You can record pop-music concerts in several ways. Listed below are a range of techniques from simple to elaborate. In general, sound quality improves as the recording setup becomes more complex:
• Record off the board (PA mixer) into a portable stereo recorder.
• Record with two mics into a portable stereo recorder.
• Record with a four-tracker: record with a stereo mic on tracks 1 and 2, while recording the PA mixer output on tracks 3 and 4. Mix the tracks later.
• Feed the PA mixer's insert-send signals to a multitrack recorder. Edit and mix the recording back in your studio.
• Use a mic splitter on stage to feed the PA mixer, monitor mixer, and recording mixer. Record to multitrack. Edit and mix the recording back in your studio.
• Do the multitrack recording in a van or truck.
We'll describe each method and list its pros, cons, and equipment. Then you can decide what's best for you and try it out.
Record Off the Board
Let's start with the easiest technique: connect the PA mixing console (board) to a stereo recorder. Some people record performances off the board at gigs, festivals, or concerts, and-let's hope, with the artists' permission- they put the recordings on the Web as MP3 files.
Using cables with the appropriate mating connectors, connect the PA mixer's tape-out or two-track-out connectors to your stereo recorder's line input(s). If your recorder's line input is a stereo mini phone jack, use an adapter cable: either two 1/4-inch phone plugs to a stereo mini phone or two RCA connectors to a stereo mini phone. They are available at Radio Shack and other electronic suppliers. Outside the US, if your recorder's line input is a stereo mini socket, use an adapter cable: either two 6.35-mm jack plugs to a stereo mini jack, or two phono connectors to a stereo mini jack.
If your recording device has balanced line-level inputs (female XLR or TRS, tip/ring/sleeve), connect those inputs to some spare master outputs on the PA mixer. Another place to connect is the insert-send connectors of the master output channels.
Caution: If you plug into an insert-send connector, you will kill the PA mixer's output signal unless you plug in halfway, to the first click. If that doesn't work, get two Y-cables with phone plugs (called "jack plugs" outside the US). At each mixer output channel, insert the Y-cable fully into the insert-send connector. Connect one leg of the Y to the insert-return connector. Connect the other leg of the Y to your recording device line input.
Pros: Simple, cheap, and fast.
Cons: Quality depends on the PA company's mics and board. The mix depends on the mixer operator's skill-you take what he or she sends you.
Equipment: Mixer-to-recorder cables, stereo recorder, and headphones.
Your stereo recorder may be a flash-memory recorder, MP3 player/ recorder, stand-alone CD burner, cassette deck, computer and audio interface, digital audiotape (DAT) recorder, or MiniDisc recorder.
The recorded mix might be poor with this method. Here's why: the sound mixer hears a combination of the band's instruments, the stage monitors, and the house speakers. So the board mix is intended to augment the sound of the instruments and monitors on stage-not to sound good by itself. For example, if the bass-guitar amp is very loud on stage, it will be turned down in the mix that you record off the board. Vocals will be turned up high in the mix because they can't be heard otherwise. Board mixes can sound good if there is not much sound coming off the stage (as with acoustic groups), and the venue is large or outdoors. It helps to monitor the board mix with headphones or isolating earphones to hear what you're recording.
Record with Two Mics
Here's another simple method. Connect two mics to a portable stereo recorder (FIG. 1). Place the mics in front of the group, set the recording level, and hit Record. You'll capture how the band sounds to an audience.
Pros: Simple, fast, and cheap. If you place the mics a few feet from a folk group or jazz group without a PA system, the sound can be quite good.
Cons: When you record a group with a PA system indoors, the sound will be distant and muddy compared to using a mic on each instrument and vocal. You'll pick up the sound of the PA speakers as well as the band itself. Also, the balance you get depends on the skill of the PA mixer operator.
Equipment: Stereo recorder, headphones or earphones, mic cables, and mics. Four microphone options are listed below:
• A stereo mic on a mic stand.
• Two stand-mounted mics of the same model number (Section 8 shows how to arrange a pair of mics to record in stereo).
• A miniature stereo mic that plugs into the recorder, or is built in.
• Two headworn mini mics. These can be clipped to eyeglass frames, either in the ear or on the temples. They make a binaural recording that sounds very realistic when heard over head phones. You could clip the mics to your shoulders instead. Mic models of all these types are described in Section 12.
Before going on the road, install fresh batteries and clean the connectors with isopropyl alcohol or DeOxit from Caig Labs (caig.com). Connect all your equipment and make a trial recording to make sure everything works. Approximate recording levels can be set in advance by recording loud music from your home stereo speakers or studio monitors. You can then place the stereo recording system in a backpack, suitcase, or cloth bag. You might even stow your gear in a hunter's vest or photographer's vest with pockets.
If possible, record in a room where the audience is attentive and the background noise is low. You might visit some potential venues in advance to check out the noise and acoustics. Avoid very live rooms because they can make the recording muddy.
To prevent crackles or loss of audio, strain-relieve the mic cable. Use tape or Velcro to fasten the mic cable to the recorder, so that the cable doesn't get pulled out accidentally. Check that the mic connector is plugged in all the way.
If your recorder can record MP3 or WAV files, consider these options.
Unlike MP3 files, WAV files are uncompressed, linear PCM recordings.
WAV recordings sound better than MP3 recordings, but WAV files consume a lot of memory: about 10MB/minute for a 16-bit/44.1-kHz stereo recording. If you select WAV, set the word length or resolution: 16-bit is CD quality and 24-bit is higher quality. Also set the sampling rate: 44.1 kHz is CD quality (good enough for professional recordings), 96 kHz is higher quality, and 192 kHz is state-of-the-art quality.
FIG. 1 Recording a pop group with two microphones.
MP3 files typically consume about 1/11 to 1/4 as much memory as WAV files, depending on the bitrate setting (in kilobits per second or kbps). A setting of 128 kbps results in good audio quality (cassette quality), 192 kbps is very good (near-CD quality), and 256-320 kbps is excellent (CD quality); 64 kbps mono is the same audio quality as 128 kbps stereo; 64 kbps stereo WMA (Windows Media Audio) is the same quality as 128 kbps stereo MP3.
Listed below are approximate recording times on a 1-GB flash memory card (for a 930-MB file size). Double these times for a 2-GB card.
24-bit/44.1-kHz stereo WAV 1.0 hour
16-bit/44.1-kHz stereo WAV 1.5 hours
256 kbps stereo MP3 9.0 hours
128 kbps stereo MP3 16.5 hours
Be sure you have enough free space on your flash-memory card before going on location.
When you monitor the mics with headphones or earphones, you'll hear the room acoustics and any background noise (audience, air conditioning, traffic). The closer the mics are to the group, the clearer and cleaner the sound will be. In other words, close placement captures more of the music and less of the room sound and background noise. Try to place the mics as close as possible to the stage where you still pick up the house PA speakers well, about a stage-width away from the stage (FIG. 1).
An alternative placement is near the house mixing console because the balance there is what the sound mixer intended. Keep the mics away from any bars or other noise sources. Some concerts have a tapers' section where you are allowed to place your mics. If you are recording your own band, you could place the recorder and mics on stage (on a stool or mic stand) and record the sound of the monitor speakers.
Another way to cut down on room sound is to use a pair of cardioid or super-cardioid mics aimed straight ahead at the musicians and spaced about 2 feet apart (or headworn). This will give a closer, clearer sound than an XY stereo mic or a pair of omni mics.
If there are dancers near the stage and the ceiling is low, you might try boundary mics (such as two Pressure Zone Microphones (PZMs)) gaffer-taped to the ceiling or mini mics hung from the ceiling.
To record a small folk group or acoustic jazz group, place the mics about 3 to 6 feet from the ensemble (FIG. 2). If the group plays in a circle (as in an outdoor jam), try placing the mics in the center. Or just walk around with the mics while monitoring the mics over headphones. Find a spot where you hear a good balance and put the mics there. Ask the musicians' permission to record them during a break in the music.
The recorder might have a record-level switch labeled "manual" and "auto." Set it to "manual" in order to retain the dynamics of the performance. If the switch is labeled "AGC" (Automatic Gain Control), set it to "off."
FIG. 2 A method of stereo miking a jazz group.
The recorder also has a meter that shows recording level. Set the level so that the meter reads about +/-6dB maximum. That allows some headroom for surprises. Peak levels up to 0dB are okay, but levels above 0dB result in distortion. (Some portable recorders include a limiter that prevents recording levels above 0dB.) After setting the recording level, leave it alone as much as possible. If you must change the level, do so slowly and try to follow the dynamics of the music.
If your recording is distorted even though you did not exceed a 0dB recording level, either the sound was louder than the mic could handle (not likely), or the mic signal overloaded the mic preamp in the recorder. You can prevent mic-preamp overload with a mic-gain switch or pad (attenuator), available in most recorders. Use low gain for loud sound sources (rock bands); use high gain for quiet sound sources (acoustic musicians).
If you need to set the recording-level control less than 1/3 up to achieve a 0dB recording level, use the low-gain setting or switch in the pad.
If you are using large-diaphragm condenser mics plugged into a phantom power supply, you might need to plug the output of the supply into the recorder line input-rather than the mic input-to prevent distortion.
You might be able to record an acoustic group on location without a PA system or audience. This gives you the freedom to make adjustment to improve the sound. Here is a suggested procedure:
1. Adjust the acoustics around the instruments. If the room is too live (reverberant), put up some packing blankets, comforters, rugs, acoustic foam, or cushions. Often a good-sounding spot for the musicians is near the center of a large room.
2. Place the musicians around the stereo mic pair where you want them to appear in the recording. For example, you might place two singing guitarists on the left and right, with bass in the center.
3. Experiment with microphone height to vary the vocal/guitar balance.
Try different miking distances to vary the amount of ambience or room sound. A 3- to 6-foot distance is typical.
4. While the musicians are playing and during playback, monitor the mic signals with headphones. If some instruments or vocalists are too quiet, move them closer to the mics, and vice versa, until the balance sounds right.
5. If someone makes a mistake, either record another take of the entire tune, or record starting from a few bars before the mistake and edit the takes together later.
FIG. 3 shows a clever recording method using two omnidirectional mics placed to get a good balance of a jazz group. Engineer Gert Palmcrantz used this technique to record the Ludvig Berghe Trio. Details can be found at discmakers.com/music/pse/2005/jarvis.asp, and recordings at moserobie.com.
Once you copy the recorded files to your computer hard drive, you can edit the recording and adjust its tonal balance (equalize it) with digital audio workstation (DAW) recording software or with Harmonic Balancer software. You might cut 1-6dB around 300Hz to reduce boomy reverb and get a clearer recording. Mini stereo mics using cardioid mic capsules tend to sound weak in the bass, but you can boost 3-6dB at 50-100Hz to compensate (or whatever amount sounds right). Headworn mics often need a cut around 3 kHz to compensate for the effect of the head. If you have recorded outdoors and the sound is too dry, try adding a little reverb and see if it helps.
A great source of information about two-track recording of concerts and jams is the DAT-heads discussion group (solorb.com/dat heads/). The Steam Powered Preservation Society (thespps.org) records folk-music jams and concerts, and posts MP3 files of the recordings along with detailed information on the recording equipment and techniques. Sonic Studios (sonicstudios.com/tips.htm) offers a wide array of tips and equipment for this type of recording. Mike Billingsley wrote some fine papers on stereo miking in Preprints 2788 (A-1) and 2791 (A-2), available from aes.org.
FIG. 3 A method of stereo miking a jazz group.
Record with a Four-Tracker
This method is fairly simple and provides good sound. Put a stereo mic or mic pair at the front-of-house (FOH) PA mixer position. Plug the mic connectors into mic inputs 1 and 2 of a four-track recorder-mixer (or any size recorder-mixer). Connect the PA mixer's tape output or two-track outputs to line inputs 3 and 4 (FIG. 4). Mix the recording to stereo back in the studio.
Pros: Fairly simple, cheap, and fast. Good sound quality.
Cons: You can't control the mix among instruments. Sound quality depends on the PA system and the sound mixer's skill.
Equipment: Stereo mic or matched mic pair, stereo bar, mic stand, mic cables, Y-cables, mixer-to-recorder cables, headphones, recorder mixer (such as models by Tascam, Boss, Zoom, Fostex, or Korg).
The FOH mics pick up the band as the audience hears it: lots of room reverb, lots of bass, but rather muddy or distant. The PA mixer output sounds tight and clear, but typically is thin in the bass. Luckily, a mix of all four tracks can sound surprisingly good. Tracks 1 and 2 provide ambience and bass; tracks 3 and 4 provide definition and clarity.
When you mix the four tracks, you might hear an echo because the FOH mics pick up the band with a delay (caused by the sound travel time from stage to mics). To remove the echo, import all the tracks into digital recording software, and delay the PA mixer tracks by sliding them a little to the right. Align the waveforms of the mic tracks and mixer tracks at big peaks.
FIG. 4 Recording two mics and a PA mix on a four-track recorder-mixer.
FIG. 5 Connecting insert sends to a multitrack recorder provides great
sound and easy setup.
Connect the PA Mixer Insert Sends to a Multitrack Recorder
Now we get into professional techniques. This is an easy way to record, and it offers very good sound quality with minimal equipment (FIG. 5). Use the mixer gain trims to set recording levels during the sound check. Edit and mix the recording back in the studio.
Pros: Easy, fast, moderate cost, and sounds great. You don't have to mix while recording-instead, mix and monitor back in your studio.
Cons: Sound quality depends on the PA company's mics and mic preamps. You might have to ask the PA operator to adjust the gain trims during the show to prevent recorder overload.
Equipment: Multitrack recorder and mixer-to-recorder cables (such as a short phone-to-phone snake, called "jack-to-jack" snake outside the US). The multitrack unit can be a hard drive recorder, recorder mixer, or multichannel audio interface and a laptop.
Connections
This section describes how to connect a multitrack recorder to a mixer's insert-send connectors.
In making a multitrack remote recording, you usually want to record the signal of each mic on a different recorder track. You'll mix those tracks later in the studio.
In the console there are several mic preamplifiers, one per mic, which amplify the mic-level signal up to line level. For each mic channel, this line level signal typically appears at two connectors on the back of the mixer:
direct out and insert send. That's where to connect to the recorder inputs.
Usually the insert send is the best connector to use. Here's why. Typically the direct-out signal is postfader (FIG. 6). This means the signal at the direct-out connector comes after the fader, so that the signal is affected by the fader (volume) settings. Any fader movements will show up on your recording, which is undesirable. It's better to connect recorder tracks to insert sends. They are usually prefader, pre-EQ (pre-equalization). So any fader or EQ changes that the PA operator makes will not appear in your recording. However, any changes the PA operator makes in the trim settings during the show will affect your recording levels.
First, find out what kind of insert connectors the PA mixer has, and what kind of input connectors your multitrack recorder has. Buy or make some shielded cables (or a snake) that mate with those connectors. FIG. 7 shows three ways to wire cables based on the type of insert connector.
FIG. 6 Simplified signal flow through part of a mixing console, showing
insert and direct out.
FIG. 7 Three ways to wire cables based on the type of insert connector.
Some boards have a single TRS insert connector per channel, instead of separate insert-send and insert-return connectors. Usually the tip is send and the ring is return. In the TRS connector that you plug into the TRS insert, wire tip and ring together, and also to the cable hot conductor (FIG. 7 top). That way, the insert send goes directly to the insert return. If nothing is connected to the insert return, no mic signal goes through the mixer.
On some PA mixers with a TRS connector, you can use a TS (tip/ sleeve) connector (FIG. 7 middle). Plug it in halfway, to the first click, so you don't break the signal path-the mic signal still goes through the PA mixer. If you plug it in all the way to the second click, the signal does not go through the PA mixer, just to the recorder. Cover the connections with a mixer case cover or board, because someone could bump into the mixer and dislodge a cable.
If the PA mixer has separate send and return insert connectors, connect the send to the recorder track input, and connect the return to the recorder track output (FIG. 7 bottom). If necessary, set your multitrack recorder to monitor the input analog signal, so that the PA mixer will receive a signal. Another option: use an insert snake with TRS connectors at the mixer end. Carry some TRS-to-dual-TS adapters to handle mixers that have separate connectors for insert send and return.
The insert sends are balanced or unbalanced, and the same is true of the recorder inputs. To connect balanced and unbalanced equipment correctly, see the article "Sound System Interconnection" on the Rane Website.
You often encounter PA consoles where some insert sends are tied up with signal processors. You must use those channels' direct-out connectors instead, which usually are postfader (unless they can be switched to pre-fader). Another option is to "Y" the insert send to your recorder and to the processor input. Or, assign those mic channels to unused groups (buses) and get your recording signals from there.
Some rack-mounted mic preamps have insert connectors. You could plug the mic-snake XLRs into these preamps, then connect the preamp's inserts to the PA mixer line inputs. That way, any gain changes made on the PA console will not affect your recording.
Caution: Any gain changes you make on the mic preamps will affect the PA levels.
If the PA mixer has a FireWire or USB (Universal Serial Bus) port, simply connect the port to a laptop that is running recording soft ware. Set up the software to recognize the mixer as its input/output device. The signal from each mic channel goes to a separate track in the software.
What if you want to record several instruments on one track, such as a drum mix? Assign all the drum mics to one or two output buses in the PA mixer. Plug the bus out insert connector to the recorder track input.
Use two buses for stereo. Adjust the faders to get a good drum mix.
Monitoring
To monitor the quality of the signals you're recording, you generally let the PA system serve as your monitor system. But you may want to set up a monitor mix over isolating headphones or earphones so that you can hear more clearly.
Here is a suggested procedure. Connect all the recorder outputs to unused line inputs in the PA mixer, or to a separate mixer. Use those faders to set up a monitor mix. Assign them to an unused bus, and monitor that bus with headphones/earphones. If you can spare only a few inputs, plug in just one track at a time to check its sound quality. Listen closely for any hum, noise, or distortion.
Setting Levels
Set recording levels with the PA mixer's gain-trim or input-attenuator knobs. This affects the levels in the PA mix, so be sure to discuss your trim adjustment in advance with the PA mixer operator. If you turn down an input trim, the PA operator must compensate by turning up that channel's fader and monitor send.
As we said, if the PA operator changes the input trim during the show, these changes will appear in your recording.
Set recording levels before the concert during the sound check (if any!). It is better to set the levels a little too low than too high because during mixdown you can reduce noise but not distortion. A suggested starting level is +/-10dB, which allows for surprises. Do not exceed 0dB because the signal will distort. Also, if you set the recording level conservatively, you are less likely to change the gain trims during the performance. You don't want to hassle the PA operator.
Some recording engineers run each insert-send signal through a potentiometer to set the recording level. By adjusting levels on a rack mounted panel of potentiometers, you don't have to ask the PA operator to change the gain trims for you. Of course, if you are operating the PA console, you can set the gain trims yourself.
If you have a spare recorder, record a safety copy on it at the same time. This provides a backup in case one recorder fails.
Keep a log as you record, noting the counter times of tunes, level changes, sonic problems, and so on. You can refer to this log when you mix.
FIG. 8 Splitting the mic signals to the recording mixer and PA mixer.
Splitting the Mic Signals
Now let's consider a different way to make a multitrack recording. Plug each mic into a mic splitter, which sends the mic signal to two destinations:
the PA mixer and recording mixer. This gives you independent control of each microphone. The splitter has one XLR input and two or three XLR outputs per mic. The third output on some splitters goes to a monitor mixer. In Section 1 we described transformer-isolated splitters and Y-cable splitters.
As shown in FIG. 8, connect the outputs from all the splitter channels to the PA snake and to your recording snake. Connect the recording snake to your recording mixer mic inputs. Connect the recording mixer's insert sends to a multitrack recording system of your choice. After the recording is done, you can edit and mix the recording back in your studio.
Pros: Ultimate sound quality. Independent control at each mixer.
Consistent sound.
Cons: Complicated. Expensive if transformer splitters are used.
Equipment: Mic splitters, maybe mic preamps, mic cables, mic snake, recording mixer, mixer-to-recorder cables, multitrack recorder, headphones, or powered monitors.
Let's explain the advantages of splitting the mic signals. You use your own mic preamps, so you are not dependent on the quality of the PA console mic preamps. Also, you are not hassling the operator about adjusting gain trims. Each mix engineer can work without interfering with the others. The FOH engineer can change trims, level, or EQ and it will have no effect on the signals going to the recording engineer. Another plus: a splitter provides consistent, unprocessed recordings of the mic signals. This consistency makes it easy to edit between different performances. What's more, splitters let you use mic preamps on stage if you wish. That way, the cable from each mic to its preamp is short, which reduces hum and radio-frequency interference.
Using Splitters
To use a splitter or multichannel splitter, plug each mic into a splitter input. Decide which mixer you want to supply phantom power (usually the PA mixer). Connect the splitter's direct outputs to that mixer's snake.
Connect one set of isolated outputs to the recording snake, and another set to the monitor snake (if used). Plug the snakes into the mixers. FIG. 8 shows splitter connections to two mixers.
Splitters have a ground-lift switch on each output channel. This switch connects or disconnects (floats) the cable shield from pin 1 of the XLR connector. When the ground-lift switches are set correctly, you should get no ground loops and their resulting buzzes.
How do you set the ground-lift switches?
1. First, turn off phantom power in each console. Turn down all the faders.
2. Make sure the direct feed's ground-lift switches (if any) are set to ground, not lift. Otherwise phantom power won't work.
3. Go to the mixer connected to the direct feed. Turn on the mixer, switch on phantom power, and bring up each fader to listen for a signal.
4. On the splitter, find the ground-lift switches for the recording-mixer feed. Set them to the position where you monitor the least hum and buzz at the recording mixer.
5. Repeat step 4 for the monitor mixer.
Multitrack Recording in a Truck
Here's the ultimate setup. Each mic signal is split three ways to feed the stage boxes for the recording, reinforcement, and monitor consoles. A long snake is run to a recording truck or van parked outside the concert hall or club. In the truck, the snake connects to a mixing console plugged into a multitrack recorder. The interior of the truck is acoustically treated, and powered Nearfield monitor speakers allow accurate monitoring of the signal. Designing a recording truck is a subject in itself and is beyond the scope of this guide.
Pros: The truck contains the console, monitors, and recorders, so you don't need to cart them into the venue. This saves setup time. Also, a truck provides a quiet, controlled monitoring environment.
Cons: Complicated and expensive. Requires an AC power connection to the venue circuit-breaker panel or to the house power distro.
Equipment: Mic splitters, maybe mic preamps, mic cables, mic snake, recording mixer, mixer-to-recorder cables, multitrack recorder, powered monitors, acoustically treated truck.
There you have a full choice of methods for recording live. Check out all the options, and you'll find a system that works well for your style of recording.