For Newport Audio show attendees

[esldude]

There was discussion buried deep in the Nordost thread about using smartphones to monitor relative volume level during live public demos. I did some testing and it appears you could do some worthwhile monitoring with a smartphone.

 

You need to use a recording app that can save to a lossless format like wav and which can turn off AGC (automatic gain control) for the recording. I have used RecForge Lite and RecForge II on an android phone to good effect. There are other such apps suitable. Using this it was possible to reliably detect volume changes as low as .3 db. when one piece of music was played twice over speakers. You need to place the phone somewhere and not touch it during the demo. Hand holding or leaving in a shirt pocket is too variable to work well. I found AC noise and fridge noise not to make much difference in detecting differences. I don't know how much crowd noise will intrude on this. All you need is a few seconds with relatively quiet conditions for this to work. Being closer to the playback speakers would help too.

 

You can open the recorded file into Audacity, carefully select the same portions of the music, then under the Analyze menu use the Contrast function. This gives an average RMS value for the selection. I found it worked well with small volume changes.

 

It also is possible to ferret out similarly small EQ changes. It is a bit more involved process which I won't describe here.

 

So just an FYI for anyone wishing to monitor some demos should they attend them at the Newport Audio show.

[christopher3393]

Thanks.

[junker]

I just the Decibel app on an iPhone all the time with my home system:

 

[esldude]

I just the Decibel app on an iPhone all the time with my home system:

 

[ATTACH=CONFIG]26410[/ATTACH]

 

The problem with those type apps is you get a reading as the music plays and it bounces around. Then they play the music again you can't get a precise comparison at any point in time. Even those that will do a time average aren't precise enough to get these very fine discriminations of small volume changes. I think you can do much better doing an actual recording under relatively stable conditions and processing the results after the fact.

 

If someone knows how to use one and get it to work please tell us.

[tuodiqi]

well,do much better doing an actual recording under relatively stable conditions and processing the results after the fact.thanks

[master]

I can see Nordost banning all smartphones and recorders from the demo room.

[esldude]

I can see Nordost banning all smartphones and recorders from the demo room.

That would be something of a defacto admission of something not kosher.

[christopher3393]

Is it safe to say that no one on this forum attended the Nordost demo?

[esldude]

Maybe they had people sign an NDA at the demo. It's odd no one attended or at least posts about it. Believers want to believe I guess.

[christopher3393]

This from Mark Waldrep's T.H.E. Show Newport post: ( T.H.E. Show Newport Beach 2016 | Real HD-Audio )

 

"On a topic near and dear to myself—and many of you, a gentleman named Rick approached me on Sunday afternoon. He asked if I had been able to make it back to the Nordost demonstration. Unfortunately, I was tied up at my sales booth. Rick spent 18 years working as an electrical engineer at AT&T. This is a guy that knows much more than I do about electrical circuitry and audio signals. He did sit through the power demonstration in the Nordost room and told me that when the switched to the most expensive cable, they also switched the disc that they were playing. “They played the same piece of music, but from a different disc”, he said. He couldn’t imagine why they would do that.

 

Can anyone think of a reason why the presenter would swap out a disc for a different disc and play the same selection of music? Why not just start the track you just played over again after switching out the power cord…or whatever other cable was being compared? I find this very curious. It simply makes no sense…unless the second disc was not identical to the first."

[esldude]

Static electricity builds up as the disc spins. So makes perfect sense. Unless you put in a fresh disc you couldn't get a handle on how the good cable sounds.

[master]

Static electricity builds up as the disc spins. So makes perfect sense. Unless you put in a fresh disc you couldn't get a handle on how the good cable sounds.

 

That made my day... LMAO!

[firedog]

To make the comparison accurate, they have to use a "fresh" disc for each test. Otherwise the wear and tear on the pits in the disc influences the sound.

[mansr]

Static electricity builds up as the disc spins. So makes perfect sense. Unless you put in a fresh disc you couldn't get a handle on how the good cable sounds.

Or they could demagnetise it between plays.

[Jud]

Or they could demagnetise it between plays.

 

Since the flow of electricity causes magnetism, they'd have to make sure there was no electricity in order to get the full effect.

[michaelD]

You guys are so cynical have you actually tested Nordost products yourself. They have a very easy policy to let you try and then buy - have any of you done this on your own system?

 

I can tell you this my son just purchased Martin Logan 13A's, ML 210 sub and a Parasound integrated amp also soon by not yet a Aurender N100H. We first tried the power cord that came with the amp and stock power on the Sonos connect along with stock power to the speakers and sub. Listened to several tracks then connected a Frey 2 power to the wall then connected the other end to a QX2 and then from the QX2 a Valhalla 2 power to their QB8 base from the QB8 a Frey 2 power to the amp and purple flare to the Sonos. I had some CLX stock power cables which are much better then most stock power cables but not great probably $500/set and a blue heaven to the sub. Also plugged in 3 sets of QK1's and QV2's in to the shared power line. The sound difference was very noticeable in that we did not have to listen long it was immediate. Before the updates the sound was very flat and two dimensional afterwords much more live like and airy. It was like a totally different system. Now this was a lot to throw at it at one time but its what I could quickly remove from mine. Probably none of you will believe this and that's fine but I just wanted to state that your collective opinions are not shared by all.