I could hear the difference. But why.

[Blumlein 88]

Your phone must be super stable for this to work. A deviation of 2.5 cm from the source would already be the .1 dB difference in gain that is needed for level matching. And even then you'll need some long averaging, and you then have no way of knowing if the differences are from some room source, or a gain difference. it would need several runs at random times to get this done. Just use the f*ching DMM and save you all the trouble

This brings us to another point: Equally for the blind test to work, you yourself cannot move more than 2.5cm as well while performing the test, otherwise the gains won't match either. Never mind different reflections and other room effects that can be highly localized. All of these things just show how silly it is to use speakers to try to perceive differences that are so tiny.


That's the whole point, isn't it

I already said you place the phone and don't move it. I'm not talking hand held here. Otherwise youare preaching to the choir. Those not in the choir just plain aren't hearing us when we tell them use a meter. It is ten times better, ten times or more consistent and about 10 times easier. Or I guess not. What they are doing is easier, and of course wholly inadequate. So if we could get them to do something the way it seems people automatically want to do it only in a way that works it would be a step forward.

Just tell me how often does somebody use a phone or SLM for matching and we tell them use a meter and they say, "okay, i didn't know I'll use a volt meter"? It happens, but at least 5 times as often there is a series of posts about it and even after all of that I don't think even half pay attention and do it right.

 

[voodooless]

I already said you place the phone and don't move it.

Yes, but that's just step 1

Just tell me how often does somebody use a phone or SLM for matching and we tell them use a meter and they say, "okay, i didn't know I'll use a volt meter"? It happens, but at least 5 times as often there is a series of posts about it and even after all of that I don't think even half pay attention and do it right.

I guess if people aren't willing to listen, it's possibly a lost cause anyway. If people can't even take the time to use a DDM, how can you expect them to follow complex detailed instructions to maybe get this reliably done via a smartphone?

... Meanwhile, those same people are willing to spend thousands of €$£ on a whim

 

[Sokel]

While obviously we cannot know what someone will use, I'd throw such a meter in the trash bin.

Yep.and if someone passes an ABX with strange claims I want a pic of the DMM too.
If it's like this feather-weight yellow one I described the test is invalid to me

Serioysly now,I think that people are afraid of the test conditions when going as far as asking a decent DMM as I do plus all the other checks.
That's why we see so little of them.
I encourage any try,even if not perfect,at the end of the day will maybe valid to the owner (even if not admit so publiccaly and laugh with its friends as I and my friends do)

 

[mcdn]

Why are we worrying about level matching when the signal is digital via HDMI?

 

[antcollinet]

Why are we worrying about level matching when the signal is digital via HDMI?

To check for DSP being applied differently across two devices? Though you'd probably want to do a frequency response for that.

 

[Mnyb]

Why are we worrying about level matching when the signal is digital via HDMI?

It might be processed or downmixed in the different BD/SACD players with a plethora of unknow settings .
It's enough unknowns to make speculation meaningless But yes i agree it should be identical bitstreams and that leave no mechanism able to alter the sound .
if it where spdiff i would not worry i would assume they where equal.

 

[Mnyb]

To check for DSP being applied differently across two devices? Though you'd probably want to do a frequency response for that.

That's another option the AVR itself has different settings for each source .

To the OP the results is extremely unlikely keep looking for experimental errors of some kind.

 

[MatrixS2000]

To check for DSP being applied differently across two devices? Though you'd probably want to do a frequency response for that.

Threads like this is another reason why I bought an RME. I would just run a bit test through the DUT, if anything was happening, the bit test would fail. End of story, the DUT is not bit perfect, so I know it is changing the bitstream.

 

[boxerfan88]

Considering the simplicity to hook up two DMM probes to whatever chassis connector or cable connector, it really makes very little sense to go the less reliable way to match level, ie install a microphone, sound card and computer in the room then take an acoustic measurement.

Yeap. And assumption is the mother of all Fups (or misunderstanding).

See the assumption that everyone has no PC, no soundcard, no microphone in their room. That it "really makes very little sense to go the less reliable way to match level, ie install a microphone, sound card and computer in the room then take an acoustic measurement." Yada yada yada.

Well, there are people like me (maybe very few no doubt) with a PC (which is also my streamer), audio interface, mic-on-stand, all hooked up in the listening room. All I need to do is to move the mic to the speaker, fire up REW, and measure away. Fast and simple. No fiddling cables at the snake pit, no fiddling with DMM and XLR connection.

As shared here the variation/error is well within the volume steps of the DAC, and therefore can be used as an alternate method to level matching.
No need to push DMM as more reliable yada yada yada. To me, both DVM method, and REW+Mic method are equivalent. User can choose whichever is more convenient. No need to beat down REW+Mic method as unreliable/much less accurate. I have provided proof that REW+Mic method can be accurate enough for the purpose of level matching DACs using their internal volume controls.

 

[boxerfan88]

Yes - that might be OK - near field with a swept frequency.

My reply was based on an expectation that REW+Mic, for most people would mean listening position and REW SPL meter which would not be IMO sufficiently accurate.

Well, wrong assumption on your part. Refer to this post ... variation/error is very well within the DAC's single volume step. See how vol93 lands almost on top of vol-3. Almost as good/accurate as DVM.

But now you have something that to me seems significantly less convenient than a DVM - especially given that in most controlled listening tests you are going to be swapping cables in any case.

Again wrong assumption. DVM is less convenient for me. REW+Mic is more convenient for me.
With REW+Mic, all I need to do is move the mic to the speaker, fire up REW, measure away. No need to fiddle with cables at the snake pit.
DACs are connected to 3in-1out XLR switch, so to flip between the two DACs, I just turn a knob.

To me, both DVM method, and REW+Mic method are equivalent. User can choose whichever is more convenient. No need to beat down REW+Mic method as much less accurate. I have provided proof that REW+Mic method can be accurate enough for the purpose of level matching DACs using their internal volume controls.