I looked at google info: here it is:
3. What Is A Good Dynamic Range In Audio Mastering?
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| Classical: | 20-30 dB |
| Rock: | 10-15 dB |
| Pop: | 6-12 dB |
| Electronic Dance Music (EDM): | 6-9 dB |
| Hip-Hop: | 6-9 dB |
Yes! and this is only the start of the problem, we are still playing only one sweep which has 0 music content.
I truly don't know. I suppose each person has their own reasons for setting out to achieve what they envision. I am new to this hobby, and what I truly do appreciate is the thoughtful questions and answers.
I am learning a bit more of the mathematics behind it, but I also admit that's a bit tedious for a guy that really just enjoys listening to music and that special feeling of accomplishment when I built something and enjoy it, even though it's not my design.
Since you asked... I'll try to provide an answer with the information I have at hand.
I think it is "worth it". Why? Because you (or others) may accomplish that 0.001% THD while changing something else that comes to light. New discoveries happen all the time 'by accident'. Your 0.00000000X% THD amp (or someone else's) may lead to something exceptional. Would I say that designing an amp AROUND achieving that level of THD and nothing else would be worthwhile, probably not. That's been done. On the flip side of the same coin, would I change an exceptionally novel design that achieves "only" 0.2% THD b/c it's not "good enough"? ... um ... heck no!
I had to think about that for a minute, and if I understand properly...
I don't know. I wish I did. Smarter brains need to weigh in on that. I look forward to learning from them.
Discussion is always good and that's the idea of a forum.
My point is that it's relatively easy to achieve, let's say, THD 0.05% or 0.07% in a high power amplifier (>100W) but dropping it down to 0.001% or even less requires much more effort. When I mean effort, I mean cost, special components, size, PCB precision/optimization, efficiency, layout etc. That's why question if it is worth.
I'm thinking about basic math.
Lastest speaker I built, has an average of 0.6% of THD, going from 0.2% to 1% with rare peaks reaching THD 2%.
It sounds really good. Several people listened to it and liked.
If I use an amplifier with 0.07% versus an amp with 0.001% THD, the final result, considering the average, will be 0.67% versus 0.601%.
Considering the speaker variation along the curve goes from 0.2% to 1%, does 0.67% differ much from 0.601%?
"Does THD accurately predict good sound quality? And is subjective SQ useful to assess amps?"
It depends on whether you're selling or buying.
It depends on whether you're selling or buying.
It's a fascinating perspective for me trying to look at it from a designer's standpoint vs. a "user or builder" standpoint. I am not far enough along on my journey to understand the engineering and thought that goes into the design of an amplifier when it's judged "as a whole".
I got started building simple and what some would consider elegant designs because honestly, they were the easiest for someone like me to build them. I thought they all sounded wonderful. There were / are also many other categories I could have chosen to start building with, but I went with nostalgia, support, community, and ease of build to lead me along the way. I started off not having a soldering iron hot in over 30 years. I was/am a COMPLETE novice. I can assemble things reasonably well (now), but understanding how "it all works" is still quite a mystery to me.
That's only to add perspective to my POV. I'm not an EE or an audio engineer, or anyone in the business. I'm a guy that loves music, and just happened to luck into enjoying building audio gear... onto your question.
I didn't know that moving from level X to level Y (within known bounds) of THD was meaningfully difficult within known topologies. If you're trying to create your own new topology or design, I can see how achieving any specific target is an unknown.
What I think you're really getting at is, would it matter if you spent that effort?
Would it matter to the sound perceived by any given listener with any given system, in any given room... My guess with the information and resources available to me, is no. It likely could not be perceived as "different" in any controlled studies by even the smallest of %s of the population on earth.
This would be particularly true if you sacrificed any other meaningful design characteristic in order to achieve the "arbitrary" THD goal.
Would it matter to you or to the marketing people, or to those that would compare your spec sheet to the spec sheet of the Ooodly Boodly Googly Woogly amplifier of tomorrow? ... Only you know.
Cheers!
That is exactly what my experience has been over the past twenty-five years of DIY building at home, with more emphasis on building preamps & line stages in the past ten years. Two speaker listening, no DSP or subs or surrounds, that stuff is a different type of listening imo.
No. I'm not assuming that. You've said that explicitly. Read just about any of your posts in this thread and you clearly state that the amps that sound the best are the ones that have moderate power and moderate THD.
You're right that I am assuming that this is your opinion. Maybe you were speaking on behalf of someone else. Were you?
I believe manufacturers should be honest about their claims. If the manufacturer claims that an amp is transparent, it should be. To me, transparent means that it is clear as glass. That it does not add anything. Or that if it does add anything it is as minimal as possible. THD, THD+N, IMD, etc. are all ways to characterize this.
An amp that adds 0.1% THD is not transparent in my book. Not when the current state of the art is 0.00001%.
Hmmm... So yesterday Nelson Pass was a genius because he makes amps that sound great that everybody loves for their harmonic distortion profile. Today those who love Pass amps are fools? I'm confused.
But opinions are subjective.
I have no idea what you're trying to say. You must have a different definition of 'subjectivity' and 'opinion' than I do.
I don't feel attacked or criticized. I'm trying to understand where you're coming from.
That's your opinion.
There are many ways to make an input stage with low distortion. JLH's method was very good at the time, but we can do better today.
I appreciate your comments about my intelligence, but the rest of that statement makes no sense. The JLH is not protected from gain errors and curved gain. What sort of protections would even be needed?
It's not hard to make an amplifier that has a flat frequency response.
Another nonsense statement. If this makes sense to you, would you mind marking the AC and the DC parts of the JLH schematic for me?
[citation needed]
I actually had a client who had a use case for a 1 kW amplifier for near field listening! I went through the math and I, honestly, could not poke holes in it. He wanted 100+ dB SPL at the listening position and a flat frequency response. This was for a recording studio. He used a mid-efficiency studio monitor and wanted to use EQ to compensate for the frequency response of the room. Some of the nulls were pretty deep, so to get a flat response he'd need about 1 kW at those frequencies.
Tom
If the gas chromatography profile of the wine is identical to that of acetic acid (aka vinegar), I'm pretty confident that I would not like that wine.
Similarly, if the multi-tone IMD of an amp shows an entire forest of intermodulation products, I'm pretty confident that the amp will sound muddy. If an amp shows 1 % THD at 5 W output power I'm similarly confident that it will sound strained and harsh when I crank it on my mid-efficiency KEF R700s. But if it shows below, say, <-100 dB THD at 100 W and low IMD, I'm pretty confident that it will sound good.
Tom
I got two projects in works since i started unpacking my hifi stuff. I reasambled my headphones rig, with one cd player, three dacks and about dozen headphone amps. Was about to post measurements (simple rightmark test) and my listening impressions. Obviously with many different headphones from 50 ohm hifiman to 300 ohm sennheiser. Lowest thd headphone amp is not the best sounding.
Similarly phono preamps, i measured about dozen using passive reverse riaa before input and just simple right mark audio test. Again, my currently best sounding tim deparaviciny tube pre does not measure best.
I am happy putting shades on mona lisa like bimo and tillerson says. As long as it sounds better to me.
Those who claim i am using something something or effect box do not bother me. Keep your low distortion fatigue inducing stuff to youself. Low distortion is just another effect box. Cold hartless no soul.
Similarly phono preamps, i measured about dozen using passive reverse riaa before input and just simple right mark audio test. Again, my currently best sounding tim deparaviciny tube pre does not measure best.
I am happy putting shades on mona lisa like bimo and tillerson says. As long as it sounds better to me.
Those who claim i am using something something or effect box do not bother me. Keep your low distortion fatigue inducing stuff to youself. Low distortion is just another effect box. Cold hartless no soul.
Just one more comment and i am gone. Halcro, company making lowest distortion amplifiers, which went bankrupt, was resurected.
I find that interesting as well. I just wish more of the "this distortion profile sounds good" debate was rooted in science and less in "Nelson Pass says..." As far as I understand the science on the topic, it's pretty clear that equipment that measures better fares better in blind listening tests.
A solid state amp will never replace the glow of a pair of mesh plate 300Bs. It's just a cool-looking amp. I'd like it for that reason alone. 🙂
Tom
Really? What's the effect of adding nothing? Same as the sound of one hand clapping?
Tom
I agree. I'd 'trust' statements a bit more if folks would simply say what they prefer vs. site the preferences of others. Heck, I don't like the food from a lot of "top chefs", but that doesn't mean that they're either bad or good chefs (to me). Others have different criteria for how they judge a chef. I simply judge the food. To me, there's a bit of a difference.
In fairness, if people read that 4 different chefs went to the same 'school' and had similar philosophies and practices.... and those same people wound up enjoying the food from those 4 different chefs, it's understandable that they might think that there was a little something to the methods. There's also a ton of bias in anything subjective. I'm 'preaching to the converted' though.
I've never had a chance to sit with Nelson and listen to the same things at the same time and discuss preferences. Who's to say that what he likes is what I like? I know I've had a ton of fun building a lot of his designs. I find that I really enjoy most of his designs shared here, and the commercial products I've heard were wonderful. Again, though... I'm not a "critical" listener. It's pretty rare that I come across something I find offensive. Perhaps it's my hearing.
I like it when engineers can state their goals; it's as simple as that. I always appreciate that you state yours plainly and never BS'ed around them. I also happen to love the amps I have of your designs. So, I will get more of them.
As yet, I haven't had a chance (better stated as gotten off my butt and taken the time) to actually build any of yours yet. I'm privileged to have one of your head amps, and two of your DG300Bs. What is particularly great (to me) is that I never had to wonder if "my build" sounded like it "should". There's always that nagging feeling in the back of my mind when I don't like an amplifier that I've built that others rave over. Did I screw up the build and/or do I just not like it?
I admit to not delving too deeply into the subject, but I've heard this mentioned often. I'd trust any resource you could point me toward. Links via PM or in the forum would be greatly appreciated. I've really enjoyed some "great measuring" amps. I never try to convince myself or others that I'm even remotely consistent in what I think I hear from day to day. It's just fun. I suppose that's the primary reason I don't understand some of the passion around the subject (again, not from you).
They are dead sexy. I'm sure someone could figure out a way to clone the look, but... I dig 'em. They're not going anywhere anytime soon.
Cheers,
Patrick
You are talking about resulting effect on the listener by emotional impression that music reproduction through certain audio components invokes. 🙂
By that, absolutely every audio component is an effect box, invoking different listener responses, which are dominantly determined by listener’s preferences.
No, ultra low distortion by itself is not introducing listening fatigue.
I suspect that it is clarity and presence of lot of details that captures and commands listener attention, which is more demanding and exhausting in log listening sessions than slightly mushy, masked details and sweetened with H2, reproduction of a good high distortion amplifier.
There are other suspects as well, but this is off-topic.
A good, low distortion amp will expose crappy recordings for what they are. Listening to crap is definitely fatiguing.
Tom
Tom
Oh, yes. That is the ‘curse and absolute joy’ of having ultra low distortion equipment. Many recordings you liked before, became exposed as a sound engineering disaster, while many other become incredible joy to listen. I will never look back.
I need to dust off the project I have sitting on my computer: Adding various distortion profiles to a track and have people blindly rate them by perceived distortion and listening pleasure. I’ve already written most of the code…