When the conversation resumed January 26th, my ModalAkustik review was in the can. This 2×12" RiPol turned out to be just 85dB efficient. It started its acoustic roll-off at 35Hz to be -6dB at 18Hz. On actual sound/pressure, 20Hz was MIA. Whilst not really adding extension to our bigger downstairs speakers, the RiPol's refusal to pressurize and involve the room made a real impression for its speed, clarity and total lack of overhang. Upstairs Martin's Vox 3awf worked brilliantly with it. "I'm hunting around to see if I can find anybody else who could do an ace analog filter. Pál is buried in orders so his R&D could be delayed. Chris isn't too keen on DSP due to latency issues. My 15" woofers are 89dB with an Fs of 25Hz. I'm hoping that RiPol loading lowers that to ~20Hz. These have the sandwich cone that's heavier than the coated paper they also do. I'll talk to Per Skaaning if I need more sensitivity. I've also been trying to talk Armin into doing larger woofers but he doesn't want to get into all-new hardware and packing."
Zu Submission sub in left corner, ModalAkustik MusikBass next to right monitor.
Such anecdotal stuff shines a small light on R&D-related explorations and supply-chain issues aggravated by a pandemic and Brexit. Consumers tend to be blissfully unaware of the many struggles preceding pretty much any new product launch. Getting a few whispers about them here is instructive; and potential deterrent for DIYers dreaming of going pro. They'd best have lots of time and money on their hands.
February 20th, "I have found what looks to be a capable electronics engineer with Polish roots who works in Stuttgart. Most of his work is bench-marking and testing amplifiers for some of the bigger audio houses. Mentioned GaN for a possible sub amp after my impressive experience with Alberto Guerra's Vivace. He got very excited. He's worked with GaN on non-audio related projects for Bosch and those digital amps he's had on his test bench were poor implementations. He also designed the active analog filters for Nubert subs which he thinks are still used today. Waiting on Chris to come back with subwoofer parameters so this engineer can start on the amp. Spoke to Pál who is up for a little licensing on filters. He's eager to get back to development work rather than just assemble boxes."