Beyerdynamic DT 990 PRO

Frequency Response (8.33)

The Beyerdynamic DT 990 PROs had excellent frequency response. They boost bass ever so slightly, but the rest of the time they evenly emphasize sound. Towards the end the graph gets slightly more erratic, but manages to stay within the scoring limits. The 10kHz mark was ever-so-slightly overemphasized, but not by any great stretch. If you’re looking for a dynamic response, you should look elsewhere. If you don’t want your headphones tweaking your music for you, then the DT 990 PROs are an excellent option.

One thing to note about the graph at right: the left and right channels play almost the exact same emphasis. Typically one channel will be slightly louder at times or, on severely bad headphones, the two channels will veer off in wildly different directions.

The DT 990 PROs trounced just about all our comparison headphones. The SE-A1000s, which had a great frequency response, were the only challengers to even come close. The AH-NC732s, which are excellent active-cancellers, paled in comparison. Most of the over-ear headphones we’ve tested have been a bit erratic in their frequency response. While a dynamic frequency response is definitely preferred by some, the poor-scoring headphones below all underemphasized higher-end sounds by a significant amount. The DT 990 PROs don’t have this problem. In fact, they really don’t have any problems with frequency response.

Headphones	Score	Frequency Response
Beyerdynamic DT 990 PRO	8.33
Denon AH-NC732	2.28
Pioneer SE-A1000	7.93
Sennheiser HD 555	3.44
Audio-Technica ATH-A700	2.07

Distortion (15.00)

The DT 990 PRO had virtually no distortion. There’s not much else to say; the sound quality you’ll get from these things is borderline pristine.

The DT 990 PRO has some stiff competition in this category, but manages to come in a very close second place. Realistically, however, the four headphones below with over 10 points would be utterly undiscernable from each other. The Ultrasone HFI-2200s had a few issues with distortion, as did the Pioneer SE-A1000s. The HFI-2200s’ distortion probably had something to do with their Natural Surround Sound feature creating artificial echoing in the lower end. The Pioneer SE-A1000s just had more distortion than the average set of headphones.

Headphones	Score	Distortion
Beyerdynamic DT 990 PRO	15.0
Denon AH-NC732	15.9
Pioneer SE-A1000	2.75
Sennheiser HD 555	13.33
Audio-Technica ATH-A700	10.5

Tracking (5.95)

The DT 990 PROs had even tracking for the most part, but towards the high end the tracking gets a bit screwy. Tracking typically goes a bit haywire towards the high end, but typically that doesn’t happen until after 10kHz. The shift isn’t astronomical, so chances are you won’t really notice it. Overall, the headphones did very well.

The DT 990 PROs had a middling tracking score relative to our comparison headphones. The Pioneer SE-A1000 only had small shifts from left to right and the Ultrasone HFI-2200s remained relatively flat until it was out of our scoring zone (lucky, that). Again, this score is based on the largest shift exhibited; emphasis that slowly meanders from the left channel to the right won’t be noticeable.

Headphones	Score	Tracking
Beyerdynamic DT 990 PRO	5.95
Denon AH-NC732	3.22
Pioneer SE-A1000	6.54
Sennheiser HD 555	5.59
Audio-Technica ATH-A700	4.35

Maximum Usable Volume (5.79)

The DT 990 PROs were capable of an average output: 102.33dB. This isn’t a bad output for a set of open-backed over-ears, because if you’re using them, you’re probably in a quiet enough environment.

We award maximum points to 120dB of output, but any more than that is dangerous and we simply can’t recommend it. If you even go over that limit by a tenth of a decibel, we will send a note to your parents.

Isolation (1.38)

No surprises here. The DT 990 PROs are open-backed headphones, so they don’t isolate particularly well. If you’re going to be in noisy environments, toss on a pair of in-ears or active noise cancellation headphones. We were actually surprised at how little noise these headphones blocked out; you won’t notice much of a difference between wearing them and taking them off.

The DT 990 PRO actually doesn’t lose this comparison, since there are many other open-backed headphones listed below. Surprisingly, the DT 990 PROs blocked out more sound than their open-backed brethren. It lost to the ATH-A700s, which are closed-back over-ears. The Denon AH-NC732s are active noise cancelling headphones, so they of course trounced the competition. Again, if you’re looking for headphones to take with you on your commute, do not get open-backed headphones like the DT 990 PROs. Stick with in-ears, like the Shure SE420s or active-cancellers like the Denons.

Headphones	Score	Isolation
Beyerdynamic DT 990 PRO	1.38
Denon AH-NC732	7.14
Pioneer SE-A1000	0.53
Sennheiser HD 555	1.18
Audio-Technica ATH-A700	3.39

Leakage (2.52)

Again, not a surprising result. The DT 990 PROs did not have good leakage control. If you need to keep quiet, they aren’t the headphones for you. Even at a moderate volume a neighboring cubicle could hear your playback. Again, this poor score is relatively meaningless for a pair of over-ears: they’re meant to be used in a personal listening environment, where disturbing others is not a concern. If you want to keep your music private, your best bet is a set of in-ears.