Equalizing headphones.

As APL FIR solutions offer very detailed equalization possibilities, it is challenge to use them for the equalization of headphones. They tend to be very accurate in terms of small dimensions, have potentially less problems as loudspeakers and „close” connection to us as room is not present. But it is a very well-known fact that the critical work, using headphones, was not reliable because of the sound coloring they caused.

First trials of headphone measurements showed that this task was more complex as it first seemed to be appearing to be impossible to measure them in a way that the result would meet APL`s equalization quality standard. The measurement must be such that the equalizer (predistortions) created is compensated by distortions of particular headphone and no new additional distortions are added. Any sound colorations should also be removed so that headphones can reproduce live sound as naturally as possible without a professional finding any differences between live sound and headphone’s sound.

First APL headphone measurement and equalization trials were conducted in 2007. The APL`s equalization quality standard requirement is now met with many of today’s professionals using APL`s equalized headphones in their everyday work.

The collection of headphone measurements is showing real world of headphone's problems. Even two drivers of one headphone pair are not similar and every one of them needs to be equalized for critical (sound engineering) work. Sound quality enthusiasts should also turn their attention to the possibility of removing 100% ... 200% of distortions in addition to attention to other distortions with level of 0.001%.


The measurement collection contains measurements of such models of headphones:
AKG K701 2 pairs
AKG K271 2 pairs
AKG 240 55 Ohm
AKG 240d 600 Ohm
AKG 271 Mk2
Audio-technica ATH-M50 2 pairs
Beyerdynamic 770
Beyerdynamic 990
Beyerdynamic DT880 pro 2 pairs
Lambo MH699v
Philips SHP2000
Philips SHP2500
Pioneer SE-M521
Sennheiser HD449
Sennheiser HD518
Sennheiser HD600 6 pairs
Sennheiser HD650 4 pairs
Sennheiser PXC450
Sony mdr-xd150
Sony mdr-xd100 2 pairs
TDK life on record
Technics RP-DH1200

Please us the Contact form to send us enquiry about your interest to use the APL headphone equalization solution for your needs.

The complexity of headphone measurement requires that particular headphones must be sent to APL for the measurement and for the creation of the equalizer file. It is also possible to order any new headphones with set of measurement files and equalizer filter files accompanied with any of APL`s FIR equalizers – hardware or software, and a headphones amplifier added.