Need Help to explain weird impulse responses.

[FargateOne]

Hi,

I am helping a friend to set up is 6.1 system. His speakers are all old Yamaha models (2005 issh don't know which model).
Trying to time align the speakers, I wanted to check if distances were correct. Looking at impulses seems kaput for me. Never saw that before.
Did I make a mistake taking measurements?
Did you ever saw this?
How to explaine it?
Is there a cure?
...
Will I lose my friend???

 

[John Mulcahy]

The centre looks OK, the others look odd. Do some of the speakers have more than one tweeter? Were any other speakers playing at the same time?

 

[FargateOne]

No only one at a time. Only 1 tweeter quite sure of that. It is not a high end system. Here what I found:

Yamaha - 6.1-Channel Home Theater Speaker System - Silver​

Model:NS-FP9500

• Number of Speakers per Package
  6 + subwoofer
• Maximum Power Handling
  120W per channel
• <a href="javascript:winopengld('1087340578114','pcmcat38200050027','cat12080')">Frequency Response</a>
  100Hz - 40kHz
• Tweeter Size
  3/4" dome
• Midrange
  4" pulp cone
• Subwoofer
  8", 130W
• Woofer
  4" pulp cone
• Connector Type
  5-way binding posts
• Magnetically Shielded
  Yes
• UPC
  027108103860

I am just an amateur. Those impulses seem to say that the speakers internal circuit is broken? Even I can get a SPL graph responses? I can't find where is the impulse of speakers other than center?.

Does impuls indicate broken speakers?

 

[John Mulcahy]

Does impuls indicate broken speakers?

Unlikely but an impulse response image isn't suitable for deciding something like that. You should post some mdat files of the measurements instead of pictures.

 

[FargateOne]

here it is

 

[John Mulcahy]

Nothing attached, probably too large. Save a few of the measurements in individual mdat files and attach those.

 

[FargateOne]

our posts crossed I think

 

[John Mulcahy]

I don't see anything suggesting there are any problems with the speakers, just a bit of distortion around 2 - 5 kHz for arr D and arr G. There do seem to be a lot of very strong reflections though, does the room have a lot of hard surfaces or large windows?

 

[FargateOne]

All The speakers are placed at the worst place possible in his room very near a wall for all except the center., WAF factor...
Maybe bad connections to the receiver or the speakers?

 

[John Mulcahy]

Probably just placement issues then.

 

[thothsong]

You could try taking 0-degree measurements close to each speaker to see if the IRs are cleaner.

 

[FargateOne]

We will try 2 desktop speakers next week and learn !