Naim and wattage

AIUI a DF of about 20 is considered the break-even point. Higher than that doesn’t achieve any audible benefit. Plus any inductor (in the crossover for instance) will limit the DF achievable. And the impedance of the speaker affects the DF. But I’m no expert in this, by any means. I think that a high DF indicates high level of negative feedback in the amplifier design, and I believe Naim use relatively little negative feedback, which, if so, would explain the lower DF. I could be very wrong here, though.

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I played around with negative feedback on a tube amp I had and the higher the negative feedback the more dead the audio sounded. Little NF = Dynamic lively sound, High NF = Dead, boring sound.

Yes, that seems to be the consensus.

Hope I’m not being too lacking in technical knowledge here but is it not the case that in audio equipment terms to paraphrase Slamdam “Watts are not Watts”.
Down the years manufacturers have used different means of measuring “Watts” ie RMS or DIN. Also when objectively tested often delivered very different output levels to those claimed on manufacturers spec sheets. Other factors such as impedance, speaker efficiency, back emf, room acoustics etc etc make the paper spec in Watts of an amplifier pretty meaningless.
It’s not like buying a 60w light bulb or electric fire where one can fairly reliably know how bright or hot it will be?

:grin:

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Those watts also need to be there in an instant at the right place and time.
No point in having that big crescendo going off in the neighbours garage once the orchestra has packed up and gone home.

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I would assume that the slew rate which is what Naim make a deal of also has its sweet spot meaning you cannot access its full potential everywhere on the output. That is atleast what I heard with my own ears trying to push my supernait 1 with Harbeth 40.1. Above 10 on the volume pot it started to compress, feeling slow and sluggish compared to a bigger 2x400W amp. And it was a MAJOR difference I can tell so no fluffy “maybe, maybe not” here :slight_smile: I fully respect and understand different amps for different purposes. Starting this thread was more to understand if jumping higher on the Naim latter will give me more power to control such speakers even though wattage specs roughly are the same.

The way I see it, when the volume is set at 9 o’clock you still have another 9 hours of headroom left on the dial for real world demands of the music. In that the majority of watts in that crucial mid range is only a few watts but some parts may need plenty more to sound all a piece within and throughout.
Once you go further towards 12 o’clock your leaving the amp less headroom so compression starts, I think this is the case in most situations, if not then the room or speakers will start saturating.
You only have to look at those speaker cones, sometimes they wobble immensely without really hearing anything, but more feel it.
If you are for ever feeling that you want to always turn up the volume - watts - then something is not right.

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According to the Stereophile review of the Harbeth M40.1, this speaker is not a difficult load and it seems that even the electrical phase angles appear to be well controlled a well. The speaker sensitivity is lower than average, so would need a bit of power to drive loudness.

So I suspect that the difference of sound performance you are hearing has a lot to do with the dynamics and character of the power amplifier.

Also the manufactures rating of amplifiers need to taken only as a guidance - the typical quoted numbers are or 8 Ohms and sometime the rating for 4 Ohms and 2 Ohms are also quoted - however looking at the reviews in magazines like HiFi News gives more information on the real technical details of any amp, where both the constant and dynamic power output of the amps are measured and quoted.

Even with this information, one cannot predict how a particular amp will perform with a any specific speaker.

Slamdam - I suspect that while the Supernait 1 drives the Harbeth 40.1 well enough, your bigger 400W amp controls it in a way that produces a sound that you like better.

The Supernait 2 and 3 had improvements over time. The NAP 250 are dedicated power amps and will no doubt be able to manage any speaker better than any Supernait - because of it’s current driving capabilities (NAP 250 has a regulated power supply) - even though it’s wattage rating is only marginally improved.

Remember at the average listening level, the chances are that the nominal wattage being used is likely to be around 10W or less - but at any specific time the combination of speaker impedance and peak music levels may ask the amplifier to deliver a wattage significantly higher - but only for milliseconds.

This is where the quoted rating of an amp cant tell you how it will perform with a specific speaker.

The other factor with Naim amps is that except for the Statement amps (and the NAP500 where I believe two pairs are used in a bridged configurations), Naim use a single pair of output transistors per channel vs multiple transistors as used by other manufactures. They do this to get clear sound. (In the case of the Statement amp - the multiple power transistors are carefully matched).

So when deciding on a amplifier, the factors that come into play are speaker sensitivity, speaker impedance (at any particular frequency), speaker phase angle, the listening level, speaker/room dynamics, amplifier power, current driving capability, dynamic bandwidth, skew rate, etc.

One cant really predict the performance based on rated wattage alone.

In the Naim range, although the wattage does not increase by a lot (save for the Statement amp) - the capability to drive speakers increase - i.e. a NAP 300 is fully capable of drive difficult speakers such as B&W 802s while their actual wattage is not a lot more vs a NAP200. At the same time if one wanted to drive these B&W 802s very loud for a longer duration, I would suggest an amp with a lot more grunt

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…and ear defenders to protect your hearing!

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Totally agree … those 1st few watts and the dynamic headroom is critical. I once had an ancient leak valve amp I think it was a TL10 … 10watt I hooked it up to my Kef Concerto’s and it sounded pretty darn good…and was fairly loud… I think the sweet spot for amps is a good solid 25watts that would more than suit most listeners … Years later I had an Audiolab 100w P2 amp … and demoed it agianst VTL 50w valve amps … the VTL amps totally blew away the Audiolab … the sheer grunt volume - slam you name it - it had it… all from a measly 50w.

Incidentally - I kept these VTL’s for 35 years - the last 15 years they were boxed up in the loft. I purchased a NAP250DR … which I was delighted with. I went to sell the VTL’s and plugged them in to test them before selling…this is a valve amp with 30+ year old valves (EL34’s) … and suprisingly it squared up to the Naim very well … it was a touch fruity in the bass … and was not as rhythmic … but it was close. Those VTL’s really rock…David Manley is sadly missed…

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Innocent Bystander - how loud were you driving your speakers to cause the clip indicators to light? Your 89dB/W speakers are sensitive enough - so either the speakers impedance rating is greatly overstated (which sometimes does happen) or you listen to very very loud music…

I know that the 4Bsst can drive difficult loads - from the HiFi News, review this amp is capable of delivering 600W into 4 OHMS and has a dynamic output of 865W into a 4 OHM load and can deliver up to 2KW into a 1 OHM load (dynamic).

To driving this amp into clipping will take some doing…

Yeah a 16 guage welding rod should do it…there’s enough power there ignite most voice coils!!!

I once saw the result of an LS35A over driven…it melted the speaker and set fire to the insulation…it was totally crispy…

Used to be that old hifi folklore that big heavy high wattage amps were like those big American cars. Great for cruising along long straight roads but came into trouble at corners without going sideways at speed.
Whereas little wattaged amps were more energetically responsive and nimble - and could even park sideways, given a wide enough road to travel down.

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@Blackbird…Are these a used pair of Harbeth’s because the current model is 40.2… and have you bought these speakers? Or this all speculation ??

Had a weekend trial with a friend having 40.1. I’m using SHL5 Plus myself. Wattage improvement was not as obvious with SHL5 as with 40.1 which is understandable even though it could be heard there too. I would describe it mostly as the high wattage amp sounded calm, detailed and relaxed no matter volume was played.

I have heard that the Harbeth 40.1/2 goes very well with the LFD NCSE mk 3 although the LFD is a very low wattage int amp?

Maybe someone here could comment?

I’m sure most amps can “handle” them but the breakpoint is when you put size of room and dB at your listening position into the equation and also of course how good are your ears and are they as mine.I do love Naim sound and would like to get close to that relaxed sound I experienced from the H390 in Naim lineup but not sure how far I need to go since Naim is pretty expensive and I’d like to find the sweet spot for my requirements. I wish one could borrow music equipment from retail stores. I would even pay for it but around me no one offers such.

I went from SHL5+ 40th Anniversary to 40.2 recently. I have the 300DR as power amp and in my room and to my ears there is more than enough power in the 300DR to blow up both my ears and my apartment, or so it seems. I don’t like to listen to music at very loud levels (around 62-ish dB according to an app I downloaded for free). I do agree with a comment made above that the 40.1/2 probably should have 252/300-level amplification and a great source to properly shine.

However, I brought my SHL5+ speakers over to a guy who wanted to test them before buying them and he had 1) a much larger apartment than I have and 2) a very large subwoofer and 3) a large powerful NAD amp. The room was somewhat acoustically treated and he used a Rega RP6 as source. It sounded very good, although very different from what I was used to. He liked to listen to music at loud levels. Perhaps SHL5+ and a subwoofer could be an alternative to the 40.1?

In any case I totally understand the urge to get the 40.1. It is IMO the coolest looking Harbeth speaker…

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