The Null Device Blog

Friday night was the late-night, barely-controlled chaos that was a Caustic show.  I mention that merely because I was rocking the theremin and some keys for that gig.  I also mention that because it meant I didn’t get home to sleep until well after 2am.

Ordinarily, a Friday night gig would just mean “sleep late on Saturday.”  This however was not an option, because bright and chipper on Saturday morning I had a carnatic classical trio coming by to record.  It was an unusual configuration, too – saxophone, mridangang, violin, and the omnipresent electronic tampura/sruthi box.  (I offered to delve into my surprisingly vast library of tampura samples, but they opted to pass.

Over the course of two days, we recorded well over two hours of music.   They played as an ensemble, which meant I had to be diligent with my microphone choices and positioning.  Also, because there were six inputs and my ULN2 only has,  well, 2, I had to do some fancy routing and device aggregation in order to get everything set up and sounding good.  These guys had to play as an ensemble, so I couldn’t simply isolate and multitrack them as I do with my own stuff.

These guys came in from parts distant – the sax player was from north Chicago, the violinist from west Chicago, and the mridangam player was from Washington DC.  I was referred to them as someone who could record carnatic music for a reasonable price and not screw it up, I guess, but I had to keep asking in slight disbelief “uh, you guys know that this is just a room in my basement, right?”  I can see people coming from, say, Milwaukee to record in my basement, but Chicago?  DC?  They apparently were fully aware of this and wanted to go ahead anyway.  It could be my remarkably affordable prices.

What follows is a technical description of what went down, merely because I lack the appropriate music theory to describe what happened musically.

I slaved my old trusty MOTU 828 to the ULN2’s clock, which significantly improved the performance of that box.  I also attached by dbx tube pre to the ULN’s SPDIF and clock-sync’ed that too.

The mrid got a pair of 57’s, run into the 828.  57’s are always reliable of percussion instruments.  They were perhaps a little dark and dense on the treble head of the drum, but they still got me a reasonably decent fidelity on the attack/decay range.  And because they have such a forward pattern with good side rejection, I didn’t get much crosstalk between the two mics, or from the other instruments.

The sax got the Oktava.  Sumanth had specifically requested a rather dark sound on his sax, so the combo of the Oktava and the dbx tube pre was a natural fit.  It was pretty warm and punchy by the time it was all recorded.  The mic was a little gainy, so I did get some “room sound” off the mridangang too, but that was to be expected.  If I’d had a good ribbon mic, that probably also would’ve worked really well.

The violin was the toughy – seeing as it’s a much quieter instrument than a saxophone or a drum, and full of all sorts of crazy harmonics, I had to be pretty careful where I put the mics.  I used the pair of Pulsar II SDC’s that I keep around for just such things.  Since I happen to have a violin, I did some experiments with configuration, and skipped doing my initial x/y stereo placement in favor of an almost guitar-like arrangement – one mic pointing at the f-holes, and the other aimed towards the neck.  The biggest challenge was keeping the mics far enough from the violinist so he could actually play, but close enough that they would get good signal and not pick up every stray noise in the room.    I ended up with a bit of a compromise – I got strong signal but still got some spillover from the sax.  There’s only so much I can do about that, short of throwing up some gobos – but then the instrumentalists wouldn’t be able to see and hear each other, which defeats the purpose.  I ran the mics into the ULN so I could up the gain pretty high without too much noise.

Some of these pieces ran upwards of 20 minutes, one coming in close to an hour, which meant to fix things there was a lot of punch-in/punch out and clever crossfading between takes.  They specifically requested a spacious sound, so I’m judiciously adjusting the panning and reverb settings to get it nice and concert-hall-y without being swamped by deep ‘verb.  I’ve still got some more engineering to do on this yet, but it’s sounding pretty good so far.  These guys were pretty serious players, so that helped an awful lot.

I also learned once again that curious kittens often hamper the recording process by headbutting microphones or deciding to get chummy with  the percussionist in the middle of a take.

Recursions is almost done.  I’m in the process of getting the final masters together.

It occurred to me, with a bit of prodding from Matt Fanale, that I’ve never actually talked about what mastering really is.  I’ve blogged passionately about what to do and what not to do, and what gear is good, and what gear isn’t, but…I’ve never actually said what it is and why it’s important.

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My Oktava 219 arrived yesterday afternoon, back from Oktavamod.  It was great working with these people – they kept me informed every step of the way.

I haven’t had a ton of time to really put this mic through its paces, but I did want to hear what it sounded like, compared to my Rode NT2.

It’s…really different.  The Rode, being designed to be an “airy” mic, has a lot of top-end.  Sometimes this is very nice, particularly with female vocalists.  But it can be rather “eshy” and brittle too, and lacks punch in the low mids.

The Oktava, on the other hand, is a much darker mic.  It imparts a very warm, punchy character to the material.   It makes my voice sound pretty damn good, I’ll give it that.

As a little experiment, I set up the Rode right next to the Oktava, plugged it into input 2 on the ULN, linked the trim settings and set the preamp characters to neutral.  Then, I sang.  The difference is very audible.

Rode NT2

Oktava 219

Given that, back in the late 90’s when I bought the Rode, I paid somewhere on the order of $400 for it (it was before the explosion in low-cost condenser mics), and the Oktava I managed to snag on ebay for a whopping $70 + the $270 charge for the mod…well, the Oktava ends up being a simply fantastic value.  The Rode is by no means a bad mic – particularly since it has a multiple patterns, very low self-noise, etc.  But for my own vocals?  219 FTW.

I do wish I’d kept a few sound files of the Oktava before the modifications, though. It really is an entirely different beast now than it was before.

I’ve been watching the eBay auctions – the trick seems to be to get the 219.  The newer 319 has a nicer-looking Neumann-style cylindrical body.  Because of that, they’re in higher demand and seem to command higher prices.  Given that the capsule design is identical to the 219, I don’t know if there’s much advantage in the 319.

The OktavaMod people also do other mics, not just Oktavas.  I’m half-tempted to buy some cheap ribbon mics and let Mr. Joly work his magic on those at some point.

I’ve been doing a lot of research on this topic, as every studio move I make means I have to re-treat a room.  So I’m getting decent at doing this, usually on a budget.

What I can’t stress enough is just how important even just a little acoustic treatment is.  Good acoustics can make the difference between a crappy recording and a good one – the best mics and monitors and consoles won’t help if there’s no way to know if the sound is accurate.  A lot goes into it, but it’s not a tremendously complicated thing to do.

Acoustic treatment is not the same as soundproofing.  Soundproofing gets you sonic isolation, and is another important facet, but not as critical to mixing and recording as one is often led to beleive.  And most acoustic treatment products have little effect on the overall sonic isolation of a room – if you live in an apartment, hanging acoustic panels will not keep your neighbors from hearing things.  Only heavy mass and airflow management can do that.  Acoustic treatment may help with the neighbors a bit, inasmuch as you won’t need to monitor at high volumes to pick out detail.

The first instinct of a lot of people, myself included, is to start by buying a mess of cheap eggcrate foam and lining their room with it.  That sort of soft batting does manage to do things like dampen slapback delay, trim reverb etc.  Unfortunately it’s commonly used as a panacea, and as such the room ends up oddly anechoic with a lot of high frequency damping but no low frequency management.  This isn’t going to help much – it’s a false sense of security.  Also, most cheap commercial eggcrate foam doesn’t absorb an especially broad range, so it may just cut some slapback but not even control midrange.  A few strategically-placed pieces of real acoustic foam or acoustic paneling, available from a lot of places online, will help a lot more than dousing the room with cheap eggcrate.

The first thing anyone who has a project studio should do is position, adjust, and decouple their monitors.  Make sure that the tweeters are pointing towards your ears, equidistant from your head, from your normal sitting position.  You don’t want them too close to you – that approaches mixing binaurally with headphones, which opens up loads of problems.  Make sure there are no surfaces the speakers could reflect off of on the way to your ears – setting them way back on a desk ofent means there’s going to be sound waves bouncing everywhere and that can lead to phase cancellation, comb filtering, and other ugly sonic smears.  Easy way to check is with a hand mirror – if you put the mirror down someplace and you can see from your normal seat a reflection of a speaker cone, that spot is a possible reflection point.  Speaker stands help with this, as do desks with multiple levels, so you can elevate your speakers to a point where they’re too high to put you in a reflection path.  Finally, decoupling your speakers from anything that can resonate is a good idea.  Heavy, sand-filled stands are a popular option, albeit an expensive one.  Industry giant Auralex makes MoPads, some molded foam pads that act as shock absorbers.  There are other varieties of this, ranging in price from $20 to a few hundred, but even a few simple pieces of squishy packing foam can work well – just something so when the speaker vibrates, it doesn’t make your workspace or your floor vibrate too.  I’ve heard of people trying to hang speakers from the ceiling to decouple them, but that’s not generally a good idea unless they’re heavy enough not to drift any – the kick from the woofer can push the speaker a few milimeters around, causing minor changes in phase and angle at a nearly constant rate.  This would negate the benefit of any decoupling, and probably make things sound worse.

Bass traps?  Bass traps.  BASS TRAPS!  No room used for mixing or recording should be without them.  The corners of any room are going to be death for accurate monitoring – they reflect low frequency like mad, set up phase amplifications on some low frequencies and damp others.  It’s bad.  Bass trapping isn’t difficult to do.  There are numerous decent commercial solutions – Auralex LENRD corner traps are pretty affordable, the stuff that the guys from RealTraps is without equal (the owner, Ethan Winer is an authority on studio acoustics who is kind enough to publish vigorously on the internet and moderate a number of studio acoustics forums), there’re some decent cheap ones from Acoustimac, there are a bunch of free plans on the internet for building your own fancy resontant-cavity traps.  You can DIY bass traps low cost with a few slabs of Owens-Corning 703, 705 insulation or Mineral Wool wrapped in burlap.  Even more cheaply, albiet not quite as effective, is a giant cardboard cement mold tube (get ‘em at home depot for about $4) packed with fiberglass insulation and sealed on both ends.  Take any one of these solutions, stick them in room corners (especially the corners behind your monitors) and it’s amazing how quickly and dramatically the bass response on the monitors tightens up.

Diffusion vs Absorption always comes up.  There are tons of products on the market that are foams or panels or suedes or fabrics that promise sound absorption and control.  No sound absorber is perfect, though,  so some sound is likely to get through and bounce around.  This is particularly problematic in the area directly behind the listener.  The answer there becomes diffusion – setting up something to keep the sound from reflecting directly back, scattering it in multiple directions.  There are a number of commercial diffusers, and many are quite attractive as wall art.  However, all a room really needs is something that takes up a lot of space, has different depths and angles, and a little mass.  The easy answer is furniture.  A bookshelf makes a remarkably good diffuser – the different depths of the books (plus the absorption factor of a lot of papery mass) and the shelves works well to diffuse random reflections.  Plus it can hold all your myriad software manuals and books on mixing.  If it’s big enough, a couch can also work, and that can provide absorption as well (and a place to sit) although usually they’re too low to offer enough help.  Even randomly hanging different-sized pictures on the back wall can assist (but the bookshelf works better).  The trickier bit is on the ceiling.  Diffusion or absorption over the workspace can help reduce reflections and smear.  Obviosuly, mounting a diffuser overhead is no mean feat, and you can’t put a bookshelf there.  A cheap solution I’ve seen is to use a thin piece of plywood, bent so that it’s a convex surface, hung from the ceiling.  Thin plywood can be tensioned with cheap steel wire so that it holds its shape, or it can be forced into a frame to hold it there too.  That will help diffuse reflections enough that there shouldn’t be much reflective interference.  Some sort of absorption above could work too.

Most sources I’ve come across recommend treating about 30-40% of the available wallspace.  That’s sort of a mixed bag for most project/home studios – it can be expensive, and there’s the mere fact that this room is not a single-purpose control room, usually.  Often it’s used for recording, mixing, mastering, rehearsals, and so forth.  For something like recording vocals, it’s often nice to have a more “live” -sounding room to add a bit of natural space or air to the recording that a reverb can’t provide.  And not everyone has a perfectly rectangular, purpose-built room at their disposal that’d be easy to treat.  And some people rent, meaning bolting a few inches of OC705 to a wall is not an option.  And, honestly, for those of us who don’t have a separate set of midfields and mains for previewing, just some simple treatment and bass management is enough.  I’ve seen other more modular solutions as well – I once knew a guy who had a very dead room for most of his recording (back in the days of the 4-track) and he kept a big slab of plywood in his garage that he’d put on the floor before he did any vocals, allowing his dead room to temporarily liven up.  Flexibility seems to be the key.

Isolation can be nice for recording a mic, but everything needs to be isolated – including any headphones.  I’ve come across many vocal takes from people where you can tell they spent a lot of time isolating their vocal booth but the headphone bleed is painfully obvious.  Vocal booth isolation is only really necessary if the engineer wants to monitor at the same time, or if there’s a lot of extraneous background noise.  Over-isolate and the vocal takes can sound strangely flat.  Really, what a good recording space needs is some degree of modularity – depending on the singer or instrument mic positioning is going to vary as is the mic’s position within the room.  Things like RealTraps Portable Vocal Booth or sE’s ReflexionFilter are meant to prevent dicretional sound sources (vocals, instruments) from transmitting past and subsequently boucing off the far walls.  They can be used behind the singer/instrument as well to prevent room sound from affecting the recording.  These things do cost money, though.  A simple and time-worn technique is the “wall of mattresses” or “blanket on a clothesline” – some big, heavy, soft material is suspended near the mic to deaden early reflextions or room sound.  This is of course only if the sound needs it.  If the room already sounds great for recording, there’s no reason to mess with success by adding a fancy isobooth contraption.  You can convert a bathroom or a closet or a spare room into an isolation booth, but that’s a double-edged sword – unless the acoustics are right there, too, the vocals will end up sounding like they were recorded in a closet or bathroom.  And of course when dealing with amps and all that, the rules all change, but I’ll leave that for a guitarist to detail.

Acoustics.  Useful stuff to know.

Actual screaming teenage girls.

This is…new.

This was the first non 21+ show we’ve played since the Burnsville Debacle, so it was a chance to play to an audience that hasn’t already seen us play 600 times.  This resulted in a knot of people in the audience who were very enthusiastic about our performance.  VERY enthusiastic.  Given that the “act” we were opening for was the return of the Rocky Horror Picture Show, there may have been a bit of a predilection in the audience toward enthusiasm.  Hey, we’ll take what we can get.

I can’t cast any aspersions – they bought CDs!  About 5 of them raided my merch bin and bought a whole mess of stuff, so I’m exceptionally pleased with that. 

Everything ran well from the laptop.  We had our dry vocals pumped through the monitors, wet vox front of house, submixed synths/backing (which the FOH guy still had a bit too low – the standard peril of an electronic band), all our monitor levels seemed pretty good (and now that I’ve got a dedicated mix bus for that, I can do funky in-ear things someday).  We did have one Audio/MIDI sync error popup during the last track but there were no ill effects to that.  I should probably set my buffer up from its current 128 samples to something a little less…dangerous.  The latency at 512samples is likely well outside the range of human detection.

Only major technical glitch was that sometime during the show, the set screw on my 58Beta fell out, leaving the xlr assembly dangling dangerously.  I’ve got some replacement screws on order.
In other news, I finally finished my Xuberx remix this weekend – I’ve been promising it to those guys since December.  It’s…different.  For one thing, it’s an effective 59bpm, and it’s all dubsteppish.  With violins.  It gave me a chance to mess around with running the fiddle into the ULN-2’s high-z inputs, and oh my god does that sound nice, especially with the character plugins giving it a bit of extra warmth.  Some effects-chain tweaking with  an ampsim and some reverb gave me the L. Shankar-ish tone I was looking for.  Now that I can get good electric violin tone again, I can record more violin parts.  All I need to do is, uh, write some non-crappy violin parts!