Audiophiles, generally don't like class D amps!

[NoxMorbis]

All of this could be from a million things. Maybe you were hangry? Maybe you didn't sleep well?

I mean seriously.

It's true what you say. You would need to account for variables and test the best you could.

A good example is my Klipsch speakers and the midrange/lower midrange between 80-200Hz. It just sounded thocky not tight and punchy. It didn't present itself in most songs, but enough to annoy me. I tried trimming it out, but then other songs sounded more dull. I also had some 8-10kHz harsh sounding highs that I could trim out, but it was still there in a matter of degree.

I saw a Youtube review that said with my Klipsch R51-M speakers, you need to pull them away from the wall about a foot or more and if you have the speakers toed in, to set them straight ahead, not toed in.

Problem completely solved. I'm enjoying these speakers more than I ever have. Recently, I was even considering buying another brand (with a technical review) just to see if that would solve my problem. Now, I'm not looking, at all. However, if I had the money, I would do it just because it is fun to sample things.

 

[NoxMorbis]

For me it's kind of like when I just don't want to listen to music anymore. I think it has more to do with the mental state at the time than anything else.

I know that phenomonon too. Early in the morning I sometimes don't turn my system on for an hour or so, just to enjoy the quite time and think. I would be annoyed if it were on, but not becsaue I wqas hearing something that sounded bad, rather, because I was hearing something I simply didn't want to hear at all, regardless of how good it is.

 

[NoxMorbis]

It depends.. I would never buy an amp I wasn't sure was load independent. And more class D than class B has turned out to be load dependent.
Edit: so I stick with A/B for now as I like my Dirac to be correct.

What if the discrepancy was at 15-20khz and was less than 1dB?

 

[NoxMorbis]

"Thocky" ?????? There's' one for the subjective lexicon!

Jim

LOL, how do you describe a sound? It sounded more like . . . I dunno, a hockey stick hitting a puck, or thock! Just not tight low/midrange. More like a drumstick hitting a plastic 5 gallon bucket rather than a smooth sounding punch from a speaker. I couldn't find the term I needed in the official Stereophile lexicon in the attached So, In made one up.

 

[NoxMorbis]

Your question ("LOL, how do you describe a sound?") is at the root of what I would describe as one of the most confusing and misleading problems in audio; trying to use subjective words to transfer aural characteristics.

It's either difficult or impossible.

You cited the Stereophile lexicon, but that lexicon is worthless. It uses meaningless words to describe meaningless words. One other reason that it is worthless is that the subjective sounds that one person is trying to describe to another may arise from the speaker itself, or it may arise from the room acoustics. It may vary with placement. And it definitely can vary with listener orientation to the acoustic design center; listening slightly off the intended vertical axis very often introduces a suckout in the frequency response. With no explicit controls, you can't tell what's going on and why.

The best way to use words to describe loudspeaker characteristics is to reference a series of tests and measurements, to include frequency response on-axis, frequency response off-axis, distortion characteristics at various output levels, off-axis interference characteristics (both destructive and constructive) cabinet resonance, frequency summing at crossover, dynamic compression plus a bunch more that I can't remember right now.
That takes time and work. Identifying which aural impression arises from which measurement can be a long and laborious task. Personally, I don't see much benefit in it, because it still reinforces the bad habit of using subjective words to describe aural impressions.

It's better to not even use words to describe sound. Learn to "read" the language of response charts and measurements. If you were traveling in China, you'd prepare by learning the Chinese language, wouldn't you? Well, audio is the same. And just as you'd be hopelessly lost in China not speaking the Chinese language, you are similarly lost in audio not speaking the "language" of tests and measurements. Just as you would learn to read Chinese, you can learn to read tests and measurements.
Then instead of saying, "This sounds thwocky", you might say, "This has an audible resonance at 400 Hz." or "There is an annoyingly high level of I.M. distortion in the upper midrange."

Look at it this way: would you rather depend on some driver giving you their "impressions" of motor performance, or would you rather have the gearing specs and dyno tests in front of you? Impressions don't mean diddly-squat when it's critical that you move a load up a hill.

I know it's natural to try to use un-referenced words, but it's a bad habit that is best abandoned.

Jim

Please define

• suckout
• audible resonance

 

[DavidM1]

Please define

• suckout
• audible resonance

Hmm… I read the post and thought it very clear. A suck out would be a reduction or diminution. An audible resonance is a resonance you can hear. In this case 400hz is between G and G# above middle C on the piano.

 

[NoxMorbis]

Suckout: a dip or null in the frequency response, in this case caused by cancellation of signals between the two drivers. This one is from Troel Gravesen's Discovery-81 DIY kit:

View attachment 282872


Audible resonance: Resonance is a sympathetic vibration. Audible simply means that the level of the vibration is high enough to hear. It can occur in the diaphragm of the driver itself, and it can also occur in the enclosure. The peaks above 3kHz in this chart are resonances.

View attachment 282869

In this chart, the peaks above 2.5 kHz are resonances within the driver:View attachment 282871

I may have inadvertently dropped a comma in my post. I'll edit that in.

Jim

p.s. - this thread from this site also addresses resonances.

Speaker Resonances - The Good, the Bad and the Ugly

Since the topic of evaluating resonances has been mentioned several times in @amirm's reviews, here is an attempt at a comparative analysis of different resonances in loudspeakers. For this purpose the measurements of the following loudspeakers are compared: focal-aria-906 buchardt-s400...

www.audiosciencereview.com

Thank you, and so you are saying that resonance in the way you are using it is always sympathetic resonance? If I remember correctly, sympathetic resonance is originally refers to string instruments, not speakers, but with string instruments and piano, it's not necessarily bad. So, how does it sound in a speaker?

Hmm… I read the post and thought it very clear. A suck out would be a reduction or diminution. An audible resonance is a resonance you can hear. In this case 400hz is between G and G# above middle C on the piano.

You are obviously a lot smarter and knowledgeable than I am. I try to keep up.

 

[DavidM1]

The reference to a 400hz resonance got me thinking. Musical instrument makers typically aim to minimise the effect of an undesirable resonance by pushing the frequency to a pitch that doesn’t coincide with frequently used notes at concert pitch. This let’s the instrument’s response be more even and easier to control day to day.

Given that the vast majority of recorded music is at standard pitch, I wonder if the specific frequency of resonances is a common part of the audio conversation? 392, 415 and 440hz are far more frequently heard prominently than 400hz. A resonance at 400hz may well colour the sound but perhaps less obviously than those that coincide with specific notes and their early order harmonics.

 

[MaxBuck]

392, 415 and 440hz are far more frequently heard prominently than 400hz.

Okay, now I'm intrigued. What on earth are you talking about?

 

[DavidM1]

Okay, now I'm intrigued. What on earth are you talking about?

It seems that discussions about audible resonances with speakers or elsewhere in hifi tend to assume that all frequencies in music are equally prominent and equally important. I haven't seen anything that relates a resonance back to the actual pitch we hear. As I said, the vast majority of recorded music is recorded at A=440hz, an international standard (yes, some orchestras play sharper but not by much). That means that we know the frequency of notes in all octaves. Just like a violin maker, if I had built a speaker with an unavoidable resonance at 400hz I would be less concerned than if it was at 392hz, which is G above middle C, or 440hz, which is A above middle C. Those notes come up a lot. They are also early harmonics for G, A, C and D bass notes at lower octaves.

In other words, a resonance that is between notes is less likely to be emphasised by music we listen to every day and is probably less noticeable.

 

[SIY]

It seems that discussions about audible resonances with speakers or elsewhere in hifi tend to assume that all frequencies in music are equally prominent and equally important. I haven't seen anything that relates a resonance back to the actual pitch we hear. As I said, the vast majority of recorded music is recorded at A=440hz, an international standard (yes, some orchestras play sharper but not by much). That means that we know the frequency of notes in all octaves. Just like a violin maker, if I had built a speaker with an unavoidable resonance at 400hz I would be less concerned than if it was at 392hz, which is G above middle C, or 440hz, which is A above middle C. Those notes come up a lot. They are also early harmonics for G, A, C and D bass notes at lower octaves.

In other words, a resonance that is between notes is less likely to be emphasised by music we listen to every day and is probably less noticeable.

Wolf notes? If the resonance is not on the note but somewhere nearby, it can be far more audible.

 

[Galliardist]

It seems that discussions about audible resonances with speakers or elsewhere in hifi tend to assume that all frequencies in music are equally prominent and equally important. I haven't seen anything that relates a resonance back to the actual pitch we hear. As I said, the vast majority of recorded music is recorded at A=440hz, an international standard (yes, some orchestras play sharper but not by much). That means that we know the frequency of notes in all octaves. Just like a violin maker, if I had built a speaker with an unavoidable resonance at 400hz I would be less concerned than if it was at 392hz, which is G above middle C, or 440hz, which is A above middle C. Those notes come up a lot. They are also early harmonics for G, A, C and D bass notes at lower octaves.

In other words, a resonance that is between notes is less likely to be emphasised by music we listen to every day and is probably less noticeable.

All well and good, until you listen to early music, when you can encounter many different pitches and resonances unrelated to notes being played.

 

[DavidM1]

Wolf notes? If the resonance is not on the note but somewhere nearby, it can be far more audible.

Fair enough. Not my experience though. Luthiers I know aim to minimise it and have it away from open strings and other frequently used notes. In any case, whether it is either more or less noticeable it is not something I’ve seen discussed with audio.

 

[DavidM1]

All well and good, until you listen to early music, when you can encounter many different pitches and resonances unrelated to notes being played.

The majority of early music groups play at either 415 or 440. 415 is pretty much a neat semi-tone lower than concert, so essentially the same family of frequencies but a lower tonality. Some early music groups use different temperaments or tune to odd wind instruments and I agree there is a bit more variation if they do.

However, compared to the mountains of music sitting squarely at concert pitch I’m surprised not to see a consideration of pitch when discussing audible resonances.

 

[NoxMorbis]

Yes, that's one example of resonance. There are others .....

" ... a vibration of large amplitude in a mechanical or electrical system caused by a relatively small periodic stimulus of the same or nearly the same period as the natural vibration period of the system ... " (Merriam Webster Dictionary)

So the sympathetic vibration in strings is "in sympathy" to the fundamental. The sympathetic vibration in physical and mechanical objects is in sympathy to the natural vibration of the medium.

See here:

Resonance - Wikipedia

en.wikipedia.org

And for "natural frequency", see here:

Natural frequency - Wikipedia

en.wikipedia.org

And if you really want to know the definition of "oscillate", here it is, in all its brutal glory:

So it all comes down to energy storage and release at a frequency that supports oscillation. Whether the oscillation is of air, wood, steel, catgut or water matters not in the least.

Jim

What does it sound like coming from a speaker?

 

[mocenigo]

Co

Here's an interesting thing... why would a company like Genelec, renowned for their active monitor technology and audio fidelity, use differential amp topologies (Class D for low and mid drivers, Class AB for treble) on many of their flagship full-size monitors?

See here: https://www.genelec.com/main-studio-monitors

View attachment 282165

Cost. For larger power output, class D can cost less. For smaller power output, class AB amps can cost less, and in fact also be more efficient. So it makes sense for an active multi-amplified design.

 

[NoxMorbis]

Co


Cost. For larger power output, class D can cost less. For smaller power output, class AB amps can cost less, and in fact also be more efficient. So it makes sense for an active multi-amplified design.

There are some small AB amps on Amazon from the brands we know, Fosi, Douk, etc. They tend to pair them with tubs. I wonder how they would test?

Fosi T3 (I almost bought this before I bought the Aiyima 08 Pro. It's an ugly little abortion, though. Top dials are a nice design touch.

THD ≤ 0.1%, SNR ≥ 80dB, Input Sensitivity ≤ 300mv. Doesn't seem that clean for AB.

I was also considering the Nobsouind/Douk B100 (I have no idea what this is, but I'm assuming it isn't AB: 2PCS Toshiba C5198 and 2PCS 1941 triode)
SNR: ≥80dB / Distortion(1kHz): ≤80dB (Whatever they mean by "distortion." Either way, neither of them are measuring well, but people tend to think they sound great. Then again, some humans like the smell of other people's farts. It's a good looking fart, though. It would be even better with two pseudo-VU meters on the front, or maybe it isn't pseudo?
:

Until I figured out that tubes are just distortion.

 

[JRR]

It's the change to the status quo they don't like. I can be guilty of that too.

It's easy to dismiss a new paradgim as being 'wrong' if it challenges the base knowledge and beliefs systems, especially if it does so, much cheaper, easier and in some ways better.

HiFi was traditionally a difficult, expensive and arduous pursuit. You had to be in it for the long run. Pay your dues, climb the ladder and pay the price. Not anymore. You can jump to the top of the class for not a lot of time, effort or money. It sounds like cheating, but it is not.

Imo…

Hifi still is a difficult, arduous, and expensive pursuit. Allthough audiophiles continue to spend their focus on gear the secret sauce has always been found in the space they occupy. Room acoustics is still a challenge but much less of an instant endorphin rush compared to buying bling.

When/if I am ever fully satisfied with my room ill treat myself to a nice Accuphase integrated. I’ll sit and watch those VU meters bounce while i sip a good scotch in my also overpriced architect drawn sofa. SINAD lemmings be damned

 

[DavidM1]

Imo…

Hifi still is a difficult, arduous, and expensive pursuit. Allthough audiophiles continue to spend their focus on gear the secret sauce has always been found in the space they occupy. Room acoustics is still a challenge but much less of an instant endorphin rush compared to buying bling.

When/if I am ever fully satisfied with my room I’ll treat myself to a nice Accuphase integrated. I’ll sit and watch those VU meters bounce while i sip a good scotch in my also overpriced architect drawn sofa. SINAD lemmings be damne

Perhaps all the attention on room treatment is a little misguided. Is the objective to match the sound of a recording control booth? Should a serious audiophile trade their gear for high-end, near field monitors and switch the couch out for a comfy office chair on wheels?

I think people quite naturally account for the sounds of different spaces. Our children’s voices are no less familiar as we go from room to room. A violin in a cathedral sounds different depending on where we sit but it is no less the sound of a violin.

 

[IPunchCholla]

I believe the point is that many residential rooms have eigenmodes and reflections that interfere with the sound of the recording. Basic room treatment reduces these. Most people don't know much of anything about acoustics, and need to be prompted to inquire. Once they know more, then the choice is up to them whether to treat or not to treat.

Room treatment is not magic. It doesn't cure all problems. We should not try to emulate a control room or any other room, but instead simply get the worst of our rooms' acoustics under control. It can make a difference, and it can be inexpensive.

Did I mention that it can be inexpensive?

Jim

I think my room treatment cost something like $200. DIY bass traps and diffusion panels knocked down the bass modes a bit and the reflections that were causing tonal changes. I already had floor tiles that seem about ideal for preventing reflections off the floor. Decent nap thickness and super dense rubber. I will probably add something on the ceiling to help with those reflections a touch and add more diffusion to the rear wall (probably in the form of shelves for books and LPs. The point wasn’t to make it like a recording studio, but to knock down the worst offending modes and reflections to ease my brains ability to do its magic. With room correction software (another $100) it really seems pretty nice.