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


Cube Audio (Poland) designs single drivers and single driver speakers. 

Principals are Grzegorz Rulka and Marek Kostrzyński.

Link to the Cube Audio Nenuphar (with F10 Neo driver) speaker page: 

https://www.cubeaudio.eu/cube-audio-nenuphar

Link to 6Moons review by Srajan Ebaen (August 2018):

https://6moons.com/audioreview_articles/cubeaudio2/

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Parameters (from Cube Audio):

Power: 40 W

Efficiency: 92 dB

Frequency response: 30Hz - 18kHz ( 6db)*

Dimensions: 30 x 50 x 105 cm

Weight: 40 Kg


* Frequency response may vary and depends on room size and accompanying electronic equipment.
david_ten

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.

   

I’ve had a pair of Nenuphar mini’s upgraded to the v2 drivers for about 4-5 years. That is the longest I’ve owned a pair of speakers for which is saying something. They aren’t perfect but what they do well they do so well. They have just a very natural sound that is very detailed without sounding analytical. When set up properly and in a good space they image exceptionally well and deep. Being a single driver the sound is beautifully coherent. It’s hard for me to describe what that means until you hear it. They will pull out every ounce of performance from your system as they are very revealing. I’ve never had speakers that reveal changes in my system like these. Different amps, tubes, dacs, cables, etc. if you change something you will hear it. A friend of mine says they have a “lit up” sound, which I think is a good description. Theyre not bright but you hear everything in the music. 
 

Regarding amps… I’ve used many with these speakers. As others have said I feel they sound best with low damped, low or zero negative feedback amps. I’ve used a few tube amps including a Tektron and even a 2 wpc 45 amp and they’ve all sounded fantastic. I’ve used the first watt SIT3 and some other solid state amps, including class D ganfet amps. None sounded bad but I’ve always gone back to the tubes with these speakers. I was actually surprised by the ganfet amp and the mids and highs were some of the clearest and most detailed I’ve heard. Bass had good detail too but wasn’t as weighty as the tube amps which I prefer. However, because I also have a pair of subs I’m not missing anything in the bass. Since you have subs you’ll have more options with amps with these speakers. From what I’ve read the reason these speakers like amps that have low damping is because the driver is well damped and controlled. Adding a high damping factor amp puts even more control on the driver perhaps restricting it somewhat in regards to bass. I’m not the designer or super techy but I either read or heard something like that about these drivers. I’m currently using a Line Magnetic LM845 Premium amp and an LTA ZOTL 40 Ref+ amp, both being fed by a Holo Serene KTE preamp. Both amps sound fantastic and different. The LTA is crystal clear and more detailed, unlike any other tube amp I’ve heard. And it should since it’s not like most tube amps, but it’s not a solid state sound either but it’s transparent like a solid state amp and I can hear very deep into the music. The Line Magnetic has a more romantic, fuller sound. Everything sounds more lush, perhaps a little bigger, but with slightly less detail. Both sound beautiful in their own ways. 
 

As far as weaknesses of these speakers the bass isn’t going to thump you in the chest. But they do get very good bass probably into the lower 40hz region. The bass is also very tubeful and textured. Almost like an open baffle speaker but maybe with a bit more heft. Again, blend in a pair of subs and you won’t be lacking bass. I use a pair of REL S510s and my room is similar in size to yours and when my wife and I get into listening we can make the windows shake. My wife is actually the bass head and she loves these speakers with the RELs. So much so that I might upgrade to the REL carbon specials even though I already have plenty of output. 
 

I would also say that I’ve learned that these speakers can be a little tricky to set up. I struggled for a while having the sound beam from the drivers. It would sound like headphones and the center image would pan left or right but not be separated from the speakers, which is one thing I love when listening to music. It was frustrating. But I learned that this can be common with single driver speakers because when you use a larger driver, especially in the vocal regions, the sound doesn’t disperse as much as something small like a 1” tweeter. My early attempts to create better imaging was to love the speakers further apart to the point they were really wide, hoping I would get a great center image. This failed miserably. I also played with toe in and got good results when I toed in aggressively, basically crossing the speakers a foot or so before the listening position. But doing this also created a narrow soundstage and did some weird things with the depth. One day I decided to try positioning again and since I had recently learned that single drivers can be prone to beaming I started with the speakers very close together and the started slowly moving them apart. That’s when I had the eureka moment. Basically, my experience is that these speakers like to be closer together than I’m used to. I would estimate I sit 12-15 feet from the speakers and they’re about 7’ apart. I also tow in slightly, 5-10 degrees. Now they image beautifully. I get depth, width outside the speakers and height. I will say I’ve had speakers with bigger sweet spots but i haven’t had speakers that are this pin point, deep and real sounding. 
 

One other plus with these speakers is they are the best low volume speakers I’ve heard. That’s important to me because I often listen early in the morning when my wife is still sleeping. The music room is just outside the bedroom. I can listen at low volumes and not feel like I’m missing anything in the music and I’ve never woken her up. 
 

I’ll end with this… About a year ago I told my wife I may want to try other speakers. Not because I don’t love the Nenuphar Mini’s but simply because I’ve had them a few years, longer than any speaker I’ve had, and just wanted to try something else. I’ve demo’s some speakers that I’ve lusted after but I still have the Nenuphars Minis. After each demo, even if I came away impressed with the other speaker, once I came back home and turned them on I was immediately resold on the Cubes. Are they perfect? No. But, to me, what they do well they do so very well. So much so that I can’t let my grip on them go. Or maybe it’s their grip on me that I can’t seem to separate from. 

@abd1   From what Ive read elsewhere the First Watt Sit amps work better with the V1 models due to the different ohms factor.  Still have my V1 Mini's brand new in the crate (Ford Mustang Blue)    Great write-up above. Im sure I'll find your notes very useful so thanks for that!!