I’m going to be recording solo woodwind instruments (clarinet, piccolo, oboe and flute) accompanied by a pre-recorded backing track of ‘electronics’, played through PA speakers in the relatively small, dry studio.

I have no details about the sorts of sounds that will be played back, but I’m inclined to put the player in the centre of the speakers, and stereo mic (ORTF or NOS) as if they’re playing unaccompanied, and then increase the playback level until it’s suitably balanced (against the solo instrument) in my monitor headphones.

I’m also considering taking a stereo line-in of the electronics track, so that if necessary I can ‘float it in under the miked pair’ for a little more presence or focus, during the mix process later.

I’m thus tempted to play the electronics track through the speakers at a fraction lower than ‘ideal room balance’…so that if I add the direct feed of the electronics as a ‘spot input’, it will make up the level that’s under-represented by the PA speakers contribution.

This latter strategy might be flawed…as it could tend to represent the electronics as too dry, present and upfront, rather than ‘ambiently blended’….as per the speaker feed.

Any suggestions ?

In my experience, the best and easiest way is, having the performers hear the electronics in their headphones only and record them dry, without the electronics bleeding into the mics.
No need to take a line signal from the electronics, if it is a pre-produced track. Just import it into your DAW. If you have to record the electronics, because it makes syncing easier, then you should replace this recording with the original track afterwards.

If it is crucial for the performers to hear the electronics in the room with speakers, because of some kind of acoustic phenomenon, that needs the direct interaction between acoustic and electronic sounds (Alvin Lucier, Clarence Barlow,... sine waves, beatings), then you have to record it like it would be performed in a concert situation. But then, it might be better, to get out of the small studio.

Too dry for me personally is not a problem from a recording perspective, since ambience and reverberation can always be added, but not easily removed. Too dry can be a problem for the performers, if they are used to a different room and cause overplaying and problems with intonation and musical interaction.

If these are the kinds of pieces I think they are... largely "new music" compositions composed in the '70s, '80s, and '90s for classically-oriented instrumental soloists... the performers are probably not used to performing with headphones and are used to speaker playback being a part of their flow. If that's the case, then I'd recommend recording them as much as possible like they're used to performing in a recital hall. No headphones, just track/speakers and musicians playing and recording together as if they were both real, live people.

If these are musicians with more "contemporary studio" recording experience and don't mind recording in headphones, then I agree with Co.'s approach. But the musicians will probably provide their best performance when they're playing under the most comfortable circumstances for themselves, and that makes all the difference in the world, as we all know.

As said, make them play with headphones listening to the electronics, you can create a very nice balance afterwards. There’s no way you can get a nice sound by playing the electronics through speakers, you’ll get a very amateurish sound no matter how hard you try. I’ve been there, and it doesn’t work even in really nice acoustics.

I forgot to add that if you’re recording in really nice acoustics (not this case, I know), it can be useful to record the room sound of the electronics played through the speakers. You get a natural reverb of the electronics that works very well if recording in very good acoustics.

I recently recorded a piece like that. It was a flutist plying with a prerecorded electronic backing. I played the accompaniment through a pair of monitors and stereo-miced them up close, while the performer played across the room, facing the monitors. I used a schoeps mstc64 on her.
https://www.youtube.com/watch?v=FMFfK3CjD3Q

I'm very much of the opinion that for a work like this ultimately the composer makes the decision if possible- a studio version of an electro-acoustic piece may be a totally different work potentially than a 'live' recording, and a lot of how this should be executed comes down to their intention. Though if they are new to this type of work maybe they are still figuring this out and they will maybe want to consider your input and ideas. As mentioned above, particularly if this is a Lucier style piece focused on acoustic interaction, phasing, room sound, etc I would record the room maybe with some spot micing for fine adjustment/balance possibilities but really focus more on conveying (what the composer considers) the most important aspects of the work as good as possible. I'm assuming here the composer has chosen live in-room playback for a specific reason.

I think one reason work like this may not get recorded well is because the time, energy, and resources that would go to say a high end orchestral or chamber recording don't often get put to this type of work. Having a haphazardly placed Mackie PA playing back the electronics out of a laptop headphone jack without time to adjust balance to the musicians or positioning is going to sound shoddy even in a nice room- especially compared to putting in some time and energy to finding balance, and positioning something like I don't know say Meyer or Geithain speakers with high spec D/A conversion and treating them like part of the ensemble. Which in my opinion they are - the GRM Acousmonium sounds different in different rooms, which is why diffusion is a live performance practice done by the composer or engineer with realtime control. Otherwise you are effectively doing the equivalent of bringing in a local amateur or hobbyist to be your soloist with a professional ensemble. But again, time and resources for work like getting its due treatment are often in short supply.

I do a lot of recording of live electronics and to me one thing that is really critical here is having very fast capsule mics. Often times electronics will have extremely fast envelopes and transients with very critical spatial aspects - to me capturing that accurately is key to capturing the piece as best as possible. A 'sweeter' or less 'harsh' sounding mic for instrumentation that misses out on those details can make what are otherwise very powerful sounds loose all of their edge and character. But again, consulting with the players or composer I think is the ticket here- maybe the work doesn't have so much transient action but the spatial imaging or acoustic phasing effects, which would be drastically affected by your mic placement, are the real substance of the piece.

There are also pieces like that from the 2000s, 2010s, 2020s.
Most musicians playing pieces like that today are well acustomed to playing with headphones, since there are also many pieces like that, that require a click for live performance. At least that is my experience with musicians over here.

Thanks guys for your collective advice and wisdom here….it’s going to help me be prepared for the various scenarios I might be up against in the recording.

I doubt the soloist is going to be amenable to headphones, so a hybrid of area miking the instrument plus speaker spill… and reasonably close miking the speakers in addition, will be a likely approach….plus some substantial effects treatment in post, to glue them together within a credible soundscape. I’ll report back with my experiences once it’s in the bag ! Much appreciation for your input everyone !!

Exactly.
Usually there has to be some adjustment of the playback system or of the electronics to the room and usually some fader riding needs to be done.
If there is nobody during the recording session to perform this, as a musician with the other musicians in real time, I strongly advise, to have all the electronics in the box and do the fader riding after the fact as part of the mixing.

I would advise, not to mic the speakers. The electronics usually should sound as clean and clear as possible, so the file directly from the composer without any unintentional coloration should be used.
Just because electronics are played back by speakers, doesn't mean, they should be recorded like a guitar cabinet.

Co - did you listen to it? The performer and the composer both liked it…

I did.

If the performer uses headphones, what’s going to be the cue reference for me to line up the electronic track with the live woodwind….there needs to be at least sufficient spill from the speakers into the main instrument mics to assist that sync ?

A handy possibility is having the electronic track in your DAW. From your DAW, you can send it via your interface to the headphones of the performers, while recording them. I think, this is called overdubbing.

Two good speakers on stands like a big headphone.
A fig8 ms mic on your soloist.
Then get the tape aligned to your recording.
Put some IR verb on the tape to get some room around it.

That is how I do it without headphones.

If you should end up using headphones anyway, I'd suggest using a very lightweight on-ear (not enveloping the ear) model such as was common a few years ago for portable devices. The musician may cover only one ear to hear the pre-recorded tracks while the uncovered ear tells him how he sounds in the room. I've done dozens of recordings in that way and the musicians find it a good compromise.

It is my experience that, if intonation is really important, most classical musicians perform better when not wearing headphones.

Is this going to be a recording of a performance in front of a paying audience? I do a lot of this kind of work and exactly none of the players I've recorded in the last several years would be likely to consent to wearing headphones or even in-ears to hear the electronics audio. They are used to balancing themselves vs the speakers in use and often want personal control of the level of the playback/electronics at their playing position.