I think we've been here before ... 😀
I've already said many times that an active setup like you mention has the capability of doing an excellent job - I don't put that in the category of the "normal standard", 🙂.
Remember, a full range speaker is working as per a single way active system - if the amplifier, etc, is competent then there isn't a problem getting intense levels of sound with that driver.
I've been there many times with a rock thrash at high levels, you're not telling me anything I'm not familiar with - your only difficulty is accepting that a driver a notch down in quality level from what you're using will also do the job ...
I've already said many times that an active setup like you mention has the capability of doing an excellent job - I don't put that in the category of the "normal standard", 🙂.
Remember, a full range speaker is working as per a single way active system - if the amplifier, etc, is competent then there isn't a problem getting intense levels of sound with that driver.
I've been there many times with a rock thrash at high levels, you're not telling me anything I'm not familiar with - your only difficulty is accepting that a driver a notch down in quality level from what you're using will also do the job ...
Normally all the drivers go straight to the pool room ...
Seriously, it's a bit of a shock when one first gets driving, intense, unstressed sound from a very conventional driver - I've done it so many times now that I just automatically expect it to happen ...
Seriously, it's a bit of a shock when one first gets driving, intense, unstressed sound from a very conventional driver - I've done it so many times now that I just automatically expect it to happen ...
It has been shown that those THD numbers tell you nothing about the sonic qualities of an amplifier. It is certainly the case that there are amps with 1% THD that sound markedly better than amps with 0.005% THD.
Using THD as a short-hand for describing sonic quality is pretty silly.
dave
yes it might explain more if people compared amp output Z effect with speaker load Z vs frequency, then EQ'd - worked for Carver's Stereophile Challenge
There we almost agree. Maybe .1% vs .001% simple harmonic distortion, but 1%? Well that is enough it sounds like garbage. Sorry bottle heads. And yes, when I had crap speakers, some amps, notably old Rotels, did not exacerbate their breakup problems as much as others. Once I built much better speakers, the difference in amps was far less. Difference yes, but the orders of magnitude are still with the speakers. I contend electronics are the 1% problem. (and cables are the .00000001% problem)
Test? yea, my SEAS based speakers sound better on my Anthem or NAD AVR than my Paradigm Studio's did on my HCA1200's/ Nak CA5. Does the Parasound improve the Seas? Yes, but ever so slightly and only when I lean on it really hard. 60 vs 250W, single output vs a bunch. Yea, there is a difference. Maybe not enough to spend the money re-capping one of them in my movie room. I may still put one back in my living room. I may not, preferring to spend the money on the next step up in tweeters. You know tweeters Dave, those things we add to the midranges to make a full range speaker SYSTEM😀
As THD numbers every one of those numbers is meaningless. One has to know the spectrum to gain anything from typical distortion measures. 1% all 2nd order is way less of an issue than 0.00x% of 5, 6, 7... they stand out to the ear/brain because they are unnatural.
dave
Hi Dave, I must introduce myself as fairly new to the forums. Although I'm starting to work in audio I have much still to learn (working my way through the NEETS series etc) and I respect your opinion from what I've seen.
This statement of yours really tickled me and is an area of acoustics/ psychoacoustics I've yet to hear about. Do you have any sources for further reading at all?
Regards, Ollie
Chip amps are OK, IME. The datasheets show distortion figures in the same ballpark as decent commercial power amplifiers, and their "problems", if any, don't show up if only asked to work within their design parameters. Even lowly ones, that the manufacturers barely see fit to give any performance details for, do remarkably well, subjectively - the "cheap as chips" ST unit in my PC speakers does surprisingly well, produces excellent treble at full volume if sufficient care is taken with optimising.
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Not directly, there has been significant work/discussion on this, the earliest ican remember being somework Hirage did. I've seen quite a few AES papers, and quite a few attempts at coming up with a single number metric based on the harmonics that have some meaning none of which have gained any traction.
Also, new kinds of distortion measure techniques, the most recent i recall from Geddes.
It became very clear in the late 70s, with the Japanese numbers race that single number THD was meaningless, the why slowly emerging over the next decades.
One also has to consider that amp, speakers, and the cable in between form a system, and that trying to establish a metric for a single component inside this system is somewhat meaningless, as the total in the system can be very surprising even with the very limited testing regimes currently in use.
Testing can be useful when it comes to design, but when it comes down to final sonics the final arbiter is the ear/brain system.
dave
Does "optimising" involve stones, rocks, magic dust, chants, self-flagellation, or any other weirdness, for that matter?
Abs
Not lately, I don't think, 🙂. Mostly it's about not taking things for granted, assuming magic things such as that the mains power is perfect, that there is zero RF interference about, that audio components are always impervious to their environment. Of course, if in your world pixie dust always guarantees such is true then you don't won't see any problems ...
Engineering Frank, these things can be catered for by good engineering, an SMPS will filter out the mains rubbish....
EMC testing CE marks etc
Personal stuff removed. Any further journeys down that road will result in read-only status for the violator.
Yes and no. Of course, at what frequencies and at what levels matters. Still, I can't stand the distortion from tube amps and I don't find 2nd order " musical" if it is exciting tweeter breakups. Others love it. .00x is just about irrelevant as far as harmonic distortion goes.
Agreed. But low end equipment won't have this sort of thing in place, to ensure that the playback is robust - so something will need to be added, or the enviroment adjusted.
My gut feeling is that currently produced gear is significantly better than it was, say, 20 years ago, in this regard ...
Hi,
Inevitably. THD+N is the standard distortion measurement and easy.
At low powers THD is buried in the noise and THD+N meaningless.
As is THD+N measured at the optimum point, just below clipping.
THD+N is also meaningless comparing valves to solid state.
Any attempt to replace an objective number with a subjective
number was never going to happen, and very unsurprisngly hasn't.
Not helped by the near impossibility of agreeing a subjective standard.
For valve amplifiers it was suggest a weighting of n/2
for each harmonic, so 2nd x 1, 3rd x 1.5, 4th x 2,
5th x 2.5, 6th x 3 seemed eminently reasonable.
But due to subsequent intermodulation the rather
more draconian n^2/4 was deemed more accurate,
so 2nd x 1, 3rd x 2.25, 4th x 4, 5th x 6.2 ....
It should of stuck, but never stood a chance, no
advertising copy would use a bigger number than THD.
High feedback transistor amplifier killed all that,
being eminently capable of producing a spray
of 1KHz harmonics of similar levels out to 20KHz,
(due to the falling amount of feedback of typical
single pole compensation), weighting would
have multiplied the 20th harmonic by 100,
and by definition produced abysmal numbers.
rgds,sreten.
Your guess is a good as mine as to any sensible
weighting, noting that for music any amplifier with
any distortion will produce far more intermodulation
distortion on complex material than the harmonic.
That is not what i was talking about. I was talking about a new (hopefully) meaningful objective number to replace the currently useless THD number.
Those are a coupleof them based on the same basic measure tech. There have alsobeen somecompletely different schemes.
dave
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