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Near-field room correction measurements: With or without chair? Occupied or not?

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echopraxia

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The OP asked about a 'relatively near field' arrangement, whatever that is in his case. The chair and body will still surely have an impact wherever the sounds come from. In fact one thing not mentioned is the type of chair. Leather chairs can reflect for example. My chair is a cloth covered type.

The main point still stands - be consistent with your measurement set up using them as a guide, not an exact solution.
Yeah, while I suppose I need to read the books quoted above to avoid repeating any common knowledge or mistakes, it seems that there isn’t a fully understood single best way to calibrate to a small room where small changes (like a solid chair present vs a more acoustically transparent one, vs none at all, vs occupied and unoccupied) might have a large impact on the result.

But I don’t know exactly what I’m talking about because I don’t know the deep technical details of these measurements and whether they’re able to ignore reflections from nearby surfaces somehow, as I think (?) @watchnerd is implying.

If these measurements will give the same results no matter what reflective surfaces may be near, as long as the mic is pointed at the speaker (e.g. even if the mic is in a acoustically reflective box open on one end, vs in a perfect anechoic chamber), then that’s really cool but completely opposite of how I had thought in-room measurements worked.

If on the other hand reflections do influence the room measurements, then e.g. a tall leather chair would almost certainly influence the measurements, right? (Fortunately my chair is mostly a breathable mesh fabric, so I don’t think this will be a big issue for me, but the topic in general is interesting.)
 

watchnerd

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But I don’t know exactly what I’m talking about because I don’t know the deep technical details of these measurements and whether they’re able to ignore reflections from nearby surfaces somehow, as I think (?) @watchnerd is implying.

It's not a matter of ignoring.

If you're mixing, it's making sure that any monitor EQ corrections (at the crudest level, the boundary switches on the back of monitors) are as minimal as necessary.

Otherwise, you may find negative impact to mix translation.

Really really suggest reading the books if you're serious about this. Dealing with boundary and desk reflections has been known about and dealt with in mixing circles for decades.

If this is just for shits and giggles, maybe that's too much homework, though.
 
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echopraxia

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It's not a matter of ignoring.

If you're mixing, it's making sure that any monitor EQ corrections (at the crudest level, the boundary switches on the back of monitors) are as minimal as necessary.

Otherwise, you may find negative impact to mix translation.

Really really suggest reading the books if you're serious about this. Dealing with boundary and desk reflections has been known about and dealt with in mixing circles for decades.

If this is just for shits and giggles, maybe that's too much homework, though.
I wouldn’t mind reading them, but for the context of this thread and it’s readers I think we would benefit from your knowledge here if you just explained whether or not you think e.g. the presence of a high back leather chair (where the mic is a few inches in front of the headrest) would in any way affect the in-room measurements.

Regarding those books, looks like they’re available for kindle so I am definitely tempted to buy them (around $45 each). If I was only going to buy one though, which would you recommend? Note that my goal is not music production, but music reproduction and enjoyment.
 

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Floyd Toole - Sound Reproduction Third Edition.
 
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echopraxia

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watchnerd

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I wouldn’t mind reading them, but for the context of this thread and it’s readers I think we would benefit from your knowledge here if you just explained whether or not you think e.g. the presence of a high back leather chair (where the mic is a few inches in front of the headrest) would in any way affect the in-room measurements.

Regarding those books, looks like they’re available for kindle so I am definitely tempted to buy them (around $45 each). If I was only going to buy one though, which would you recommend? Note that my goal is not music production, but music reproduction and enjoyment.

"Mixing Secrets for the Small Studio"

It's by the editors of Sound on Sound and more approachable to those who aren't trying to become full time recording engineers.
 

watchnerd

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if you just explained whether or not you think e.g. the presence of a high back leather chair (where the mic is a few inches in front of the headrest) would in any way affect the in-room measurements.

a) I would have to measure. But rest assured leather chairs are common in mixing set ups amongst guys that do it full time.

b) The total in-room measurement isn't the right question. The near-field measurement is the right question. The impact of boundaries behind the speakers and desk reflections are going to be far more important than your chair.
 

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whazzup

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Oh, I was wondering about this just a few days ago. Have a nearfield desk setup with a mesh chair. I noticed if I made a measurement with my mic a couple centimetres in front of my face, vs me sliding my body down my chair (so the mic's in the same position but without my head behind it), I remember seeing a bump around the 500-700hz region (I think...have chucked out the measurements so not 100% certain about the freq region with the bump).

The bump was a substantial >5db increase over the non head reflection measurement, but I remembered thinking that if I played some singular 500-700hz tones in both scenarios (mic w/ head reflection and mic w/o), will my ears identify with the >5db (head reflection) result or the 0db (non head reflection) result.

However, life and work intervened, so I had to put away my toys before I could do any further tests. When I get some free time I'll probably try it.
 

Hipper

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It's a great book.

But it's not really great on how to optimize a desktop environment.

The mixing books are better for the near-field use case.

I didn't realise we were talking exclusively about a desk top environment. Perhaps the OP could clarify what his set up is.

Toole's book is one of the general science regarding sound reproduction, mostly geared for home music and home theatre listening. There are nine pages specifically on control rooms (p255-363). I therefore agree with watchnerd if you are listening only at a desktop.
 

whazzup

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I'm sure I posted something like this before but can't find it.

Using REW I did some tests on various aspects to see if there was much difference:

What Difference does a Person Sitting in the Chair Make?

View attachment 65502

1/24 smoothing, full range, purple being with me in the chair (I place the microphone where one of my ears would be then carefully got in the chair without knocking it it).

Oh! The right speaker had broadly the same effect, notably the increase from 600-1500Hz

I may have the same bump as yours, though mine's maybe in the 500-700hz region. But can't be sure, will measure again when I find time.
So to me, I am curious if my ears hear the same frequency 'bump' as the mic captured, or our ears do not hear this bump (meaning the mic capture could be 'boosted' by the reflections from the head).
 

Hipper

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I may have the same bump as yours, though mine's maybe in the 500-700hz region. But can't be sure, will measure again when I find time.
So to me, I am curious if my ears hear the same frequency 'bump' as the mic captured, or our ears do not hear this bump (meaning the mic capture could be 'boosted' by the reflections from the head).

I made no efforts to find out if I could hear the 'hump' caused by my presence in the chair. I suppose the way to do it would be to listen to test tones and try and evaluate them.
 
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