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Lawrence
Ha`aha`a
USA
1597 Posts |
 Posted - 12/10/2004 : 6:30:14 PM
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Well here goes,
Given the Caveat that I am not the world's foremost authority on Music Recording, here are my answer's to some of Reid's recording questions.
quote:
This means no click tracks.
LB- Don’t worry about it, if you don’t like click tracks don’t use them. Many of the academic Musician’s I have worked with like them very much, but lots of the self-taught Pro’s do not.
quote:
This means no multi-tracking. It also probably means no punch-ins.
LB- No! – Multi-tracking is good, mult-itracking is your friend (just uses more data space). You do not want to do overdubbing, which is understandable and OK. Overdubbing can take some of the “life” out of a recording (Can you imagine a jazz performer like John Coltrane overdubbing !) – However, you do need to read Ilio Nui’s post on using two microphone’s on a Guitar (and more can be even better if you are careful), then when you add the vocal you end up with three or more tracks for one performer.
quote:
We do not like idealized recordings or those that have sounds that don't naturally occur in nature. We don't like even slightly "improved" recordings. One of Dennis Kamakahi's pieces starts out with a guitar introduction of moderate loudness. Then, when he sings, the volume of his voice and guitar together increase, as you would expect. During the pa`ani, the guitar rises in level to equal that of his voice and guitar together. Since the increase in volume is somewhere between 9 and 11 db and the dynamics are that of a normal guitar, I don't believe that he just picked harder. Someone must have been riding the sliders, and it is distracting, because it sounds as if the guitar just jumped forward at you.
LB- maybe just some mediocre mixing. I did the same thing myself on the last TaroPatch CD cause I was in a hurry
quote:
Sarah performs best when she is under no pressure, which means, practically, that she does everything herself at her own pace. In our present recording experiments, my only function is to click the start and stop recording buttons and it would be lots better if I weren't present at all. Of course, I do all the postproduction, and right now, that's not much.
So, all this means we need a system that is set up and broken down quickly and easily, and then removed from the bedroom to be hidden away. It also needs to be set up precisely the same every time we (or Sarah alone) record. It doesn't matter whether it is only an instrumental or whether it is a vocal as well. I have two microphones of medium, or better, quality that are not the same, and they must be in the same position every time, because there will be no one else there to tweak the adjustments.
LB – you should get some more mics when you have the opportunity. Also you may not actually want to have it sound the same every time, but there is nothing wrong with being precise.
quote:
So, how would you construct such a system? What would the physical setup look like?
LB- Your setup seems to be a very good solution to your situation, except for a lack of channels, mics and preamps.
quote:
Where would these two mics be to record both guitar and voice accurately, that is, that it would sound as if a live person were singing and playing the guitar in the room when a CD was being played?
LB – It's Philosophy time!: What you seem to want is the sound of Sarah in that particular room, like she was Andre Segovia on a classical stage (which is fine!). This means the use of predominantly “distant mic” technique. For that, you probably want to use a Matched-Pair of Cardiod Mics arranged at right-angles to each other on a horizontal plane (XY configuration) and placed 4 to 8 feet away. This is a standard stereo arrangement for live events. I would recommend another two mics be placed close to the Guitar (in Ilio Nui’s positions) and recorded as another two tracks. Also add another close mic for the Vocal (about eight inches) These last three mics do not have to be matched. After recording you can blend the close mic sound(s) with the distant mic sound(s) to achieve just the right amount of ambience for your taste. This means you need FIVE tracks and FIVE channels of preamp, etc. I know you have just a Gina, but this is why I bought a Layla, cause you always need more channels than you think (JUST LIKE RAM).
Be aware that a room that sounds fine to your ears when you are there will not necessarily sound fine on the recording and by all means do not play the stuff back in the same room for post production.
Personally I would prefer to record in an anechoic chamber because that gives me the most control as to exactly how the final product will sound. Also I like “dry” recordings because, when you play them back it does not sound like you are listening to “some other room somewhere” but it sounds like the performer(s) are actually in your room.
quote:
I think our bedroom *is* a good recording space.
You are lucky – but it is possible that you have a near ideal space. As you must know from your study, the ratio of the main dimensions of a room are very important for the sound. Look up “Acoustics of Studios and Auditoria” by some Russian Guy.
quote:
My room and system (with preamp at recording level)on these days has a noise level of between -55 and -60 DBFS with the majority below 200hz. Is that good enough, given that I can take about 40 db out with Audition?
Sounds OK – My Audition meters bounce around minus 70 on a good day. Don’t use the Mic rolloff switches, you will have better control in Audition. It is a good philosophy to record “flat and clean” and then make sure you save the originals before processing.
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Mahope Kākou...
...El Lorenzo de Ondas Sonoras |
Edited by - Lawrence on 12/10/2004 6:37:06 PM |
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Reid
Ha`aha`a
Andorra
1526 Posts |
Posted - 12/11/2004 : 07:42:14 AM
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Lawrence,
A partial response:
I have tried that xy configuration at various ranges and we did not like the results. (We also tried *every* othe configuration suggested and each did not do the job we wanted) I am conviced that "distance" micing is the way for us to go, but settled on 2 feet to the lower bout and 2 1/2 feet to Sarah's mouth. With XY, the further away we got, the more we were recording wall/room reflections and, even though the capsules were near each other, the phase cancellation went bonkers. And, the room noise to music signal ratio was really high. Live events are in large venues and you can get away with it there, I suppose. The compromise we have now settled on, and it works pretty well, is the distance I mentioned above, with the cardioid mic capsules 7 inches apart (like in ORTF) and (but?)*parallel* in the vertical plane (the mics both face toward Sarah and the guitar). The left mic is angled slightly down so that it points directly in the middle of the lower bout half way between bridge and butt. The right mic is angled slightly up toward Sarah's mouth which happens to be just above the 13th or 14th fret. So, the results are: The phase plots are nicely elongated cigar shapes on Audition's 45 degree line, and the amplitudes in each channel bounce around nicely near each other. When we burn a test CD, after only noise reduction and Peak Normalization, and play it on our quite good stero system in the living room, it is nicely clear (I give it a B+), and the guitar is slightly left and Sarah's voice is slightly right (as you face the speakers) and that is what I normally hear when she plays live.
Now, when the mics were moved 4 inches farther apart horizontally, things went down the terlet as everythig was out of phase, with the audible result being that it sounded like Sarah was singing and playing in a big tube.
I'll add more and ask for more later, OK?
...Reid |
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Lawrence
Ha`aha`a
USA
1597 Posts |
Posted - 12/11/2004 : 10:38:12 AM
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Reid,
For the distant mics I was NOT reccommending ORTF, but a co-indcident
XY using cardiod mics at right angles. With matched microphones
(even just mics of the same model) it is not likely to have out of
phase components below a few kilohertz as the diaphrams will be
within 1 to 1 1/2 inches of each other. And of course, you should
stay within the "critical distance" in the room. It seems like your
room is not such a good one after all, because you are being forced
to use something nearer to close miking than distant.
You did say that your mics were of differing kinds (if I recall
correctly) so the coincident XY will not work very well anyway.
Here is something from the Shure site regarding critical distance.
------------------------------------------------------------------------
What is Critical Distance?
In every room, there is a distance (measured from the talker) where
the direct speech and the reflected (or reverberant) speech are equal
in intensity. In acoustics, this is known as the Critical Distance
and is abbreviated Dc.
Why is Dc important to microphone placement?
If a microphone is placed at Dc or farther from a talker, the speech
quality picked up will be very poor. This poor sound quality is often
described as "echoey", reverberant, or "bottom of the barrel". The
talker's words will also be hard to understand as the reflected
speech overlaps and blurs the direct speech.
How may Dc be estimated for a room?
Tools required:
25 foot tape measure
Sound level meter (Radio Shack part #32-2050 or equivalent)
Portable "boom box" with FM radio
Place the "boom box" in one end of the room in place of a talker. Tune
the FM receiver between stations. This steady "white" noise will
be used instead of a talker.
Extend the tape measure from the "boom box" to the far side of the room.
Lock the tape measure in place. It is the reference for distances.
Set the sound level meter to "A" weighting, "slow" response, "90"dB range.
Using the tape measure as a guide, place the sound level meter microphone
one foot from the "boom box".
Increase the "boom box" volume until the sound level meter needle points
to "0", which is 90 dB of sound pressure level (SPL).
Move the sound level meter back to the 2 foot mark. The meter reading
will drop 4 - 6 dB.
Reset the meter to the "80" dB range. Move the meter to the 4 foot mark.
The meter reading should again drop 4 - 6 dB.
Continue to double the distance each time the meter is moved. When the
distance is doubled, the meter should drop 4 - 6 dB if Dc has not been
reached.
During one of these meter moves, the meter reading will not drop the
predicted 4 - 6dB, but will remain relatively constant in level over
several feet. Note the distance where the meter reading first remains
steady. This is Dc, the Critical Distance.
For excellent audio, where should a microphone be placed in
relation to Dc?
In general, an omnidirectional microphone should be placed no farther
from the talker than 30% of Dc, e.g. if Dc is 10 feet, an
omnidirectional may be placed up to 3 feet from the talker. A
unidirectional microphone (cardioid, supercardioid, or shotgun)
should be positioned no farther than 50% of Dc, e.g. if Dc is 10
feet, a unidirectional may be placed up to 5 feet from the talker.
What if the microphone must be placed farther away than 50% of Dc?
Make the room less reflective via acoustical solutions. This will increase
Dc. or... Accept the substandard audio provided with a >50%
of Dc talker to mic distance.
THERE ARE NO OTHER SOLUTIONS!
---------------------------------------------------------------------
The above discussion applies to speech, for music I would divide Dc
by another factor of 2.
Also - remember there SHOULD be some out of phase components
otherwise you do not have stereo. If it sounds good and there are
not out of phase components below 250 Hz or so, then you are good.
With a CD, there is not a particular requirement to be in phase at
low frequencies, but it it still a good idea for radio broadcast.
F.W.I.W.
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Mahope Kākou...
...El Lorenzo de Ondas Sonoras |
Edited by - Lawrence on 12/11/2004 10:53:24 AM |
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Reid
Ha`aha`a
Andorra
1526 Posts |
Posted - 12/13/2004 : 11:09:58 AM
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LB – It's Philosophy time!: What you seem to want is the sound of Sarah in that particular room, like she was Andre Segovia on a classical stage (which is fine!). This means the use of predominantly “distant mic” technique. For that, you probably want to use a Matched-Pair of Cardiod Mics arranged at right-angles to each other on a horizontal plane (XY configuration) and placed 4 to 8 feet away. This is a standard stereo arrangement for live events.
For the distant mics I was NOT reccommending ORTF, but a co-indcident
XY using cardiod mics at right angles. With matched microphones
(even just mics of the same model) it is not likely to have out of
phase components below a few kilohertz as the diaphrams will be
within 1 to 1 1/2 inches of each other.
RK - I have tried the XY configuration, and it wasn't bad. The reason that I did not continue with it is that it did not seem to have enough stereo separation for me. Even though the two mics are not matched it worked pretty well. However, our present setup is sort of a combination or compromise between XY and AB. The only reason I tried ORTF, was that for some reason it was included in an Acoustic Guitar Magazine article. It was stupid of me (as it was stupid of them). Because ORTF stands for Orchestra Radio Television Française, and their 105° separation was because they were micing an orchestra.
LB- I would recommend another two mics be placed close to the Guitar (in Ilio Nui’s positions) and recorded as another two tracks.
RK - Lawrence, if I had another two grand lying around loose I would do that. But that's just not in the cards, so I've got to go with what I've got. (I want to get back to Hawai`i sometime in my lifetime.) As a rule of thumb says, "50% of the quality of the sound is due to the music and 50% of the quality of the sound is due to the room." So I'm going to mess with the room, within the limits that I have, which are all practical considerations. More of that below.
LB- Be aware that a room that sounds fine to your ears when you are there will not necessarily sound fine on the recording and by all means do not play the stuff back in the same room for post production.
RK- Yes. You are right. We burn a test CD and play it on our stereo down in our living room, which has different acoustics.
LB- And of course, you should
stay within the "critical distance" in the room. It seems like your
room is not such a good one after all, because you are being forced
to use something nearer to close miking than distant.
You did say that your mics were of differing kinds (if I recall
correctly) so the coincident XY will not work very well anyway.
RK- As I said above, the coincident XY works pretty well, even with differing mics, and I'll try variations of it again. About our room: your comment has made me go back and remeasure it, read up some more and do some more calculations. It turns out that the reverb time is not as close to one second as I thought; it is closer to .8 seconds. So it is a little bit more absorbent than it ought to be for a 50 m³ room. But I can correct that easily. An alcove behind Sarah that was acting as a sound trap will be screened off by a reflective slide or movie screen that we have. In addition, it just so happens that Sarah has a dressing table, with three movable mirrors, that I can position to focus sound at the mics without even moving furniture. I will also pull back Sarah's gauzy drapes to expose the window glass. As for critical distance, the scientist in me agrees that it must be measured, but the engineer and poor retiree in me made me do boundary value calculations. It turns out that the critical distance is smack in the middle of our queen sized cherry four poster bed. I should have realized that because the antinode or maximum of the major room mode is also there. That will not be moved. So I must make compromises. As for "good" room dimensions, you must mean the book by Mankovsky. Actually, that has been superseded by more modern research, and it turns out that there are quite a large number of good room dimensions. The ratios of sizes of our bedroom's dimensions are 1: 1.44: 2.5; the first two are nearly perfect, and the third number is right on the edge of being good.
Look at:
http://www.acoustics.salford.ac.uk/acoustics_world/room_sizer/room_sizing3.htm
It is also true that no first reverberation will hit the mics in over 35 ms; so that means there will be no echo sounds. However, the low frequency noise in our bedroom is due to room resonances. And those are forced by the constant hum of traffic that saturates our area. I don't worry too much about them because I can remove them. As Fran noted, the real-life problems are those that are transient, like motorcycle gangs, or whatever.
Thanks for the consultation, every time I read something like this, it makes me think more and do more. If anybody cares, I plan to compile a posting of rules of thumb and some of the simpler equations that will help determine which rooms to choose for recording, and what to do with the rooms.
... Reid
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Lawrence
Ha`aha`a
USA
1597 Posts |
Posted - 12/13/2004 : 5:37:54 PM
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Thanks Reid,
for this link:
quote:
Look at:
http://www.acoustics.salford.ac.uk/acoustics_world/room_sizer/room_sizing3.htm
I think I did come across this site some time ago , but did not investigate it much, this time I looked much further.
If you go to this site: http://www.linkwitzlab.com/rooms.htm you should find an Excel spreadsheet calculator that you can enter you room size into, and it will give you the modes for your space.
Of course, these are simplified rooms, and and item like a queen bed in a bedroom will substantially alter a rooms acoustics (usually for the better). My little space has a non-parallel ceiling and lots of
stuff that make the walls non-parallel. That being said, it is more of a vocal booth that a scoring stage, so I have to apply substantial absorbtion using Sonex panels and other things.
Having a short reverb time is not a problem, (I prefer zero) but when it comes to adding reverb with Audition, be aware that the presets stink. The best reverb is the "full reverb" and you will want to play around a lot with the settings. If you were doing fully close-miking, I would give you some hints as to easier ways to treat the vocals versus the instruments, etc.
However, this is a GOOD RULE. Save a copy of the track (both tracks for stereo). Do the reverb transform with 100% reverb and save as ANOTHER track. That way you can use multitrack to control the amount of reverb dynamically.
If you have not already done so - go to http://www.audiomastersforum.org/amforum/viewforum.php?f=17AudioMasters.com for the best BBS info on Audition, plus there is a Historical copy of the Cool Edit Pro BBS at this site that is full of good ideas that are still relevant.
Another thing - the ambient mics (XY) do not need to be expensive (as you will be mixing them down -6 to -12 db in the mix) and the midrange is most important for the ambience, but you still need another two preamps and another two digitizer inputs! If I had to choose, I would take the trip to Hawaii too.
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Mahope Kākou...
...El Lorenzo de Ondas Sonoras |
Edited by - Lawrence on 12/14/2004 07:40:32 AM |
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Reid
Ha`aha`a
Andorra
1526 Posts |
Posted - 12/14/2004 : 09:40:30 AM
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Lawrence,
I used that linkwitz spreadsheet and I had to laugh. I spent about 2 1/2 hours measuring and calculating to get that 800 ms reverb time figure, and it came up with 700 ms instantaneously. In addition, as I said in an earlier post, the third dimension was a bit short, and on the edge of being a good number. The spreadsheet calculation, said exactly the same thing: it was equal to the middle dimension's number when it should've been greater than it. I suppose they're using some approximate average, but boy are they close. Everything in acoustics is an approximation anyway.
... Reid and Dragon |
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Reid
Ha`aha`a
Andorra
1526 Posts |
Posted - 12/17/2004 : 08:58:11 AM
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OK, I recant. I just burned a CD of our best takes, and played them in our living room. They simply weren't clear enough. The sound had the correct quality, that is the guitar sounded like the guitar and Sarah sounded like Sarah, but listening to the music was like looking at the world through a filmed window. Rereading what Dr. Dave, and Mark, and you, Lawrence, said, a couple of things became clearer to me. First, my mic position was what Dave suggested for close micing, except pulled back 2 feet, in order to include Sarah's singing. Second, my circumaural earphones were convincing me that the room sounded good with the playing. And, it did, but there was no allowance for what the room in which the recording was to be played sounded like. So my earlier comment: "50% of the quality of the sound is due to the music and 50% of the quality of the sound is due to the room" is only true if the live source is in the room with you, or if that source is carefully engineered so that it sounds good in most environments. So, since I'm not going to get any more microphones or signal inputs anytime soon, it is back to the drawing board for me and the two microphones.
... Reid
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Lawrence
Ha`aha`a
USA
1597 Posts |
Posted - 12/17/2004 : 12:59:13 PM
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Reid,
If you are going to stick with just the 2 mics then it looks like you have no choice but to move them closer to the guitar and voice, so that you get out the no-man's-land you are in now (not close and not far)(reminds me of one of my favorite movies "Faraway,So Close" by Wim Wenders, who also did "Paris Texas" and "The Buena Vista Social Club"). The voice should be easy enough, somewhere between 6" (with a pop screen) and 18" and maybe slightly to the side. With the guitar, you will have to play around with the lower bout position or the 14th fret upper bout position to see which sounds best. Also try to align the mics so the that the "other instrument" is in the null of each mic (if possible) for maximum isolation of channels. Also use the 3:1 rule and make sure each mike is three times the distance as the other mike is from it's primary source (gives 9:1 isolation or about 15 to 18 db). Record as two mono channels and then mix down with vocal slightly off center one way and guitar slightly off the other way. You will get some phasing due to bleed (at about 15db down) but you can probably find some mic positions where the phasing is not objectionable. Add some careful verb to cover the existing room sound and extend the decay time (season to taste). That is about as good as you will do with your present situation. Either that or do overdubs. Guitar first with voice-over after, which then gives you infinite isolation.
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Mahope Kākou...
...El Lorenzo de Ondas Sonoras |
Edited by - Lawrence on 12/17/2004 5:17:45 PM |
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Reid
Ha`aha`a
Andorra
1526 Posts |
Posted - 12/18/2004 : 03:34:23 AM
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Thanks, Lawrence. I *was* going to move in, but I had so many ideas about where, and in what direction, to put the mics, that I was terminally confused. I had done searches in rmmga and al the other web sources and found as many configurations as there were people. Things like over-the-shoulder pointing down, parallel to the strings pointing up and down the guitar, all kinds of things that work for some people. But, yours is the most straightforward and sensible suggestion. So, we will try this over the next week or so.
I'll report back (if anybody cares).
...Reid |
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Mark
Ha`aha`a
USA
1628 Posts |
Posted - 12/18/2004 : 09:51:09 AM
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Reid -
I'm only chiming in cuz the mic'ing issue is somewhat universal and other readers may be foloowing this...
Although what you get depends totally on what (mics, pre amp, room, guitar, voice, planetary alignment and mood ring) you are using, here's how many engineers place mics: they listen.
As in, have Sarah play the guitar, and jam one ear up close (say 6-8 inches away) to where you think a mic might be placed . If you want, hold the other ear shut with a finger. Yes, you'll look dang silly. Move your head around, and make a mental note of where the instrument has the most "natural" sound (or whatever you want -- some folks like the bridge, some like the sound hole, some like the 12 fret --- and some like the instrument's back).
Stick a mic there, go back to your monitoring position, and listen thru whatever you are using to monitor. (BTW: Headphones are a very poor choice -- but if you are going to use them, get some studio type cans -- like the Sony MDR 7506. There is a reason they are one of the standards -- they don't sound "good" - they sound like the real world listening situation - ie, consumer stereo speakers. Little high boost, little bass boost -- you can hear what you need to.)
Adjust as needed. Do the same for the vocal, then listen to both mics (ideally on speakers, collapsed to mono so you an hear pahsing issues. If you can't monitor live -- record some stuff, and then play it back through speakers.) Adjust accordingly.
Tedious? You bet. Effective? Ditto. After a while you get fast at it, too.
Now then, all the fancy "over the shoulder," "under the legs" (aka "fart" mic-ing --- yes, it's real) etc. are all dependent on some very specialized combinations of singers, guitars, rooms and mics. In most cases, they would be a waste of time in the home studio world, where you are fighting the room -- but your mileage may vary.
Want to capture the really cool old sound of a singer/guitarist like they used to do? Use a single large condensor, set to either omni or figure 8, placed sorta midway down the throat, at a distance determined by your ears. Better yet, run it through a nice fat tube mic pre, with a little mild compression....
It's the easiest, and best sounding solution. If you want stereo, do some stoopid 'verb tricks when mixing.
But if you just want a good sounding reference, mono rules.
My advice is to read less and listen more.
So saying, I'll stop writing now. Tee hee.
M |
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Reid
Ha`aha`a
Andorra
1526 Posts |
Posted - 12/18/2004 : 1:01:52 PM
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This is funny. Mark, guess what I was doing *immediately* before I fired up the laptop and started reading this. On my hands and knees with one finger stuck in my ear (and another stuck in...nah!) listening all around Sarah and her guitar while she played and sang. The mic (my left ear) directed at her voice sounds best within the 30 degree cone of the mic (my ear moving around) and I have some leeway in pointing angle - up, down, sideways, But it will still pick up some (I don't know how much yet) of the guitar. The other place that is great for the guitar for the other mic(my right ear says), is out of her way, and picks up almost none of her voice, is placed at the butt (close - a few inches), pointing/skimming the top of the soundboard and pointed at the bridge in a line that ends at the waist of the guitar. This might be "fart" micing, but my ear said it sounded really good, if a little bright.
I really did not like my ears in close, pointing directly at the guitar. I have done the "proximity effect bass thing" before and really hate it. Fran has noted that it starts about 18 inches out from the guitar and my ear says that, too.
As for jamming an omni down the throat, you and Ty Ford must have gone to the same old school :-)
Thanks,
...Reid
So, this will be another starting point. |
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