KLH Ultimate One headphones

April 13, 2021

By Steven Stone Jun 23rd, 2020


Some audio firms are forever written into the history of high-performance audio. Acoustic Research (AR) and Kloss, Lowe and Hoffman (KLH) are two that immediately come to mind. Over the years the trademark KLH has appeared on a variety of components, few of which achieved the same levels of importance as their early offerings. But that may change. Former Klipsch Global Sales President David P. Kelly is now the CEO and owner of KLH and is looking to bring the brand back to prominence, in part through the firm’s first headphone product, appropriately named the KLH Ultimate One.

The Ultimate One’s design is built around a 50mm ‘pure beryllium’ driver that according to KLH has a frequency response of 18 Hz–22 kHz (± 3 dB) and a high sensitivity specification of 97dB. The Ultimate One’s circular, open-back enclosure is made of genuine Ebony wood with a mesh opening at its centre. Supplied accessories include a two-metre detachable silver Litz braided cable with 3.5mm terminations, a 6.35mm adapter, a travel case, and a soft velour carry bag.

The fit and finish of the KLH Ultimate One is exceptionally fine, especially considering its price. There’s no “carbonized plastic” where there should be metal. And instead of the usual lateral pivots that have some flex or play, the side-pivots on the KLH Ultimate One are tight, smooth, and move without a trace of wobble. This same level of construction quality extends to the ear pads, cushioned headband, and extension detents on the headband. Everything is tight, carefully finished, and exudes a sense of solidity. Unlike many mid-priced headphones, the KLH Ultimate One carries a two-year warranty.

The KLH Ultimate One is an extremely comfortable headphone. Together, the combination of light weight, wide range of band adjustability, adequate (but not excessive) side-pressure, padded headband and large over-ear ear pads, make it easy to forget you are wearing headphones, especially during extended listening sessions. My only ergonomic quibble is with the termination where the cable connects with the headphone. The 1.9cm long stiff barrel on the end of the termination could, if torqued sideways, damage the headphone’s input connector (a soft, flexible barrel could eliminate this potential problem).

Sonically, the KLH Ultimate One delivers a classic large-diaphragm dynamic driver sound. The soundstage (with the right music) is large, cohesive, and dimensional. Listening to my recent live recording of the local neo-old-timey band, Masontown, I noticed that the KLH Ultimate One reproduced all the subtleties of the recording. Compared with several of my reference headphones the KLH harmonic balance was quite close, with the exception being the bass, which was fuller and slightly less controlled than through the Focal Elegia or Abyss Diana Phi. Lateral focus and image definition was good through the KLH Ultimate Ones, but again the two reference headphones delivered a somewhat more precise and better-defined three-dimensional image.

One especially attractive aspect of the KLH Ultimate One’s sound was an extremely natural and relaxed sonic presentation that always sounds musical. Unlike many “mid-priced” headphones that aim for a spectacular sound that emphasizes certain parts of the harmonic spectrum, such as the mid bass or the upper midrange. The KLH Ultimate One’s would be an excellent choice for someone who wants a musical over-ear headphone that allows for a high level of situational awareness. 

I mention ‘situational awareness’ because the KLH Ultimate Ones do not isolate you from outside noise like a noise cancelling or noise blocking earphone. If your airline decides to change gates, you will still know about it. On the airplane itself you will find the KLH Ultimate Ones do little to reduce noise, so you may need a second pair of earphones that can isolate you from jet engine sounds.

Listeners looking for exceedingly comfortable, open-back, over-ear headphones that deliver a relaxed and musical presentation would do well to try the KLH Ultimate Ones. After a couple of minutes, you may find them hard to take off… 


Type: Over-ear, open-back headphones

Driver complement: 50mm dynamic drivers with Beryllium diaphragms

Frequency Response: 18 Hz–22 KHz (± 3 dB)

Impedance: 32 ohms

Sensitivity: 97 dB/1mw

Connector: 3.5mm single-pin custom

Weight: 340 g

Price: £299 UK, $299 US

Manufactured by: KLH
984 Logan Street, Noblesville, Indiana 46060 USA

Tel: +1 (833) 554-8326

URL: www.klhaudio.com