The beyerdynamic DT 990 is one of the world’s best open-back dynamic headphones. It’s been a favorite among professional recording engineers and music lovers for 25 years because of its great sound, moderate price and today solid construction. The DT 990 has unusually clean, clear, uncolored and open sound suitable for almost any music.

The DT 990 has been around beyerdynamic’s catalog for a long period. I still use my original couple of beyerdynamic DT 990 that I purchased in 1988, when it only came in the professional 600 Ω version with a ¼” plug – but housed in a delicate plastic frame. The initial DT-990 have a black plastic housing and two-piece harp that appear to be that era’s state-of-the-art, the Stax Lambda, but with round drivers and fuzzy ear pads.

I’ll mention both 1988 and 2012 versions throughout this review. EASILY don’t specify, almost all of this review identifies today’s 2012 version.

Today’s DT 990 looks somewhat as an homage to today’s state-of-the-art, the Stax SR-007 MK2 Omega II, and so are mostly crafted from drawn sheet metal.

Today’s DT 990 includes a dinky 3.5mm plug with an included screw-in ¼” adapter, and will come in 32 Ω, 250 Ω and 600 Ω versions. I am reviewing the 600 Ω version here.

The DT 990 is a beyerdynamic DT 880 with boosted bass and treble to meet the house Hi-Fi market. Aside from the tonal balance and cosmetic differences, they will be the same.

The DT 990 can be an open headphone, without isolation except at the highest frequencies. There is sound leakage, which means that your neighbors will hear them, too.

They are tough, well-built, economical and great-sounding headphones. I favor the beyerdynamic DT 880 for more natural sound, even though many persons will choose the boosted bass and treble of the DT 990.

I favor today’s DT 880 over today’s DT 990, however I favor my original 1988 group of DT 990 to the brand-new pair. A few decades of break-in may or might not exactly change the sound of the new pair. Most persons will most probably prefer today’s DT 990 over the more-intended-for-professional-monitoring DT 880, since today’s DT 990 has more bass and treble.

Impedances

The beyerdynamic DT 990 will come in at least three different versions with different impedances: 32 Ω, 250 Ω, and 600 Ω. I’m testing the 600 Ω version here.

The largest difference among the many impedances is sensitivity. The 32 Ω version will play super-loud from your own iPod, as the 250 Ω and 600 Ω versions will demand higher volume settings for the same level – or a dedicated headphone amplifier.

beyerdynamic’s Impedance Suggestions.

beyerdynamic DT 990 plug. Note molded “600 Ω” marking.

Despite the fact that beyerdynamic doesn’t recommend this 600 Ω version for use with iPods per the table above, it works great from an iPod, however with pop music you’ll will often have your iPod set at near maximum volume, and with classical music, you’ll will have your iPod set to maximum, and may wish you’d another 5 to 10 more dB of gain. It sounds great, nevertheless, you can’t make your self deaf.

(Classical music is recorded at lower average levels since it gets very loud in addition to soft, so playback level settings ought to be higher for accurate reproduction – and invite higher peak reproduced sound levels. Within an idiotic try to make every CD sound as bad and loud as another, almost every other music today is severely dynamically compressed and limited by be at 100% loudness constantly, so playback levels should be set lower, eliminating musical peaks and dynamics and half the music with it.)

Sound

The DT 990 sounds clean and open right out of your box without the break-in, however when compared to DT 880, the DT 990 has its bass boosted a few dB around 60 Hz, with less bass below that. Most persons will most likely prefer this boosted bass, nonetheless it will annoy careful listeners, making us choose a 60 Hz slider to dip a few dB. The DT 990’s bass bump obscures deeper bass, which isn’t hidden in the DT 880. The 1988 DT990 is less boomy. I have no idea if a few deceade of break-in changes the 2012 DT 990.

The “boomy” bass of the DT 990 is boomy only in comparision to other very fine headphones just like the DT 880. It really is nothing beats the boom from your own neighbor’s kid’s car stereo; the boom is merely a few dBs of boost around 60 Hz, not 15 dB.

This 2012 DT 990 is solid to 30 Hz, and bass continues to be still audible at 16 Hz. Of course below 20 Hz “audible” is more the area noise modulating itself from intermodulation with the headphone’s subsonic input, but that is the way it works in live sound, too. Even driven to deafening levels with a genuine headphone amplifier, I cannot get sine waves to buzz, rattle or distort with the 2012 DT 990. (My 1988 DT 990 always buzzed somewhat if driven too much in the bass.)