Cube Audio Nenuphar Single Driver Speaker (10 inch) TQWT Enclosure

Here's the WBF Masters & Makers Interview of Mr. Rulka (by Ron Resnick).  Though primarily focused on his Qualio Audio brand, the discussion is general and provides insight into Grzegorz and Marek's thinking / approach / trade-offs. It briefly  touches on Cube Audio (in a few places).

WBF Interview of Greg Rulka

I have read this thread with great interest and enjoyment.  Thank you Charles and David and others for all the great information you have shared.  I’ve learned a lot from your experiences and observations.  I am a recent owner of a pair of Nenuphar speakers. 

I've been researching the Nenuphar Mini's for a few weeks. Given that there's no way for me to audition them, I have been mainly gathering data from youtube videos and forums like this. Frankly, the more I read, the more confused I get :)

Some people claim they are not easy to work with, requiring very specific amplification and being very fussy with placement. I've also heard that the bass is anemic. Yet, there are many who claim they're the best speakers they've owned regardless of price or pedigree.

In other words, there doesn't seem to be a consensus, which should not be surprising to most seasoned audiophiles, haha!

My question: how well will they do with Audio Research Reference 250 mono blocks. Here are the specs for the amp:

• Input Impedance: 200k ohms (balanced)
• Output Taps: 4, 8, and 16 ohms
• Output Regulation: Approximately 0.9dB 16 ohm load to open circuit (Damping factor approximately 10)
• Overall Negative Feedback: 8.8dB
• Input Sensitivity: 2.4V RMS Balanced for rated output (25.5 dB gain into 8 ohms)
• Power Output: 250 watts per channel continuous from 20Hz to 20kHz
• Frequency Response: 0.5Hz to 110kHz, -3dB with 1W output
• Power Bandwidth: 5Hz to 70kHz, -3dB

My room is roughly 20x15 with 11 foot ceilings. I do have a pair of subs to augment the lower frequencies.

Any feedback is greatly appreciated.

Most use low powered tube amps with them.  When Cube are doing audio shows they use TEKTRON amps with them which are Flea watt amps. First Watt SIT Amps are an excellent solid state pairing as well.

I don't have the Mini's but have the Nenuphars with the upgraded v2 drivers. I believe both follows the same design philosophy. In my experience, the bass can be very anemic if you have an amp with high damping factor. The Cubes in general like low damping factor and least or no -ive feedback amps. When these two conditions are met, the Cubes do really sounds very musical. These speakers are ruthlessly revealing and will show every weakness or strength in your system. When I get a new cable or any component that needs break-in, I can't hear the speakers until the cables or components break-in totally. What I am trying to say is every small little things in the chain will matter in how they sound.