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SEAS Jenzen-NEXT, built by Ronald
Copyright 2023 © Troels Gravesen

Dear Troels,
I hope this finds you well.
Nearly 18 months after receiving two substantial cartons from Michael Dahl Jantzen, I completed my set of SEAS Jenzen Next speakers. The construction process took more than nine months. That means most Saturdays and a few Sundays as long as it didn't rain. The front yard was my workshop. What an exhilarating project!
I aimed to craft something divergent from the norm, reminiscent of what I did three decades ago with my Vifa Format concept. While achieving uniqueness in the speaker domain might be elusive, I'd like to think my redesign holds a special place.
The cabinet I designed resembles a wing shape, with a gentle 7-degree inclined top. Beyond this aesthetic tweak, the volume, front baffle, transmission line, and internal panels strictly adhere to your design guidelines. Frankly quite a puzzle to get all parameters in place. It proved to be a complex endeavour to shape and fit all MDF elements. It is not a project for a novice do-it-yourselfer, there are quite a few challenges. The rounded sidewalls were particularly time-intensive. However, the rewards, once realized, were wholly gratifying.
I implemented several crossover enhancements. For instance, I replaced the tweeter capacitors C1021 from Silver Z to Alumen Z, and upgraded the coils L2041, L1031, L1041, and L1051 to 16 AWG Wax Coils. Your guidance, along with Michael Dahl Jantzen's, proved invaluable. Despite the extensive crossover design modifications, everything snugly fits at the cabinet's base.
Having played the Jenzen for roughly 200 hours, I'm profoundly impressed by its 'neutral' sound quality, harmonizing beautifully with my Luxman amplifier. The audio experience these 1,2 meter high and 80 kg heavy speakers offer is exemplary. The Seas Crescendo tweeter is a revelation. The synergy between the T29 Crescendo and the Nextel-coated W18NX003 exceeded my expectations, delivering astonishing clarity and detail throughout their range. From the very first note, the experience was enthralling. Both high and low frequencies are well-balanced, filling the room with sound waves which carry you through the room as gracefully as a surfer rides the waves.
There's a welcoming warmth in the mid and high frequencies, underpinned by an unwavering bass foundation. This bass can be strikingly direct when needed, either caressing the ears or resonating with the soul. Regardless of the genre – be it jazz, classical, organ, opera, or rock – the sound captivates, pulling listeners deep into music's enchanting realm. Each track beckons for more. Lovely, just lovely!
Thank you once more for your outstanding design! I've attached some photos for you to peruse. Additional introduction, pictures and drawings are available on my ‘hobby’ website.
https://www.van-haaften.nl/loudspeaker-design/seas-jenzen-next/intro-seas-jenzen-next
Thanks again for a great design Troels.
All the best,
Ronald