It’s not a field of design where it’s easy to pull off timeless aesthetics though for a range of reasons relating to the context of audio components and forming up as a marriage of systems beyond themselves. Fragments synthesising into a whole.
This is the core fundamental challenge not just of the aesthetics in audio design but also in the fundamental music experience itself in audio systems especially in more complex processes often found in high end audio approaches.
The component nature of system building makes unity or cohesion more of a challenge but then the journey of pulling a system together is rarely about off the rack solutions… less is more is just a safer design pathway than when the audio ecosystem is flapping its feathers in a buy me dance and form mixing can be very diverse and conflicting.
It’s being unable to elevate function through to form that caps this off as craft rather than operating as a level of art in design.
That said often it isn’t just good basic form making at play… much of it seems unconfident so the excesses come about as engineers struggle to resolve form and add more and more design flourishes or overt materiality or complicating processes… but like I said it is a difficult discipline to be designing in.
Design is, or should be, fundamental to any good consumer brand, hifi included.
One example is the Musical Fidelity A1. This design classic from the 1980s, which was reissued a few years ago, launched the brand. The owner went to Pentagram, now one of the world's leading design companies, and commissioned them to come out with something completely new. Not only is it great design, and was completely radical, it pioneered using the top plate as a heatsink. (It is 20w Class A and gets very hot.)
On a larger scale, Native Design
https://native.com/ has worked with many consumer audio and automotive (including automotive audio) companies over decades. The were responsible for iconic designs like the B&W Nautilius, B&W 800 series and B&W headphones. They were also responsible for the design of the Naim Uniti range, which completely rebranded the UK's leading audio company, for the next generations. The chief designer at Native moved over to being head of product design at Focal Naim.
The 30+ year relationship between Native and Laurence Dickie also resulted the Zuma.ai product that I use throughout my house, which is the ultimate in form and function - getting a complete 75w audio system with multi-platform streaming, 24/192 wifi operation and an intelligent lighting system, all inside a unit 135mm high and 95mm in diameter with totally proprietary software and Roon Ready. It took 5 years and cost many millions to achieve.

There are many other examples, in particular Devialet D-Premier. To create the Zuma Lumisonic and Devialet Premier both required a huge amount of innovation to to meet the physical design requirements.
The Daddy of the all is Dieter Rams' designs from Braun. They lacked a bit on the audio performance, several were effectively copied by Jonny Ive for Apple to create some of the most successful audio products ever, like the iPod. (I have a Vitsoe office, designed by Rams 60 years ago.)
What I personally don't like is bling design for its own sake that is not intrinsically functional, which is why all my components are boring black boxes (excepting my turntable and speakers). The turntable is a design classic and my speakers are boring metallic grey boxes with the WAG seal of approval.
If you don't think design is fundamental, you need to look at real world hifi.
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