Build Quality (8.5/10): The build of the HFI-450 is typical Ultrasone – tough plastic forks and hinges, a thick but minimally padded headband, and a 10-foot straight cable come together to form a well-constructed DJ headphone. Like most DJ cans, the HFI-450 is both flat-folding and collapsible. A soft carrying pouch is also included for storage and transport of the headphones.
Comfort (8.5/10): The HFI-450 clamps harder than the majority of similarly-priced DJ headphones but the fairly soft padding and oval-shaped cups allow the comfort to remain on-level with the others. Sadly, the small pleather insert on the headband does not deserve to be called padding but the essentially unpadded headband is only bothersome when compared to the generously-padded ATH-M50 and Denon DN-HP700. As with the other large pleather-padded cans, the HFI-450/RH10MS can get warm after prolonged listening sessions.
Isolation (8/10): Isolation is better than that of the lighter-clamping Denons and Numarks and stacks up well to my higher-end Ultrasone Pro 650 despite the smaller size and thinner pads of the HFI-450.
Sound (7.5/10): The Ultrasone HFI-450 (rebranded as the Yamaha RH10MS) is Ultrasone’s entry-level DJ model. As is often the case with entry-level gear from major manufacturers, the HFI-450 sacrifices a bit of sound quality here and there compared to my pricier Pro 650 and Pro 2500 sets but retains their general sound signature. Though smoother overall compared to the similarly-priced Denon DN-HP700 and Audio-Technica ATH-M50, the HFI-450 is limited in frequency response and resolution by tuning and driver choice. The low end doesn’t roll off particularly early but the bass of the HFI-450 is neither as deep nor as punchy as that of the ATH-M50. The Ultrasones are certainly capable of producing both note and impact but neither feels visceral next to the Audio-Technicas despite being plentiful in empirical terms. Low-end detail is quite decent but texture is lacking slightly – the HFI-450 generally sounds a bit smoothed-over, almost glossy, when it comes to texturing.
The mids are clear of bass bleed but take a half-step back in terms of emphasis compared to the bass. The notes are a bit thick, which is also the case with my higher-end Ultrasones, and transparency suffers slightly as a result. Male vocals generally come across smoothly and powerfully while some female vocals lack the luster provided by the more mid-forward Numark PHX Pro. The treble is in good balance with the midrange but possessed at least one huge spike out of the box, which brought about bucketloads of sibilance on certain tracks. After a couple of dozen hours the headphones seemed to have smoothed right out, leaving behind competent but not attention-grabbing treble response. The high end is clearly less prominent than those of the Denon HP700, ATH-M50, and Sennheiser HD25. In fact, mediocre top end extension is one of the few obvious limitations of the HFI-450.
Like almost all of Ultrasone’s headphones, the HFI-450 / RH10MS boasts Ultrasone’s S-Logic technology, which promises to create a realistic 3-dimensional soundstage using the wearer’s outer ear geometry just as ‘natural’ sound would. The HFI-450 is indeed quite ambient-sounding next to my (rather forward) HD25 but misses out on the positioning precision of the Sennheisers. Soundstage width and depth are above average but everything sounds a bit smeared and imprecise. The HFI-450 also seems to place the headstage a bit farther back in my own head than I would like – the cheaper Ultrasone Zino had this problem as well. I keep on wanting to move the headphones forward on my ears. In terms of general tone, the HFI-450 / RH10MS is slightly warmer and significantly darker than both the Audio-Technica ATH-M50 and Denon DN-HP700. The thickness of note, combined with the darker tone, makes the Ultrasones sound a bit dull compared to the Denons, Audio-Technicas, and even the Numark PHX Pros. Conversely, the HFI-450 is the least tiring and demanding of the listener – a trait it shares with the higher-end Pro 650/2500 models but not the budget-minded Zino. A final point to note – the HFI-450 is nearly as efficient as the Numarks and benefits little from a high-powered amp. A portable amp might be of limited help if using them with a weak portable device but anything greater yields no real benefit.
Value (8.5/10): The Ultrasone HFI-450 / Yamaha RH10MS is a well-built, well-isolating, and very comfortable closed headphone that retails at a slightly lower price point than the Denon DN-HP700 and Audio-Technica ATH-M50, as it should. The HFI-450 is the smallest, most securely-fitting, and arguably the most portable of the bunch, making it a very well-rounded choice. In sheer sound quality, however, it doesn’t quite keep up with the Japanese competitors. When listening to the HFI-450 it feels as if Ultrasone could’ve done much better but didn’t want the 450 to compete with higher-end products, which happens very often with entry-level models from manufacturers with large lineups. Too bad, really, as the HFI-450 / RH10MS does lots of things very right. In sound quality, however, it will always be second (third, fourth, etc) best.
Frequency Response: 20 – 20,000 Hz
Impedance: 32 Ω
Sensitivity: 96 dB SPL/1mW
Cord: 9.8ft (3m) single-sided; Straight Plug
Space-Saving Mechanism: Flat-folding, collapsible