Choir Mic Shootout

Price versus Value
October 11, 2016
Post Easter Audio Wrap Up
October 11, 2016

Choir Mic Shootout

I work some with an 80+ voice choir and decent size “orchestra”.  They also have eight hanging miniature choir mics and a modern sound reinforcement system.  The building seats between 1000 and 1500. the choir never seems “loud enough” and the sound produced is not very natural.  Typical! How did we get to this place that is so very common?

Many churches today have moved away from the traditional choir, piano, and organ opting or a more contemporary setting with a band and “worship team”.  I see a lot of churches with no choir at all.  The more contemporary churches I see still using a choir often do so in conjunction with a worship team, and most of the vocals are provided by the small team on handheld mics with the choir used more as “fill in” sound – almost like an effect.  And yet, there are still a large number of churches where the choir is the primary music source during worship as well as celebration music (musical specials). Some of these choir focused churches are in facilities that were well designed acoustically for choral music.  Many (most??) are not.

A common complaint in modern facilities is, “We can’t hear the choir!”  Of course not – the building was ill-designed for this purpose.  The only way to hear that choir is to add some mics and pump the sound into the “PA”… Enter the hanging choir mic.  White, so no one can see it. Maybe that is so you don’t notice how the little bugger twists and pivots.  Forget that they never seem to be in the best spot anyway.  A little closer and all we hear is one or two voices.  Further away – just noise. What noise you ask?  Organ?  Maybe, but in reality – in an attempt to be more “current” the church decided to add guitars and drums and maybe an “orchestra” made up of four trumpets, a clarinet and flute…  Oh that noise.

OK, before I get completely off topic; isn’t there a better way to mic a choir??

Glad you asked! Back to where we started.

For many years I have advocated the use of choir mics on stands for all but the most traditional worship environments. These could be anything from studio quality, large condensers (AKG414/C3000, Shure KSM32/44), to small “pencil mics” (Neumann KM184, Audix SCX1), to any number of in-between sizes.  These are typically mounted on tall tripod boom stands and can be placed where needed, moved as needed – even completely removed for special productions. There is the added benefit that they sound better than the typical $175 hanging choir mics about 101 time out of 100. Yes, there are some very good sounding hanging choir mics – including versions of the three I am about to discuss – but they still have the same location limitations as all hanging mics.

The most stated complaints about choir mics on stands is they are ugly and get in the way.  Enter the small form factor mic and boom stand.  I remember seeing the Three Tenors on PBS years ago singing into these tiny mics on tiny stands – the Schoeps CCM series. They were true miniature condensers – as opposed to what we usually see hanging above choirs, an electret condenser with an unbalanced feed to a preamp module mounted above the ceiling.

Fast forward a decade or so and we have competitive offerings from the likes of AKG, DPA, Audix, CAD (Astatic) and more. These are small mics, so not visually distracting.  They are also mounted on small stands with a small footprint. Most have capsule options for picking the optimum coverage; cardioid, hyper-cardioid, omni (typ. for recording), etc.  And the best part – they all sound pretty darn good!

In an effort to solve my choir dilemma, we demo’ed three mics:  The AKG GN155CHOIR with CK33 hyper-cardioid capsule, the Astatic 2700VP with electronically controllable infinitely variable pattern control, and the Audix MicroBoom with M1255 preamp in both cardioid and hyper-cardioid capsules.

The demo was during a mid-week choir practice – part of the time with orchestra and part of the time without. We started with all three mics set up center of choir.  The choir loft is three rows tall with 12″ rise between rows and the first row 12″ higher than the stage floor.  The plan is to use one row of mics on the stage floor.  The capsule will be aimed at the faces of the third row singers.  That provides a nice balance of all three rows at the mic capsule which is only a few feet forward to the front row, which is the greatest degree off axis. Gains at the console (Yamaha M7 digital) were set to achieve the same output level for all three mics . With just orchestra playing and no choir in the loft, we pushed the levels on all three into feedback just to see how much headroom we had with an empty loft and where the acoustical hot points seemed to lie (what frequencies wanted to take off first).  All three mics rang out at around 212 Hz, but the AKG also rang in the 7kHz range well before the other two.  At this point, we have all three set up as hyper-cardioid patterns.

Once the choir arrived, right off the bat the AKG had the edge for intelligibility – literally.  That 7k ring was the same reason the AKG sounded so clear – it has bright, “edgy” sound.  No problem, a little EQ can take care of that.  I did not have the cardioid capsule for the AKG to compare, but I suspect it would be bright as well judging from the on-line frequency plots. Interestingly, all three mics show about the amount of HF bump looking over their spec sheets, but only the AKG exhibited it so strongly in actual performance. That brightness helped bring out the consonants that provide clear intelligibility, but many choral directors try to avoid excessive brightness. The Audix and Astatic mics seemed to have a warmer, more robust tone.  They were actually very similar in sound quality. The Audix did seem to provide a little more detail, which would be expected due to the preamp’s pedigree, the SCX line. We also moved the mics to a section of all male voices where the more robust sounding mics really showed well.

In addition to sound quality, we considered aesthetics.  The Audix mic we auditioned had an 84″ carbon fiber boom, which allowed the use of a short base stand, making it by far the most “invisible” of the three. You can also order it with a 50″ boom or even 24″.  The black carbon fiber has a nice matte finish and very small joint section where it attaches to your mic stand. There is a very short (4″?) goose neck between the carbon fiber boom and the mic capsule.  It appears to be very stiff and should remain so for a long time because the capsule section is VERY light weight.

The AKG has an interesting matte gray finish, which actually works better than black, especially on camera.  It is only available in one height and with a double goose neck design.  Over time, the lower goose neck bend  weakens and the mic is a bit less stable.  AKG has easily the widest selection of capsules, including miniature shotguns (Super-cardioid).  It is a great sounding mic – especially if you like that top end EQ bump. For this situation however, it was the first to be eliminated due to the height limitation and overly bright sound.

The Astatic boom is also black carbon fiber and is 56″ long, which did require the floor stand be raised higher than the Audix. That made the joint where the boom attaches to the stand more visible in our situation.  The joint is much larger than the Audix which made the Astatic less “invisible” than the Audix or AKG.  Also, the mics capsule is larger – no doubt adding to the fine sound quality, but also the more conspicuous look.  Still – this is picking nits.  All three are very tiny and to me, are far less “ugly” than any mic cables hanging from the ceiling.

Having eliminated the AKG at this point, we decided to try the cardioid capsule on the Audix and also try changing the pattern on the Astatic. This is the point where the Astatic mic really differentiates itself from the competition.  The ability to continuously adjust the polar pattern of the mic capsule is a HUGE bonus.  As your choir changes size or stands in different locations, or performs in a different venue, you can adjust the pattern of your mics to the best fit for each situation. They also have lectern mics, conference table mics, boundary mics and even hanging mics with this same feature.

FINAL TEST:  So, we have the cardioid capsule in the Audix and are about to open up the pattern on the Astatic.  Two things I noted immediately.  The Audix sounded really great after the capsule switch and provided roughly the same gain before feedback with the cardioid capsule as with the hyper.  The “sound” seemed a bit more open.  There was a distinctly more “choral” quality to the sound, as would be expected from a wider pattern mic.  But the pattern control would have to be pretty precise to NOT reduce the gain before feedback.

We first listened to the Astatic mic through headphones as the pattern was “opened up”.  While you can hear a difference sweeping from a tight hyper pattern to a wide cardioid pattern, the difference is negligible until you reach a true cardioid pattern.  Three things immediately happened when the pattern went completely cardioid.  The sound field (just like the Audix) really opened up. Two, the tone shifted MUCH brighter – more like the AKG, and three, we lost several dB of gain before feedback.  We pulled back the pattern to what should have been a more narrow cardioid or wide-hyper to see if that made a difference.  What we found is the mic very quickly went from brighter and wider with less gain available, to warmer, but but more “closed off”.

The winner for us was the Audix with the M1255-cardioid.  Hands down.  We all agreed it was the best fit.

We went from eight hanging mics with all the associated problems, including phase cancellation, a pinched sound with little warmth, twisting mics, etc., to four very discrete, high quality mics that provide a warm and natural choral sound.  Audix earns the best compliment I can give any mic – especially for choir.  When the system is on and the choir is performing, you hear them, but they do not sound like they are coming from the reinforcement system.  And THAT is high praise.