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/

----------------------------------------

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
@abd1 looks like RCA 45, and RCA 6sn7.  I have not heard RCA 45, yet, but my experience with RCA 6sn7 is that they are very dull sounding and not as musical as other 6sn7 out there.  I really like Brimar cv1988 6sn7 but they are pretty much unobtainium now a day.  Other NOS tubes I like is the Tungsol black glass, get the cheaper 6f8g with adapter, they sound the same as their 6sn7 counter parts.  I also like the new production tubes like the black treasure.  

I have the Brimar, Tungsol and JJ will report back when I get I get the chance to try them.  Alan mentioned it will take him 2 weeks to build.
@abd1,
I'm impressed with the use of Tamura power and output transformers.  This builder was serious about pursuing very high quality sound. I bet this amplifier sounds beautiful driving your Nenuphars. 
Charles 
Alan is building me a set of his 45 mono as well.  Which 45 tube are you using?
Sounds like an awful experience but glad it’s just material damage and you’re able to be in the home. 
I’ve never heard a 2a3 tube. I’m using 300b SET monoblocks right now from Sophia Electric. Beautiful mids and highs but I’m not getting the bass I like. I have an Alan Eaton 45amp and I really like the sound it produces. Not quite as refined but the bass is more alive, punchy. Thinking about trying a Primaluna Evo300 amp as I really like my old Dialogue series and love the EL34. Not sure if anyone has tried Primaluna with Nenuphars. 
On a very positive note, I have beautiful music. 

There is a gentleman interested in my Pass XA 30.8 amp. I powered it up yesterday and have it playing music via the Nenuphars for about 2 hours now.

Have to say it is holding its own. Very good... in fact quite good!

Scott's new 2A3 amps have 80 hours of playtime on them since being re-powered up (once the electricity was restored, post Ida).  I'll post more about how they are performing, in a day or two.
@abd1  Things are slowly moving along. The downed tree is scheduled to be removed on Tuesday. After that the collapsed chimney and major debris from the side of the house will be removed. There is a section on the inside of the house that will need to be sealed for protection from dampness and mold, etc. This is just the start. 
Thanks David, hope you’re well. 
I’m going to try and get the speakers further apart. I’m sitting 11’ away and they’re about 8.5’ apart. Then I’ll try toing in. I’ll report back as I experiment. 
@abd1  Re-enforcing what you already know. Since you are in a new room, with different dimensions, etc. etc. experimentation will take time but you will find the sweet spot!!!

Let us know what ends up working best for you. All owners posting here have slightly different position setups specific to their rooms and needs.
@abd1

Rough (and general) numbers for my system with the Nenuphars:

~ 9.5 ft from the front wall (to the front of the speakers)

~ 7.5 ft apart (center of driver to center of driver)

~ 7 ft from the listening position

~ 15 to 20 degree toe in

Room size: 26 by 19 by 9
For Nenuphar (reg or mini) owners, how far apart are your speakers and do you tow them in? I have minis and I just moved. My new room is bigger than the one before. I’m working on setting up the speakers and they’re very “beamy” at this point where the sound seems to coming right from the drivers. I just moved them further apart with almost no toe in and it’s better but still a bit beamy. Maybe I’ll move a bit further still. Just wondering how everyone else is set up. Thanks. 
I like the tempo electric solid core silver in Teflon (and use VH audio solid core silver in my interconnects and components).
No, do not own Cube speakers nor know anyone who does.  No one in the world has done what I suggest......you could be the first!  I do know someone who has done this to his $1200 a pair Lii Silver 10 speakers (mounted on the open baffle described above).  Yes, I have done this to many speakers and make my own speakers and have since the mid 70s.  I have modded and manufactured gear since the late 70s.  I bean around the block.  People will argue all day about what is the worlds greatest hook up wire.  I really don't know.  But any great wire will work fantastic in the scenario described.  It is the removing of the banana jack, the banana plug, the WBT connector and (if possible) your spade on your speaker wire that will make the most difference.  Of course, you want great wire....here are some suggestions:

Parallel single strand PCOCC Chris Venhaus wire
Parallel silver gold Mundorf wire.
Neotech copper litz braid wire....parallel several 20 gauges or get some 14 gauge from Zen Wave.

ricevs Do you own speakers made with Cube Audio drivers or similar widebanders?  Do you know anyone who owns complete (with cabinet) Cube Audio speakers who has replaced the wire as you suggest?  Do you have a recommendation for "some great sounding wire" that would make us "guys weep with joy over your sound"?  Pls suggest what would be the very best wire regardless of cost.  We don't have to buy much and while my Nens do make me weep on occasion I could handle more.
A reminder......the Neo 10 drivers are $6500 the pair directly from the US distributor. You can build an even better box for way cheap. However, if you mounted it on a four foot high by 2 foot wide open baffle....with four foot by one foot wings going straight back on each side......you would have even better sound......and you would still get flat to 40hz bass. You could buy some 13 ply baltic birch three quarter inch plywood and use three layers with green glue in between each layer.....pretty darn dead.

For even better sound (whether in a box or open baffle). You can hardwire some great sounding wire directly to the voice coil wire (the point where the voice coil wire is soldered to the banana jack). Then you solder that wire (either hanging out of the box.....or dangling off the driver in open baffle) directly to your speaker wire......so there would be no speaker connectors what so ever......this will blow your mind. You an also solder a Ground Enhancer directly on the negative voice coil wire, as well for even more info. WAY, WAY more transparent. or you can keep your speaker stock and enjoy the veiled sound.....he he. You can do what I suggest and put it all back to stock later on when you sell the speaker (if ever).

You guys have never heard your speaker......you do the above and you will cry and weep it will be so good.  One of you wants to do it.  One of you is not a sheep.  One of you wants to get sound to die for.....all it takes is one person willing to do it.....costs really nothing to hardwire.......just some labor.....and you can put it all back to stock without anyone ever knowing.  Don't be a wimp.....he he.  You can do it.  I will talk you though it on the phone, if you like....really.  I want you guys to weep with joy over your sound.
Sorry to hear about your house David. Hope everyone is safe and the audio equipments survived the damage.  

Best wishes for a quick and safe recovery

Scott Sheaffer’s Found Music custom 2A3 amplifiers went in the system two Thursdays ago. Initial impressions are very positive.

Unfortunately, Hurricane Ida meant having to power off two Saturdays ago. Power is estimated to be back up this coming Wednesday. I should be able to report back with more initial impressions in a week or two.

Our house sustained significant damage from a large uprooted tree which took out one side of our home. This is where the audio room is. I doubt construction and repairs will start anytime soon, but when they do I will have to forego the audio system as we are short three rooms in our home.
@stephendunn  All the best on going forward with the Thoress EHT integrated and TotalDac D1 Direct.
david_ten Yes, I am seriously considering the Thoress EHTs although more likely the integrated version which would allow me to sell the VR L2iSE and bank the difference towards an upgrade to a Totaldac D1 Direct. Reinhard did offer a 10 day in home audition. I am gathering info on the EHT integrated but have not been able to find anything beyond Hifi Knights review which was very positive. This is all a bit of a stretch since many of the qualities that SE enthuses over in his review of the EHT monos I feel like accurately describes the advantages the VR L2iSE had over the SIT 1s when I got to A/B them.

Look forward to hearing your impressions of your new 2A3 amp. BTW, I can’t recommend the Linlai 2A3 tube highly enough, although sad to say I blew the filaments in mine because I had the voltage switch on 5 Volts as opposed to 2.5 Volts. Must have inadvertently moved the switch dusting. Back in go the Elrog 300bs till a new set arrives. They’re great, just don’t have the delicacy and detail of the Linlai.
McIntosh has always been recommended with Zu and works beautifully. Won’t be surprised to work ok here. 
@david_ten Thanks for the bit of info.. excited to hear your thoughts.. I used to own purposed built 300B amp for headphone listening, these builds really do bring out the best from our speakers.  Please share some photos of the amp when you get the chance.

@charles1dad From Stereophile I also see this:

The output impedance was lowest from the 8 ohm Autoformer tap, at 0.09 ohm at 20Hz and 1kHz, rising to 0.13 ohm at 20kHz. The 4 ohm tap’s output impedance was almost twice that of the 8 ohm tap—not what I was expecting—while the 2 ohm tap’s was 0.14 ohm at low and middle frequencies, rising to 0.185 ohm at the top of the audioband.


So from the 4 ohm taps, the output impedance is double (almost) of the 8 ohm taps, going to 0.18 to 0.26.. giving the damping factor of <50 (similar to the SIT-3) going into 8 ohm loads.. so yeah, crossing my fingers and toes that it’ll work out.
@khargon  I've been (mostly) hands-off through the build process. I'll share the design elements / approach later. 

The incoming amps will output around 3 watts... which is by design...the focus being on maximizing sound quality over power output. To illustrate the point, my current amps were designed to maximize output from the 2A3s and deliver ~ 4 to 4.5 watts.
@tomic601  @charles1dad  Thanks!  The credit goes to and is well deserved by everyone!!!
From JA at Stereophile.

"McIntosh specifies the MC462 as being able to deliver 450Wpc (26.5dBW) into a load matched to the nominal output Autoformer tap. With clipping defined as being when the THD+noise reaches 1%, fig.6 indicates that the MC462 exceeded its specification even with both channels driven, its 8 ohm output clipping at 516Wpc into 8 ohms (27.1dBW). The trace in this graph stops at 1%, as that is when the amplifier’s protection was triggered. Into 4 ohms (fig.7), the McIntosh’s 8 ohm output clipped at 720Wpc (25.6dBW). It’s fair to note that I don’t hold the wall voltage constant for this test; with both channels clipping into 4 ohms, the wall voltage had dropped from 121 to 115.4V. The MC462’s 2 ohm output delivered 190Wpc (22.8dBW) with both channels driven into 8 ohms at 1% THD+N, 298Wpc with both channels driven into 4 ohms (21.7dBW, fig.8), and 536W (21.3dBW) with one channel driven into 2 ohms"

This type of amplifier (On paper) is truly the opposite of the kind of amplifier the Cube Audio designs of the Nenuphar had in mind to drive this speaker. Single driver crossoverless with intentionally easy impedance load and highly damped driven design.

It will be very interesting to see how this pairing works out. You just never know until you listen. Best of luck @kragon. 
Charles
Congrats.. what are the specs for these beauties?
I'm going a completely different route.. put in an order for a McIntosh MC462.. hopefully they will pair well with the cube.  It's a 3 months wait now aday.. no fun at all.
@tomic601 
"what a lovely thread with great contributions by caring people. What audiogon could be…"


Yes, the OP @david_ten runs a tight ship😊.
Charles 
what a lovely thread with great contributions by caring people. What audiogon could be…

Grace

the Thoress phono enhancer was on my radar, would appreciate impressions of that
@david_ten,
David congratulations!!! True state of the art of effort from Found Music. I believe that they will sound spectacular driving your Nenuphars. I truly look forward to your  listening impressions. Scott is an immensely talented builder of Uber quality tube amplifiers.
Charles
I happen to have the Thoress full function super preamp available if someone is interested.  Thoress is a very interesting company making hand crafted point to point wired gear with great build quality. Seems very few tube pieces are made this way anymore. 

I listened to the line stage portion only, as I don’t own a turntable, and it sounded so engaging and fun.  Their amplifiers  must sound beautiful! 
An update regarding my system:  Scott Sheaffer's Found Music custom 2A3 monoblocks will be delivered by Scott tomorrow evening. I'll share more once they have had time to settle, post the eight hour drive from north of Dallas to New Orleans. The amps are fully run in...over 500 hours.
@jollytinker  Thanks for the additional detailed findings driving the Nenuphars with your EHT monoblocks!!! Looking forward to the EHT - Teresonic pairing and comparisons between your two systems. - David.
@khargon Thanks for sharing your findings using IsoAcoustics’ GAIAs and for the photographs. The photos really help!!!

Can you share the height at the bottom of the Nenuphar cabinet (front and rear)? Thanks. - David.
@totetapaudio  Richard, have you compared your approach against Townshend's options? If so, your findings? Thanks. - David.
@kevn  Thanks for your post!  Looking forward to your results as you upgrade and tweak your Nenuphar based system.
Hi pulinap, this response is coming a little late I think - David alerted me to your post regarding the nenuphar, and from a read, I see it in specific reference to ‘holographic imaging, overall balance, and bass performance’.

ok then, I’m running my nenuphars with a 19W line magnetic 125 211 tube amp with a tube preamp. My prior experience with audiophile bass is from a 120W ss amp and a 30W tube amp paired with Larsen6.2 speakers going down to the high 20s, proac D30rs speakers going down to an accurate 20hz, and the tekton moabs with a claimed 20hz that doesn’t actually sound like it goes that low. 
I think excellent bass is absolutely vital for everything higher up to gell well, and at the very beginning listening to my nenuphars, I felt that the bass wasn’t performing as well as my proacs - this not in relation to depth of frequency, obviously, but with respect to total nuance, speed, and accuracy. With the right speaker cable, fuses, and power cables, however, the bass is now not only performing better than my proacs, but with such subtlety of timbre, I am moved to tears at times. It will never go down past 30hz, nor hit the subwoofer-like bass of my proacs, but it does something better - something which David first mentioned to me as sounding more ‘right’, having to do with the same driver that’s driving everything also driving the bass on that single unsplit signal. (I hope I’m explaining that correctly, David).

The outcome of that single driver and the amazing cabinet that drops the bass to ‘just’ 30hz, is that the lower frequencies I’m hearing has this cohesion to everything else I don’t hear with the other speakers I own, or any other speaker I’ve heard - on most speakers, the bass is just that, bass; great for the feel, rhythm, and depth, but mostly sounding unplaced and just there as bass coming from the speaker, however solid and deep, but expected. Nenuphar bass is a psychedelic thing for me, a teleportation to the very venue and air that resonates with a bass that belongs to everything else and becomes part of the sound decay of the music in the air - its so effing ‘real’. 
Ok, the bad news haha - there are three tracks I use to gauge the effectiveness of bass depth (nothing else regarding nuance or accuracy) - ‘temple caves’ - mickey hart, ‘raiders march ’ - john williams, and ‘fading sun’ - terje isungset. About 6 and 18 seconds into ‘fading sun’ there are these crazy deep thumps - they are not just casual events or accompanying background support, but absolutely vital and visceral parts of the track. These are so light with the nenuphars and my 19W tubes that they barely register, in comparison to my proacs and the Larsen with the same amp. The good news is that the Tekton moabs only do marginally better. With the ‘raiders March’, there’s this massive background orchestral bass drum hit that caps the movement at about the 1.32 mark - its deep solid boom resonates to cradle all the other instruments for that single moment - this is noticeable, but is still pretty weak from the nenuphar. Finally, about 12 seconds into ‘temple caves’ there is a super deep note of an earth drum immediately following the opening of the track - this drum strike lacks any presence whatsoever on the nenuphars, as would all similarly deep notes from tracks that go way down deep. I have not been disappointed in the depth of its bass performance in any other way, be it bass heavy numbers like Lorde’s ‘royals’ or Paula Cole’s ‘tiger’. And almost every full orchestral tracks. But do not bother listening to billie eilish’s ‘you should see me in a crown’, and you won’t get the same visceral chopper blade thud in your belly with Pink Floyd’s ‘the happiest days of our lives’ ; p

I have not made any mention of ‘holographic imaging’ or ‘overall balance’ because the nenuphar will not disappoint in any way on these two counts - it is an amazing speaker ; )

In friendship - kevin
I have to say I’m not a big fan of IsoAcoustics solutions using rubber or solutions using spikes for that matter either. I’ve had much better results using rollers and cups in combination with springs. It can make it complicated when trying to seismically isolate speakers. It’s far easier with components where one can use the rollers directly under components arranged in a equilateral triangle on plan around the centre of mass and they in turn sit on plates of slate with springs under the slate to take care of vertical isolation. You can use small inner tubes for the springs set at a low pressure to achieve a low resonant frequency or appropriate metal springs like the ones on ebay or Machina Dynamica.
@stephendunn Glad you got in touch with Reinhard and got some up to date info. I can't recommend him highly enough as a businessman, electrical engineer, aesthetic designer and builder (though maybe not as webmaster! lol. I don't think the EHTs have ever had a presence on his site).  
I've been listening to the Nenuphar with IsoAcoustics GAIA II for a few days now.. so far I can say that it's improved the center image and increased depth, really enjoy the Cube even more now.  Also noticed improved treble, I think that maybe because I'm no longer tilting the speakers up.  Note however that my listening room is a converted garage, the floor is already sloped down, which give a similar effect as tilting the speaker up.
These looks great and sounds great.. I've no plan of going back to the standard feet.

Some photos here:https://photos.app.goo.gl/NT6eiMgeea91o2Tt5
@jollytinker  Thanks for your response.  Reinhard Thoress just responded to my inquiry via their website, which he says is sorely out of date.  He does offer the newer version of the EHT monos for 12.950 Euros and an integrated version for 8.950.  I haven't inquired about in-home auditions.
@charles1dad Thank you for your comment. I had been planning to write a post on this for some time but I suppose I needed a nudge.

@stephendunn I’m not sure I can be of much help in acquiring these. I originally spoke to the US dealer about the EHTs (Audio Arts in NYC) about 2.5 years ago. At that point they were $15k retail but there was no demo pair to listen to (that might be contributing to the obscurity of these amps.) I wound up finding a pair at a more reasonable price after a very long wait but I’d rather not go into the details online (not to be secretive, just respectful of others involved). I don’t know what the situation is now with Thoress’ US representation but I expect that the price has risen. The amps have changed slightly too (since Ebaen's review) - they now go up to 50w as the Positive Feedback piece mentions (40 before) and the color is green rather than black.


@jollytinker, 
I join @stephendunn in appreciating you taking the time to post further listening experiences of your audio system.  I'm happy for you that you've found such an ideal pairing of the Thoress EHT  amplifier  and Nenuphars. 
Charles 
The EHTs totally missed my radar.  SE's review inspired poetic writing you rarely see from him and this together with what @jollytinker has added has whetted my curiosity.  After some reading I'm very intrigued by the design of the EHT's and looked to see if any were around since they no longer appear on Thoress or their distributor's website.  No history of a sale on HiFiShark even.  
jollytinker  do you know anything about availability?  Special order from Thoress?  And many thanks for sharing your experience with them and your set up. 

Nothing major to report since last time. I find that Ebaen is right when he says that the EHTs and Nenuphars together sound like “something cracked open.” good words for the sensation. “Benign psychotropic drug” is also good. it sounds like a quantum leap in resolution without the tipped-up feel of other similar drivers. In this regard I’m comparing the Nenuphars to a pair of Teresonic/Lowther speakers I have in an upstairs system (which are smaller btw). When everything in the system is right it can be really spectacular and if things aren’t right, you’ll know.


The EHTs are really special amps in my estimation and I’m not sure why they’re so little known. If you find yourself having to choose between warmth and detail, the EHTs just seem to leave that whole problem behind. They’re “warm” in the sense of being full in the midrange with gorgeous timbre, but also open and airy and pinpoint in the presentation of a soundstage. I’d say they’re just genuinely linear. They also sound great with both Proac tablette 50 signatures and the nenuphars, obviously very different speakers. I’m about to try them with the Lowther/Teresonics so I can update further on that pairing. 


On the Nenuphars, I’ve settled on the basic layout I started with. Slight toe-in as recommended by the manufacturer, with slabs of rock wool against the wall next to speakers to damp the first reflections. That really helps to crystallize the images lying outside the speakers, ironically. I have a tough room to work with at the moment - about 14’ square with 10 foot ceilings - and it’s our living room so I don’t want to make it look like an audio lab (any more than it already does). in the next year we’ll be doing a re-model that will give us a much larger and longer room elsewhere in the house, so at that point I should be able to dial it in much further. As for amps, I’ve been happy enough with the EHTs that I haven’t thought about trying anything else (besides the SIT3 which was very nice but not like the EHTs).


I will say on the very slightly negative side that the Nenuphars seem to have a bit of a …. not sure how to phrase it. I hear it as a certain lack of resolution in the bass as compared with the mid and high freqs. Or maybe you could say they have a dip in the lower mids or upper bass. I take this to be the crossover point between the driver and the cabinet and as such it makes a lot of sense to me that the subsequent efforts from Cube Audio appear to be concerned with bass reproduction (larger drivers and subwoofers). That said, the bass can be immensely satisfying on the right recordings (acoustic basses often sound just right), and I take this to be an inherent aspect of this kind of speaker design (if you need a car for shopping you wouldn’t pick the Lambo).  


also I found Stillpoints Ultra SS to work well in place of the OEM spikes at the front of the Nenuphars. There are adapters made by Stillpoints that work perfectly - I’ll get the name and measurements if anyone’s interested. 


@jollytinker  Thanks! Any updates from your post in March? Changes in the positioning of your Nenuphars, comparisons with amps other than with your SIT 3s, etc.?   Thank you. - David.

@charles1dad  Charles, thanks for reposting Jolly's initial feedback.