Sound Quality Vs. Measurements

[scottjoplin]

Yes, but he's also saying some of the distortions aren't actually there to the degree implied by the published figures of THD and IMD and explains why.

 

[syn08]

Haven't you ever wondered how it is that you could hear .1% of electronic distortion through a loudspeaker that is typically 1-5%."

I don't know, can we? Was this already established beyond any reasonable doubt? Is 0.1% a threshold? Markw4 claims hearing -130dB, that's 0.00003%.

 

[peufeu]

In the end you should measure all the possible combinations amps/speakers/rooms available.
This suggests that the measurement of the single component of the audio chain is almost useless to evaluate its quality.

Not really: SS amps have adopted the standard of near zero output impedance, which is good, and the frequency response of commercial speakers is measured with this kind of amp, so you can mix and match and get the same frequency response. Of course, then comes the room.

What I'm saying is, if you look at only the THD of your LM3886 and tube amps, and ignore the difference in output impedance, then you'll miss an important point, since the latter can change the frequency response of the speaker, and that will produce audible differences.

If you optimized your crossover to sound good when powered by an amp that has a bit of output impedance, like the tube amp, then it will sound different, perhaps worse, with a low impedance amp.

 

[TNT]

This changes things a lot.
In this way I measure the result of the interaction between multiple components of the audio chain.

Then you need to add the room which greatly affects the result.

In the end you should measure all the possible combinations amps/speakers/rooms available.
This suggests that the measurement of the single component of the audio chain is almost useless to evaluate its quality.

You mean like e.g. a clock...?

//

 

[gpapag]

What I'm saying is, if you look at only the THD of your LM3886 and tube amps, and ignore the difference in output impedance, then you'll miss an important point, since the latter can change the frequency response of the speaker, and that will produce audible differences.

If you optimized your crossover to sound good when powered by an amp that has a bit of output impedance, like the tube amp, then it will sound different, perhaps worse, with a low impedance amp.

George

 

[picowallspeaker]

So why the need of power over 30 W?
LM 3886 and the likes are sufficient.

Making a comparison with some 6 W amplifiers or worse with a LM 386, when you can really listen to 10 %THD

 

[peufeu]

So why the need of power over 30 W?
LM 3886 and the likes are sufficient.

Just stick a scope on the output of your amp, play Sheffield Drum&Track at satisfying volume, watch the peaks, and you'll know how much you need.

 

[picowallspeaker]

I stay at 50 cm, strongly off_axys to each speaker

 

[indra1]

That's the shtick, me and others have no other motivation than protecting (time permitting) others from audio BS...
Otherwise, you could promote your...

Does not sound like so and I have no need to promote anything here, my business is fish ball finger food. The interest on the subject is because I want gears I build for my own more in line to my taste.

My original question to Chris:

... I'd like to know if there is a measurement we can make that show a recorded piece is really holographic, a bit compressed in depth, compressed in height or just plain outright flat.

- I can pinpoint sound source with my 2 ears, saved my head a couple of times. Not an illusion.
- I hear location of instrument and other recorded sound source on a playback - no physical instrument therefore an illusion.
- Sound below my hearing threshold does not create any soundstage illusion.
- Paul McCartney made sketches on where he wanted a particular instrument appear in the sound field. Therefore mixing experts can create an illusion somewhat common to a lot of people.

Suddenly ...

... audible effect of suspending clocks by rubber bands, or the noise reduction in Bybee devices, etc..., the onus to provide this is on you and your posse...

And you spray this nonsense to what purpose? The way I get it is that you want me to stop asking question, not the end of the world, no more question from me.

Only the people making money in the "illusion business" would risk losing if the true understanding of the matter becomes common knowledge. Therefore anybody hampering spread of knowledge and progress deserves a treatment of presumed guilty until proven innocent. You want me to leave because I ask? There is no other conclusion I can think of.

 

[peufeu]

Just get the record (in lossless obviously), unlike a lot of ******** audiophile test records, it's fun to listen to

 

[scottjoplin]

Indrawan, correct me if I'm wrong, you asked a question of Chris, he answered it, you don't like the answer, others have tried to explain why it can't be measured, you think they are wrong and there is something that can be measured?

 

[syn08]

- I can pinpoint sound source with my 2 ears, saved my head a couple of times. Not an illusion.

Prove it.

- I hear location of instrument and other recorded sound source on a playback - no physical instrument therefore an illusion.

Prove it.

What, you cannot? Then it is only the product of your brain. I, for example, cannot identify the location of an instrument, other than in the plane defined by the speakers and my listening position. No 3D, probably I did not take my meds.

 

[indra1]

Come to Bogor, throw something making a sound at my head, see for yourself. Or send someone to do it for you. I'll do it blindfolded.

 

[scottjoplin]

Some people can't even do that, they hear the sound located at the speakers' positions.

 

[indra1]

Sure, I've seen enough heads banged up in construction site.

... you don't like the answer, others have tried to explain why it can't be measured, you think they are wrong and there is something that can be measured?

As I understand it Chris said there is no problem in having the acoustic measured, but have not arrived at clear correlation of the measured quantity to perception of location. I stated I hope to see some progress before my time is up. That is all.

 

[picowallspeaker]

Only the people making money in the "illusion business" would risk losing if the true understanding of the matter becomes common knowledge. Therefore anybody hampering spread of knowledge and progress deserves a treatment of presumed guilty until proven innocent. You want me to leave because I ask? There is no other conclusion I can think of.

So damn right!!

 

[andrea_mori]

You have made statements making it clear you prefer the sound of tubes in general over ss. Is that not an indication? Not taking you to task here, we're having a friendly conversation. I have not used the term "superior". I think it's very possible you may think ss is superior tech yet still lower sq than tubes, at this point in time.

I also said that I will try both tube and ss amp when the time comes to design it.

But here I'm talking about the comparison and the measurements of two specific amps.
Peufeu aside it looks like no one is interested on performing a few measurements to understand if there is a relation between the measurements and the perceived sound.

Measurements of the Neurochrome Modulus-286 amplifier from the other site, are they useful to understand the sound quality of the amp (since it just implements the LM3886)?

 

[scottjoplin]

Sure, I've seen enough heads banged up in construction site.

As I understand it Chris said there is no problem in having the acoustic measured, but have not arrived at clear correlation of the measured quantity to perception of location. I stated I hope to see some progress before my time is up. That is all.

Ok, have you any suggestions where to start?

 

[billshurv]

Yes, very true. I can't stand listening to a drum live. I can't stand to stay inside Planet Hollywood due to the loud music for example. But most of the characters of instruments, techniques (fingerings etc.) or vocals come from the low level detail that is easily lost (or modified) in speakers and amplifiers.

We are on the same page then give or take a few semantics that don't really matter

 

[syn08]

Come to Bogor, throw something making a sound at my head, see for yourself. Or send someone to do it for you. I'll do it blindfolded.

See what? How could I peek into your brain?