SR1a

Reviewer: Srajan Ebaen
Financial interests: click here
Sources: 27" iMac with 5K Retina display, 4GHz quad-core engine with 4.4GHz turbo boost, 3TB Fusion Drive, 16GB SDRAM, OSX Yosemite, PureMusic 3.01, Tidal & Qobuz lossless streaming, COS Engineering D1 & H1, Denafrips Terminator, Soundaware D300 Ref and D100 Pro, Questyle QP1-R, Kinki Studio Vision DAC-1 [on loan] Preamplifiers: Vinnie Rossi L2 [on review]
Headphone amps: Nagra Classic, Bakoon AMP-12R, 2 x Questyle CMA 800R, COS Engineering H1, Vinnie Rossi LIO with no-tube AVT, Eversound Essence, Kinki Studio Vision THR-1 [on loan] Speaker amps: Job 225, Pass Labs XA-30.8. FirstWatt SIT-1,SIT-3, F, Crayon CFA-1.2, LinnenberG Liszt, Nord Acoustics NC500 monos, SAG AIO [on review]
Headphones: Final D8000 & Sonorous X, HifiMan Susvara & HE-1000, Audeze LDC-2 & LCD-XC, Sennheiser HD800, Meze 99 Neo 
Cables: ALO Audio & Forza Audio Works replacement looms, Crystal Cable, Zu Event MkII
Power delivery: Vibex Granada/Alhambra on all components, Furutech rtp6 in upstairs system
Review component retail: $3'499

Requisite. Exquisite?

As it so often does, today's story began with an innocuous email. Ultra terse, it just read "not sure if this came up on your radar but being a headfi enthusiast, I though you would be interested."

Signed Martin Gately, soundkaos, religious user of Raal's superior ribbon tweeters.

The link Martin had embedded led to Aleksandar Radisavljevic's new headphones which a decade prior I'd seen as very early very raw prototypes in Serbia's Zajecar [right]. So actually, this story began with a visit long ago. Once upon a time.

Looking radically different now, our ribbon earspeakers were finally in production under the same Raal Requisite branding I'd first encountered with Alex's full-bandwidth Eternity omnis. Their early prototypes had been actually playing up a 360° storm during my visit that long ago.

One look at the SR1a's web page and off went a short inquiry to Alex to learn status. His answer was far more generous:

"Thank you very much for your email. It should have been me writing you first but I'll explain. I was thinking about you since October. As soon as it looked like I'd have something to show for Denver's CanJam, I was getting ready to ask you about doing the first formal review just as I promised you 10+ years ago.

"There have been a lot of headphone reviewers asking us for a sample since the show but Danny and I wanted you to be the first because you were in this ribbon headphone adventure from the very beginning. There was simply no way that anyone else would do the first official review!

"The reason I hadn't written yet is that we haven't finalized the user manual. Knowing that you don't miss any details, we wanted you to have the completed product. However, if that's not a big deal, we can certainly send you a set in a matter of days and subsequently supply the manual by emailed PDF.

"The headphones ship inside a nice Pelican case but I don't have any of those here in Serbia. I ship the product inside transport boxes to Danny in California who mates them with the cases over there. So Danny will be sending your set.

"He does everything related to their sales & marketing to keep me free to design and build. I'm at your disposal any time about any technical explanations, design decisions etc. We need just a few more days to finish the White Paper. That will contain explanations on all the how's and why's which should be helpful to your review."

But first, a few images from my prior Serbia RoadTour. They remind us of Raal Requisite's unique omni speaker as a precursor of no-holds-barred design extremism presaging today's headphones.

It combined what I believe were 9 narrow ribbons in a circular array on top followed by a stack of 18 aluminium-cone widebanders mounted to a hexagonal column assembled from phenolic pieces. This acoustic phallus sat on a massive five-woofer quasi sphere sand-cast by actual sculptors from genuine bell bronze. Below we see the prototypes as they were set up during my visit, sundry external crossover parts hanging off clip leads to fine-tune the filters. Then we see an initial render with a stem of still square cross section; then a formal shot of the finished product with round stem.