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
Thks guys. 
I was sure these specs will fit well the cubes.
to be continued.......,,
Hi everyone,
I had planned on purchasing the Cube Nenuphar 10 this fall for my 14 x 18 room but my system is now being relocated to a 11 × 12 room.  Is this room to small the the Nenuphar 10's?  Should I being looking at the Nenuphar 8's instead?
@bobheinatz Bob, I would personally choose the Nenuphar Mini (F8 Neo driver) speakers for that sized room (11 x 12).

Keep in mind, I have my Nenuphars (10s) pulled way out into the room and listen to them in a somewhat nearfield position. My room is 19 by 26.

Perhaps those who have their Nenuphars placed much closer to the front wall will provide their recommendations?
Dave,
Thanks for your opinion.  My guess is also the F8's would be a better match in that room. Any one else with experience in a small room?
I have the Nenuphar 10" in a 15’ x 13’ room. Drivers 60" from the front wall and 7’ apart center to center. Listening position 7’ triangle so also in a near field configuration. I’ve tried them in every position I could think of and always come back to this. Toe-in is important. I started with them straight on then toed them in in tiny increments looking for a balance of sound stage and center image.
I’ve noted that in the last year or so Peter B. from AV Showrooms and others have placed them on the front wall and prefer that position in those rooms. It doesn’t work at all in my room. The sound stage collapses in depth, imaging disappears. The bass isn’t all that much if any better. These speakers have magical properties that will manifest for you if you find the right formula for them in your space. If the rest of your system and placement are right they will create sonic places, architectures, landscapes...places for you to go. When Srajan said they are a benign psychotropic drug, maybe he was having a similar experience.
11' x 12' = 132 sq ft = 12.3 sq meters

At the Cube Audio website we find these recommendations:
Nenuphar Basis -- 25-100 sq m
Nenuphar 10" -- 20-40 sq m
Nenuphar Monitor 10" -- 12-25 sq m <====
Nenuphar Mini Basis 8" -- 20-60 sq m
Nenuphar Mini 8" -- 12-25 sq m <====
Nenuphar Mini Monitor 8" -- 12-20 sq m <====
Magus 8" -- 15-30 sq m
Bliss C 8" -- 15-30 sq m

Robert
I know that John from Refined Audio has said he slightly prefers the 8" over the 10".

Another avenue to consider is using the 10" with room correction software.  I have 10" Nenuphars in a relatively small room 13 x 15 x 10 and think they work great, but have noticed that some mid to lower bass notes get muddled (I have no acoustic treatments other shelves of records).  I am going to borrow a Dspeaker anti-mode x4 to see if it corrects this.  Won't happen till late July, but I'll report back.
Thanks for all the replies.  I had a strong feeling that most would recommend the 8".  I had my heart set on the 10" but room changes dictate looking at the smaller option.  Will also look at the 10" small monitor.  Btw flooring  is suspended with carpeting.
@stephendunn There are certainly posters out there who's ears I trust that use and enjoy digital correction.

Unfortunately my only experience was *not* good. I had a Lyngdorf tdai-3400 for some time and turning on room perfect kind of made me sick to my stomach... the music sounded "blended" for lack of a better term. Definitely less natural than without.  I had the amp for about 6 months, so I knew it well and had obviously done RP setup many, many times. Just couldn't get it to sound right with my Coincident PREs. Every time I turned off any form of digital processing it got better actually, but never quite right.

Very curious to hear about your experience and add another data point.
Bob, you will probably need longer spikes if the carpet is thick, in order that one maintains the gap as intended. Or arrange for them to stand on something solid.
Since many people in here are considering the bakoon 13r, I thought I'd quote a post from @almarg on the input impedance:

"Re the Bakoon 13R, be aware that the input impedance of its RCA input is only 10K, which will not be a good match for many and perhaps most tube-based components.

I believe the other input choice provided by the 13R, a "Satri Link," would only be usable if driven by a Bakoon component providing that kind of output.

Regards,
-- Al"
Not sure that's going to effect too many people. Multiply by 10 to get your number.  REF 10 by Audio Research comes in about 60% of the Input Limit.  The Luxman C900 comes in at 10%. I'd love to see a list of how many amps would go over that 10K figure....maybe some Boutique stuff.

You wouldn’t want your preamp output impedance to be more than 1/10 (preferably 1/20th) of the amplifier’s input impedance. Al’s correctly points out that some tube preamps have output impedances that can exceed that level (particularly at certain frequencies). Good warning from Al. Not an issue with nearly all solid state preamps. To be clear divide the amp input impedance by the preamp output impedance.

Charles


Chris ( @cal3713 ) thanks for quoting my post from another thread in this one, where it is also relevant as you indicated.

@riaa_award_collectors_on_facebook, keep in mind that the majority of tube-based components having line-level outputs employ coupling capacitors at their outputs, which often cause their output impedance at deep bass frequencies to rise to **much** higher levels than the specified output impedance (which is usually based on a mid-range frequency such as 1 kHz). So in those cases the 10x ratio should be applied to the 20 Hz output impedance, if it is known. (If the component has been reviewed by Stereophile JA’s measurements will indicate that number).

If the 20 Hz output impedance is not known, and there is reason to believe that the tube-based component employs an output coupling capacitor as most of them do, I suggest applying a ratio of 50x to 75x to the specified output impedance. Some here have even suggested 100x.

Also, the minimum recommended load impedance ARC almost invariably recommends for their line stages and preamps is 20K, including for the Ref 10, even though its specified output impedance is 600 ohms balanced and 300 ohms single-ended. And for a few of their designs I’ve seen recommendations of "60K recommended, 20K minimum."

And just to cite one further example, the Herron phono stage which I use has a specified output impedance of 400 ohms, but its manual recommends a minimum load impedance of 50K "for optimum performance."  Although Keith Herron has indicated that 20K would usually be acceptable, in most systems.

Perusing JA’s past measurements of tube-based line-level components will reveal numerous other such examples.

Regards,
-- Al



Thanks Al.  I should have paid more attention in school :)  Somebody gave me that formula and told me the REF 10 and Bakoon would be fine. Thanks for stopping me from blowing up my gear!! LOL
Although I know RIAA's above comment is in jest, just to be clear for future readers... If you don't follow the 1/10th ratio rule, you will not get a flat amplification of the preamp signal with frequency aberrations in the bass response.

Also, it may be possible to modify the amplifier to address this issue (depending on amplifier design). My first watt f4s (simple class A without feedback) have a 47.5k input impedance, but can be modified to have a higher I.I. simply by changing out the resistor on the input.  I was informed that I could use anything up to 250k without changing the operation/sound of the amp. Doing so enabled me to use much smaller output caps on my Don Sachs 6sn7 preamp, and allowed me to afford some top end duelund's that greatly improved the sound. No idea if this is possible on the bakoon... but hopefully useful information regardless.
Having an outstanding tube line pre driving a 10k load is possible. I fact I had Don Sachs configure one output to drive a 10K load and one to drive the normal 100k load. Sounds fantastic!  Just takes a big ass high quality cap.
EnjoyTheMusic has a short news item on Aries Cerat and their new Ianus series of electronics:
www.enjoythemusic.com/news/0720/

Aries Cerat Ianus Series amplifiers is a showcase of the company's unique TriodeFet technology. After years of developing and refining their technologies, they are proud to introduce the TriodeFet technology, and a Series of amplifiers that implements this truly innovative technology. This technology is neither a hybrid topology (in the usual sense of a tube-driving solid-state stage type), nor a solid-state driving tube kind of stage. TriodeFet is a new way of using hollow and solid-state devices. The concept is to have a low voltage / high current active device, which had the linearity of a triode, and at same time would be able to source enough current to drive low impedance loads directly.

The TriodeFet, can be seen as a three terminal active element, just like a MOSFET or a triode. The company's breakthrough is that its transfer curves are identical of a true high quality triode, with the only differentiator from a true triode is that, the Y-axis (current) is in scaled in Amperes and not mA. What this means, is that you can design circuits that were never before possible either by using tubes or transistors. This new active element can be used to develop simple, very linear circuits, which are stable down to very low impedances, while the TriodeFet's inherent linearity is making the use of the problematic negative feedback redundant. New models within the Ianus Series include the Geminae (€110,000) Class A amplifier that produces 130 Watts @ 8 Ohm. Aries Cerat's Essentia (€39,000) is the little brother that produces 40 Watts @ 8 Ohms.

The Aries Cerat website has a News section:
http://aries-cerat.eu/news

Be sure to scroll down, look at the show pictures and check out the speaker drivers....
Just received a lightly used (less than 20 hours) Cube Nenuphars 2 weeks ago. I purchased them on Agon from Salon1Audio (excellent experience). I wanted a speaker that could take full advantage of my beloved First Watt Sit-3 amp that was driving some modest bookshelves to amazing heights in my second system. My second system had taken over my main system for most listening sessions. The main system (Magnepan 3.7i speakers, Pass X250.8, LTA MZ3 pre, Antipodes EX source with Roon and Qobuz) was not shabby either. I bought the Cubes on faith. I had not heard them before buying. That is a first for me. The reviews and the forums were overwhelmingly positive and the match up with the Sit 3 seemed to work well.

Out of the box the experience was disappointing. The speakers seemed to need more power than the Sit 3 was giving them. I have a second Sit 3 and considered bi-amping. I assumed more break in was required and sat tight while it ran. After 50 hours the sound was still dry. A fellow audiopal came by with a few of his best toys and we listened for about 4 hours. He convinced me to give the X250.8 a try. Boom- the Cubes opened up. We cautiously drove them knowing the 40 watt speed limit. The sound relieved me that the speakers were getting there but the more powerful Pass was not a long term solution.

We then brought in his Zu Undertone sub. Without so much as dialing in the phase the improvement and the match with the Cubes was amazing. We rolled through a number of tracks and finally just started to listen instead of analyze. Closer yet. Closing on midnight and with work looming we called it a night. Sean Casey's sub is an absolute dream match up for the high efficiency Cubes. I'm getting a shiny gloss black Undertone to match the Cubes and would recommend it for those who are considering the hybrid Cubes now offered. You only need one Undertone. No need for 2 subs here. It is fast and blends in with the Cubes as if they were designed for one another. My neighbor is now on the search for a used Undertone to go with his Druid 5s after taking the system in yesterday. His words-this is the best system I have ever heard and better than anything we listened to at RMAF (2019).

Now after over 100 hours the Sit 3 is back in and the Cubes are receptive. This is what I was waiting for. 6 moons describes the sound very well, in my opinion. I suggest that read. Despite turning it up for a long listening session yesterday my friend and I felt absolutely no fatigue. The coherence and imaging are as advertised. The hype is very well deserved. The Sit 3 can now show off its brilliance to the fullest extent (thank you Nelson Pass!). My guess is that the break in isn't over yet, either. If I don't get more out of the break in it won't matter much at this point. I haven't heard anything come close to this for less than $100k.


Congratulations @bebruatigan and thanks for interesting information.

If you can try and borrow a Bakoon 13R.

Hi bebruatigan,

You experienced a very dramatic form of the 'break-in' process. I am glad you had the patience to give the Nenuphars a chance. Some listeners would have  come to a premature conclusion and given up on them. I have no doubt that your are hearing superb sound with your new system. Congratulations and enjoy this for many years.

Charles

The preamp is the Linear Tube Audio MZ3. I use the speaker taps to the Zu Undertone. The dac is a Border Patrol SEi (I leave the tube buffer off). An Antipodes EX running Roon and Qobuz is the source. 
Over on AudioShark I came across an interesting post about Nenuphars and the Gryphon Diablo 300:

www.audioshark.org/amplifiers-8/gryphon-diablo-300-vs-vitus-audio-sia-025-mk-ii-16909.html?h...
Yesterday my friend brought all his system to my home. He wanted to know why i m so happy with my new speakers, Cube Audio Nenuphars.
Full range, single driver, no crossover 6 ohm and 92db.

His system consists of: 
Gryphon300+dave+mscaller+n10.
PC from True Signal, SC Sablon t.o.r, IC Atlas Mavros
PC for gryphon: Sablon t.o.r.

I drive my speaker with mbl c51, 300w class D.

Guess what? Gryphon is an amazing match to these moderately sensible speakers! My friend was speechless, anticipating a bad match! I guess Gryphon, when used at low volume, throws class A only power, and that's what these babies like the most.
Diablo 300 is a Darkish sounding amp....I guess as long as you like that kind of presentation. Have ordered a pair of the Mini Nenuphar's but they wont arrive till the Fall. Completely sold out of everything except 1 pair of the Magnus is available from the distributor according to my dealer
Robert, thanks for the link.

I suggest trying some other amps mentioned in this thread as being compatible with the Nenuphar’s. My own experience is with the Bakoon 13R which I can highly recommend.
Maybe the best way to get the very best sound out these speaker drivers is to just buy these speaker drivers and put them in Cabinets made of Granite. 
You get a cabinet maker to do these granite speaker cabinets for you
  
https://www.cubeaudio.eu/cube-audio-f10-neo

On paper I don't see what would make the Gryphon Diablo a particularly good match with the Nenuphar given the specific design objective of this speaker. However as has been shown before there's no substitute for actually listening and judging.

I don't know why granite would necessarily be superior to the original Nenuphar cabinet. This is a very well thought out cabinet to match the superb driver and no doubt is a major factor in the overall sound quality.

Charles

Related to the cabs...the finish anyway...they are going to start offering multiple Wood Veneer finishes you can choose instead of just the Black/White option. Im looking forward to seeing those designs.
Wood veneers would be interesting. The black can be a bit hulking, kind of like a Carnac stone in your living room. :-)

- Robert
dear all, 
have anyone compared the sonic differences between Cube Audio Nenuphar vs any of Reference 3A speakers? just curious how do they sound since 3A do not use crossover in their main driver too, and with only a cap before the tweeter, i guess the soundstaging , imaging, speed, dynamics etc.. generally very similar ? Thanks for any comments. 
-phil
as I looking towards getting a pair myself, I would like feedback on the following:
1. any suggestions on a solid or tube integrated amp not costing a fortune ?

2. for those who are using SIT-3, what preamp are you using ?
@david_ten I see that you are using Edensound spikes. Did you get the extra large solid brass spike for the front and regular hemispikes for the back ? In that case, did it match the original rack angle ?

SIT-1 Mono’s are supposedly superior to the Sit-3 on these speakers. I have both so look forward to seeing for myself down the road. There are numerous YOUTUBE Videos featuring these speakers and Flea Watt Amps from Tsakiridis,Tektron and other Foreign tube amp manufacturers...dont think any of these marvelous sounding amps cost more than 2-3K. DECWARE might be a USA alternative although they dont have any 2A3 amps which sound awesome on these.
@philipwu Philip, check out Srajan Ebaen’s very recent review of Aurai Audio’s M1 Classic speaker. At the very end of the review (bottom of the last page / Page 11), Srajan compares the M1 to the Cube Audio Neuphar.

I do not know if the Reference 3A speakers are similar to the Aurai M1’s, or if the comparison is apt,...but his short summary relative to the Nenuphar might provide insight.
@debjit_g You are correct. Eden Sound Extra Large Solid Brass Spikes in the front AND Regular Hemispikes in the rear.

The angle / tilt (front to back) is very close to the original. It resulted in a slight increase in height.

Overall, the improvement in sound quality and performance (on my hardwood suspended flooring) was significant and immediately heard and experienced versus the stock footers.
SIT-1 monos (when they can be found) are much more expensive than than the SIT-3s. Occasionally you will find a SIT-2 for sale, usually cheaper than a 3. The SIT-2 is stereo and provides that immediacy of a tube SET amp. The Bakoon 13R integrated ($5K used) sounds good with Nenuphars, although I prefer going FirstWatt.

For a preamp, the Pass Lab ones make for a great combo. On the tube side I have used LTA and Backert, with Backert being my preferred choice. Easy tube rolling if you enjoy that.

- Robert
It would be interesting to try the sit3 in a dual mono configuration for a more fair comparison to the sit1. All you need is a second chassis, power supply, and then you just move one channel over. Anyone over on the pass labs forum of diyaudio could do it. As I've mentioned earlier in the thread, I found independent power supplies for each channel to be a very substantial upgrade when I did it for my first watt f4s. I think I've said this before too, but it's a really beautiful amp that doesn't get the attention it serves, btw.
Thanks @riaa and @rwpollock Looks like you guys are lucked out getting a pair of SIT-1. All the SITs are unobtonium these days. I will keep my eyes and ears wide open in the used market but if anybody is willing to offload any of the SITs, pm me please :-)
btw, I currently have a PS Audio BHK Pre - can anybody tell if it’s a good match with the SITs ?

@david_ten thanks for the confirmation. You happen to also use a Townsend podium - did it make a bigger difference then just using the Eden spikes on the bare floor ?
@cal3713 interesting thought. There is no question that a separate power supply on each channel can make a substantial difference depending on the original power supply design. I haven’t seen the inside of SIT-3 but if there is enough space inside, you could install the 2nd one in the same chassis and rewire into a dual mono configuration. You would then have to recalculate the fuse rating (if it has one) and drill another hole for the 2nd fuse. It’s another option for someone wanting a stereo amp and saving real estate :-)
If one had two SIT-3s could you turn them both on and run the right channel from your preamp to one and the left channel through the other amp? One amp would then drive the right speaker and one the left.
@rwpollock Definitely.  The idling board of the unused channel does (in my experience) still create a little extra distortion though, so if I settled on that solution, I'd eventually disconnect that board from the power supply. If a friend had a unit, your method would be the easiest way to see what the benefit would be.
Speaking of Tektron tube amps, they are the 2a3 amps used by Cube Audio at shows. Robyatt Audio carries four of their smaller amps/preamps.
www.robyattaudio.com/TektronProducts.htm
I may purchase one this winter to check it out.

- Robert
Speaking of Tektron tube amps, they are the 2a3 amps used by Cube Audio at shows. Robyatt Audio carries four of their smaller amps/preamps.
www.robyattaudio.com/TektronProducts.htm
I may purchase one this winter to check it out.

Looks like the amps with 2a3 tubes are 2.5 watts/channel. Is that enough to hear at sane listening level, assuming you sit 8-9ft from the speaker ? What about 300B tubes ? has anybody been able to listen to a 300B amp with the Nenuphars ?
@rwpollock Wow, had seen the name in print, but didn't known anything about those amps. They look like a ton of fun.
"Looks like the amps with 2a3 tubes are 2.5 watts/channel. Is that enough to hear at sane listening level, assuming you sit 8-9ft from the speaker?"

For my "sane" levels it would be, but it also depends upon the size of your room. 20-40 sq meters is 215 to 430 square feet (20' x 20').

From the Cube Audio website:
"The Nenuphars are dedicated for rooms of 20 - 40 square meters. They are a perfect match for a tube amp with at least 3 Watts per channel. Our personal preference is somewhere around 2A3, Px4, 45 tube-based amps. Nonetheless, most solid-state amps (especially those working in A-class) are also an amazing match for the Nenuphars."
"I bought my SIT-1 Mono's (Demo's) for about $500 more than what the SIT-3 goes for new."

That sounds like a great deal. Didn't they sell for $11K when new?