How Loud is 1 Watt?

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1 hour ago, PeterSt said:

But the big sport is to have a 100dBSPL or so, and NOT deafen.

 

It is THE big sport Peter and until one actually hears a speaker capable of big dynamics often they will not believe it possible to have 105dB peaks and be able to hold a conversation.  I often think of it in terms of compression, like compression from the loudness wars, where the gaps between the notes/sounds get squeezed out by whatever it is the speaker is doing instead of making the right sounds.  Holds true for electronics as well, in a lesser way.

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8 hours ago, sandyk said:

Hi Anthony

Given that the dynamic range of RBCD is 96dB, and quiet suburban neighborhoods experience ambient noise levels of approximately 45-50 dB, (USA figures) I find that hard to believe . Perhaps your speakers are acting as an Expander ? 😜

IIEC, you prefer valve amplification too, which has markedly poorer S/N than the best of solid state ? e

Kind Regards 

Alex

 

 I'm in rural Qld Alex, not suburban USA and room noise is <40dB... which is another thing to get under control of course,  but with 105dB peaks at my chair I have access to 65dB+ dynamic range... but like Peter says, to get more just turn up the volume., which I can do with only a watt or two at my disposal.  105dB peaks are still only a quarter watt of power...

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53 minutes ago, fas42 said:

Giving the small speakers very high effective mass, and locking them to their position in the room.

 

Same with big speakers, but small speakers are really limited in terms of spl at bass frequencies...it's physics.  We band-aid the physical limitations of small size with high excursion transducers and loads of amplifier power but it is never the same as a well produced larger speaker...although the big ones can be messed up just as easily as the little fellows.

 

53 minutes ago, fas42 said:

Know those small bank vaults you get sitting in the open space, when you walk into a branch - trying pushing against the side of such a unit ... you're aiming to get as close as possible to that solidity, 😉.

 

My subs are 8 x 10" scanspeak paper cone drivers per side driven with a dedicated 9w SET amplifier.  They weigh 400kg per side (800kg total) and to the knuckle test are more inert than the best bookshelf speakers.  They go to 100Hz.  Upperbass is a 150kg 100Hz horn...circa 1m diameter...with an 8" high efficiency paper cone driver.  In between that I plan a pair of 15" alnico paper cone drivers per side to do 40Hz-100Hz, mainly to be able to moderate a room node without electronic DSP, but also because I think they will be better than the subs in the transition to the horn at 100Hz. 

 

That will be three bass channels, each independently amplified.  Before this I had really good bookshelves, some of the best you can get anywhere, and for many years I thought they sounded very good and very real, and in the crossover period with the new speakers they still sounded decent in the midrange and treble, but anything below say 1kHz was a tremendous compromise.  The difference in SQ is akin to going from inbuilt tv speakers to a decent dedicated home theatre setup...not close at all, and until you experience what competent fullscale loudspeakers are able to offer you just don't know what you are missing. 

 

Saying all that, most do not have the resources or commitment to put together a fullscale system so what I have said here is moot..sticking with small speakers and big amplifiers is easier, but it only ever gets you half way there.

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18 minutes ago, fas42 said:

Below 1kHz?? That's a mighty far stretch ... 🙂

 

Below 100Hz is where I start to compromise - I would drive a speaker with a frequency sweep between 100Hz and 200Hz, and push the volume - if it stays clean until starting to get mighty loud, then I could live with it.

 

Not a stretch at all.  The three octaves above 100Hz are the most important for setting the 'sound' of the loudspeakers.  This is partially in the range controlled by the room (below Schroder frequency) but most importantly is in the frequencies that give the sound the dynamics (i.e. punch, kick) and warmth.  With any decent SPL all bookshelves are struggling at 100Hz and really the issues start higher than this.  The sound of the speaker can be completely changed depending on how 100Hz-800Hz is handled...totally changed...it is the most important region and with bookshelves this is handled with a small woofer of high excursion getting more and more stressed lower in the range (this difference in 'stress' between 100Hz and 800Hz changes how things sound too).

 

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2 hours ago, sandyk said:

Neither do I accept that a SET setup is necessarily  the way to go, due to the S/N being quite a bit lower than what is achievable with the best of Solid State such as a certain extremely well measuring Benchmark amplifier.

 

Not your typical SET amps though Alex...six stereo pairs each individually matched to their task...certainly not a stick a stereo amp on it and see how it goes kind of affair.  Forget what you have heard with SET amps poorly matched to their speakers...that is not my system, and as far as SNR goes all channels are dead quiet with your head in 110dB/w/m horns...most of the SS amps I have had here were noisy into even 86dB bookshelfs!

 

Measuring well and sounding good are not directly related, at least not in terms of distortion and signal to noise ratios, good enough is good enough, but I do agree that decent measurements are required, just not a "chase to the bottom" in specmanship.  For instance Peters dac, I retain because it sounds fantastic, not because it measures wonderfully, and although Peter is more concerned about distortion that I, if it did not sound right to him I know he would not be making them.

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I wish it would rain Alex... nothing yet...cows are easier to feed if you have grass and it has been a horrible few years in that regard.  Fingers crossed we do cop this system. 

 

Tube hiss, transformers,  capacitors...haha... where do you get this stuff Alex?  All are problems that can be overcome.   I could counter with problems in conventional systems regarding feedback and speaker level crossovers,  neither of which I use,  but each of us must pick our problems. 

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My amps are DC coupled Alex and are devoid of either transformer input or capacitor input... like I said,  you pick your problems and work around them if possible.   In this case an extra +ve power supply for the grid bias is used which negates the requirement for caps or transformers at input.

 

 

18 minutes ago, sandyk said:

For the highest quality results amplifiers should be direct coupled with no capacitors in the signal path and if you weren't using valves you wouldn't need impedance matching transformers with their phase shifts and LF and HF rolloffs . 

 

What about the capacitors in the crossovers of passive speakers?  They are in the signal path.  My speaker drivers are direct coupled to their amplifier... nothing but wire.  The band-limiting (crossovers) is done at the input to the amplifiers which means much smaller value filter components and lesser sonic trade-off.  This also means my amps only amplify their allocated bandwidth and the output transformers are specially wound to exactly suit their task.  Again,  you pick your problems and you solve them if possible. 

 

You are thinking of SET amps in terms of a 'normal' audio system where their simplicity more often means a compromise on parts of the SQ.  I am using them in a situation where their technical shortcomings have been negated and I only have their positives to work with.  I even think that if/when Peter makes it to Aus he will find my system enjoyable even though it does not tick all his technical preconceptions... he may even like my vinyl collection too... hehehe.

 

 

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10 minutes ago, sandyk said:

You can get used to and prefer a certain sound until other experienced listeners point out shortcomings, which I reckon Peter could also do for Anthony if he was game enough to do.😜

 

If we are sharing semi-serious tongue-in-cheek pseudo-insults Alex, please remember that I've built your preamp...Peter may need two sonic re-adjustment visits if he ever makes it here...

 

Saying that though, I've built and bought more than a dozen preamps before finding one that does the job right for my setup...yours was not alone.  And guess what, it was not the pre with the best measurements that got the job, rather one with good enough measurements but it uses a pair of US Navy DHT's a similar vintage to yourself.  I still find it amazing that this abandoned technology when mixed with modern components is capable of the highest levels of sound quality.  You can rubbish transformers all you like, but your experience is likely a long time ago and in very different situations to how they are able to be used these days, and the truth is that when you use quality transformers and do not try to push their envelope too far, there are nothing but benefits. 

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4 minutes ago, sandyk said:

Possibly due to your preference for the valve and Vinyl sound ?

 

What valve and vinyl sound Alex?  Explain it to me, because they are rubbish generalisations in a post where you seem to be railing against generalisations.  You seem to correlate valves and vinyl with warmth...I don't...so what is the valve and vinyl sound all such systems have in common as opposed to the SS/digital?  School me...

 

 

13 minutes ago, sandyk said:

Note also that numerous members of a UK based  forum built both Preamp/HA  and 15W Class A versions and their impressions were very different to yours.

 

Of course they were...either their expectations were lower or the gear fit their system requirements...or both.  Seriously, I'm not rubbishing your gear but it just did not meet my requrements of being able to drive 6 pairs of PLLXO's that combine to give a circa 5kR reactive load.  I tried many solid state preamps of different topologies several with extraordinarily low noise and distortion (s.o.t.a. levels), one even qualified into a 600R capacitive load, but they failed in being able to drive my amps successfully.  One SS that could was unable to provide any gain, and I need gain at the preamp.  The one that worked is a diy effort that uses an 801A/10Y DHT from the 30's/40's with a smd SS mu-follower...it's got a bloody cap output which I am not happy about but it works better than anything else I've tried.  It may even be the cap output that makes it work by limiting radio frequencies from entering the amps...who knows.

 

I've got those caps Alex but never put them in..not sure why Nichicons are not up to the task.  Am happy to send the whole thing down to you and pay you to make it sing if you think it is the right tool for the intended task...I am open minded...but I have more or less moved on.  The diy hybrid preamp will get shoved in a couple of boxes as soon as possible and I cannot imagine how the sound could be bettered at this stage.

 

 

27 minutes ago, sandyk said:

In this day and age , we shouldn't need to use often expensive and sometimes custom designed signal coupling transformers other than in the Digital area . 

 

Of course I disagree strongly here, there is so much custom wound iron in my gear it would make your head spin Alex.  Plus I find comments and conversations about the cost of something awkward because each of us have our own benchmarks for 'expensive', and not everyone has a desire to keep things 'cheap'.  Don't expect sound to get better with expenditure, but also don't expect sound to necessarily be equivalent on a tight budget. 

 

2 minutes ago, sandyk said:

WTF are  US Navy DHT's ? 

 

Answered above.  The preamp uses tubes manufactured under Roosevelt (the ones I have were for the Navy - it's all over the boxes) while the amplifier uses some  manufactured under Stalin...it's like the cold war never happened haha.

   

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1 hour ago, sandyk said:

Mike Grierson, the Admin from Rock Grotto Forum used to have a huge selection of valves like that for sale, even willing to closely match them. He may still have many unless he sold them all to pay for his expensive drinking habits. 

 

 

I like the expensive single malts a little too much so can sympathise with Mike (assuming that is his sort of vice).

 

Would love some 50 mesh plates or globe 10's, but they are like hens teeth and priced accordingly...not that we would not be able to come to a deal.

 

 

2 hours ago, sandyk said:

Let's not get into the well known area of additional even order harmonics with vacuum tubes, unless in Grounded Grid topology .

 

Yes, single ended valve amplifiers make pretty much all second harmonics, and push pull generally make thirds...but the threshold of audibility of 2nd is something like 0.5%, 3rd 0.1% depending on volume and a few other things.  Those are simple numbers to hit with solid state or hollow state preamps and you don't need a grounded grid to achieve it.  Not that I really care, but one day with time I will do a full suite of measurements of all the valve equipment that I have made and publish it somewhere online.  At the output levels that I use I also expect the SET amps to all exceed the 2nd harmonic audibility thresholds (on paper they should).

 

So, warm sound with valve amps due to 2nd harmonics?  Yes, for sure, sometimes, especially when not used within their limitations, or designed that way, or built on the cheap, but please do not assume that is the sound that I have here or even find satisfying, because it is not.  I've dislike more valve amps/preamps/systems than I have really enjoyed and the glowy bits are not really necessary for enjoyment...but when their shortcomings are addressed, those simple amplifier circuits produce an effortless clarity and immediacy and 'realness' that I cannot forget nor ignore.

 

 

2 hours ago, sandyk said:

I think that we need to Agree to Disagree in this area ?

 

Lets.

  

 

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13 minutes ago, sandyk said:

The threshold of audibility may be a little lower than you wish to believe, with a few of us in John Dyson's PM group regularly hearing differences of just over 0.1dB

 

Interesting.   I wonder what the constitution of the harmonics you are hearing is?  The research I read some time ago showed that higher order harmonic distortion is much more audible than lower order HD.  Basically 2nd can be about 5 times louder than 3rd before it is heard, which is why single ended amps,  whether SS or valve,  can get away with more assuming the 2nd is dominant and the 3rd negligible.  My understanding is that this continues in this way to higher order HD so that 4th, 5th... 10th need to be minuscule to not be heard,  which makes sense given how far separated they become from the fundamental. 

 

A bottle of scotch a day... yikes... that's more than I could handle. 

 

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2 minutes ago, fas42 said:

Sorta hilarious to me ... those poor Laws of Physics go crash, into the ground - Yet Again, 😁

 

Oh my Frank. 

 

Did you notice these are nearfield monitors?  What is nearfield distance for a speaker of this size and in the average listening room?  Did you see the 50mm voice coil?  That's some ...massive... excursion to get any sort of SPL and curiously no SPL limits are mentioned in the specs...why do you think that is?  Those 7000i and others like it from Genelec, JBL, Adam blah blah are meant to be very close to the listener so that the direct sound levels are much higher than the reflected sound...they are not designed to fill a room with sound and are rather incapable of doing so because they are grossly SPL limited.  Have a look at an equivalent Genelec monitor at you will see they are limited to about 100dB SPL and I doubt that SPL would include the bass frequencies.  Put them in a lounge room, sit three metres away and suddenly that 100dB SPL is probably 90dB peaks with crappy bass because the speaker is pushed too hard.

 

I can see the case for using these woofers for sound production in a guitar speaker as mentioned earlier in the thread, afterall distortion and guitars go hand in hand.  Reproducing audio using these little can-do woofers is probably ok in the right listening circumstances, but their small cone area means large excursion for any kind of spl and while they might be able to handle the task better than their contemporaries there will be an order-of-magnitude difference in sound quality to a decent speaker system where size is a less limiting factor. 

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1 hour ago, fas42 said:

if your game is massive amounts of deep bass, or absurd SPL levels, then everything changes ...

 

But music is loud!  110dB in an orchestra, that's why many musicians wear earplugs.  Oh my, on one hand you want realism but on the other you don't want volume...they are mutually exclusive in a good system which only gets better as you crank it up.

 

 

17 minutes ago, sandyk said:

 It is more than possible to scale down the SPL in a typical domestic situation and still have it sound great

 

Sure, no arguments there, but at those SPLs we don't hear the bass frequencies and it does not sound "real".  Remember the old loudness buttons...that was what they were for...some EQ for the bass if you could not turn it up to realistic levels...Fletcher-Munson in action.

 

 

1 hour ago, fas42 said:

Ah, the magic of words! Because they are called "nearfield", everything changes - it's like entering another universe! 😁

 

They are called nearfield because they are meant to be listened to up close...nearfield or farfield changes the required crossover among other things.

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6 minutes ago, sandyk said:

Yeah, but most people don't need to entertain the cows in the paddock, and not everybody has a wife that will tolerate loud music for very long.

Many SWMBOs prefer their music at a level where they can still carry on a conversation.

 Even the kids will complain despite wearing earbuds with their mobiles to listen to their music

 

Yep, certainly no arguments there.

 

As an interesting aside, we had friends over (when restrictions permitted) to watch the live stream of Nick Caves "Live at Alexandria".  So, two audiophile husbands and two wives, Nick Cave on the big screen, and the music cranked to realistic piano levels, which as we all know is loud.  Piano fortissimo is supposed to get to 103dB or so so I set the volume by ear and then sat back and really enjoyed the show, it was magnificent, while the two women took notice of the show from time to time, sang along to the songs they wanted to and in between chatted and drank wine and ate cheese while my friend and I refained from asking them to be quiet and let us enjoy the show (that would be nasty). 

 

Anyway, I pulled out the SPL meter at one point between songs and to the girls surprise the loud peaks of the music were sometimes hitting 105dB just like they should.  No-one complained about it being too loud (that was my question that led to the SPL meter being pulled out).  So four people sitting comfortably in a room listening to a solo piano concert for a couple of hours, peaks up to 105dB and chatting and holding a regular conversations. 

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9 minutes ago, sandyk said:

What resolution was the Audio ?

 

Couldn't say Alex.  It sounded good and I listened in stereo.  Saying that, I don't expect top-of-the-range sq from streaming or even bluray like I would expect from my dac.  Most of my concert bluray or dvds get watched/listened to on the stereo mix...just sounds better in my room.  The surrounds are decent JBL Pro 708P's, bi-amped with 8" woofer and waveguide tweeter but they just don't seem to run with the fronts in terms of SQ.  Perhaps it is that I have not spent a great deal of time sorting them out or perhaps I just don't get 5.1 sound for music, not sure, and they are great for movies, but music is not quite the same.