AudioQuest Nighthawk Impressions for the AudioQuest Nighthawk seem all over the place. (By the way, if you are in SoCal and want to listen to them, visit Audio Element in Pasadena. They are a vinyl shop, but with a bunch of headphones.) By "all over the place", specific impressions seem to either be that the Nighthawks are bassy warm, but pretty good or that they are a warm bassy gooey mess. Personally, I have experienced the Nighthawk both ways. This is what I believe it comes down to in order of effect: Selection of music and recordings used. Some recordings are bassier than others. The spectral distribution of the CD master of Daft Punk Random Access Memories does not mesh well with the Nighthawk. On the other hand, k.d. lang's Hymns_of_the_49th_Parallel works quite well. The Nighthawk has a nominal impedance of 25 ohms. Because the Nighthawk uses a dynamic driver, it's very likely going to have an impedance bump of some sort in the bass. (I will need to verify if I can find the time.) This means that the Nighthawk on certain amps with high output impedance is going to sound even more bassy and perhaps slow and syrupy. This seemed to be the case with the Zana Deux Super, which has an output impedance of about 20 ohms. For purposes of subjective evaluation, I used a variety of other amps with output impedance less than a few ohms. System matching. A few months ago, we were able to steal the Nighthawk from Audioquest and play it back on one of my reference systems. I will only say that the AudioQuest setup at the meets (Dragonfly fed into Woo 7) does the Nighthawk absolutely no favors and probably accounts for the many of the early pyrate impressions such as this: "Audioquest Nighthawk - muddy, indistinct, warm in a boring way. Looks cool, comfort's all right, but the plankton have been buried under a layer of cement." In comparison to my reference, a tweaked HD650: The Nighthawk is cleaner sounding. Less gray, less veiled. Resolution seems about equivalent for mid to mid/high headphone setups. This is indeed impressive as the HD650 scales like mad. I don't have the Studio or a BA on hand, and the ZD Super's output Z is too high, so I can't say how well it will scale with top tier gear; but my sense it that it will do quite well. Nighthawk has better bass quality, better articulation, better control; albeit the bass is much stronger and the warmth bleeds well into the mids. The HD650 frequency response is smoother and better integrated. The Nighthawk's middle and high midrange sounds recessed in comparison. The HD650's treble tilts dark. The Nighthawk continues to provide plenty of air in the last octave. The Nighthawk's treble is a bit tizzy. It's more a matter of a tizzy timbre as opposed to a nasty peak or horrible ringing. I'm really being nitpicky here because I so love the sound of bio-cellulose drivers. There's a bit of internal cup reverb with the Nighthawk. My brain got used to it over time and filtered it out. Staging is about the same with both headphones. EQ does wonders to the Nighthawk. Here are some quick settings by ear: -4db shelf at 800Hz Q = 1, -4db at 7000Hz Q = 2.5 (Note that I do not believe in surgical EQ and prefer simple settings with a light touch). Other Notes: Supremely light and comfortable. A really smart design. Termination is 1/8" with a 1/4" adapter. Cables are removable from the cups so you turds can buy a $600 cable to go with your $600 headphone. I suspect that the phono jack end of the cable can be re-terminated with a 4-pin. There appear to be sets of wires under the cable jacket instead of a shared ground wire. Very efficient. Lively and not compressed. Just slightly on the soft side of things in terms of impact and heft despite elevated bass. Conclusion: The Nighthawk in a nutshell is bassy and warm resolving headphone. The treble could be a bit smoother, but distortion is impressively low throughout. At $599 street price, we should be thanking the AudioQuest for not engaging in the oneupsmanship games of pricing stupidity other headphone manufacturers have embarked on. Figure 1: Nighthawk Frequency Response and Distortions (0dBr = 100dbSPL) Solid Plate Coupler Note that I could did match 1kHz with 87db per usual practice - there was too much rolloff. In hindsight, I should have cranked it up a bit. The deeper dips on the R channel are measurement artifacts. Note excellent distortion characteristics. Figure 2: Nighthawk CSD Solid Plate Coupler Figure 3: Nighthawk Frequency Response and CSD (0dBr = 100dbSPL) Foam Coupler "Free-Air" I'm bringing these back from V1. These are measurements on a foam coupler to simulate sort of a "free-air" response. Because there is no seal, bass measurements could be lower than the solid plate coupler. It depends on the electrical and mechanical characteristics of the driver and radiation pattern of the headphone. OJ recommended that these be brought back because it shows the behavior of the driver while minimizing the influence of the pads and the cup design. Note that this measurement can sometimes result more ringing in the CSDs because of less damping (no internal air spring). Figure 4: Nighthawk vs HD650 Frequency Response Yellow = HD650, Green = NH If you've enjoyed this post, help me help you, I have a growing family, blah blah blah, consider buying the AudioQuest Nighthawk from Amazon.