I emailed the Phaedra's Folks and they said the software version is pretty current. Still did not answer if it was M1 AS native. They did say it was not plug-in, but a stand-alone app... Just FYI for those interested (like me).

As I mentioned in another thread, it isn't necessary to do LR > MS > LR shuffling just make headspaced recordings speaker compatible; the necessary increase in LF Interchannel Level Difference to compensate for the too-small Interchannel Time Difference can be done in a DAW without a plugin:

- Make a copy of the track.
- Invert the copy.
- Low-pass filter it at around 400-700 Hz (for approx head-spaced pairs).
- Flop this track.
- Mix it at a low level (approx -12 to 15dB).

Thank you all for the fine brainstorming, I see there are vastly different ways how people would approach this, with some common ideas.

I have a few more questions for debate:

1. what would the narrower spaced omni spacing (22cm) with shuffling benefit over a "normal" spaced omni pair (30-60cm), with no shuffling required?

(My intuition is slightly against baffles between spaced omnis and too narrow omni spacings and "fix it in post" approaches. I prefer techniques where you achieve the end result solely with the right position of mics and when needed and possible - some room treatment. And when you hear what you do, not imagine how it will sound in the mix.)

I like the idea of the treatments as proposed by Earcatcher, but most won't be possible - the floor is wooden, so I don't fear those reflections that much... I also have no diffusors and risers... I will ask for some stage felt/carpet, if they will be able to provide - maybe it could help some additionally.
I will also open all the side doors and perhaps group the stacked chairs around the orchestra...

ddy's approach also makes much sense to me, but I have no blms. Also, the ORTF pair is not that euphonic to me, it is nice, but I wish for a deeper sound.

I wonder about the bigAB ambis then - if one mics everything very close and adds this in the end - isn't then a careful placing of not so close mics equally satisfying - to capture a balance of direct to room on the spot? I guess the answer is - options in the mix.

About the height - I can relate to the idea of ear level mics as proposed by Earcatcher - but mostly I see mics used much higher and also in those examples - http://soundmedia.jp/nuaudk/01Vn/index.html - I prefer the "I" or "V" position over the lower ones - I feel the overall sound of violin is captured - the lower positions have more body, but maybe too much. Violin is a bit strident instrument after all... I feel that some element of sound and spaciousness is missing in all the lower positions - at least in those examples - I think exploring between "I" and "V" would be how I hear violin...

I will take in account to try a tiny bit lower positions, though, but for spots that might single out the separate instruments too much?

Does anyone have any cool links to the recordings made in the mentioned Sofiensaal? String orchestra and such?

I am leaning to this idea:

- spaced fig8 pair, just slightly angled downwards (10-15 degrees), but not too much, to not pick too much floor reflections - on the orchestra - angled out - basically Faulkner array, but very likely wider spacing - 30cm perhaps... some 2,2 m high above the orchestra,
just a bit behind the soloists.

- spaced omnis at "ear height" of standing musicians (ca 1,8m) - in front of the soloists, ca. 1m - 1,5m away - to capture "warmth" and depth of soloists and some ambience from the room, but not excessively so.

Sort of "low spaced omni pair" that will function as close soloist mics, too - and it will be true stereo - not two stereo sets for each soloist... it might work wonderfully (or not )

I liked some minimalist recordings that were done with a lower positioned spaced pair in very reverberant space - like this:
https://www.youtube.com/watch?v=qObUnXis4mw

I thought it might work as one of the pairs, if I also have the orchestra covered with a "tighter" pair behind...

- additional mono spot mics on violins, violas, cellos and double bass (probably closer and a bit lower than I was doing it before) - only as a safety net - will try to get enough good and balanced sound from the two main pairs. Each spot mic also adds random sense of room and increases the "bathroom", I feel.

I will very likely try this set up first - it came up intuitively - if it won't work, I'l try something else...

Thanks again and keep brainstorming and if you will, address the questions... Very helpful overall.

Also the proposal to just do what I already did and fine tune it... as kludgeaudio suggested... but I have no hypercardioids at the moment to try also that...

You are the recording engineer, no? So why can you not bring a rug, buy some diffusers and make a few risers? Taking care of this is your department. That hall is full of chairs that you could use to create a wonderful big diffuser around your players. Don't ask permission (some janitor may feel entitled to sabotage your project), just put them up and when anyone complains promise to put all the chairs back afterwards (which you will do of course).

As for the lower position of the mics: only when you control floor reflections you will be able to use this position. That hardwood floor will be almost as reflective as a hard stone floor. It's a mistake to think the reflections won't matter much. Acoustics first and your microphone technique will improve accordingly.

The reason why I did not suggest a larger AB for the group is because at such a close distance (to get the best direct to reverberation ratio) the large AB's will give a washed out image, with doubling of the impulses. I'd think you want a coherent group. I just tried the small Blumlein AB at 20 cm and a 10 cm thick baffle of Basotect foam between the mics and it sounds pretty great. Shuffling in addition is better, but I'd say it is optional if you are not too concerned with frequency dependent width positioning.

Fortunately you have two great fig8's that you can employ in such a way that you can pick your soloists up with them, the orchestra positioned in the "donut of silence" of the fig8's. You'll get a focused yet open sound of your soloists that way. Your second pair of omnis will be great as room mics, high above the center of the orchestra and soloists circle. Just six mics, mix them together and you'll get a pretty good recording in that glass house, I promise.

you don't need blms: any sdc can get usedin this application (and even many mdcs/a few ldcs) - and as far as the 'bathroom' is concerned, the opposite is true: you can get a much more clear picture, provided you're using all but (highly) directional mics (maybe except for the soloist) and apply the usual/necessary processing.


[i might start a thread on a 'modern approach to recording/mixing of unamplified instruments' one of these days so i don't have to repeat thingsall the time...]

Yes, i thought if putting a sdc o some foam on the floor would work, too. Thinking for using it for double bass and cello spots...

Your take on "modern" approach would be appreciated, but some audio examples would be needed, too, to demonstrate... at least of others, if not yours... to hear what is the outcome of it...

Thanks for tbe ideas, yes it is up to me, but for that budget, I won't organize hiring a big van, building risers, etc. I will use what I have and can transport and will be available at the venue...

samples from me? not in this life! - i provide the knowhow/my view on things but everyone who is seriously interested has to make his/her own hands dirty (or assist me on occasion)...

Yes, I know your answer, but to at least understand what's the aim... Sort of - this album was done like that and it sounds like this... That's the only way to know if one should even bother...
(apart from real world assisting, of course)

I would never bother setting two mics 5m high and 5m apart, etc. if I did not hear what it can do...

I'd argue that you are going to need that stuff in the future anyway, so better use this opportunity to organise it now and have it at hand for all those wonderful classical recordings you are going to make next. You'd be surprised about the budgets I have to work with sometimes, but that is never going to define the quality of what I bring to a session.

By the way: I have never rented a big van for transporting my risers, diffusers and carpets (plus all the other stuff that I need for a recording, which is A LOT more than you use at the moment). If built and stashed smartly everything will fit in a decent normal large car, driving once to the location. Have a look at my cello risers for example: these are platforms of no more than a few centimers high, with crates as their lifters. In these crates I transport exactly fitting bags that I remove when arriving at the recording venue. In these bags there are headphones, cables, bits and pieces for arrays, acoustic curtains, felt sheets, power supplies, et cetera. In the car the platforms go at the bottom of the trunk and the crates with stuff are piled upon them. You need to think in solutions in our job, not in obstacles. Don't spend your energy creating "Yes, but..."-problems in your mind.

True.

As proof of concept of the Blumlein 20cm AB setup I built a simple prototype. It sounds excellent, albeit very different from ECA, for example. The Blumlein AB gives a well defined L/R image, with very good positioning of the medium to high frequency sources. The mid-lows are also quite fine, while the lowest of frequencies could use some widening. The sound of this array is as if it is a bit further away, especially in comparison to ECA, but that is also why I recommend it for such close placement as in the center point of a half-circle ensemble. You will still get a nice roomy perspective, while you can improve the direct to reverb ratio enormously.

In the pictures you can see my line of thinking: the Basotect baffle (covered in sonically transparent cloth) is clamped between the two arms that hold the mics. That way you can move it back and forth or up and down and also rotate it with one corner forward for best functionality. The whole array can be tilted back and forth, so the relative position of the baffle can be kept intact, no matter what the angle of the mics will be. Super simple and easy to use.

The reason why I chose Basotect foam as a baffle material is most easily explained by its wonderful absorbtion properties at 10 cm thickness. Look at the attached graph. The dark blue line shows the absorbtion of the block I used. Basically Basotect does not reflect any significant sound and absorbes it in a very even way above 400Hz. Most baffles in the style of a Jecklin disc (a solid core with badly absorbing surfaces) diffract and reflect many frequencies, which results in a very colored shift from the sides to the center of the image. But Basotect foam gives you a beautiful neutral isolation of both sides. The front corners of the bloc (evenly getting thinner) result in very gradual growing transparency towards the center of the stereo image. By moving the bloc more or less forward you can very precisely set the amount of channel separation and cross-over.

Interesting, I use 10cm thick rockwool for most things, could work, too, for this? I won't experiment with that, just yet.

What is your mics and baffle holding contraption made from?

Btw - I will experiment with fig8 as main pair and close omnis for soloists first and then your vice versa idea - omnis (but 30 - 60 spacing) with balls, a bit higher up, for orchestra and fig8s for soloists, in both cases adding cello and double bass spots near the floor MKH20s... and wide cardioid spots for violins and violas, fairly close. No additional room mics.

I will stack chairs around the orchestra and use some carpet or felt below soloists and cello, double bass... no risers this time. Also not sure if they are needed in this group.

I probably sort of mutilated the suggestions of all, but that feels like the way to start at the moment. Hearing it will be decisive, anyway.

Thanks again for very informative posts.

You asked for advice and you got a number of suggestions. What you do with them is up to you and all that gave advice will have their own thoughts about that. Such is life...

You were concerned that Blumlein AB with a baffle could not be judged in situ, but the great thing is that it is a binaural technique and can as such be judged on headphones excellently. Only for speaker optimization you will have to use the shuffling technique in post (or, if preferred, during the recording already).

For my prototype I used the FOBA Combitube system, which I use for all my first tries with microphone arrays. Only later, when the functionality has been proved and optimised, I may change to other construction materials. The Combitube system allows for very fast and sturdy complex setups. It is Swiss made and priced accordingly, but indispensible for empirical researchers such as me. But now that you have a working sample to work from it will be very easy to make something similar with wood or something else.

If you are going to use rock wool as a baffle you will get a different sound than me, because it has a different absorbtion of most frequencies. If it is very dense it will probably go a bit lower, but it will never be as linear in the higher frequencies as Basotect is, with more diffraction colouration as a result.

Cello risers are meant to bring the sound radiation body closer to the radiating body of the other instruments, so one pair of mics can pick up the whole group without the need for cello spots. The riser also helps creating more time between core sound and early floor reflections, with a more focused cello sound as a result. Cello usually is the instrument that gives most problems with a washy sound, even when spotted. Low notes with a certain tightness are so much nicer in reproduction than vague low frequencies with lots of phase anomalies. A riser really helps achieving that.

Basotect IS a great material for that sort of thing, although the foam used in some Jecklin discs is better than you might expect. And the midrange attenuation of the Basotect is a big deal because if you have a half-meter baffle, a wave the width of the baffle is only around 700Hz and you're getting directionality from the baffle at least an octave lower.

But..

I would put all of these things... the baffled Blumlein A-B, the Jecklin pair, the Schoeps sphere, all into the same basic category of baffled omnis. I am a big fan of the technique when it works, in part because good omnis have such a deep and solid low end. It's a win over ORTF for live concert work because it can get a good image when placed close to the orchestra where audience noise is less of a problem. But in my experience it doesn't work in rooms with any sort of acoustical problems and it can be awful in very live rooms or rooms with slap-echo from the sides.
--scott

Thanks Ear for the Basotec recommendation, I gave up on both Jecklin and Schneider commercially available discs because they were both to my ears creating some reflections around 1KHz that make everything sound wonky. When I measure it at home, I could confirm they both were enhancing the region around 1KHz.

Yes, I know the role of cello risers, it might help, but also - it can reduce the low end "warmth" in the reverberant space - making them brighter and more direct... I guess it's the question of clarity vs. low end fullness (that could be too much and too messy, I know).

Ah, cool, thanks for the info - that FOBA Combitube system looks super nice...

I wonder if there are elements like this that are not specialized for photo (or even worse - fancy audio) applications that are much less expensive - something from "Bauhaus" - "Home depot" kind of stores...

There's the Manfrotto Multi Clamp system (see attachment), but it is more aimed at semi-permanent constructions. I have a few arrays outfitted with these things. In DIY stores you can find a simple tube system with connectors that is quite affordable, but it is made of steel, thus pretty heavy. Available in black and chromium. I also like to work with a combination of several K&M tubes and Manfrotto Dado balls, or the pretty cheap (and often more useful) RoadWorx Thread Cubes. (A sample of this stuff is visible in the picture with the carpet: Recording string orchestra with duduk and violin in very reverberant, mirrored, hall)

By the way, the Basotect baffle as shown above is readily available from HOFA as HOFA Absorber in many different colours and costs around 55 euros, VAT included.

Unfortunately this is not exactly the case: comb filtering of low notes can also lead to lack of "warmth" when the cello is not high enough from the floor. This all depends on the placement of the microphone picking it up. Only a BLM warrants even pickup of all frequencies coming from a low- or higher-placed cello. A riser simply gives you a wider window of movement for the placement of your main mics. When you find out that you need a riser but don't have it, you are f*ck'd, but when you find out that you don't need the riser that you have with you, you simple take the player off it. I like to tackle problems before they occur. That's what makes me a reliable partner for a recording in unforseen circumstances.

I bring a number of those baffles to any recording: to use them as a separator between two BLMs, or as a backside absorber if a hall has too much reflection from the depth. They can also be great to drape on the floor around a double bass when the space is a bit small for such a big instrument and you need it to sound a bit dryer. Lots of uses.

Ear, what cloth have you find to be transparent for covering the basotect baffle? Thanks!

The HOFA Absorber ECO is sold with the cloth around it. For the functionality of Basotect it is just fine without cloth, but it will be a lot less resiliant against abrasion or tearing. Basotect can be squeezed together without problem (it is even used in furniture upholstery), but do not pull it to a larger size as it will easily tear up then. The cloth will prevent this stretching of the foam block. Basotect is a foamed version of what is otherwise known as Formica, the top layer of heavily used tables in cheap diners and café's. BASF discovered it by accident when doing some chemical tests. Basotect will not deteriorate over time like most other acoustic foams do. I'm using big sheets of it as a ceiling cloud in my mixing room, glued to a wooden frame. Works extremely well.

If you want to make your own consider Guilford of Maine FR701, the same stuff used for gobos and speaker grilles. There are plenty of comparable fabrics out there and they should all come with attenuation plots.
--scott

Good news, the hall has an option to cover all the mirrors with heavy curtains and they also have a professional stage riser that I can use for cellists...

I'll bring a carpet for soloists and a couple of rockwool "pillows" to drop on the floor before the sections, if needed. The orchestra will be slightly bigger, 7 violins, 2 violas, 2 cellos and a double bass, plus soloists...

I guess this changes everything... if the space with curtains will sound tame enough, I might still go for Big AB (M221s with balls), stereo micing soloists (MKH30s for violin, MKH40s for duduk), 1 MKH20 and RB500 as violin spots, 1 CM3 for violas, 1 CM3 for cellos and MKH20 on the floor for double bass...

Carpet under soloists almost never sounds good.

having different ratios between direct, reflected and ambient sound between instruments - be it due to different type of mics, different patterns, different distance, different reflective or absorptive materials, different mic techniques (mono and stereo spots/section mics) etc. imo leads to a blurry picture - hence my preference for using a directional (mono) spot on each instrument (or then section mics in a semi-circle, equidistant to the main mic system) and adding (close, medium distance and distant) ambis...

There are obviously so many different preferences and ideas how to do things.

I appreciate your input as I do many others, but don't necessarily feel every idea suits my preferences.

Lacking years of hands on experience I have to rely on what others do, something that you don't (need to) care about.

I examine a recording, an album, a concert video and decide if I like the approach and try to understand the circumstances that led to certain decisions. But it is sound first - if I like what I hear, I examine what they did.

I liked the approach of Tritonus with Big AB, stereo spots for soloists and mono spots for sections, that they mostly use and I love that sound...

I also like minimalist spaced omni recordings that you obviously don't like from certain past comments. So I guess there is a certain aesthetic difference what anyone considers "good sound"... and since certain recordings got big awards or were released by big labels, it also works commercially. Despite anyone not liking the approach (and/or the final result).

For example - I really loved this sound:



And still can't wrap my head around the comments that it is lacking in some way, or is not good, not "broadcast ready"...

So, anything that would stir away from that kind of sound might not be my preference...

Also - I don't see blurry picture in this recording (it is Big AB, stereo spot on violin, mono spots on sections) - if anyone does - fair enough, but then it also means that I perceive that kind of "blurry picture" as euphonic.



So, I don't know... we are all different. Not everything is rational and logic, either.

If the acoustics will seem controlled enough with curtains, I'll go with this Big AB approach, if too lively, I might try more minimalist (1 omni AB for both soloists a bit closer, spaced fig8 for orchestra higher up or vice versa), closer and/or more spots in the mix.

I'll throw anything on the floor (including the carpet), only if the sound would appear too bright to me... otherwise I like the floor reflections... I am also not too sure about the double bass floor spot... might raise it at the position I like for double bass, if it would "stick" out too dry-ish... but will certainly try it - if I can get more double bass presence in the final mix.

My goal is to have the mix of lushness, spaciousness and strong (enough) bass as in those "Spheres" string orchestra recordings, but still not a sense of being "too close"...

Also, if I can pull it off with big AB, it would be good, because the other material for the same album is recorded that way... and using something dramatically different might be too distracting if one listens to the album as a whole.

Thanks again for all the ideas to all. There were certainly enough ideas to (re)consider.

edit:

So, here's a pic from the Sphere's recording - Pärt's "Fratres" - the strings have the same spots (and overall it is the same set up) for all the compositions they recorded - as I've seen in other sections of the session video.

Soloist stereo pair is even facing away from the orchestra, section mics are at the distances and heights where there is nice projection of the instruments, not in come equal distances and precise semi-circles, there's the Big AB and the mic in front on the left of the video is probably not used - put to the side - doesn't seem to serve a function. (and there is only one - when camera zooms out there is no pair - I thought it might be some "low ambient spaced pair", but obviously, just a mic that is not used in this session.)

I am certainly not criticising or saying your "semi-circles" and "equidistant to main pair" idea is wrong or anything - just that this different idea also works and sounds fantastic to me.

I also know that it is a great room and great players, great instruments... of course.

But still - a completely different approach to what you describe that ALSO works. That's all.

Actually, I wanted to "copy" that sound for this upcoming session, but when I realized we will be in that "glass house", my hopes were crushed... now, with the curtains, I am enthusiastic again, that we might do and achieve something nice...

Owning MK221 capsules, I’d only suggest you to not use the APE spheres, you’ll get a too brightish-weird sound for such a relatively small ensemble. The MK221 capsules without the spheres, as they are, will sound just lovely.

Thanks, thought to try out because of the distance... but you confirmed my second thoughts!