12 Apr Beyerdynamic DT 900 Pro X: The Headphones Producers Love

Posted at 13:39h in Exclusive, Exclusive, Gear & Tech, Review, Review by Elias Kollböck

▶ 5:17 Reading time

I put on the Beyerdynamic DT 900 Pro X and started Bonobo’s “Kerala”. After thirty seconds I stopped the track and started it again. Not because something was wrong, but because I heard details that I had never noticed after a hundred runs on other headphones. A shaker track in the left‑rear. A room echo that builds up slowly. That’s the moment when you understand why open‑back headphones exist.

DROP

▸ Beyerdynamic DT 900 Pro X: open over‑ear, 48 Ohm, STELLAR.45 drivers, from 219 Euro
▸ Made in Germany. Hand‑crafted in Heilbronn. Not a marketing label, but a fact
▸ 48 Ohm: Works on a smartphone, laptop, DAC. No headphone amplifier needed
▸ Frequency response: 5 to 40.000 Hz. Wider than most competitors
▸ Comparison: AKG K712 Pro (from 267 Euro, 62 Ohm) and Sennheiser HD 600 (from 294 Euro, 300 Ohm)

What “open” means in headphones

Open‑back headphones have perforated ear cups. Sound goes in, sound goes out. That sounds like a drawback, but it’s the opposite. An open design creates a soundstage. Instruments don’t sit inside your head, they surround you. A stage that closed‑back headphones can’t physically reproduce. The cost: zero isolation. Your seat‑mate on the train hears what you’re listening to. Open‑back headphones are for the home. For the moment when you really want to listen.

The DT 900 Pro X leverages this openness better than most competitors in its price range. The STELLAR.45 drivers are Beyerdynamic’s latest development, introduced with the Pro‑X series. They deliver a frequency response of 5 to 40.000 Hz. For comparison: human hearing extends to about 20.000 Hz. The extra bandwidth isn’t a gimmick. It ensures the headphone performs cleaner across the audible range because the diaphragm isn’t operating at its limit.

48 Ohms: Why It Matters

The Sennheiser HD 600 has an impedance of 300 ohms. That means it needs a headphone amplifier to play loud and controlled. On a smartphone, it’s too quiet and sounds thin. The AKG K712 Pro sits at 62 ohms—better, but still not ideal with weak sources.

The DT 900 Pro X has 48 ohms. That’s low enough for any device: smartphone, laptop, audio interface, DAC. It plays loud enough everywhere without losing control over the bass. No extra amplifier needed. Just plug in and go. For a product marketed as a studio headphone, that’s unusually flexible.

48 Ω

Impedance (HD 600: 300 ohms)

5-40k

Hz Frequency Response

219€

Starting Price (Geizhals DE)

How It Sounds

Neutral, but not boring. That’s the shortest description. The DT 900 Pro X doesn’t color the sound—no added bass, no boosted highs. What you hear is exactly what’s in the recording. For some, that’s a letdown because they miss the bass boost of consumer headphones. For everyone else, it’s a revelation.

The soundstage is wide—wider than the HD 600, which is slightly more present in the mids. The K712 Pro is even wider but sounds a bit less focused in comparison. The DT 900 Pro X strikes the perfect balance: spacious enough for an immersive experience, precise enough to pinpoint individual instruments.

Where it truly shines: complex material. Layered electronic music, orchestral pieces with large ensembles, hip-hop tracks with three synth lines playing at once. The DT 900 Pro X untangles it all cleanly without sounding clinical.

The bass is there, but it doesn’t overpower. A closed-back Beyerdynamic DT 770 delivers more sub-bass punch. The DT 900 Pro X, however, offers bass that decays more controlled and doesn’t muddy the mids. If you want physical pressure in your ears for techno, an open-back headphone isn’t the right choice. But if you want to hear how the kick drum was produced, which overtones the hi-hat has, and where the synthesizer sits in the stereo image, the DT 900 Pro X is spot-on.

The DT 900 Pro X doesn’t sound like a 220-euro headphone. It sounds like a 400-euro headphone that cut its marketing budget.

Comparison: DT 900 Pro X vs. K712 Pro vs. HD 600

The AKG K712 Pro (from 267 euros, 62 ohms) delivers a warmer sound. More bass foundation, a wider soundstage. But less precision in the mids. If you mainly listen to ambient or classical music, the K712 might be the more emotional choice. Downside: the cable isn’t detachable on the original model. And 62 ohms are borderline for smartphones.

The Sennheiser HD 600 (from 294 euros, 300 ohms) is the legend. For over 25 years, it’s been the reference headphone for HiFi enthusiasts. Its strength: a natural, slightly warm midrange reproduction that makes voices sound three-dimensional. Its weakness: 300 ohms mean you need an amplifier. On a phone, it’s useless. And the price has risen significantly in recent years.

The DT 900 Pro X is the most pragmatic of the three. Not the warmest, not the widest, not the most emotional. But the most versatile. It works everywhere, sounds great everywhere, and needs no accessories. If you want a single open-back headphone that works with everything—from your smartphone to a studio DAC—this is the answer.

For you if

You want an open-back headphone that works with any device
You prefer neutral sound that adds nothing and leaves nothing out
You value German-made quality that lasts for decades

Hold off if

You prefer bass-heavy sound (closed-back headphones would be better)
You mostly listen on the go (open-back headphones don’t isolate)
You already own an HD 600 with an amp (the upgrade isn’t worth it sonically)

♫ Reference Tracks – What the DT 900 Can Do

Songs that reveal what a great open-back headphone does with details.

Bonobo – Kerala Layer upon layer. Open-back headphones untangle them.
Yosi Horikawa – Bubbles Field recordings that fill the space. The perfect headphone test.
Steely Dan – Aja An audiophile reference since 1977. The drum solo starting at minute 3.
Billie Eilish – everything i wanted Sub-bass you’ll feel properly for the first time with open-back headphones.

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Q&A after the Show

Click a question to expand the answer.

Do I need an amplifier for the DT 900 Pro X?

No. With 48 Ω impedance and 100 dB sensitivity, the DT 900 Pro X runs loud enough on any smartphone or laptop. A DAC such as the iFi Zen DAC V2 can improve the sound, but it isn’t required. Unlike the Sennheiser HD 600 (300 Ω), which sounds thin and quiet without an amp.

What’s the difference compared to the DT 990 Pro?

The DT 990 Pro is the older model with 250 Ω impedance and a V‑shaped sound (emphasized highs and lows, recessed mids). The DT 900 Pro X features the new STELLAR.45 drivers, only 48 Ω, a more neutral sound and a detachable cable. If you don’t already own either, the DT 900 Pro X is the better choice.

Is the DT 900 Pro X suitable for music listening or only for the studio?

Both. The neutral sound makes it a studio tool, but that very neutrality also makes it an excellent headphone for conscious music listening. You hear the music exactly as the producer mixed it. Many users in hi‑fi forums prefer it over the HD 600 as an all‑rounder.

How comfortable is the DT 900 Pro X during long sessions?

Very comfortable. The velour pads are soft and breathable. It weighs roughly 345 g, lighter than the K712 Pro. The clamping force is moderate. I wear it regularly for three to four hours straight without pressure points. Beyerdynamic offers replacement pads as accessories, should the originals wear out after years.

Elias Kollboeck

Editorial IBS Publishing