Why do people care about gear measurements when most rooms suck?

[DonH50]

I, and I am certain many others, have personally experienced the vast differenece in sound when sitting at the recording console out in the audience when we take our monitoring headphones off... There are lots of very good reasons why the recording mics are not placed the same as someone out in the audience. In this case I am on Tim's side.

 

[microstrip]

Since you are discussing smear, I think that this quote from F. Toole "Sound Reproduction" can be of interest:

 

[fas42]

Excellent quote, micro ...

@Don: would you care to enumerate those reasons, or possibly point to material that's relevant?

Thanks,
Frank

 

[Phelonious Ponk]

Excellent quote, micro ...

@Don: would you care to enumerate those reasons, or possibly point to material that's relevant?

Thanks,
Frank

Frank...really? You have the gall to ask someone for sources and verification? Really?

Tim

 

[fas42]

Dear, oh dear, Tim, talk about overreacting! I merely want to see the discussion continue, and it helps me and most likely others to be able to quickly access, and read up what the thinking and experience of people in the game is.

Sorry you took it the wrong way ...

Frank

 

[audioguy]

Frank...really? You have the gall to ask someone for sources and verification? Really?

Tim

+1

 

[fas42]

I guess this is shaping up to a difference between cultures: Australian and American. No-one down here would think my request/comment was unreasonable ...

Frank

 

[RBFC]

I guess this is shaping up to a difference between cultures: Australian and American. No-one down here would think my request/comment was unreasonable ...

Frank

Frank,

Other members have continually asked you for details and clarification of many posts you've made. You have been less than forthcoming in honoring those requests, so it's surprising to see you ask for something that you would not provide in return.

Lee

 

[fas42]

Lee, what I was responding to was Don's point, "There are lots of very good reasons why the recording mics are not placed the same as someone out in the audience", all I was looking was more details, to help flesh out the thread. Of course, I could have jumped on Google for a personal perusal of various people's thoughts, but that wouldn't have enhanced the content of the thread.

As regards details of what I do, I have repeatedly said some things are IP, and others are too messy to be meaningful. If I said I check every single cable everywhere in the system, inside and out, to see what playing with it in various ways, like making sure it can't move or vibrate more than necessary, that's extremely relevant, but most people here would immediately pooh pooh that as being silly and irrelevant. So I can't win ...

Frank

 

[Phelonious Ponk]

Frank,

Other members have continually asked you for details and clarification of many posts you've made. You have been less than forthcoming in honoring those requests, so it's surprising to see you ask for something that you would not provide in return.

Lee

Lee is a subtle and tactful man. To put it a bit more bluntly, after months of reading the most outrageous claims flowing from your fertile imagination, Frank, claims with no basis in anything substantive whatsoever and never supported by anything outside of your own observations flowing out of rather unique, ahem, methodology, I was a bit taken back to see you, of all people, ask someone for sources. The courage was impressive. You must be on song today...



Tim

 

[DonH50]

There are plethora of recording and mic'ing technique books around. Unfortunately, I sold or gave away most of mine, and the rest are buried in the black hole erroneously termed "the basement storage room". Try Google.

Some reasons for close mic'ing:
1. Maximizing the dynamic range of the recording chain (even a sensitive, low-noise large-diaphragm mic will struggle with soft sounds from 20'/6m or more away).
2. Reducing venue artifacts (some are good, some are bad, but all are difficult to deal with in a recording; it is hard to correct sounds added or taken away by the hall).
3. Maximizing flexibility in the mix (e.g. bringing out solo instruments, emphasizing key sections in the mastering).
4. Capturing subtle details of the instruments (attacks, the mixing tones of multiple players, etc.)
5. Reducing audience noise.

Hopefully that's a start. - Don

 

[fas42]

Thanks for that, Don, I appreciate your input, hopefully the thread's back on track again ...

I'm curious about point 1. Everything I've seen on mic's points to their remarkable ability to have enormous dynamic ranges, so I find it hard to believe that a suitable mic couldn't pick up the low level ambience as well as the direct sound.

And regarding point 2: if the point is to capture the glory of the pipe organ echoing in the venue, surely in one sense there are no bad artifacts? Or are the engineers just being hyper sensitive?

Again, thanks for your help here ...

Frank

 

[fas42]

after months of reading the most outrageous claims flowing from your fertile imagination, Frank, claims with no basis in anything substantive whatsoever ...



Tim

I've had a number of people also hear what I hear, Tim, it's not just me. If you like, you can ring me up on the phone and hear what it sounds like: my wife has had a number of people amazed at how good the sound is coming through in the background when they ring her up ...

Frank

 

[Orb]

I think adding microphone/recording techniques is distorting (pun intended ) the original point, because it was relating to perceived hearing and people care about gear measurements when most room suck.
More important is the fact IMO is how many natural instruments are used in homes without room treatments, this is greater number than audiophiles so in a way room suckiness needs to be kept within some context.
After all, why buy an incredibly expensive piano if you do not have a perfect small listening hall to play it in (designed specifically for natural musical instruments such as piano - some of the best are a moderate sized wooden panelled studio-room that would fail waf factor) , that is just one example.
Now a good room example is that of Ken Ishiwata that is specifically designed for sound quality, it seriously fails the waf factor and is very similar to my example of the piano wooden panelled moderate size listening hall by using same materials and similar size.
However it must be mentioned the room has very specific-calculated absorption-diffusion, but this is integral to a bespoke made room, costing 120,000 euros.

The other that most audiophiles probably do not appreciate though, is understanding the speaker and the how it will work within a room, critically as well how/where to place the speaker.
We see the same with musical instruments in homes, worst case pianos against walls, other instruments reinforced by reflections,etc.

What would be interesting; how many have experimented by having a musician friend play say a saxophone with them repeating this in different rooms in the house and critically different positions in a room?
It provides an interesting insight that while the room does affect sound traits, it is not applicable to all factors associated to an instrument/tone/timbre.
So one needs to appreciate a sucky room affects sound in specific ways, and then positioning and type of speaker implemented will then affect others.
On top of this, due to specific sound traits being affected, audio measurements do still matter as the quality/dissonance can still be picked up, and as anecdotally seen in forums usually is.
So we need to appreciate just what factors are affected by room and how it relates to either the musical instrument, or soundstage-imaging-depth-etc, and on top of this we need to appreciate just what factors are affected by speaker type chosen for room and positioning (site and angle) with same factors and considerations.

That is my take on this and will post about how even listening to orchestra at a concert is not truly ideal listening for most (what came out in the academic lab research paper on sound quality), and is more complex than most would think.

Cheers
Orb

 

[Orb]

Ok here ar a couple of links on Ken Ishiwata's room with an interview about it, fun to read.
Page 1-2
http://www.hfxsystems.com/siteimgs/HFC_KI_01-02.pdf
Page 3-4
http://www.hfxsystems.com/siteimgs/HFC_KI_03-04.pdf

Cheers
Orb

 

[DonH50]

The AKG C414, an excellent mic for recording, has an A-weighted SNR of 88 dB @ 1 Pa and max input SPL (without attenuators switched in) of 140 dB (200 Pa); sensitivity is rated 23 mV/Pa (-33 dBV). Max dynamic range is stated as 134 dB (A-weighted, again). These numbers I pulled from the AKG website.

I'll let you do the math, but when you take into account typical SPLs and distance, it doesn't take much to see why a mic in the audience catches a lot of noise. (In dBv, you lose about 6 dB for every doubling of distance, and assuming you are starting with maybe 100 - 110 dB peaks you are likely down to maybe 70 - 80 dB out in the audience, so your dynamic range is now only [134 - (140max - 70realized)] = 64 dB. Then add the preamp and rest of the recording chain... You just give up way too much SNR with a far-field mic.

 

[fas42]

Thanks for that input, Don. As you say, a good mic is almost a miracle in its abilities to pick up sound. So, going back to Tim's comment:

If you play an organ in a cathederal, and I record it with a stereo mic from a pew in the center of the room, I'll probably get a recording that is one big ambient smear.

... it still doesn't make sense, assuming no audience and a time of day with minmal outside traffic, why that mic wouldn't pick up a remarkable sound picture from that position, without any enhancement mic positioning techniques ...

Or are you saying that the sound level of a cathedral organ in full roar never gets above 70 - 80dB for someone in that space?

Frank

 

[DonH50]

You are mixing two things and I need to get back to practicing...

The SNR drops with distance, whether the source is an organ or single violin. The organ gets loud, sure, but the quiet passages are still going to be noisier than if the mic were closer. I have never measured the SPL of an organ from the middle pew, or rather I have but do not recall the result. I can say with some assurance it's a lot closer to 70 - 80 dB than 110 dB.

Comb filter effects, reverberation, reflections, standing waves, etc. all still matter and are worse with no audience (no damping). Yes, you could make a recording from there and it might be great, but I would not.

Maybe you should start a recording business to pay for your new amp design?

Back to tootin' - Don

 

[fas42]

Hmmm, instinctively I felt that a pipe organ would certainly top 80dB in the centre of the cathedral, with all the stops out: after all, that's nothing more than a lot of people listen to systems at. Hunting around via Google it's not trivial to find some real figures, must be a special secret handshake agreement between recording engineers to not make this easily available. The best I've got so far is an amateur's readings on a small organ, peaking at 86dBC, and at the other end of the spectrum, claims that the Atlantic City Hall Convention centre organ has the world record for the loudest musical instrument, measured at 140dB in the middle of the space. So somewhere in the middle of this huge range is the "truth" (you, I, everyone can't handle the ...).

So, more research to get some real numbers, at a later time.

Don, I'm just trying to get a handle on why common sense recording techniques "don't work", or why the ears are miraculously so superior to technology in making something sound impressive ...

Frank

 

[DonH50]

Frank, I am sure you can find all sorts of counter examples, but I would not want to be in the center pew with 140 dB pounding on me. I just do not think that's a realistic scenario, but I certainly haven't done a lot of organ recording. A lot of fine detail gets lost as sounds carry (are attenuated) across distance and interact with the room differently at different frequencies. Mics have large dynamic range, but are routinely biased toward maximum output since they are usually used close. The diaphragms are small, which limits their sensitivity (displacement is small and limited so area plays into it), and you cannot make them large without compromising other aspects (e.g. too much mass ruins HF response and tends to, again, reduce sensitivity).

I do not know what you mean by "common sense recording techniques" -- how much recording have you done? Putting a mic way out in the hall does not match my definition of "common sense recording technique", but I have not heard that term used. There are many techniques, and virtually all involve closer mic placement than you seem to be advocating.

This has diverged enough, I think... The best thing you could do is to get a recording device, hardly matters what sort, record yourself speaking into the mic from maybe 6" - 12" away, then repeat from 10 - 12 feet (3 - 4 m) and tell us if the sound is the same.