DT990 Pro (250Ω)

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published: Feb-28-2015, updated: Apr-8-2019

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NO SMOOTHING is applied to the shown plots. Most measurement sites have some smoothing applied which ‘irons flat’ sharp peaks and ‘wiggles’. I do not use smoothing because some info about sound quality is lost when plots are smoothed.

Aside from a small correction of the microphone itself also some correction in the lowest frequencies is applied to the plots to compensate for the perceived loss of bass when using headphones. This is described HERE in more detail.
A ‘horizontal‘ frequency response curve on the shown frequency response plots on this website thus indicates a perceived ‘flat’ tonal signature.

ALL measurements are made with a good SEAL on a flatbed measurement rig.
shape of your head, bone structure, pad size, pad ‘softness,  (compliance), hair or no hair and or wearing glasses may (drastically) change the frequency response of some headphones, so… your personal experience may differ substantially from these plots.

Frequency response (tonal balance) is the most sound-determining aspect of headphones. A horizontal line shows audible neutral response in the plots on this website. Deviations in different severities at different frequency bands have an effect on the sound character.
The bigger the deviation the stronger the effect.

Below an aid to help determining the sound character of headphones with relation to the frequency response.


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Beyerdynamic DT990 Pro-250Ω

DT990 Pro 250

The DT990 Pro in 250Ω impedance is a well known headphone in the headphone community.
It is a rugged headphone intended to be used from amplifiers with a higher output voltage.
The 32Ω version is better suited for portable use. The ‘editions’ are said to be slightly better sounding and are closer to the old DT990-600.
The edition version is slightly less bassy and treble sounds slightly more refined.

This one has black velours pads, they measure exactly the same as the grey DT990 pads.
These headphones are very comfortable and have a decent clamping force, albeit slightly higher than the edition version.
The cups swivel in all directions and the sliding mechanism works problem free and has proven itself in this classic design.
It can be taken apart pretty easily and components can be replaced easily and support for obtaining spare parts is excellent.
The cable for the Pro version is partly curled and strurdy. Not ideal when using it on the go but it is not intended for this anyway.
The coiled cable is better suited for studio work. The plug is 3.5mm and comes with a 6.3mm adapter.

Below the frequency response of the DT990Pro (Left, Right):

dt990-250 fr

This represents pretty well how it sounds. It is U-shaped and has lots of ‘warmth‘ and is bassy. It also has a LOT of treble energy up top.
The mids thus are relatively ‘sucked out‘ which gives it a ‘musical’ and ‘forgiving’ nature on popular music and other not so well recorded studio material. Recordings that sounds ‘midrangy’ on flatter headphones and lack bass and treble will sound guite ‘full’ on these headphones.
Music that is recorded pretty well sounds overly bassy/fat and sharp/shrill/piercing though.
Jazz, classical as well as vocal or ‘hifi’ lovers may find this headphone too euphonic, as it lacks ‘realism’ but is ‘pleasant’ on most pop music.
The DT990 also lacks sub-bass but is more or less ‘masked’ by the overblown bass/lower mids.
Depending on music genre and taste, these headphones may be a good choice as they are relatively cheap and ‘forgiving’ and have a ‘fun‘ sonic signature.

Below the differences between the (old) DT990 – 600Ω and the current DT990Pro -250Ω version.
Both with slightly used but still fresh pads (left channel only).
The newer DT990 Pro obviously has almost 4dB more bass and appears to have even more ‘sucked out’ mids.
The older DT990 is more realistic and less ‘warm’ sounding, but still sounds somewhat ‘sucked out’.
The treble on both headphones is a bit too much and gives the headphone a (false) sense of ‘hyper detail‘.
The highs, even though a bit piercing at times, sounds ‘smooth’. The DT990Pro is slightly ‘better’ in the treble but these differences are marginal.

dt990 600 old vs 990pro 250

When this headphone is driven from a 120Ω output resistance amplifier it becomes a tad more ‘fat’ sounding (about +1dB) as the bass/upper bass is slightly boosted and the rest is untouched. The effect is shown below, driven from 0Ω  amplifier and 120Ω amplifier.

dt990 250- 120 ohm

The usage of felt in front of the driver can often help with removing sibilance and sharp treble. 3 mm thick wool-felt is most effective in the 4kHz to 13kHz area. For this headphone this is also the case. A 3mm felt disc, that replaces the foam driver protection, lowers the treble in the sibilance area (5kHz – 10kHz) by a good 5dB. It also seems to apply some extra damping for the lows as the bass extends slightly lower and the peak around 150Hz is lowered by 1dB. Below stock (left driver) and with 3mm wool-felt in front of the driver.
The headphone still sounds bassy and detailed but is less ‘shrill’ and will possibly be less fatiguing.

dt990 3mm felt

Below the CSD of the stock DT990Pro – 250Ω (Left, Right) It is actually pretty decent and doesn’t show any long lived resonances that may be problematic. The small ‘dip’ at 4kHz is a small but ‘non-lethal’ resonance.

All in all a nice sounding ‘fun’ but not realistic sounding headphone that is very forgiving/flattering with lower quality recordings.
Applying a bit of felt makes it less sibilant sounding.

passive filter

A more ‘targeted’ lowering of the treble peak can be done using a passive filter. Below the schematic for the DT990-250 (not suited for other impedances)

One can also use (parametric) EQ or use the Kameleon.

Of course this headphone can be corrected with the Kameleon amplifier quite a bit further.
Below the difference between the stock DT990Pro-250Ω and via the Kameleon amplifier.

DT990Pro-250 kameleon

Bass extension is formidable and below 10Hz, the bass hump has been removed which ‘tightens’ the bass.
I gave it a bit of extra ‘bass’ because the headphone is open and DT990 owners do prefer ‘strong’ bass. The treble peak has also been removed.
As both the bass and treble peaks have been removed the midrange isn’t recessed any more. Treble extension, clarity are excellent.
Below the frequency response (L and R) of the DT990Pro-250Ω on the kameleon.

DT990 kameleon filter

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