Recording an orchestra

Steinberg Lounge
#66

Here’s an extract of what I recorded and mixed on Saturday. As mentioned earlier, this is a pair of very cheap AT-2020 mics in an ORTF configuration into the Steinberg MR816CSX interface into a 10-year-old IBM laptop into Cubase. I did my best mix within Cubase, which consisted primarily of equalization and loudness processing. I also added a touch of reverb – the dress rehearsal didn’t seem to need it, but the concert night was full of warm bodies. Some of them were humming, but the mics didn’t pick it up. But a lot of them were coughing – waiting for the quiet parts, apparently. The loudness processing is through Ozone 5. I did have redundant recording, but I didn’t need it since the main path caught the whole thing. It could be that the other path had better quality, but I’ll never know.
https://soundcloud.com/incontinentals/scheherazade-extract

Would love any comments before I take it down!

#67

It sounds excellent to my ears. Nice balances of the parts, very clear and clean sound, no harshness, good dynamic range, good imaging. Very listenable and enjoyable. You worked really hard to make this come out so well and it really worked.

#68

Thanks Stephen, it was an interesting project. You can hear a lot of audience in the quiet parts, but you can also hear the conductor stamp his feet at certain moments! He was quite enthusiastic, by the way. Talking to the musicians, they were happy and energized by the performance.

#69

Hi Early,

Nice work. Imaging is great. Sound is balanced. You should be happy with that recording.

I had to chuckle when I read your comments about people talking and coughing. Welcome to live recording! It happens all of the time. Hiking the mics up helps, but nothing really cures it. You also had the benefit of using directional mics with the dead side of the cardiod pattern pretty much to the audience. Another benefit of the ORTF technique and is part of the reason that array almost never sounds bad. It picks up what it’s aimed at without pulling in much of the room sound.

Over the years I’ve had to deal with sounds from coughs, doors being closed, sneezes, talking, phones ringing, babies crying, and more. Usually I let it go and don’t try to edit it out as its part of a “live” performance. However, if it’s really bad, I might try to do some editing. I usually accomplish this using spectral editing in Wavelab. It’s tricky to do, but can be effective. The goal is to minimize the offending freq without messing with the sound. Sometimes if the noise is in the same freq as key elements of the music, you’re simply screwed and have to live with it.

I’ve been sorely tempted to leave a bowl of cough drops out at the entrance for people to take to reduce coughing.

-Tom

#70

Ha, good idea about the cough drops! Thanks for listening and commenting.

#71

A sharp, swift blow to the back of the head with a large, dense pointy object works best! :laughing: :smiling_imp:

#72

But then you need a scream filter on the mix.

#73

I once recorded a group of Tu Van throat singers with a Schoeps CMC 6 MK/21. It was very good at minimizing the audience noises. Another time I added basketball bouncing because an interview had started without anyone on the court and during it, the players came out and started warming up – bounce, bounce, bounce. So, we took that as “room tone” to put under the earlier quiet part of the interview – sometimes worse is better. :wink:

I’d also consider handing out a little slip or even making an announcement explaining that a recording is being made tonight – so please try to keep things quiet, particularly during softer parts of the music.

I’d like to see some screen shots of the Project just to see how it all looked inside Cubase. It really is a nice recording. I’m glad to see the positive comments about it.

#74

Tom, thanks for all your comments on this thread. I’m glad you took the time to post such long, detailed and useful comments here. Great job.

#75

Yes, I’ll second that! Rather than post a bunch of screen shots, I’ll just describe what I did, based on guidance here and some other articles I found on other forums.

Based on Tom’s advice, as previously discussed, I bought the very tall stand and placed it about 12 feet from the conductor, and some of the musicians were actually in front of the conductor on the stage. It also seemed to be about the right distance to get a good Stereo Recording Angle based on the ORTF mic configuration. So that’s basically the input side. Mics into MR816csx into my old laptop running Cubase 4.5. I had set up a template with two mono tracks going to left and right on the output track. So I just had to hit the record button. I tried to peak somewhere around -12 db, based on the dress rehearsal, but I think I hit about -9 at the highest point, so I had plenty of overhead.

I then copied the whole Cubase project from the laptop to my deskside running Cubase 8. I did not change anything about left and right panning - the left mic is hard left and the right mic is hard right. I cut the tracks so the applause was in separate segments. Then I selected all of the audio segments with the orchestra in it on both channels and normalized to zero. I’m now thinking I should have normalized left and right separately. Maybe somebody has a thought on this. After all, the gain was set manually by me looking at the input levels I was getting in dress, so they weren’t necessarily equal in any way.

Processing after that was basically equalization, loudness, and reverb. With equalization, I was primarily trying to boost the bass a little. They had four basses; probably could have used more in the loud sections of Scheherazade. I do most of this in Ozone 5, and my first try was to boost the bass in Ozone, but I wasn’t happy with the fact that I was also boosting timpani, which were really too loud in the peaks of Scheherazade. I thought it was strange that they placed the timpani right behind the first violins, and close to the front of the stage, but talking to the Executive Director, that was just done by custom for this orchestra. It was a guest conductor who didn’t want to break their normal routine. So then I gave up on that approach and instead boosted the bass in the right channel only, as the basses were on the far right, and it had less of an effect on the timpani.

For loudness, I first tried using a hard limiter on the master channel. Looking at the wave images, it was obvious that the peaks were all coming from the percussion (and this is always the case), so I just wanted to get those down without affecting other dynamics. But something about the hard limiter sounded harsh to me. So I instead used the Maximizer in Ozone. Reading the manual, it describes the function as an algorithm that anticipates peaks by looking ahead and then applying psychoacoustic science to lower the peaks in such a way as to make the lowering less noticeable. If you think about it, a limiter in the digital world is just a model of the circuits developed to do that before we even had digital. And it now makes sense to me that now that it’s all digital, it could be done in entirely different and more satisfying ways. So instead of applying a limiter, I found that the Ozone plugin sounded a lot better. And I set the point of starting to limit at -7db, which seems extreme, until you look at what is in those last 7 decibels, which is all percussion transient peaks.

And last, for reverb, since the hall was largely full, and my mics were not so far from the stage (and cardioid), I added some reverb. I tried all the versions in Cubase, but it sounded best with the reverb supplied by Ozone. As someone said in another forum, you don’t really need to put Hall convolution on something that was already recorded in a hall; you just need a light simple reverb.

In the end, I still felt the recording was missing “body”, and I added a small wide hump of midrange in the equalizer of the Cubase master channel.

No compression anywhere, but limiting as I’ve described.

So that’s it; would love any comments.

#76

The best approach here would be to set both channels to the same gain (on mic pres) when capturing the event. Then when you normalize - do it as a stereo file (as you did).

If you normalize channels independently, you mess with the stereo image. ORTF is designed so that both channels have the same gain in capture and replay. Most portable recorders (including the zooms and SDs mentioned earlier in this thread) have the capability of linking channels so their gains move together.

I almost always add reverb when recording with ORTF as you capture some, but not enough of, the hall. I thought your reverb was tasteful.

Tom

#77

I’ve been helped many times by generous and knowledgeable people on audio forums. I’m glad I could return the favor and provide some useful feedback. I’m also glad Early took the time to post files and explanations of what he did. This was a worthwhile thread.

-Tom

#78

Hi Tom, thanks for good advice, as usual. Back to the subject of channel levels. My left and right were not linked when I recorded them. Maybe there’s something in Cubase that does that; I’ll have to investigate. What I did was adjust left and right inputs to be approximately the same based on the dials on the MR816. But I did surmise that the tracks were not at equal levels; maybe I wasn’t really at center, or maybe these cheap mics are not so equal as they should be. I do suspect that this is the case with my mics. One of them has fallen to the floor at least once in a band recording with wobbly stands (I use them as drum overheads). Anyway, based on that, I felt free to adjust the left and right tracks to my taste. When I mixed, I went to sections where the whole orchestra was playing and adjusted left and right to get a good center stereo sound to my ears. Possibly I violated an ORTF principle?

Also, you didn’t hear it, but I did increase the left channel ever so slightly in the cello concerto, because the cellist was on the left, and he was not coming through as much as I thought he should. So I definitely took liberty with left and right mic volumes. I’m wondering if I broke rules!

Appreciate any thoughts on this.

Thanks for the good discussion!

#79

You did violate ORTF principles. But this is probably OK.

When recording ORTF, the best approach is to have the gain on the interface or recorder the same for both channels. Then have the gain for each level the same in Cubase when playing back. This was how ORTF was designed to work. Other settings can distort the stereo imaging. When I wrote that I link channels, I meant that I link the inputs on my 788T. This recorder has stereo linking functionality. Then one gain knob controls gain for both the left and right channels of the stereo pair. This is a good convenient feature. When in cubase, I set up a group channel and route the left and right ortf channels to the group. I do all processing on the group - to keep the stereo linked image intact.

Mic positioning changes would be my first choice to adjust relative volume concerns. This could include adjusting players’ positions (relative to the stereo array) to the extent possible.

But, sometimes its not until post that you realize adjustments are needed…if you’re being careful with what you’re doing when you make adjustments, and you’re layering on 'verb after the fact, it’s probably not a big deal to adjust relative channel gain. Listening to the end result is the ultimate determination if it works.

I’ve adjusted relative channel gain when the image seemed lopsided. The lopsidedness was often caused by the group playing louder on one side than the other. Not adjusting makes it feel like you’re carrying a bucket of water with one arm. Better to carry two buckets (one in each arm) and be balanced. :smiley: When I do this - I typically use a similar gain offset for all songs so that players don’t wander around in the stereo image.

Tom

#80

Hi Tom, I’m still thinking about that… but only because I think my two mics were not providing the same level of signal, possibly because one of them fell to the ground during a recording of a drum set. Enough to break the mic mount. I never replaced that mic, because it still works. I ordered a new mic mount from Audio Technica. I mean, I’ve really been going low budget! LDC’s can sometimes pull the mike stand down if you’re not careful!

Before the concert, I positioned myself in front of the array and snapped my finger to see where it would register in Cubase. One of the mics was lower than the other, so I increased the input on the lower one until the two registered about the same. (I routinely do the same for drum overheads, and always place the mics equal distance from the center of the snare. Previously I had recorded the overheads on one stereo track, but I found that it was better if I balanced them by ear). But, as I said, given the timpani situation, and the relative volume of the cello soloist, I made some minor volume changes per performance. And I suppose the timing differences still produce good stereo for ORTF, but I might have compromised the volume differences that are also supposed to help create the image.

So still learning, and thanks for teaching!

#81

Hi all, just getting ready for the next recording session. Now I have two SDC’s (AT-4041) going into a field recorder (Zoom F4). I’m intending to use my laptop as the backup, since the Zoom pre’s seem to be rather good, and probably quieter than the pre’s on the MR816, and I can run the Zoom on battery power (using Eneloop batteries, I’ve tested well over 3 hours continuously, with phantom power to the two mics). A friend is loaning me the ART-S8 to split the mic signal to feed the two recording devices.

So I didn’t realize that SDC’s in the ORTF configuration bump into each other in the back! If you want to get the two mics 17CM apart and at an angle of 110 degrees, one has to be on top of the other! At this point, I’ve rigged it so that one of the mics is higher than the other (using an SM57 mic clamp stuffed with cardboard). I would have had the same issue with an X-Y configuration.

What do you guys do in the ORTF situation (or X-Y situation)?

#82

I’m interested to hear how you make out with the 4041s. I’ve not used them, but are interested in how they sound. Hopefully you can post a clip and some pics.

Some other thoughts:

Redundancy - strong move. One day something will happen and you will thank your lucky stars you created a redundant recording path.

ORTF - yup, SDC mics often bump into each other when mounted in ORTF. The normal solution to this problem is to do exactly as you’re doing - raise one. I use the space bar from Grace, which has different height mounts which are designed to solve this problem.

Here’s a link to for the spacebar:
http://www.gracedesign.com/products/spacebar/spacebar_stereo.html

Notice that the SB-MHS is standard height, while the SB-MHT is the “tall” version.

So…stacking mics on top of one another for ORTF is common and works well. No need to worry about this.

If doing XY (which I’m not a fan of for orchestral recording), can stack too with no problems.

Good luck on your next gig!

-Tom

#83

Yeah, I did a little test with my jury-rigged rig today, also to learn how the F4’s filing system works. Seems I can automatically route left and right channels 1 and 2 to 3 and 4 respectively, with a lower trim level, in case the first pair clip. It also goes to the second SD card at the same time, in case there’s any problem with the first SD card. So two mono inputs record 8 tracks. Backups of backups of backups!

There is also a digital limiter that can be applied, and my understanding is that it works by adjusting the analog trim, so if set up right, could prevent clipping in the ADC. So if a transient is detected in the limiter at the level I set (-6dB), it will start limiting at a 20:1 ratio, and the manual says it has 10dB of additional headroom, which I don’t really understand, since it’s in the digital realm. But considering that in recording classical, the transients that are likely to clip are all in the percussion section, and very short, maybe it will help. I mean, I could just cut the tops off those transients with the edit tool in Cubase, and it would be fine, so maybe this is a good safety net. Experience will tell.

I compared my AT-2020’s to the AT-4041’s with some acoustic guitar recording, and it did seem that the AT-4041’s were, how shall I describe it, a smoother sound. Something is harsher about the 2020’s, although I do realize that if my position in front of the mics is different by a couple of inches, any mics will sound different.

Anyway, I don’t want to put up four mics this weekend right in front of the audience, so I’m only using the 4021’s. Not to mention I don’t have any solution for getting four mics onto the stand in ORTF configuration so I could do a true compare.

I found a suggestion on Gearslutz for raising one of the mics - buy a couple of European to NA mic adapters (5/8" to 3/8"), for a couple of bucks, and then combining them with 3/8 to 5/8 that I already have, I hope I can raise one of the mics about 3/4 of an inch. I have to get my hands on the parts to figure it out!

One question; in ORTF, the two mic bodies probably shouldn’t touch each other, right? Physical vibrations between the two?

#84

Gig is over; both F4 and MR816CSX into laptop seem to have worked flawlessly. I’ve got to get all the files over onto my desktop to see how they came out, and how they compare. Cool thing about F4 is I had it up and running in minutes via battery power. Cool thing about recording in Cubase is I can see the peaks on each track in case I need to adjust and other things that a full screen allow. Venue was not very good. Lots of curtains on the stage to dampen the sound, and a giant constantly running fan to keep the stage lights cool enough so that they would not overheat the system. You can hear it in all of the quiet parts (I’m talking about my ears, not about the recording, although I do assume you can hear it in the recording too). Pictures and samples to come.

It did occur to me that redundancy is good to have, but if the mainline recording system craps out for some reason, you could lose your phantom power to the backup system (using a passive mic splitter). I suppose that this sort of catastrophe is highly unlikely, and that what we’re really using two recording systems for is something like, did you remember to hit the “record” button or did you remember to put an SD card in the recorder. Interested in what others do about phantom power.

#85

ORTF - probably better to not have mic bodies touching. Might not be that bad if they are touching, as long as they stay touching.

Redundancy - I often use more than one main pair. I have the first recorder providing phantom for the first pair, while the second recorder takes the passive split. I have a second recorder providing phantom for the second mic pair, while the first recorder takes the passive split. All bases covered in that any single element of the recording chain can fail and I’ll still have something recorded. I typically do this type of redundancy if I’m not entirely sure which mic config I want (and hence put up more than one pair), or if I’m going for an inner/outer setup. The inner/outer setup is typically 1 pair of near coincident on inside with 1 pair of spaced omnis on outside (blended to taste in post). I usually run ORTF or wide ORTF as the inner. Would like to experiment with NOS here at some point. But I digress.

-Tom