Atom and 40wpc?

I’m new to the Naim product line. I’m looking for an integrated streamer/amp for my next setup.

I like the features and price point of the Uniti Atom, but I’m concerned if the power rating is sufficient to drive my older set of B&W Nautilus 805 speaks (circa 2004). The specs on those speakers suggest 50wpc or more at 8 ohm load. I don’t have a large room to fill (about 4m by 5m with a rug and fabric covered sofa and chairs). I’ve been told the Naim products can provide more current than comparable brands, not sure how this translates to my speakers.
I’ve listened to both the Atom and Nova at the dealer on different speakers – the Nova was noticeably better, but the price delta was material.

Advice welcome!


I am shure that Atom perfectly fit to your BW805. In my case Atom is pared with B&W685s2 and room is about 24sqm.
But trial at home is best practise, request yor dealer for trial.
Edit: I didnt hear that Nova is noticeably better, more power yes, but SQ so-so…

The 805 is a top notch speaker that thrives on power. I’d say that the Atom isn’t up to the task. You want something that is both better and more powerful. The Nova may be up to it.

It’s not just a matter of power but also of impedance, dynamics and control, the B&W Nautilus 805 is a difficult load and tortures power amps into submission!

HH is right.

1 Like

Welcome to the Forum T_Seattle,

Not sure who you are working with in the Seattle are but one alternative may be looking at a NAIM streamer into an integrated amplifier. A two box solution vs the one box solution.

Have you thought about a ND5-XS2 with a NAIT XS 2 (70W)? This may be a solution for your speakers.

I started with a ND5-XS with the NAIT XS 2 a few years back and loved the set-up. Have you dropped by Hawthorne’s?

1 Like

I can’t help thinking that the 805 is really too much speaker for any of the options mentioned, and that something like a 272/250 or better is really required. This is the trouble building a system around fixed speakers. I guess it depends where the OP intends to take things going forward. Demo with a Nova is probably the place to start.

1 Like

I’ve had the 805s for 10+ years, and I’ve been pleased with the sound. My prior McIntosh amp is no longer an option for various reasons, thus the need for a new stack. I’d prefer to keep the existing speakers for cost/sound quality reasons if possible, while improving the overall streaming ease-of-use.


The ND5 XS2 already works well with Nait5si. Imagine with the XS2 … My next goal!..


Dear T_Seatle,

If you have a smartphone? Down load an dB SPL meter App and see what dB SPL level you like listening at. I find for classical from 40 dB SPL up to mid 70’s as peaks. With rock, mid to high 60’s with the odd peak hitting 80 dB SPL.

I am not familiar with your speakers though what I found on the net is that they have an efficiency of 88dB SPL. Which is 4 more dB than my Celestion SL6Si speakers which are 30 years old. I used this online calculator to determine how much power I required and allowing a 23 dB headroom for large peaks.

You have to use the calculator backwards in a sense. Decrease amplifier power to see if you can output enough db SPL to include the necessary headroom.

This might sound confusing and is. With my 84 dB SPL speakers I found that at normal listening levels above I was only consuming about 0.53 watts per channel. 10db above that is 5.3 watts another 10 dB above that was 53 watts and 3db above that brings us to 106 watts. Though this is PEAK PEAK wattage.

Using the dB SPL meter on my iPhone I found that when listening to classical I was listening at 40 dB SPL to 70 dB SPL and that was my db Headroom included there. All the rest of the available power was for gravy. Never used. If we take into account that your speakers are 4 dB more efficient than mine then the required 106 watts comes down to some where below 53 watts. Just being rough here. If we need to go finer I will have to get the pencil, paper and calculator out. But the link I left does the job with a bit of fiddling.

On another point, this is me speaking and not NAIM. I have noticed that NAIM quote an 8 ohm power capability and a 4 ohm power capability. So in your case 40 watts /channel into 8 ohms. Using the NAIT series amplifiers as a reference. They appear to have a capability of suppling 50% more power into 4 ohms. The Super Naim 2 is rated at 80 watts per channel into 8 ohms and the the 4 ohm rating is 130 watts.

So in your case I would guess that yours is rated at 40 watts into 8 ohms and 60 watts into 4 ohms. The NAIT XS 2 does 70 watts into 8 ohms and 100 watts into 4 ohms.

Saying this I would agree with you it the Atom is capable of a little more. I sit back from my speakers at about 9 feet/3metres at the fore said power SPL levels and find it quite loud enough. The volume dial rests between 8:30 and 9 o’clock. I have no need to go any louder.

In conclusion I draw about 0.53 watts at the top of peaks when playing classical. This allows me an extra 20 plus dB of head room to go which I will not use.

Take dB SPL measurement from your seated listening location on your phone and you might be surprised at how quiet you actually do listen at. This is only if your speakers are what the web says that they 88 dB SPL. Use the calculator and if you have any questions. Post them here.

Warm regards,



I have Dynaudio speakers with 4ohm rating and have driven them with Nap 200, non DR 250, non DR 300, 250 DR, Olive 180, Olive 250, Unitiqute 2 and now Uniti 1 rated at 50 into 4 ohm so about 75 into 8 and I’m very happy and have been with every Naim amp best of all though was 250DR.

Dear Bob,

Would these values be the other way around?

Kind regards,


Yes, it’s a simple typo.

I don’t believe it’s possible to decide whether a system will work well using a calculator. There is so much more to it than watts and efficiency. Speakers can look ok on paper but be a nightmare to drive in practice, sometimes dipping to one or two ohms which can cause underpowered amps huge problems.

It’s also not possible to say that speaker X works and therefore so will speaker Y. Engine suggests above that because his £500 B&Ws work, then so will the OP’s 805, which is equivalent to a £5,000 speaker today. These more elevated speakers are simply not built to work with very modest systems such as the Atom.

I have no doubt that the Atom will get noise out of the B&Ws, but it won’t be a satisfying system unless expectations are low and the OP accepts that they won’t be working at anything like their potential.

1 Like

G’day HH,

Point taken and you have made a good one at that. It worked for me. Even though my speakers are meant to be very hungry for power. Listening around 75dB SPL more than floats my boat and I can treble the intensity/loudrness of the speaker out put if I want to. Though I am not. I hope the OP finds a suitable solution. In todays money, what value would you put on an old Celestion SL6Si that cost 1,750 AUD in 1990 please?

I have been contemplating a new speaker setup. Though I must say I am very happy with what I have at the moment. Even thought it is 30 years old. It’s 84 dB SPL efficiency keeps niggling at me.

Warm regards,


Don’t sweat it. My P3s are 83dB @ 6 ohms. My Atom drives them well. Plenty loud enough and I don’t notice any issues with headroom.
Rarely go above 50 on the volume but when I do it’s no problem.

1 Like


Sorry Raym55, I am not the OP. He is the one with the issue with decision to purchase an Atom or not. I have a pair of Celestion’s that work fine down low, even if they are dummy loads that work wonderfully.

Warm regards,


Why not try an Atom at your home and see if you are happy with the results … I’d believe it has a very capable amp :smiley:

Bear in mind that apps aren’t necessarily accurate - and they vary, I have compared a number and found differences of up to 6dB or more between them on the same phone. I settled on Decibel X and dB Volume on my iPhone, and prefer the former which seemed to be the best and most consistent of the free ones when I tried them. How accurate they are in absolute terms Indon’t know as I haven’t a calibrated source and haven’t had a chance to borrow a calibrated meter for comparison.

That said, if your app is the same accuracy as mine, you seem to listen at very much lower levels than I! For me, more typical is low to mid 80 average, peaks often up to 90 or so. More spirited listening maybe 5dB higher. Occasional quiet listening 5dB lower. Infrequent very loud sessions might be in low 90s average, peaks 100 or so, but I rarely do that, and not beyond an album or two. One exception in this lot is Tchaikovsky’s 1812 in 24 bit. I haven’t actually measured levels when playing (reminder to self to do so), but to not reach clipping on the cannons, which with my amp and speakers is about 108dB at the listening position, the average has to be lower than I would normally play such classical music, down in mid 70s.

The figures I’ve measured are dBA, average as displayed as such by the app, peak likewise using fastest sensitivity setting (‘impulse’j.

1 Like

Which begs the question what amp you used in the mid 70s to get these cannons sounding right!

In those mid ‘70s in terms of years rather than dB the 1812 recordings were limited by the dynamic range of LP, so less of a factor!