Folks, mix some broadband pink noise with a given rms level with a pure tone of a given rms level and with a frequency in a region of high aural acuity, say 2kHz. See how much that tone's level can be reduced before it becomes completely inaudible.
Then do the experiment in reverse. Bring up the tone's level from nothing and note when you begin to hear it within the noise.
Or, start with the tone and bring up the noise. When does the tone become inaudible?
Monochromaticity helps a lot.
Then do the experiment in reverse. Bring up the tone's level from nothing and note when you begin to hear it within the noise.
Or, start with the tone and bring up the noise. When does the tone become inaudible?
Monochromaticity helps a lot.
So SY, you have a recording of an acoustic event. You were there so you know what it sounded like live. We all know the transducer and the preamp and your un-identified recording device mangle the true sonics of the event. My point is you have a first person reference and now can hear the reproduced event. Now, when you play that though different gear you, hopefully, have an idea what has been done by said gear to the waveform of the recording by careful listening. Then make coponent level judgements as to how have a circuit translate the waveform to best recreate the recorded event.
Notice I use the term "waveform" as opposed to "data". It says a lot about you when you label an audio event "data".
Notice I use the term "waveform" as opposed to "data". It says a lot about you when you label an audio event "data".
and an understanding of spectral noise density, human hearing critical bands helps
over simplified, and from memory, but total energy in each critical band is what we hear, a ~1% change is noticeable well above the human hearing absolute lower threshold
critical bands are ~100 Hz wide below 500 Hz, ~20% of center frequency above
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The first does, the second two, not so much. The biggest factor is compression into two channels.
Yes, a waveform is a subset of "data," a more general term.
My experience with the MBL was not good. I noticed a strong HF coloration and traced it down to the magnet on top of the tweeter. A very high Q bell with NO damping. I wrapped it with some duct tape and it made a significant difference. All pointing to issues that need to be addressed. The MBL rep was NOT pleased.
Before pointing at something like electronics verify that the speakers are free of issues. That means more than a quick listen. The MBL is really difficult since is very low sensitivity, omnidirectional and may have internal issues to sort out. Omni means the rest of the room has an outsized influence on the sound. Low sensitivity means the amps work very hard and operate at a higher current than normal. There may also be issues around the crossover.
Obviously picking the right amp may be a blessing for the MBL- one with lots of extra power and a "soft" top end. Possibly from an excessive RL isolation network. Does two wrongs make a right?
I have done my homeworks. I don't just make conclusion based on books or other people stories, making reference to ancient amplifier tests...
I have experiences with blind tests. Even in this site I participated in Foobar ABX blind tests. My conclusions are gained from hands-on experiences.
I know what I can do (based on past experience) but I don't know what I haven't tried. That is why I used 'I feel', 'I expect' or 'my intuition'. There are experiences where certainty is 100%, there are others with less than 100%...
I was offering a chance for others who want to know the truth. I feel that some people like to draw conclusions without doing some proofing works.
IMO, we don't need to worry the THD. It's not difficult at all to achieve better than 0.1% right? So the question is: what else, other than THD, are the important variables of amplifier performance?
Such question has no answer. Either because nobody knows the answer, or everyone keep it as a secret
Build the VSSA from scratch, you will find that 0.002% is easy to achieve with high stability. So if all amps with THD less than 0.1% are indistinguishable, then we can say that no amp is better than a VSSA!
But that's not the case. Even LATFET is perceived with weaker bass than HEXFET or BJT. So where does this bass performance represented in the performance metric?
For me THD is an indirect goal. Some kind of side effect. Not all topology can give similar THD number so I don't really have a fixed THD threshold for an amplifier in general. The simpler the topology, the more I focus on THD.
For example, a VSSA can give you 0.002% THD easily. Improving the sound quality seemed to be difficult without adding complexity. So I used 2 extra buffers to achieve what I want to achieve (of course not THD). By adding extra buffers, of course the THD is automatically improved (<0.0002%), even tho it was NEVER the goal.
For most type of loudspeakers positioning close to back wall is not recommended.
How about M2?
I don't think anything about MBL is correct, from my privy. I heard their big guns, all the parts, and... it was all wrong. I mean subjectively maybe people are all about it, but it sounds like excessive current loading / unbalanced signal lines from the electronics. The soundstage was nonsensical because it scaled really large from the center but the rest dropped off?
Again, maybe people are into it, but it sounded very unauthentic to the recording. It might be fair to call it the antithesis to our local hero, Bruno.
I don't understand your request.
Of course, for you it is just a phenomenon that some people found ('sighted') that latfet amps have "soft" bass. It could be just like a single-knob tone control phenomenon: you got the highs, you lost the bass
For me, I know what variable to look at and have set a threshold for that.
I would question the amp rather than the latfets.
FTR i have a basic 2 x 120W latfet amp and it was compared to a 2 x 200W bipolar QSC amp using a bass guitar played live by the QSC owner, he just aknwoledged that the latfet was far better, and it was indeed audible as i experienced it live as well.
How could that be? After all, we have been told that JA has a degree in physics.bcarso said:
A question: why is that JA et al having degrees in physics seems to validate their opinions when they agree with JC, yet the same qualification seems not to validate my opinions when I disagree with JC?
The Occam's Razor explanation would be that some audio reviewers don't actually like hi-fi sound reproduction. They don't like 'clinical' or 'boring' but prefer 'slam', 'warmth', 'musicality' etc.bcarso said:
Many years ago I learnt something about my hearing ability. I won't bore you with the details but on one occasion I discovered that I did not readily detect when an RIAA filter had been accidentally left in position - of course once I noticed the switch position I realised why the sound was a little dull. On another occasion I noticed that an FM tuner I was debugging sounded not quite right in the treble; I fiddled with the de-emphasis capacitors until it sounded about right, then re-did the calculations and was pleased to find that what sounded right to me actually was right (my original calcs had been wrong). So I missed a huge frequency response error, yet could fairly accurately spot a minor response error. That taught me not to fully trust my ears, yet to 'listen' to what they were telling me.
Not really, noise is just the random part. You can distinguish a signal below random noise. Imagine a noise level just above your limit of perception, and a sine signal slightly below it. Without the noise, you would never be able to hear the signal. However, thanks to the introduction of noise, enough of the signal can be pushed above the threshold for your brain to distinguish the periodicity of the signal. Actually, you don´t even need a brain for this. I first came across it when I was studying neural networks a couple of decades ago. The artificial addition of noise can push some signals above detection thresholds and is thus used. There is some family relationship with dithering btw.
So, in stead of being buried under the noise, the noise can actually push signals above it. I don´t think it is a coincidence that ears are never completely silent, even in the absence of sound, and eyes always show noise, even in pitch black. Without it, our sight and hearing would be much less able to discern low level inputs.
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