This is an interesting one, with digital audio. When I first picked up on this behaviour, years ago, it was night and day, and took about 5 minutes to fully emerge. It drove me nuts at the time, trying to work out what was going on, and how to stop it happening - and I never did get a firm grasp on it at the time.
Much current gear seems to be vastly better, it can be very subtle in effect, and can take from the order of minutes to an hour or so to really be noticeable. However, once you tune into the signature of this distortion, you'll pick it happening quite easily.
Easiest way to pick it is with music with strong high frequency harmonics, cymbals are perfect for the job. As the distortion intensifies the shimmer of a cymbal strike steadily turns grey and dead, there's no life or sparkle to the sound, a saucepan would sound better. At this point, switch off all the gear, let all the power supplies discharge, and switch back on again; play that same track immediately. If you have the problem the cymbal sound should have bounced back completely, full of life and sparkle again - only to slowly start to degrade once more.
I'll be surprised to find that Bob has dropped all discussion of PSR from the latest edition of his book. Is that now your claim? Also discussed extensively by Self, Morgan Jones (on the tube side), and every IC opamp data sheet with which I'm familiar.
Another angle on the PSR thing: there's a vigorous debate on Cordell's amp book thread about the pluses and minuses of types of compensation schemes, TMC, TPC, etc. Nothing about correlation with PSR. Well, quite some time ago I did some sim's, comparing behaviours with the different schemes, using somewhat realistic PS's. And there was major differentiation in performance, trying this - I can't remember now what the results were ...
FSM forbid that you actually present any data or analysis. Keep those hands waving!
Perhaps we need an agreed parameter to express how supply rail variation affects amplifier gain (and hence PSU-related IM). In most cases it will be found that PSRR improvement measures also improve PSU IM. A classic exception is a valve push-pull output stage, where second-order signal distortion is cancelled in the OPT but second-order signal-PSU IM adds in the OPT. Fortunately it only needs a back-of-envelope calculation to show that PSU IM is low enough to be not a problem.
Sometimes things are not mentioned in textbooks because nobody has thought of them. Sometimes because it is assumed that it is obvious from what has been mentioned. Sometimes because it turns out that the issue is not a problem and a textbook can't mention everything which does not need to be considered - textbooks get long enough just by mentioning things which do need to be considered.
Sometimes things are not mentioned in textbooks because nobody has thought of them. Sometimes because it is assumed that it is obvious from what has been mentioned. Sometimes because it turns out that the issue is not a problem and a textbook can't mention everything which does not need to be considered - textbooks get long enough just by mentioning things which do need to be considered.
I'm still impressed by what my ultra, ultra low-end sound system, of an Aldi Blu-ray driving Aldi LCD TV is achieving: in the area of "natural timbre" of sound it's doing an excellent job, yes, easily beating what a hifi dealer normally produces, no matter how expensive the gear is. Key is disabling every device in the house that produces RF signals of any type, without doing this the sound loses much of its quality.
Anyone else game enough to own up to trying something like this, and getting results one way or the other ...?
Anyone else game enough to own up to trying something like this, and getting results one way or the other ...?
So If I understood well, you say that almost any low end system as crappy as it can be, can outperform any other gear disregarding its price just by plugging out every device in the house that produces RF?
Perhaps a little bit more than that,
... . "Crappy" systems normally sound really crappy, you don't want to listen to them any more than you have to ... but, if one is prepared to do a few experiments in various areas, one might be surprised at how clean and musical nominally "nothing" components can sound. Which is something that very expensive systems quite often get wrong; they may go loud and be impressive in certain areas, but they are not something you want to keep listening to ...If you do this sort of thing, and the crappy system still sounds crappy, that's fine: no guarantees about anything, it's all an experiment ... but in some cases, it's just possible that something interesting may be discovered ...
Do you mean this for real? Maybe with 'girl and guitar' or solo violin but not a symphony orchestra, surely..? For many people, the key to good sound seems to be to be some notion of omnidirectionality, and projecting sound backwards as well as forwards, open baffle dipoles and all that - if not done correctly it can sound weird and 'phasey' from what I've heard at shows. But presumably if the TV's plastic enclosure is far from sealed and it vibrates in sympathy with the music, you might achieve the effect of the instrument being in the room with you..? You might even be able to walk around it and still maintain the illusion (there was another thread about that idea).
Maybe you have achieved this without the expense:
Violinspeaker - Product
More or less what I was saying some pages before, some low end equipment have some kind of...mmm... good flavour! Maybe just some frecuency areas, and while not being high-end in the sense we are use to, they are fun to listen to.Perhaps a little bit more than that,
If you do this sort of thing, and the crappy system still sounds crappy, that's fine: no guarantees about anything, it's all an experiment ... but in some cases, it's just possible that something interesting may be discovered ...
It's like comparing a kart versus a full sized car, a truck or even a Formula One car. It has nothing to do with them, but it doesn't mean it ain't fun to drive them from time to time.
I think this is true. Kids, and even adults, enjoy cartoons because the images are simplified and easier to interpret, with less distracting detail. I suggest a less-than-hi fi system can be a way of 'cartoon-ising' music where the details are smeared together into one easy-to-interpret whole. Mono-ish presentation is also part of that.
Of course you have to be realistic about it, it's not going to do orchestral at elevated levels!! Jeez, this "girl and guitar" thing, if I ever buy one of these silly albums that people listen to of that sort of stuff, hmmm ...
The main thing I'm achieving is clear upper midrange and treble, which is key to getting "naturalness" in the sound; not quite an "invisible" sound box,, but very effective - it passes the Listening In Another Room test fairly well ...
The main thing I'm achieving is clear upper midrange and treble, which is key to getting "naturalness" in the sound; not quite an "invisible" sound box,
, but very effective - it passes the Listening In Another Room test fairly well ...
And, no, I'm not talking about smearing making things acceptable! The latter is what I often hear in ambitious setups, they often wreck the sound of cymbals badly. It's about getting the triangle struck at the back of the room coming through clearly, and hearing some real depth in the sound ...
Let's limit the discussion to the TV thing.
I have owned and opened several HDTV. My current HDTV was produced when (at least in my country) Samsung had not yet produced one (Currently I think Samsung is the most popular). So I think I know a bit about the limit of such system.
Frank mentioned use of blue-ray player in his tweak. Well, this plays extra role for the good sound, no doubt.
Frank mentioned string sound which was better than those in hi-fi dealer. Well, this must be TRUE.
Most TV don't have tweeters. Only one mid-range, a full-range driver, crossover-less (means good sonic and reverberation/details). High frequencies which often is problematic in a speaker and amp is rolled-off. No bass as well, so the driver only produce narrow band, for what it is designed for. Easy job, so usually a good job.
Acoustic guitar works in midrange frequency. Any peak in guitar reproduction often brings "sweatness" to the sound.
Acoustic guitar has (1) Attack, which is good on crossover-less speaker (2) Reverberation, which is good on crossover-less sensitive paper cone driver (3) Echo of the body, which is not complete without bass driver.
The absence of point#3 will not reduce enjoyment or beauty. But Very good system must have all of them. Many speakers on the dealer usually worse at point#1 and #2 so the existence of #3 won't help.
SMPS, as often used in compact devices, well, I'm one of the DIYers who will say no to this power supply type. Engineers (Those who think they are. Actually I'm an engineer and work with numbers, but consider myself as subjectivist) will speak about good design, good grounding, but have they really experienced the effect of interference?
This is why I always mention the importance of "enjoyment". Because it may disappears easily from expensive systems.
There are ways to get this "enjoyment". Just look at it from science perspective, not voodoo or taste.
Yes, genuine bass won't happen, but decent midrange and treble can. It's the latter that's the big problem if you don't jump through all the hoops I've mentioned so far, it's the same problem that's dogged digital sound since it first got off the ground, no matter how expensive the gear. Digital treble is very fragile, and the slightest interference problems immediately turn it into a dull, unpleasant sound.
Diffraction, scattering doesn't come into it: when it works right it sounds good a foot in front of the set, and just as good as you walk down the hallway to the other end of the house. The key for me is that the treble of piano is "correct", the sharp ring, dynamic impact of a high note hit hard reproduces well - most ordinary hifi setups I listen to make piano "a dull boy", there's little life or sparkle, no bite to a hard hit note ...
Diffraction, scattering doesn't come into it: when it works right it sounds good a foot in front of the set, and just as good as you walk down the hallway to the other end of the house. The key for me is that the treble of piano is "correct", the sharp ring, dynamic impact of a high note hit hard reproduces well - most ordinary hifi setups I listen to make piano "a dull boy", there's little life or sparkle, no bite to a hard hit note ...
No top treble, such that diffraction is not an issue. Only lower treble by paper cone, which is "safe/better" than dome tweeters.
The absence of genuine bass will not ruin most string reproduction (but not double-bass
). So guitar will still sound beautiful tho not complete.But there are musics where absence of bass will remove most of the beauties.
Double-bass is beautiful, and it is not really that low.
Frank mentioned about Adele 21. Many of her music requires bass reproduction lower than a double-bass. I have a speaker where the bass driver can be connected/disconnected without changing the sound reproduction, except where extra low bass is present. And I noticed that several music/song doesn't sound as good when the lower bass is missing. But not so serious, as I don't think her music is good
Nice analysis, Jay, I agree with your rundown. If the music doesn't have much true or sustained bass content then the TV does a remarkably good job, classical chamber is good, concertos are fine; a Steve Earle struggled because of the strong bass accompaniment; Rolling Stones, Exile on Main Street, did surprisingly well considering it's a sludgy album, as well as being on a badly scratched disc from the library, the unit was struggling to play in some areas.
Plus, some more tweaks: pulled the plugs on the computer power supplies at the far end of the house, and used surge busters as crude RF filters on both the player and TV. This lifted sound enough that the pop hits compilation that I mentioned earlier, disc 2, did pretty well, compared to disc 1: a lot of depth to the effects, and the treble content came through cleanly, wasn't aggressive or in your face ...
Plus, some more tweaks: pulled the plugs on the computer power supplies at the far end of the house, and used surge busters as crude RF filters on both the player and TV. This lifted sound enough that the pop hits compilation that I mentioned earlier, disc 2, did pretty well, compared to disc 1: a lot of depth to the effects, and the treble content came through cleanly, wasn't aggressive or in your face ...
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