Request for general recording support

[UrsusArctos]

Dear sound engineering and recording community,

I am new to this forum and I am not a professional sound engineer. I therefore beg your indulgence with me. This is not really going to be about specific equipment queries but rather an attempt to tap into the communities vast expert knowledge in sound recording. I hope this is the right place to start such a thread. Note that all my so far conducted internet research did not provide any meaningful results, which is why I hope to get some answers from this community.

First a few words about myself in ways of a self-introduction to the esteemed cummunity: I am passionate about classical music. My wife and I have somehow managed to transfer this passion to our two kids, who happen to be very talented musicians, both playing string instruments.
I am also a hobby photographer which grew into a little videography, mainly to record music performances of our kids. When I started this videography, I soon learned that in-camera audio was far from giving me any results that do the performers justice. So I quickly acquainted myself with the basic knowledge for audio recording and thereby discovered the obvious. Much like I did with the optical part of the recordings, I would have to invest into audio recording equipment. To make a long story short, I currently use the following audio recording equipment to complement my Canon EOS 5D MkIV DSLR:

• TASCAM DR-701D: This was the only recorder that I found to be able to receive a Start/Stop signal from the DSLR, so that video and audio recording can be started simultaneously by means of an HDMI connection. I quickly discovered that the despite this connection the audio recording lags some tenths of seconds behind the video but this is not a problem as it can be dealt with easily enough in post. But really this simultaneous start and stop of the recording was the one feature that drove me to the DR-701D.
• Matched pair of Røde M5 cardioids (very cheap but nevertheless quite acceptable sound quality)
• Pair of Audix M1280B omnis (very unobtrusive due to small size, they spoil the visual very little for both the video recording as well as the audience)
• A pair of Røde Film Maker kits for wireless audio signal transmission
• Some auxiliary equipment such as tripods and mic stands as well as a 26'000 mAh Anker power bank to supply external power to both the DSLR and the DR-701D

Depending on the recording set-up and how obtrusive I am allowed to be during the performance, I often use only the omnis mounted to the Audix active carbon rods (which in fact are merely combining the function of cable and stand). Due to the small size auf the M1290Bs and the sleek profile of the rods, I can get the omnis in most of the cases placed in decent overhead and front distance from the musicians. To have some independence between mic stands and the DSLR/DR-701D combo, I often use two Røde Film Maker Kits to transmit the audio signal wireless from mics to recorder. This also prevents mic cables presenting any tripping hazards to the audience. This set-up actually already gave me surprisingly good results of various chamber music recordings from duets all the way up to entire string orchestras. I use the DR-701D's channels 3 and 4 in stereo recording setting.

Very recently, however, I had the opportunity to take a recording of a solo string instrument accompanied by piano in a more studio like setting. For this, I used all 4 of the DR-701D's input channels. The omnis were used to record the general sound field, including some characteristics of the room in which the recording was taken and one each of the M5s served as support mics close to the string instrument and the piano, respectively. I originally wanted to have the omnis recorded as a stereo signal and the cardioids as a mono signal each. However, this is not possible, and I therefore switched all channels to mono. Before, I haven't ever experimented with 701D's settings on its menu page 2, where the mics' positions can be adjusted from L12 (left most) to R12 (right most). Now, bear with me, I am slowly getting to the point:

To be very honest, my hearing is simply no good enough to prevent me from getting lost in the gazillion of possible combinations provided by these simple parameters for each individual mic. I did actually start with translating the real position of the mics into something that might represent this geometry, i.e.:

• L12 and R12 for the cardioids, respectively, as they were positioned directly in fron of the two musicians and probably about 3 meters distance from each other (tribute to SARS-CoV-2)
• L2 and R2 for the omnis, respectively, as they were positioned some 45 cm apart from each other and about 2 m overhead and 2 m in front of the musicians

Again, the result is reasonable but I doubt ideal.
Now, I have two questions:

1. Are there any recommendations, how I can best reflect the mic positions in the the DR-701D's mic panorama setting section of the MIXER page?
2. Assuming that I do not want to use the combined signal out of DR-701D's mixer, can anybody recommend an easy to use software (for MacOS) that can do the mixing of the four mono signal into a nice stereo signal in post?

Thank you for your patience with me. I am looking forward to receiving some inspiring comments, which will likely trigger more questions.

 

[Mark Richards]

You wrote:

• often use only the omnis...placed in decent overhead and front distance from the musicians...
• I had the opportunity to take a recording of a solo string instrument accompanied by piano in a more studio like setting...
• omnis were used to record the general sound field, including some characteristics of the room...
• one each of the M5s served as support mics close to the string instrument and the piano, respectively...
• switched all channels to mono...
• L12 and R12 for the cardioids, respectively, as they were positioned directly in fron of the two musicians and probably about 3 meters distance from each other ...
• L2 and R2 for the omnis, respectively, as they were positioned some 45 cm apart from each other and about 2 m overhead and 2 m in front of the musicians..

Some general comments on use and positioning:

• Cardiod mics are directional. They pick up sounds from the front, partially reject sounds from the sides, and reject sounds from the rear. Their best use is close placement (about 1 meter) pointed at the desired instrument' s sweet spot (as the instrment is played use your ears to determine by moving around the instrument). The channel pan control (side to side) and fader control (front to back / near or far) are used to place the mic signal in the sound stage.

• Omnidirectional mics, as the name implies, pick up sounds from all directions. Their best use is to provide ambiance and a sense of spaciousness. Again, using your ears by moving the omni mics around as the music plays, locate the positions where you hear the sound you want to capture. Depending on the size of the room, the height of the ceiling, the distance of the instruments from walls, the "liveness" of the room, omni mics generally should be placed well above and pointed forward toward the instruments, and far apart, but not so far apart as to create a hole in the middle of the sound stage. The pan control for each mic should be hard left and hard right.

• The other thing to watch for is phase cancellation once all the mics are in place. Phase cancellation occurs when mic placement causes the sound received by one mic to be 180° out of phase with another mic. When that happens you get an undesirable and obvious "hollow" sound in the sound stage. One way to check for this is, as the music is playing, to first pan the cardiods to center with the omni mics off; then do the same for the omnis with the cardiod off; then for all four simultaneously. Often only a slight position correction will solve the problem if it occurs.
• If you choose to use the cardiod mics to create a natural stereo sound stage, you can achieve a better and more realistic stereo image with the cardioid mics if you mount the capsule end in an X/Y position (one directly over the other) at about a 45° angle relative to each other as a starting point. The X/Y mounting also eliminates any possible phase cancellation between the cardioids.

These are my personal preferences as starting points. Hope this is helpful. I'm sure others will come along to share their own techniques.

 

[UrsusArctos]

Thank you Mark. This is certainly valuable and much appreciated advice.
It turns out, as I was experimenting a bit further with Garage Band (MacOS included basic audio tool), that I was not so far off the mark with my recording set-up, after all.

One thing I discovered - and I find this confirmed by your explanations above - is that I need to set the omnis to hard left and right, respectively. With hindsight, this is quite logical since with these mics stereo is down to time difference only. They record a very similar signal and therefore it makes a lot of sense to have the signal of the left mic on the left ear and that of the right fully on the right, respectively. All other settings would dampen the stereo effect recorded by these mics.
The distance between the 2 omnis was by the way selected in accordance with information taken from "The stereophonic zoom" by Michael Williams. A separation distance of 50 cm yields a recording angle of ± 50°, which seemed to be a good compromise to capture the entire sound field by having the mics relatively close to the musicians and still getting some stereo effect coupled with room ambience. I also like omnis because they do not show bass roll off. This is important to me as one of the solo instruments is actually a double bass and I obviously want the full flavour of it in my recordings.

I am also aware of the directional characteristics of the cardioids, which is why I use them as the "support" mics for each individual musicians of a duet. This also gives me the advantage that I can reduce the level of the piano should that turn out to be too loud in comparison with the solo instrument. If I can, I do place the cardioids approx. 1 m away fro the main source. That's easy with a double bass where you can place the mic just about 1 m in front of the f holes of the instrument. I find this a bit more challenging with a concert piano to which only 1 cardioid probably does no justice. Well, that's what I have. I still need to keep things simple, i.e. I have to work with the 4 channels the 701D gives me. Perhaps I could eventually replace the cardioid that records the piano with a hypocardioid.

As a matter of fact, my original question about sound panorama setting in the 701D's menu kind of disappeared due to my discovery of setting all these parameters in Garage Band in post rather than relying on the 701D's mixer.

If I find out how to implement a file here, I will provide a sample of some post production work I did today. Again, yeah, it is not perfect, but I think reasonably okay for a hobbyist.

 

[UrsusArctos]

I finally figured out that I cannot directly upload audio material to this site. I therefore prepared something in Youtube and hope the link to this clip will work. Youtube does in turn not allow me to publish audio material only, hence the picture of the first part of the score.

I further hope, this will be enjoyable to some of you. Suggestions for improvement of future recordings welcome.

 

[Arjan P]

Sounds great to me (just on my laptop), nice feel of the room and a good balance between piano and double bass. A very nice recording, and then the playing is very good too!

 

[UrsusArctos]

Thanks Arjan. This is one of the pieces that were recorded for a virtual audition for admission to the conservatory (no physical auditions due to corona virus). There was no rehearsal before and the professional piano accompaniment was a bit under practiced. In total it was a 90 minutes session for a musics program of about 15 minutes, hence not cuts just 2 to three takes for each piece after some very limited rehearsing. The main piece auf the audition - Reinhold Glière's Intermezzo and Tarantella Op. 9 for double bass and piano - is a lot more difficult to play than the one in the example above. So, yeah, I agree with you, the double bass player, who just turned 16, can indeed be very proud, although there is still a long way to go.

 

[GTBecker]

A superb recording I'd be proud of, Ursus!

I can't decide if I love the bow slaps or don't - but I enjoy the intimacy and separation either way. Very nice under phones.

I would like to hear this recording in mono. Can you post that?

 

[UrsusArctos]

I guess I can do that. Just give me a few days. What will the mono file tell you that the stereo does not? That‘s perhaps a very stupid question but I really don‘t know, so forgive me my ignorance.

 

[UrsusArctos]

Oh btw, what do you mean with bow slaps? A that level of virtuosity it is sometimes extremely difficult if not impossible to avoid any unwanted side noises despite superb bow control. The double bass is a lot less forgiving in that regard than e.g. the cello is.

 

[GTBecker]

> ... What will the mono file tell you that the stereo does not?

Often times a mono mix will reveal phasing - multipath and polarity - that can result from multi-microphone placement and cabling errors.

> ... bow slaps?

I mean no offense to the bassist. To my ear, it sounds like she is hitting the instrument body - I'll guess an edge - with the wood of the bow, I think well beyond hair contact. If that is an intended sound, I suspect it is mic'd well; there it is.

If that bow contact sound is undesirable, though, you might find you can use the pattern nulls of directional mics to reduce it.

 

[UrsusArctos]

Yes, you are right of course with regard to occasional contact of the bow‘s tip with the instrument‘s corpus. Clearance is very small particularly when playing on the G string (orchestra tuning), which most of the high pitched passages are played on. What I find a lot more disturbing though ist the totally off-tune piano ;-)
It is not intended and could probably be corrected in post. However, since this was for an audition, no such sound engineering improvements were allowed. And, honestly, I would not know how to do it. Eventually, I might want to tap into your know-how in this regard ;-)
I will see to get you the mono file as soon as I can.

 

[UrsusArctos]

A superb recording I'd be proud of, Ursus!

Out of excitement about your very favourable comment I apparently forgot about my manners. Apologies.
Now, better late than never: Thank you.

 

[GTBecker]

> ... the totally off-tune piano [] is not intended and could probably be corrected in post...

Individual notes of a chord from a piano can be retuned in DAW? Wow, says this old-timer. In real time?

 

[UrsusArctos]

Here comes the mono version for your review, GT, or should I say rehear ? ;-)

 

[Arjan P]

Individual notes of a chord from a piano can be retuned in DAW? Wow, says this old-timer. In real time?

Well, not in real time, but you might wanna check this out and be dazzled. The future is here!

 

[UrsusArctos]

Pretty impressive indeed, despite the horrible sound of the digital piano. Whether this really is going to be the future remains to be seen. It may help correcting an off-tune piano in post. However, the thought that e.g. any singer's off-tune voice could be corrected after the fact is somewhat frightening. In this demo, we can only see the magic being performed on the basis of a digital source. I wonder what it would do to a real piano recording with some ever so slightly off-tune notes.
Nevertheless, cool stuff, thanks for sharing, Arjan.

 

[Arjan P]

Oh, but pitch correction on vocals is a passed station - it's common practice in current pop production and has been for quite some time. The unique thing about Melodyne is the fact that it can analyze polyphonic sources and act on a single note of it. It's just the next step..

 

[UrsusArctos]

So, from a pure artistic point of view, the only real thing ist live performance on acoustic instruments without amplification, right?

 

[-mjk-]

> ... the totally off-tune piano [] is not intended and could probably be corrected in post...

Individual notes of a chord from a piano can be retuned in DAW? Wow, says this old-timer. In real time?

Yes, it's called autotune and it has caused the destruction of music.

 

[Arjan P]

So, from a pure artistic point of view, the only real thing ist live performance on acoustic instruments without amplification, right?

Well, IMO that's a quite narrow definition of artistic - maybe if you want to assess a musician's quality of playing. But even then, why should it be acoustic without amplification?

And I think any use of studio gear can be very artistic and the beautiful result very 'real'. Take any record by the Beach Boys (or Beatles, or well, so many others) - not very real in the sense of being able to do it live, but exquisitely artistic all the same. I feel the same way about Autotune: it can be deceptive in showing the artist's 'real' capability, but it can also be used in a very artistic way (James Blake comes to mind). I do agree that in the classical world these things work differently, but also there a recorded live performance of an orchestra for instance can be post produced in such a way that different sections of a piece come from different performances (and maybe more goes on that I don't know about..).