Dynaudio Heritage Special

[PLB]

I'm trying to follow your logic train here...

So if, hypothetically, my hybrid class A/D amp has more distortion than your class A/B amp....then I'm not seeing excessive woofer movement, and you are, because....?

Help me out, because I'm not mentally connecting the dots.

I’ll try and explain this so you can understand. You began by criticizing the amp I was using, implying it was to wimpy. So I was simply retuning the favor. This has nothing to do with whether or not your amp could reproduce the coil movement I was experiencing, I’m quite sure it could.

 

[watchnerd]

So...

a) I turned off my infrasonic filter

b) Tried the Tidal track

Problem reproduced.

Ergo:

1. The Tidal track exhibits the problem

2. Because the Devialet infra filter eliminated the problem, and it manifested when I turned the filter off, it must be an infrasonic issue

 

[watchnerd]

I’ll try and explain this so you can understand. You began by criticizing the amp I was using, implying it was to wimpy. So I was simply retuning the favor. This has nothing to do with whether or not your amp could reproduce the coil movement I was experiencing, I’m quite sure it could.

It was a joke, dude. That's why it had a .

Try turning on the infra sonic filter on your Accuphase and see if the problem goes away.

 

[PLB]

It was a joke, dude. That's why it had a .

Try turning on the infra sonic filter on your Accuphase and see if the problem goes away.

Sorry I took the wink face as added sarcasm.

 

[watchnerd]

Sorry I took the wink face as added sarcasm.

You should read the thread I had about getting an amp with VU meters to replace my laptop/pizza box-looking Devialet pair.

 

[MrPeabody]

If it's a Tidal track, what's the procedure for analyzing a streaming file without RTA?

Not something I have much knowledge of, but surely there is a way. Does Tidal make it difficult to download and save the file? Is this something you're not supposed to do?

 

[PLB]

So not the speakers.....

Then why did you think you had defective speakers?

Like I said, I should have done this before I panicked.

 

[MrPeabody]

As I noted above, my subsonic filter is turned on all the time because I listen to TT regularly.

I had noted that you had mentioned this, and it is one reason why I discouraged trying to sort out the issue by asking others if they see the same thing.

 

[PLB]

Not something I have much knowledge of, but surely there is a way. Does Tidal make it difficult to download and save the file? Is this something you're not supposed to do?

https://tidal.com/track/35467662

 

[MrPeabody]

So...

a) I turned off my infrasonic filter

b) Tried the Tidal track

Problem reproduced.

Ergo:

1. The Tidal track exhibits the problem

2. Because the Devialet infra filter eliminated the problem, and it manifested when I turned the filter off, it must be an infrasonic issue

Good work there, and it is just what I anticipated, but to nail the coffin shut, there still needs to be spectral analysis of the file. Even if it is streamed and not locally stored.

 

[MrPeabody]

Now, if you two want to do something way more fun that slinging spitballs, go look at that thread where Amir tested the UniFi 2.0 and get the file that he was listening to when he encountered The Problem, and see if you can observe the low-frequency cone movement (with the infrasonic filter bypassed of course). If you see it, try it again with the infrasonic filter engaged. See if your ears can pick out what Amir heard, and see if it goes away with the infrasonic filter inserted.

 

[richard12511]

Your right, just played the track with my LS50's and Hegel h190 with the same result. Should have tried that first before panicking.

I think we've all done the same at some point.

 

[richard12511]

July 2020

Haha. That actually gave me a real chuckle

 

[Soniclife]

Does Tidal make it difficult to download and save the file? Is this something you're not supposed to do?

That's exactly what you are not meant to do .
You can do it by recording it in real time in something like audacity.

 

[watchnerd]

Now, if you two want to do something way more fun that slinging spitballs, go look at that thread where Amir tested the UniFi 2.0 and get the file that he was listening to when he encountered The Problem, and see if you can observe the low-frequency cone movement (with the infrasonic filter bypassed of course). If you see it, try it again with the infrasonic filter engaged. See if your ears can pick out what Amir heard, and see if it goes away with the infrasonic filter inserted.

Amir can hear infrasonic things??

But I can induce audible-range bass IMD with infra sonic harmonic components via my bass guitar, anyway.

Low F# is 23 Hz.

 

[PLB]

From measuring hundreds of class D modules, the specs are true. Note that an AES-17 filter is required to filter the ultrasonic crud.

So you need to filter out the distortion before you measure?

 

[MakeMineVinyl]

So you need to filter out the distortion before you measure?

It is not distortion. All class D amplifiers generate a switching frequency which is generally filtered out by a combination of the output inductor and the inductance of the tweeter. When measuring on a test bench, a load resistor is used which does not have the inductance of a speaker. The AES-17 takes that fact into account.

 

[PLB]

I see, that’s what you meant by crud.

 

[richard12511]

It is not distortion. All class D amplifiers generate a switching frequency which is generally filtered out by a combination of the output inductor and the inductance of the tweeter. When measuring on a test bench, a load resistor is used which does not have the inductance of a speaker. The AES-17 takes that fact into account.

I think it's telling that the best 3 amps measured here so far have all been Class D.

 

[MakeMineVinyl]

I see, that’s what you meant by crud.

Would you be happier if I described it by its proper name, or is 'crud' too pejorative?