The Atom is Amazing

You’re missing a required Supercap in there. But yeah, the point is still well made.

Excellent explanation!

Thank you anyway

Hi Strah,

No it doesn’t exactly work like that. The decibel scale isn’t an absolute measurement, and has no units, It’s merely a way of expressing a ratio between two values on the same scale; so two decibel measurements in different contexts can’t really be added together (and the result of you ‘calculation’ should have been 117dB anyway!).

The sensitivity measurement for the speaker is the logarithmic ratio of the loudness of the speaker fed by a 2.883V sine wave at 1kHz in an anechoic chamber at a distance of 1m, as compared to the nominal threshold of sensitivity of human hearing.

The gain of a voltage amplifier is the logarithmic ratio of the output voltage to the input voltage when fed with a sine wave (at 1kHz for an audio frequency amplifier); this measurement is only valid when the input to the amp is very much greater than its noise floor and the output of the amp is significantly less than it’s clipping level.

The two measurements aren’t really comparable.

When Naim launched their Nova at the Bristol HiFi Show back in 2017 they paired it with Sopra 2 speakers and that system never sounded anything like a ‘mullet’ to these ears…

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Exactly what does a ‘mullet’ sound like?

unbalanced? But like some are saying here, there’s more to it than just price or specs…

A system can sound unbalanced in many ways, a system can also sound perfectly balanced when one component is completely out of it’s depth.

When mucking about with my system I have experimented with a Denon DM40 (£250) that I happened to have lying around (it actually belongs to my ex), and used it to drive a pair of Spendor SP2s (£2,500) that I use. The Denon drove them fine - it showed it’s own characteristics very clearly and it didn’t sound at all unbalanced. It was still a complete mullet system though, as the ‘upgrade’ from £120 Wharfedale speakers to the SP2s gave only a relatively small uplift in sound quality!

(Whereas driving them from a 272+555DR & 300DR gives an enormous uplift in SQ showing that the speakers are a lot more capable than the little Denon.)

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Of course. I was rather surprised that Naim were using £10,000 speakers with the Nova but they did and it sounded fantastic. It went totally against my belief system too but after hearing that system I’ve changed tack and am a lot more sceptical.

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I think the difference is that I have a fairly good understanding of how power amps and speakers interact (knowledge gained from designing audio power amps!).

So, I understand how some cheaper power amps paired with some for more expensive speakers can still sound really good, but when paired with some other speakers that have equally good sound capabilities (but different electrical characteristics), the combination can sound absolutely dire.

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Thank you for the answer.

I would like to know how that gain (dB ratio of Volts) has impact on loudness regarding speaker sensitivity. The gain is constatnt but it is decreaces by potentiometer so we decrease the gain to silent the volume - am I correct? Power is here to mantain desired that gain when some dynamic part of music is on?
Is this on the right path?

When late David Wilson visited the show in my country he gave an interview about the speakers for local audio magazine. He stated that they are building the state-of-the art speakers for people who aren’t necceaery audiophiles but simply rich. When they present them their speakers they realized that is the one of the best in the world and they buy it. For audiophiles they create entry level since the audiophiles always measure value for money while rich people don’t.

Naim Nova, Star and Atom are for multiroom houses in which you have something special in the living room while you can still connect music to the other rooms - it is a solution for the entire home but for the living room you want to have something that distinguishes you from the other and that is Sopra or Kanta.
IMO that is an excellent market approach. More to that is very simple to operate without too much fuss - almost like plug and play.

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Yeah sure. And I bet it sounded great. A mullet is a great way to show your electronics punch above their weight.

But the real proof would have been the same total budget (or less) on several Classic boxes driving more modest speakers. That would be an eye opener for many. Wouldn’t be intelligent marketing for selling Unitis though.

The few years I spent in the trade, we’d often run in speakers in the dem room off of whatever was in there. CDI/82/HC/180 into GBP130 speakers wasn’t uncommon. Occasionally you’d get some punter in who heard music from there, wander in and be gobsmacked that these nothing speakers sounded miles better than their mullet at home.

You need a little background on how (most) amps work…

You have an input from a source component (at ‘line’ level - i.e. 0VU = 250mv).
The input Selector switch(es) select the source.
The signal is the buffered (and possibly amplified a little by a fixed gain amp - typically about +3dB).
This is fed to a volume control (a passive attenuator) that reduces the signal to the desired volume.
This attenuated signal is well below line level.
The signal is then buffered again before being fed to the power amplifier.

The Power amplifier is a fixed gain amplifier (+29dB in the case of Naim power amps)
For Naim amps, the output from the power amp is 28.2x the input voltage, so the output tracks the input, just with 28.2 times greater voltage.

Since the volume control controls the attenuation of the signal before the power amp (hence varies the signal level being fed to the power amp) and the power amp is fixed gain, the resultant drive to the speakers varies as the volume control is varied as this in turn varies the input to the power amp.

That’s really interesting and something I’d not thought of before. Is the 29dB the same as the 28.2x increase in voltage, rounded to 29? I thought dB increased on a log scale, but the 28.2 sounds like a straight multiplication. I suspect I’m confused, but is there a relationship between the 28.2 and the 29? Sorry for the dopey question!

Thank you very much, things start to becoming clearer for me
So this is the part of the measurements from the magazine:

It says 41.5 dB gain - so preamp gives the difference of 41.5 - 29 = 12.5 dB that can be attenuated?
Now I have another dilema. 3dB increase of loudness needs doubling of wattage - how’s that related to the gain if gain is fixed -at least in power amp?

Hi Nigel,

It’s just a quirk of the maths that 28.2x voltage gain happens to be 29dB!

The Nait 5i to Nait 5si are not representative of the wider Naim ranges as they use a passive preamp.

Naim’s separates pre-amps also have a higher voltage gain than do most pre-amps.

Ok, but the logic of the gain is correct? The gain of preamp is attenuated while power amp gain stay fixed?

So the entire loudness calculation depends of entire chain from the voltage output of the source to the impedance curve of the speaker and it can not be simply calculated by given numbers such as sensitivity, power or gain? Is this correct statement?