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miniDSP Ltd, Hong Kong / 

www.minidsp.com

 / Features and specifications subject to change without prior notice

 

1

 

P

RODUCT 

O

VERVIEW

 

Thank you for purchasing a miniDSP

 EARS

 headphone measurement system. miniDSP EARS is a measurement jig 

for headphones and IEMs (in-ear monitors) that we've built using the same core technology as our extremely 
popular UMIK-1 calibrated speaker and room measurement microphone. 

EARS designed to be a useful and practical tool for headphone enthusiasts. It is ideal to: 

1.

 

Check that your headphones are operating correctly e.g. balance of left/right frequency response. 

2.

 

Take measurements that you can use as a basis for equalizing your headphones. 

3.

 

Observe the effect on frequency response of different earpads and eartips. 

4.

 

Measure the effect of modifications to the headphones. 

5.

 

Compare your headphone measurements with other EARS users. 

Please note that EARS is not an industry-standard measurement head. Even expensive (i.e. tens of thousands of 
dollars) heads can produce measurements that are different to each other. Our goal with the EARS is to produce 
something that is affordable and fun to use! 

Summary of Contents for EARS

Page 1: ...miniDSP Ltd Hong Kong www minidsp com Features and specifications subject to change without prior notice 1 MINIDSP EARS HEADPHONE MEASUREMENT JIG User Manual...

Page 2: ...2 Revision history Revision Description Date 0 1 First draft 12 Sept 2017 0 2 Second draft 15 Sept 2017 0 5 Fifth draft 15 Dec 2017 0 7 Preliminary version OK for public release 17 Dec 2017 1 0 First...

Page 3: ...Measure the other channel 13 2 6 5 Changing the calibration file 14 2 6 6 Measuring at higher SPLs 14 3 More about measurement 15 3 1 The frequency response graph 15 3 2 Other types of measurement 16...

Page 4: ...potential to cause damage to your audio system Please also note that many of the questions we receive at the technical support department are already answered in this User Manual and in the online app...

Page 5: ...nt off and on the user is encouraged to try to correct the interference by one or more of the following measures Reorient or relocate the receiving antenna Increase the separation between the equipmen...

Page 6: ...ne enthusiasts It is ideal to 1 Check that your headphones are operating correctly e g balance of left right frequency response 2 Take measurements that you can use as a basis for equalizing your head...

Page 7: ...particular are susceptible to external noise Even if you cannot hear or are not aware of external noise sources they can still show up in your measurements If you are not getting consistent measuremen...

Page 8: ...er of your EARS unit Table 2 Naming of calibration files for EARS Code Type Channel File name HEQ Over ear headphone Left L_HEQ_xxxyyyy txt HEQ Over ear headphone Right R_HEQ_xxxyyyy txt IDF IEM diffu...

Page 9: ...ots Here is the documentation 2 6 1 Calculate SPL calibration target 1 Work out your SPL calibration target By default this is 40 for headphones and 30 for IEMs a Open one of your calibration files e...

Page 10: ...output and the EARS as the input source Choose the sensitive channel Left in this example for both output and input and set the Sweep Level to 20 dBFS 4 On the Mic Meter tab click on Browse Select the...

Page 11: ...pen the REW SPL Meter window and turn it on the red button at lower right Increase the volume on your headphone amplifier until the dBFS meter lower half of window reads the SPL calibration target In...

Page 12: ...up Close both the Generator and SPL Meter windows 2 6 3 Measure the first channel 11 Press the Measure button top left of the REW main window Set Start Freq to 20 and End Freq to 20 000 Check that Le...

Page 13: ...t Left now 14 On the Mic Meter tab click on Browse Select the other calibration file for the selected channel Make sure that the Mic or Z weighted SPL meter option is set 15 Press the Measure button a...

Page 14: ...measurement thumbnail on the left hand side Then select the correct calibration file 2 6 6 Measuring at higher SPLs If you measure headphones at a reference SPL higher than 84 dB or IEMs at a referen...

Page 15: ...at 4 kHz the SPL is 75 dB as shown by the blue markers overlaid on the graph Underneath the graph is a set of checkboxes usually you will need to display only the amplitude response named Left in this...

Page 16: ...an read off the distortion in percent at any frequency by placing the cursor on the graph then reading off the distortion next to the graph names underneath Impulse EARS is not suited for impulse resp...

Page 17: ...ositions one channel only for an open headphone AKG K702 while Figure 4 shows measurements at five positions for a closed headphone Audeze LCD XC We recommend that you measure your own headphones at s...

Page 18: ...cusPad in red The difference in the bass area is most likely due to the old pads being torn and therefore unable to seal properly Some headphones are very sensitive to the amount of seal and or any pr...

Page 19: ...sides that is don t change the headphone amp volume just check the level and move the IEM out or in a little until the level is close to your reference level Additional notes and things to be aware of...

Page 20: ...s the amplifier s output impedance and Zphones is the headphone s nominal impedance Zamp Zphones 10 20 50 100 Worst case variation dB 1 2 3 6 6 In practice real headphones will have less variation tha...

Page 21: ...l get poor results if you don t use the right type 4 1 RAW VS COMPENSATED RESPONSE When a measurement is made of a headphone with the EARS the raw measurement tends to look something like the green gr...

Page 22: ...g will be required Please follow the guidance in this application note Headphone EQ with EARS and REW 4 3 IEM DIFFUSE FIELD COMPENSATION IDF The IDF compensation for IEMs is intended to equalize an IE...

Page 23: ...owever that for headphone EQ we now recommend the HEQ compensation 4 5 RAW CALIBRATION WITH NO COMPENSATION RAW The RAW calibration files provide only the calibration for the microphone capsules with...

Page 24: ...ue microphone calibration file for each channel referenced to serial number Analog gain DIP switch to select analog gain 0 to 36 dB in 6 dB steps Dimensions H x W x D 250 x 180 x 130 mm 5 2 OBTAINING...

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