Effect of chair and listener on room measurements.

[Daverz]

I move my listening chair out of the way when doing room measurements for room correction as usually recommended. I was curious about what effect the chair and my body had on the frequency response, so did a series of measurements with the mic at the same position (mdat here):

• Chair & listener present with the mic next to my left ear (and hearing protection, of course.)
• Chair with some blankets in place of the listener (no attempt to reproduce my head, though).
• Chair with no blankets.
• Chair moved out of the way.
• No chair, but mic pointing up.

Since my shoulder was in the way, I pointed the mic down. The 90 degree cal file was used throughout.

The chair is a Stressless leather recliner with matching ottoman. Speakers are bookshelfs on stands (Buchardt S400). The mic is 209 cm from the speaker and the capsule end is 85 cm above the floor whether pointed up or down.

He's the frequency response with the chair and listener present (green) and then out of the way:

So the same up to about 190 Hz in my room, then elevated midrange and some treble bumps above 2kHz.

The ETC shows that the chair is reducing the floor bounce, which probably accounts for the less attenuated midrange (0.1 ms smoothing).

The floor bounce is the peak just before 8ms, which is knocked down about 13 dB by interaction with the chair.

How well do the blankets do in place of the listener?

But with a bare chair we also do well up to 400 Hz and with less elevation of the treble region.

Just to make sure that pointing the mic down rather than up didn't cause any problems, we compare:

So takeaways:

• Correction can be done in my room up to 190 Hz without worrying about effect of chair or listener.
• Or up to 400 Hz without worrying about effect of the listener.
• Blankets don't replace the effect of the listener (at least the way I'm doing it), so don't bother with them.

Any other experiments I should try? Or thoughts on how to deal with the effect of the chair and listener?

 

[Grimoire]

Well done! I've often wondered about this myself and have read threads about it, but they were purely subjective and of course came to wildly different conclusions from each other. Great to see some fairly conclusive answers at last.

But what about a comparison between Stressless leather and fabric chairs?

 

[Daverz]

Well done! I've often wondered about this myself and have read threads about it, but they were purely subjective and of course came to wildly different conclusions from each other. Great to see some fairly conclusive answers at last.

But what about a comparison between Stressless leather and fabric chairs?

I could try a Poang chair. I also have a low-backed cloth-covered desk chair that has minimal effect on the measured response, but it's not very comfortable for long listening sessions.

 

[Grimoire]

I could try a Poang chair. I also have a low-backed cloth-covered desk chair that has minimal effect on the measured response, but it's not very comfortable for long listening sessions.

That would be interesting, so yes, please!

 

[Joachim Herbert]

Room correction should be based on seated chair, as you take them to listen in room at hearing position.

You are part of the experience.

I had some nasty early reflections coming from an empty chair.

 

[NotInYourHead]

Room correction should be based on seated chair, as you take them to listen in room at hearing position.

You are part of the experience.

I had some nasty early reflections coming from an empty chair.

Do you have measurements taken with and without you in the chair?

 

[solderdude]

Could be interesting when repeated with in-ear microphones.
I suspect the effects might well be different and more practical.

 

[Joachim Herbert]

Did some last year and let GLM prepare grade reports. When I started out I left the chair in the listening position. Less early reflections with a blanket covering the leather upholstery. Even less with me sitting there.

One is part of the listening experience no matter what. True for body and mind.

 

[NotInYourHead]

Could be interesting when repeated with in-ear microphones.
I suspect the effects might well be different and more practical.

I second this. Not only is the in-room response captured, but also what the ear actually hears, especially in higher frequencies.

 

[Joachim Herbert]

I'm am interested in room eq, not personal eq. So no in ear mics for me. Also no eq above 300 Hz or so.

This is a rabbit hole.

Variables with in ear mic

room
speaker
mic (calibration)
ear

 

[solderdude]

I'm am interested in room eq, not personal eq. So no in ear mics for me. Also no eq above 300 Hz or so.

This is a rabbit hole.

Variables with in ear mic

room
speaker
mic (calibration)
ear

It would all be about the relative differences not about absolute values.
In this case there is no rabbit hole.

I thought the idea was about how sitting in a chair or not would make a difference in the perceived sound.