fun with pzms

I've had access to a nice pair of crown PZM mics for several years, but only recently have I really been running them through their proper paces.

My interest was really piqued a while back when I decided to mount one to the license plate of my motorcycle and take it for a drive.
 

The fact that the mic could go 80mph with zero wind noise and capture that much punch and detail really impressed me.

Later on, we had a gun recording roundtable on Tonebenders featuring Charles Maynes and Frank Bry.  Charles spoke very highly of the PZMs in his rig for capturing punch and low end there as well.

With all of that in mind, I took the mics out a few times in recent weeks to really get a feel for how they would react in a few different situations.

The first test was the explosive percussive impact test.  Every fourth one of my coworkers lights off some giant mortar style fireworks at his lakehouse, and this year I decided to bring the pair of PZMs and just run those exclusively.

here's what it looked like:


so

That's cool. Here's the unprocessed recording:

Then to hear the boom I used some parallel limiting to make it much louder, and eq'd some more low end into the crushed channel. The main takeaway for me is that the PZMs really have super fast transient response, and very tight low end response.  They really don't require any wind protection even outdoors in moderate conditions, and they caught a surprisingly small amount of the reverberation in the space out at the lake house.

The next test was to run out and get some ambiances with them.  For both of the following recordings I had the mics on the ground about 8 feet apart.

First up was a residential neighborhood at about 8 am on a Sunday. I eq'd out some of the low end to reduce the traffic rumble, and left the high end untouched.

Second was some rain out by a business park.  similar eq to reduce traffic rumble down low.  high end untouched.  Mics were vertical against a wall.

In both of these cases I got what was a very detailed but not very binaural sounding recording.  Very wide and flat compared to ORTF and XY techniques.

After all of this I certainly feel like my PZMs are underused in big percussive recordings, but I feel like I need to experiment more with placement to get the ambient sounding recordings working just right.  I could try jecklyn disk style back to back placement, but before I do that I need to place some of this stuff against picture and maybe try panning it around a bit in the surround field to see if I like what it's doing.

living vicariously - my friends trip to mexico

go ahead and hit play, then listen while you read.


Last month my friend Mario took the whole month off and traveled to the Yucatan Peninsula in Mexico for a vacation.

Before he left, he generously offered to take one of my recorders and roll some audio when he was down there.  Now, Mario is a brilliant chef but he's got about zero experience rolling audio so when he made the offer to take some gear down there with him I figured my Sony PCM M10 would be the best choice for a few reasons:

- The M10 has top shelf battery life.  I figured he'd need to change batteries one time max for the whole trip, and that's if he was recording a TON.  The more likely scenario was that he wouldn't have to change batteries at all.  Battery life on this device is the best of any that I own, and far superior to most others on the market.

- The M10 has the most storage.  It has 4 Gb built in, and another 8 on the micro SD card that I have in it.  The storage also rolls over seamlessly from the internal to the SD card with no user interaction required.  Thats an advantage it has over my PCM D50, and over many other handheld recorders on the market.

- The M10 doesn't require wind protection.  Sure, if it gets up to 15 mph or so it'll blow out, but south of that the built in wind protection works fine.  That can't be said of my D50 or of most other devices with exposed electret condenser mics.  In fact, my D50 often requires wind protection indoors, since even the slightest AC gust will blow it out.

- The M10 is about the size of an iphone, and can easily fit in a pocket.  Its about half the size of the D50 or H4n.  

-The M10 costs about $200.  If it gets destroyed for any reason I won't feel too hard of a loss.

So low maintenance, high capacity, super portable, and moderatly expendable.  I have higher resolution rigs obviously, but this is the only one I could really send out in this capacity with a non-audio guy as the recordist.

And oh man did Mario deliver.  I've only posted a small compilation of some of the stuff he brought back to me, but it really was impressive.  Mario took great pride in his recordings, he just nailed his gain structure and technique, and enjoyed taking some time in the various locales to just sit and listen to what was going on around him.

This horse was pulling a cart that rode on the railroad tracks.  He had pretty good speed too!

Great peacock recording right at the outset.

That's Mario on the right.

Even the traffic ambiances had a smattering of jungle creatures in them.  I love it!

I couldn't be more happy with how it went, and I'm super impressed with the quality that the internal mics on the M10 were able to deliver.

When an opportunity arises, you have to be ready to seize it.  The process of sorting out and listening through all of his recordings from that trip is one of the most enjoyable things I've done all year.

Thanks Mario!

quad miking dual MS update

So instead of running more controlled experiments with regards to my quad setup, I ended up with a quick and dirty dual MS rig out in the field this past week.

The rig consisted of a pair of schoeps CMC6 bodies with the Fig 8 capsule and the hypercardiod capsule making up the front portion, and a Line Audio CM3 rigged up for the rear M all inside of a big rycote blimp.  The schoeps mics went straight into a 744t 1-2, and the CM3 went through a sound devices M1 and into the 744t channel 3. 

The obvious compromise in this setup was the fact that all three capsules weren't exactly coincident on the vertical plane, and since the idea was to use the figure 8 mic as the S to decode both the front and the rear M mics, I was interested to see how well this configuration held up to scrutiny.

The whole rig fit into the rycote blimp very well, and when I took it out of doors the blimp still provided great wind protection to all three mics, since non were very close to the edges.  I generally monitored the schoeps rig decoded, but sometimes listened to all three mics in mono.

I took this rig to a local hospital to record ambiances for a documentary that we are working on.  I came back with about 3 hours of recordings from a half-day all access shoot, and got some really killer stuff (including a real live surgery).

Back in the studio, I decoded and evaluated.

I protools I decided to align all three tracks and mute them.  From there I sent the Schoeps MK41 (supercardiod) to bus 1 prefader, the Schoeps  MK8 to bus 2 and bus 4 prefader, and the CM3 to bus 3 prefader.

I then set two stereo aux inputs up - a front one fed by bus 1-2 and out to LR, and a rear one fed by bus 3-4 and out to LsRs - both with Waves S1 Imagers on them set to decode MS.

I was shocked at how good it all sounded.  Maybe some of the best recordings I've made in my life.

Imaging was spectacular throughout, the balance of direct to reverberant sound was excellent, and that $150 CM3 played so nice with the crazy expensive schoeps rig you'd never guess the price of that thing.  I didn't find the time differential between the CM3 and the schoeps MK8 capsules to present much of a decoding problem, probably because most of my sources were ambient and were sending as much reverberant sound to the mics as they were direct sounds.

Summing all three decoded mics to mono caused zero issues.  Summing this rig to mono effectively removes the Fig 8 mic from the sound, leaving only the sum of the schoeps mk41 and the Line Audio CM3.  Given that they were both aimed in opposite directions and recording ambient sources, the non-time alignment didn't do anything particularly strange or phasey.  It's possible that time aligned capsules would lock together even more tightly, but  the 2 inch or so differential was insignificant in this specific setup.

This is without question a killer rig to take into situations where you need to capture lots of surround ambiances while on the move.  I think I still prefer the spaced mic technique sound to this one when I have to luxury of setting it up and not having it change the vibe of the ambiance I'm recording, but honestly I only prefer that technique over what I got here a little bit.  Things didn't feel as "narrow" as they did in my initial dual MS test, and the use of the same fig 8 on both ends really locked the image down tight from front to back.

Color me impressed.  As I go through and edit the recordings more closely I'll find a couple of nice bits to post up of both the front and read decoded recordings.

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update: here are some choice decoded sounds from the shoot:

quad miking techniques and listening test

In anticipation of an upcoming quad sound library for echo | collective, I've been looking to build a specific quad kit for recording ambiances. 

I ran some tests to help in purchasing decisions that I'd like to share.  To hear everything properly, you'll need a DAW, an MS decoder and a surround setup.  Files are downloadable here.

I really like quad for surround ambiances - four mic perspectives really does give a very cool spacial perspective to ambiances, and for film work they drop into bgfx tracks seamlessly while leaving the center channel open and clear for dialogue and foley.

The biggest question I needed to answer before upgrading the kit was: is it better to run dual ORTF, spaced pair, or dual MS to get the most natural sound?

Each setup has its plusses and minuses outside of the pure sound of the setup, but I chose to evaluate the pure sonics first, and then use that as the jumping off point for any further decisions. 

The main thing I was interested in was in seeing how the imaging would work for sounds that move around within the ambient field.  If a bird or person or whatever moves from front left to rear right, I want the clearest imaging of that movement I can get.  Of particular interest to me is the way the different setups track movement from L to Ls or from Rs to R, as this is the trickier movement to track realistically.

I chose to use four Audio Technica 4050s to conduct the test, primarily because  I have access to four of these mics, and secondly because the AT4050 can switch from cardioid to figure 8, so that meant that I could objectively evaluate the setup on its own merits without having to compensate for listening to different mics for the diff setups.  

I also chose to record in our warehouse because I wanted to test these arrays in a reverberant space with a moderate noise floor, since that'll be the primary type of ambiance that I intend to record.

My methodology was a follows:

1. set up the mic array
2. run all 4 channels direct into a 788t, and set the preamps to 3 oclock.
3. no highpass, no pads, no limiters.
4. suspend a string on a mic stand directly above or in the center of the array.  This string will be used to keep me exactly equidistant from the array as I move around it.
5. record a pass of walking in a circle around the array while holding the string
6. record a pass of walking the same circle while counting
7. record a pass of walking the same circle while jingling some chimes
8. stop and setup the next array

 -----------------

First up was the dual ORTF array.

ORTF is defined as two capsules about 17cm (6.69 inches) apart and angled 110 degrees from one another. 

110 degrees adds up to 440 total degrees, so adhering to that standard would end up with the wide 100degree  front and rear angles and a more narrow 70 degree angle between the L and Ls and the R and Rs (if all capsules are equidistant from one another)

Since I was so concerned about tracking from front to rear and back, I decided to narrow the angles a bit and go with a more symmetrical four corner design.  here's the difference:

In the recordings, I found this setup to be very natural sounding, and to have the benefit of being relatively compact.  If I were using small diaphragm condensers I'd be able to pack a rig like this into a large blimp or a pair of blimps.  I could also custom build a square framed mic mount that could just pop on top of a single mic stand in an indoor environment.

Tracking around the room seemed to be very stable with this setup, if a little compact sounding.

--------

The second setup was a spaced pair.  

I left the angles of the mics at 90 degrees and set the mics themselves 6 feet apart at the corners of a square. 

In my final evaluation, this was easily my favorite sound.  the ambiance was super wide, yet the tracking across the various speakers was superb, and far more defined than the other, tighter arrays.  I could really feel where I was in the room, and at no point did I feel any holes or dropouts. 

If I have total control over a quad environment, this is going to be the way that I will record. 

-------

The last setup was dual MS. 

 I ran each M at 180 degrees from one another, and kept them relatively close to each other. 

After running the test, I came across this photo, which showed a dual MS setup sitting comfortably inside of a single blimp.

In that setup the rear M channel is slightly offset, so if you'd like to approximate that sound with my test, just decode the rear portion using the S from the front portion (discarding the rear S channel I recorded)

Here's what my setup looked like:

Upon listening, I found the dual MS setup to be the least satisfying.  The fridge in the room kicked on during this test, but I felt that after decoding it sounded even noisier than what the fridge added. 

The pattern was also super tight, and it was more difficult to track movement around the room from the distance that I was walking it. 

The dual MS rig is clearly the most convenient, but also the least impressive sounding of the three setups I tested. 

-------

In the end, I encourage you to pull down the files and listen to them to make your own assessments.  

After hearing the tests I opted for a quad cardioid approach rather than a dual MS one, and if I control things to the degree that I'd like, I'll be spreading those mics out very wide within the rooms that I'll be recording.

Quad four corners is probably the most cumbersome to setup, and it's impossible to do it stealth style, which is a shame because it yields what is to my ears the best overall results.  It'll be my default for quad nature recordings though, and for interiors where I have control over mic positions. 

When I need to have a smaller footprint the narrower four corners is a nice substitute for public space recording, and proper wind protection is probably achievable. 

I'm a little bummed that the dual MS didn't stack up better because that's by far the most convenient rig to put together (3 channels and it fits in one blimp), but I suppose that's why we do the tests.  :)

In the future I may run one more test where I place the mics in the corners of the room and walk the same circle inside of the mics instead of outside of the array. 

enjoy!

Neighborhood Dogs

One of my favorite things about the new collaborative way that the internet has brought us sound people together is The Sound Collector's Club.

TSCC is the creation of Michael Maroussas, and the basic premise is that all members pay a nominal fee to help with hosting the files, then each month a new theme comes out and we all go out into the world and record it, with each contributing member contributor getting instant access to the other recordings from the group.

Its an insanely cool way to beef up your library, because it has you out recording on a regular basis, and it puts you in contact with a group of great sound recordists from all over the world.

Its multiplicative recording.

So after some twitter riffing on themes a while back Michael had decided to roll with one of my favorites:Dog Barks-BGs

In my personal library I call them neighborhood dogs.

I have a moderate collection of these recordings, the first of which I made when out walking my own dog.  She's actually very good at staying quiet while others are going nuts, so for a few weeks I just went on my walk and brought my trusty D50.

They say that if you take a closeup photo of someone and put it across the room, that doesn't make it into a wide shot.  The same is true of audio, and the reality you get from recording the dogs in space like that trumps faking it every time.




Once I had a few of these, they went into immediate effect as I was cutting BGFX for various films and shows.  The texture of the dogs is really great to add a little bit of stress or drama to just about any urban or suburban environment.

Having individual dogs was nice when I could get them that way, because it allowed me to just kind of edit it in some drama in the gaps when I needed them.  They make great little punctuation marks on an outdoor scene.

They're also fun to establish and have going for a while, then pull them out to jolt the subconscious mind into noticing that they're not there anymore. 

BGFX are all about the one off elements, and neighborhood dogs are one of the more useful outdoor oneoffs you can find.  I highly encourage any sound people to record some dogs from a good distance, join The Sound Collector's Club, and share with the group!

recording my moto: the VTX1300

My motorcycle has been sitting for too long, so I'm going to sell it.

Anytime an audio person makes the decision to sell a vehicle the first question is always "have I recorded it sufficiently?"

In my case the answer was no.  I'd recorded the bike before, but I had never really given it the full treatment, so I rolled it to work last week and set about recording it after hours but before the sun set.

This bike is a Honda VTX1300 with aftermarket Vance and Hines big shot exhaust.  Honda's VTX line has a big, beefy transmission that clunks loudly when you drop into and out of first, and the big shot exhaust really does that distinctive chopper cruiser sound well.

Outside of those two main elements I didn't see much else on the the bike that I felt as though I could record cleanly and at speed.  Tires were pretty out of the question, as was any noise that my feet made on the gear kicks.  My plan was to find the best compromise of drafting placement and proximity to the transmission/exhaust for the onboard mics.

Drafting is a huge deal anytime you want to record a vehicle going faster than about 10mph.  Drafting is the concept of placing mics within the shape and structure of a vehicle in a way that minimizes direct wind exposure when the vehicle is in motion.  No amount of wind protection will stop an 80mph direct exposure to wind, but proper placement will allow for minimal wind protection to be sufficient even at that speed. 

Motorcycles are a little trickier than cars and trucks when it comes to this because they have less surface area on which to mount things and the bodies don't divert nearly as much wind around them, so drafting options are more limited.  This bike is pretty sporty and stripped down, which limited my drafting options further.

I decided to go with the following mic placements, wrapping each mic in a few layers of a cut up T-shirt:

• Line Audio CM3 behind the shock and near the exhaust
• Line Audio CM3 behind the engine block and aimed at the transmission
• Sanken COS11 lav behind the engine, under the seat for general engine bite
• Crown PZM 6D behind the license plate and near the exhaust.

here are the placement pix and isolated tracks of a 60mph run.

 

Of all of them, I feel as though I could have walked away happy with just the combination of the PZM and the Lav (which I almost didn't put up).  Both mics capture a ton of detail, and the PZM in particular felt like the gold standard of someone behind the vehicle moving at speed with a mic aimed right at the exhaust and no wind.  That mic just had tons of low end, and got the quick transient nature of the cylinders just right.

The CM3s acted a little wooly and took on the most wind of all the mics, though they were certainly still acceptable and in the end gave me some interesting lower mid punch that the other two mics weren't picking up.

When they all came together I just about came out of my seat because I heard for the first time a representation of what it really does sound like to be piloting that bike.



Everything is there.  The transmission kicks when I'm climbing the gears,  the whine as the engine lets up, the fluffy kind of release in the exhaust, and all of the power of that bike feels like its there.  The only thing missing is the wind, which is a pretty crazy experience given how intimate I am with the sound of this thing.

Its easily one of the best recordings I've ever made, and I feel like that PZM near the exhaust is going to be my new secret weapon when it comes to the exhaust portion of vehicle recordings.  That thing took zero wind behind about 4 layers of cotton T-shirt even at 80mph on the highway over a 10 minute ride I did the same day.  It was kind of magical.

I had my intern out helping me on the shoot, and he captured a perspective that I'm less familiar with: the exterior by.  He was running a 416 in a blimp and was tracking me as I passed.  These recording also came out great:



In all I got a full compliment of sounds from the favorite moto I've ever owned in about 3 hours of recording (including setup and teardown).

Things never seem to come together this well, so its important to sit back and appreciate it when they do.  Feel free to use these recordings in whatever context you see fit.

Enjoy!

contact mics and guy wires

Everyone knows that Ben Burtt made the blaster sounds in Star Wars by striking guy wires and recording them with contact mics.

Countless others have done this as well, but I needed to test out some new gear so I figured I'd give it a go.

Gear included my recently acquired Jez Riley French contact mics and my new Sound Devices mixpre that I bought to use as a front end for my PCM D50.

The entire signal path was:  doublesided carpet tape --> JRF contact mics --> Hosa MIT-129 impedance transformer --> mixpre mic ins --> mix pre tape out --> PCM D50 line in.  These recordings are 100% unedited (including gain changes - this is the level I cut them at)

re: contact mics, Tim Prebble has an excellent post outlining the entire process, but the long and the short of my setup was that the impedance transformers were absolutely required to get all of that low end out of my rig.  This is because contact mics are high-z sources and the mixpre is a low-z preamp.  In the past I've also had good luck running straight into an H4 with other contact mics, but I suspect that's because the H4 takes hi-z inputs by design.  With that said, I've never quite recorded low end like this with contact mics to date, so I was very happy with the result.

Also, I laughed a little when I saw that the BBC went into an anechoic chamber and recorded a few very tiny insects using these exact contact mics and preamps.  It's quite the testament to what they're capable of to hear them seamlessly running from centipede feet to the huge guy wire hits I got.

Here's that BBC vid (check out the contact mics visually at 2:00 and then the recording at 3:40):





Now onto my vids. First up are the guy wires.  The single most interesting thing that I discovered was that I could resonate one wire by striking the other, probably through some connection that they were making underground.  You'll see in the vid that they're not buried right next to each other though, so it's possible that the contact mics are actually just picking up sympathetic vibrations.  It's all very cool though, and there is TONS of low end, so crank up the speakers.

Again, this audio is 100% unaltered - not even gain changes.




Next up is the metal fence that was nearby.  I did some similar stuff where I was striking the surrounding objects and getting indirect vibrations, which was pretty cool.  The distortion sound in one of the channels isn't clipping, its the effect of the sticky tape losing its grip.


And for fun, here's a 96k downloadable soundcloud vers of the guy wires.  Enjoy!

slingshots and dishes

I have a project in the house that requires the creation of a ton of bullet impacts, and while I'd love to do what Frank Bry does and go record some targets shot up with custom subsonic ammo, I don't have the resources to get that done for this specific project.

I had to get creative for many of the surfaces, using a rockhammer and a mobile rig for many things, but for the glass impacts I found myself with a slingshot, a stack of dishes and about 45 minutes in an empty warehouse to get the sounds I needed.

Since the warehouse wasn't onsite and I knew I had limited time, I decided to roll with the venerable Sure VP-88 and a 744t as my rig.  The VP-88 isn't a great ambient mic because of its relatively high self noise, but it works great as a spot fx mic when the preamps are going to be at 12 o'clock or below, and I wanted a stereo rig that would be quick and easy to set up and tear down.  I set the pre's down to zero with no pad on the 744 to leave enough headroom for the close miked impacts I was setting up to record.

I needed the sounds to be able to pass for outdoors, so that meant I had to dry up the verb in the space as much as possible for recording.  I also needed to contain and direct the debris to keep myself safe and keep cleanup quick.  I solved this by building a little pup tent using packing blankets and laying down a cheap plastic tablecloth on the floor with a light layer of sand.   I also placed a board against the wall as a backstop, and angled it away from me so that any projectiles that hit it directly would (hopefully) direct away and into the side of the tent.

I protected the mic by placing it behind a heavy wooden box that was holding up the left part of my pup tent, and just poking it through the packing blanket.  Next I set up the plates.

 Not the best picture, but you get the idea.  I stacked several towers of glasses and dishes with the intent of getting as much peripheral debris as I could when stuff fell down.

I also ended up with a happy accident regarding ammo, since my original intent was to buy solid metal slingshot ammo for the recording.  It turned out that I didn't have time to make the purchase before I had to record, so I opted for quarter sized rocks from outside. That ended up being the superior choice though, because the rocks tended to shatter on impact, and if they didn't do that they would riccochet and make generally interesting whizzing sounds on their own.

20 minutes of recording yielded these final results and a few others: (these sounds are unprocessed except for MS decoding and some slight limiting)


In the end, I was surprised by how happy I ended up being with both the noisefloor and the debris detail I managed to get.  I didn't get the warehouse verb all of the way out, but layered with an ourdoor ambiance those sounds will play.

I also don't think the soundcloud conversion does these particular sounds justice, so feel free to download them to really hear what went on there.

Here's the aftermath:

death of the D50?

So a SSD thread today brought to my attention the apparent death of the Sony PCM D50.






I commented in that thread, but I figured I'd elaborate here.

First off, this may just be a weird Sony play to phase out the D50, since it still seems to be listed as available on the pro website:



With that said, its a stark reminder that these things exist at the whims of massive multinational corporations and can be taken from us at a moment's notice.


I can guess what's happening: the PCM M10 is eating up up all of the D50s sales.  Its $200 cheaper, the mics sound better than a lot of the non-D50 market, and the battery life/recording media options are actually superior to the D50s.

IMO, handheld recorders are all about the built in mics, and that (along with the battery life) is where I feel the D50 run circles around the rest of the market.   The primary function of a device like this is to make a good impromptu or low profile recording using the built in mics.   If the D50 is indeed on its way out, I think its a shame because I feel like the D50 is the only handheld recorder in the sub 1k range that has very good internal mics. 


This is not to say that the mics are particularly quiet or neutral (because they're not), but they do a better job than the others in the market at getting something that sounds good and usable in a variety of contexts, and they'll beat the M10's internal mics in most applications.  I've made tons of recordings with my D50's built in mics, and used them in countless projects.  The device is particularly useful for stealth crowd recordings.

In a larger context I'd pay a heck of a lot for a handheld recorder that was made up of Line Audio CM3s for mics, a Sound Devices front end like the mixpre, and an interface and battery life like the D50.  

anyone?

Bueller?