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German Maestro GMP 250 (Test report)

Test report - general data headphone German Maestro GMP 250

Frequency response, Impedance, Frequency response with standard AMPs


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Range, dB:

General results German Maestro GMP 250
Channel
Summary (Right + Left)
Sensitivity average in band from 100 Hz to 10 kHz, dB/V
103,8
Impedance average in band from 40 Hz to 15 kHz, ohm
107,8
For 94,0 dB SPL need, VRMS
0,325
For 94,0 dB SPL need, mW
0,979

The table shows a most important technical characteristics of German Maestro GMP 250

*Center channel headphone is received by averaging between left and right channels

Report earlier version
Version report: V1

Reports and testing methodology is gradually updated. We try to generate the report in such a way that it would have been a single kind of report for all devices, convenient for direct comparison.

We constantly introduce new tests and improving the options for displaying graphs and parameters. It introduces different changes in reports. Because reports are generated automatically, the updates do not take much time.

In the development and implementation of new tests, new reports are more complete. To update some charts and tables may require additional time to process the raw data separately for each device.

Some devices require re-testing.


The device was tested for a long time. For a more accurate frequency response, it is necessary to retest at the HDM-X stand. Directly one can compare sensitivity data and impedance characteristics.

This model was tested for a long time and the report does not have the following graphs:

  • Impulse response
  • Step response
  • Impulse Response Envelope (ETC - Energy Time Curve)
  • QSD / Watterfall
  • Delta QSD / Delta Watterfall

The history of the development of the report:
CloseMore detailed
Version report: V1 (Stands: HDM1, SF, SIEC)
  • Frequency response
  • Impedance
  • Sensitivity
  • Electric phase
  • Frequency response of amplifier with constant output resistance
  • Variation in frequency response with amplifiers with constant output resistance
  • Frequency response with an amplifier with zero output resistance and raising of output resistance in low frequencies
  • Variation in frequency response an amplifier with zero output resistance with raising-up of output resistance in low frequencies
  • Perception of headphone frequency response curves of equal loudness ISO 226-2009
Version report: V2 (Stands: HDM-X, SIEC)

Stands HDM1 and SF replaced by HDM-X stand.
Measurements in the extended frequency range 10 - 45000 Hz
  • Impulse response
  • Step response
  • Impulse Response Envelope (ETC - Energy Time Curve)
  • QSD / Watterfall
  • Delta QSD / Delta Watterfall

Test conditions

  • Type of headphones: Over-ear
  • Measurements were performed on the stand:
    • with on the simulator of human head with ears HDM1
  • Calculate headphone's SPL German Maestro GMP 250 taking into amplifier by online calculator based on table's data
  • Headphone: Hi-impedance
  • The type of acoustic design Open




Report content

Detailed measurements report of technical characteristics

Sensitivity headphone German Maestro GMP 250


Graphics setting view
Channel:

  • Type of headphones: Over-ear
  • Measurements were performed on the stand:
    • with on the simulator of human head with ears HDM1
Calculate headphone's SPL German Maestro GMP 250 with the amplifier it is possible in an online calculator based on the data in the table

Sensitivity German Maestro GMP 250
Channel
Left
Right
Sensitivity average in band from 100 Hz to 10 kHz, dB/V
102,8
104,6
Sensitivity at 500 Hz at 1 V, dB
104,3
105,1
Sensitivity at 500 Hz at 1 mW, dB
94,4
95,2
Sensitivity at 1000 Hz at 1 V, dB
104,0
107,0
Sensitivity at 1000 Hz at 1 mW, dB
94,1
97,1

The sensitivity was calculated by data from the measuring stand HDM1



Frequency response headphone German Maestro GMP 250


Graphics setting view
Range, dB:
Channel:

  • Type of headphones: Over-ear
  • Measurements were performed on the stand:
    • with on the simulator of human head with ears HDM1
Frequency response German Maestro GMP 250
Channel
Left
Right
Variation in frequency response in band from 100 Hz to 10 kHz, dB
-8,55, 4,42
-8,02, 6,60

Impedance headphone German Maestro GMP 250


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Channel:

Impedance German Maestro GMP 250
Channel
Left
Right
Impedance average in band from 40 Hz to 15 kHz, ohm
107,8
107,8
Resistance at 500 Hz, ohm
101,0
101,0
Resistance at 1000 Hz, ohm
100,8
100,8
The minimum value in band from 40 Hz to 15 kHz at frequency, Hz
749,8
749,8
The minimum value in band from 40 Hz to 15 kHz, ohm
100,7
100,7
The maximum value in band from 40 Hz to 15 kHz at frequency, Hz
14990,4
14990,4
The maximum value in band from 40 Hz to 15 kHz, ohm
143,4
143,4

Electric phase headphone German Maestro GMP 250


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Range, degree:
Channel:

Electric phase German Maestro GMP 250
Channel
Left
Right
Average variation in phase response in band from 20 Hz to 20 kHz, degree
7,6
7,6
The minimum value in band from 20 Hz to 20 kHz at frequency, Hz
183,1
183,1
The minimum value in band from 20 Hz to 20 kHz, degree
-1,9
-1,9
The maximum value in band from 20 Hz to 20 kHz at frequency, Hz
19682,2
19682,2
The maximum value in band from 20 Hz to 20 kHz, degree
37,0
37,0

Frequency response of amplifier with constant output resistance from headphone German Maestro GMP 250


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Range, dB:
Channel:

Frequency response of headphone German Maestro GMP 250 with amplifier with a constant impedance
Channel
Left
Right
Variation in FR from AMP 0 ohm in band 100 Hz to 10 kHz, dB
-8,55, +4,42
-8,02, +6,60
Variation in FR from AMP 10 ohm in band 100 Hz to 10 kHz, dB
-8,53, +4,54
-7,99, +6,69
Variation in FR from AMP 20 ohm in band 100 Hz to 10 kHz, dB
-8,50, +4,64
-7,97, +6,75
Variation in FR from AMP 50 ohm in band 100 Hz to 10 kHz, dB
-8,45, +4,86
-7,91, +6,91
Variation in FR from AMP 100 ohm in band 100 Hz to 10 kHz, dB
-8,40, +5,10
-7,86, +7,07
Variation in FR from AMP 300 ohm in band 100 Hz to 10 kHz, dB
-8,32, +5,47
-7,78, +7,33

Variation in frequency response with amplifiers with constant output resistance from headphone German Maestro GMP 250


Graphics setting view
Range, dB:
Channel:

Variation in frequency response with amplifiers with constant output resistance from German Maestro GMP 250
Channel
Summary (Right + Left)
With amplifier impedance at 10 ohm in band 20 Hz to 20 kHz, dB
0,3
With amplifier impedance at 20 ohm in band 20 Hz to 20 kHz, dB
0,6
With amplifier impedance at 50 ohm in band 20 Hz to 20 kHz, dB
1,2
With amplifier impedance at 100 ohm in band 20 Hz to 20 kHz, dB
1,9
With amplifier impedance at 300 ohm in band 20 Hz to 20 kHz, dB
3,0

*Center channel is received by data averaging between the left and right channels


Frequency response with an amplifier with zero output resistance and raising of output resistance in low frequencies from headphone German Maestro GMP 250


Graphics setting view
Range, dB:
Channel:

Frequency response with an amplifier with zero output resistance and raising of output resistance in low frequencies from German Maestro GMP 250
Channel
Left
Right
Variation in frequency response in band from 100 Hz to 10 kHz, dB
-8,53, 4,45
-7,99, 6,63

Variation in frequency response an amplifier with zero output resistance with raising-up of output resistance in low frequencies from headphone German Maestro GMP 250


Graphics setting view
Range, dB:
Channel:

Variance of frequency response German Maestro GMP 250 depending on the total output resistance of the amplifier with zero resistance and a rise of resistance at low frequencies
Variance frequency response at the frequency 20 Hz, dB
-2,0
Variance frequency response at the frequency 40 Hz, dB
-0,7
Variance frequency response at the frequency 80 Hz, dB
-0,2

Perception of headphone frequency response curves of equal loudness ISO 226-2009 from headphone German Maestro GMP 250


Graphics setting view
Channel:

Perception of headphone frequency response curves of equal loudness ISO 226-2009 from German Maestro GMP 250
Channel
Summary (Right + Left)
From level 48 dB at 72 dB SPL in band 100 Hz to 10 kHz, dB
-12,8, +9,0
From level 36 dB at 72 dB SPL in band 100 Hz to 10 kHz, dB
-11,6, +5,9
From level 24 dB at 72 dB SPL in band 100 Hz to 10 kHz, dB
-10,5, +4,3
From level 12 dB at 72 dB SPL in band 100 Hz to 10 kHz, dB
-9,3, +4,7
From level 0 dB at 72 dB SPL in band 100 Hz to 10 kHz, dB
-8,2, +5,2
From level -12 dB at 72 dB SPL in band 100 Hz to 10 kHz, dB
-7,1, +5,7
From level -24 dB at 72 dB SPL in band 100 Hz to 10 kHz, dB
-9,2, +6,2
From level -36 dB at 72 dB SPL in band 100 Hz to 10 kHz, dB
-11,9, +6,7

*Center channel is received by data averaging between the left and right channels




Voltage levels from the load at the output of the amplifier of German Maestro GMP 250 headphone