Listening Room Intelligibility Test

[Phelonious Ponk]

If I were looking at that graph, I'd say there was either a polarity or DC offset issue as well.

Well there are semantics involved, John; we're talking across each other. It can't be a slide and 3 of the same not in quick succession. Those two things are mutually exclusive because a slide changes the notes, and for some people to hear 3 of the same notes in quick succession as a slide, their systems are not only losing attack detail, they're adding notes. Quite a trick, that. I'm listening to it right now. Just ran it by several times in a row on headphones and speakers. I hear what you're talking about, but I'm not sure what it is. One thing is certain, I was wrong earlier today. It's not a slide over frets, because that's a standup bass. No frets. It is a slide, there's no question in my mind about that, but there's a bit of texture of some kind in there. I'd have to see the guy playing it to tell you exactly what's going on...unless it's the recording.

Tim

 

[Phelonious Ponk]

Just looked at your graphs, John. I don't know what you're talking about but it occurs a full second before the slide, at 0:47, I've been trying to ID.

Tim

 

[jkeny]

Yea, Tim, I might be confusing you & me - I'm doing this from memory but I'll check it tomorrow.
In the meantime, so we know where we are, I've extracted the 3 seconds before Shelby starts singing & linked it here for download
Just to clarify, there are only two bass notes on this excerpt - you are hearing the first as 3 plucks & the second as a slide, right?

Edit: BTW, this is not a copy from the CD, I think it's a download so there could well be problems on it, as Bruce has indicated - there seems to be a buzz on it listening to it via laptop analog out into cheap headphones. I will try to get the original excerpt tomorrow.

 

[Bruce B]

Can you educate me Bruce, I'm no expert in this?

Just like a sine wave, you have a plus or minus. Technically you should have just as much energy on the plus side as you do the minus side. This graph looks like most of the energy is focused in the downward position. That could be either (or a little of both) of two things. You could have a negative DC offset where most of the energy is focused in the negative, or below the line (zero crossing).
Also, when you have a transient, like a kick drum or a plucked string, if the polarity was recorded correctly, the initial transient would go in the positive (pushing the speakers out). If it was recorded in reverse polarity, or something was wired incorrectly, the initial transient would go in the minus, where it appears this is.

 

[Phelonious Ponk]

Yeah, I'm hearing a slide. No fret bump. No pluck. A slide. At 0:47.

 

[jkeny]

Yeah, I'm hearing a slide. No fret bump. No pluck. A slide. At 0:47.

So are you hearing the separation into 3 of the note before that slide - the first one on the audio extract file? I've confirmed that this is the correct one!
Here's what the guy says "It's on the up-beat to the bar where she starts singing, so not the very final note before her voice enters, the one just before that."

 

[jkeny]

Just like a sine wave, you have a plus or minus. Technically you should have just as much energy on the plus side as you do the minus side. This graph looks like most of the energy is focused in the downward position. That could be either (or a little of both) of two things. You could have a negative DC offset where most of the energy is focused in the negative, or below the line (zero crossing).
Also, when you have a transient, like a kick drum or a plucked string, if the polarity was recorded correctly, the initial transient would go in the positive (pushing the speakers out). If it was recorded in reverse polarity, or something was wired incorrectly, the initial transient would go in the minus, where it appears this is.

Thanks Bruce, a good analysis & explanation. It does look to be skewed, doesn't it? As I said - it's a download, I'll try & get the CD & extract it unless someone who has the CD gets there first. BTW, have you bothered to listen to this to determine if you hear what I'm talking about - the 3 note separation?

AFAIR, you had one of the best rooms with a MATT score which showed very good intelligibility but some issue down in the bass region.

 

[Phelonious Ponk]

So are you hearing the separation into 3 of the note before that slide - the first one on the audio extract file? I've confirmed that this is the correct one!
Here's what the guy says "It's on the up-beat to the bar where she starts singing, so not the very final note before her voice enters, the one just before that."

Am I hearing separate beats on what's played just before the slide? Absolutely. On headphones and speakers. I'm also hearing more than one note (tone, value), though now I'm back at work and unable to re-check. Are you hearing 3 strikes of the same note? Still not sure we're in the same place...

Tim

 

[jkeny]

Am I hearing separate beats on what's played just before the slide? Absolutely. On headphones and speakers. I'm also hearing more than one note (tone, value), though now I'm back at work and unable to re-check. Are you hearing 3 strikes of the same note? Still not sure we're in the same place...

Tim

Tim, I'm talking about the parts on the audio extract I linked to - that's why I extracted the section in question so that there would be no confusion. I believe you are talking about the 3 different bass notes at 0:39 0:40 in the track - very distinct & very different bass notes - could not be mistaken by any system. It's not that!

 

[Phelonious Ponk]

Tim, I'm talking about the parts on the audio extract I linked to - that's why I extracted the section in question so that there would be no confusion. I believe you are talking about the 3 different bass notes at 0:39 0:40 in the track - very distinct & very different bass notes - could not be mistaken by any system. It's not that!

Maybe our clocks aren't in sync. I see the slide at 0:47. What I'm talking about comes just before that -- 0:45/0:46 -- not 8 to 9 seconds earlier.

 

[jkeny]

Have you listened to the extract? Can you not identify the part I'm talking about?
What part of it do you hear 3 distinct notes?

 

[Phelonious Ponk]

Have you listened to the extract? Can you not identify the part I'm talking about?
What part of it do you hear 3 distinct notes?

I haven't listened to the extract and now I'm at the office again, away from the system. I'll try it tonight.

 

[jkeny]

I haven't listened to the extract and now I'm at the office again, away from the system. I'll try it tonight.

OK, that will clarify any confusion, I hope

 

[Phelonious Ponk]

OK, that will clarify any confusion, I hope

Hopefully, but to no great end. We appear to be the only interested parties.

 

[jkeny]

Hopefully, but to no great end. We appear to be the only interested parties.

Indeed, but hopefully others are waiting until we have sorted out the exact excerpt that is the focus of this discussion before they participate?

 

[Phelonious Ponk]

Indeed, but hopefully others are waiting until we have sorted out the exact excerpt that is the focus of this discussion before they participate?

A possibility...

 

[Phelonious Ponk]

Listened to the sample, John. I don't hear what you're talking about. Maybe someone else will.

Tim

 

[jkeny]

Listened to the sample, John. I don't hear what you're talking about. Maybe someone else will.

Tim

That's what I am saying, the first bass note you hear on the extract is actually divided into 3. Only rooms/systems that are able to stop very quickly will be able to hear this. It seems to me a good test of room/system intelligibility! The quote I posted was from a guy who only heard it when he changed his interconnect cables - AFAIK, nothing else in his system was changed.

Edit: Yes it would be interesting if others confirmed that they could hear this!

 

[Phelonious Ponk]

That's what I am saying, the first bass note you hear on the extract is actually divided into 3. Only rooms/systems that are able to stop very quickly will be able to hear this. It seems to me a good test of room/system intelligibility! The quote I posted was from a guy who only heard it when he changed his interconnect cables - AFAIK, nothing else in his system was changed.

Edit: Yes it would be interesting if others confirmed that they could hear this!

Couldn't even hear it on my headphones. None of it. A perfectly clean, sustained bass note, not even any finger vibrato or modulation. Typically I can hear extremely subtle stuff on the headphone system. Maybe I need a new cable.

Tim

 

[jkeny]

Couldn't even hear it on my headphones. None of it. A perfectly clean, sustained bass note, not even any finger vibrato or modulation. Typically I can hear extremely subtle stuff on the headphone system. Maybe I need a new cable.

Tim

I guess listening on headphones rules out room intelligibility & brings the focus to system intelligibility. This is where I came into this thread & referenced Fas42's question to Art - to paraphrase "can the electronics have a role in this intelligibility & how much of a role?" I am of the opinion that it can & this is a test to determine this.

So, if what is coming out of your speakers is not intelligible, it doesn't matter how good your room is, it will still be "unintelligible"