from 5 kHz (WITHOUT smoothing):
Clearly "fidgeting" with aluminum and titanium
The individual peaks and peaks are in section 6. Measurement Impedance
considered in more detail.

6. Measurement Impedance
475BePB
Total impedance than the JBL and JBL / Radian driver. Genuine 8 Ohm driver.
Peaceful course moderate response in the listening area to 1.5kHz
2 tiny resonances at 12kHz and 18kHz, waterfall and THD measurement are clean. The
12kHz disorder seen in the frequency response measurement, but is not critical
2426 / Radian Alu
In fact, a 4 ohm driver
Very quiet course, poor response in the listening area to 1.2kHz

In fact, a 4 ohm driver
Moderate resonance in the listening area to 1.2kHz
2 small, measurable and audible resonances at 3.5kHz and 7 kHz, see waterfall, THD and
Frequency Response Measurement
For all drivers, the impedance control is with the treatment of pole effect.
The impedances remain flat until the Höchstton area.

7. Measurement distortion at 90dB (THD, k2, k3 and k5)
475BePB
Blue = THD Red = K2 = K3 Violet Green = k5
THD from 1kHz to -48dB or 0.4% very quiet uniform course without interference
2426 / Radian Alu
Blue = THD Red = K2 = K3 Violet Green = k5
THD barely higher than the 475, minimal unruhigerer course without interference
Includes a correspondingly larger Horn also below 1 kHz usable

Blue = THD Red = K2 = K3 Violet Green = k5
THD total higher than aluminum and beryllium to -45dB or 0.56% and from 2 kHz yet
ascending, unruhigerer course with disorders at 1.2 kHz, 3.5 kHz and 6 kHz from

8. Measurement waterfall
475 BePB
2426 / aluminum
2426 / Titan
475 BePB
2426 / aluminum
2426 / Titan
As expected, with obvious benefits for beryllium drivers.
The Radian membrane in 2426 reflected amazingly well!
Compression driver Comparison Test on JBL 2342 Horn
JBL 2426H vs JBL 2426H / RadianAlu vs Radian 475BePB

9. Conclusion
All 3 drivers are undoubtedly very good driver.
If someone is having a JBL 2426 is strongly encouraged this with the Radian
revalue aluminum membrane.
Sonically and metrologically this membrane is clearly ahead of the original titanium diaphragm.
Titan has no place precisely in the audio sector.
Yet gained a lot of places 475BePB with beryllium diaphragm. that beryllium
sound not to beat is has by now spread. Metrologically
the 475BePB also presented flawlessly.
Genuine and resonance-free treble to over 20kHz is not possible without Beryllium.
Also seen from the price, the decision is easy.
RADIAN with BERYLLIUM.
still hesitates who?