(There’s a shorter version of this on the Tape Op blog.)

I’ve recorded a lot of very loud bands — including my own — in cramped practice spaces, using a mobile rig that I bring in for tracking. It’s a challenge, but it’s kind of cool. And laptops have gotten powerful enough that even older ones can loaf through a 16- or 24-input session.

But a few years ago I started getting bit by a nasty problem: intermittently, my DAW (Cubase) wouldn’t stay in record for more than a few minutes. A few minutes into a take, Cubase’s hard drive performance meter would freak out, then I’d see a “Too many tracks recording” dialog as recording stopped. This is the Nuendo version of the same dialog, but you get the point:


This really rattled me — how can you focus on what matters if you’re always worried about your recorder failing? — and it was hard to track down the cause. I had upgraded some hardware and software on my laptop, and the problem was very intermittent. But it always seemed to happen during real takes (ugh).

Steinberg support said it was probably the 5400 rpm drive in my old Thinkpad. I know you’re all saying “Of course! You can’t record with a slow HD!” but I had used a 5400 rpm internal drive for many sessions prior and never once seen a glitch.

But one or two fucked up sessions later, I gave in and upgraded my 7-year-old Thinkpad to a fairly recent Macbook Pro. You can’t have something like this threatening to ruin sessions.

And during my first session with the new machine, I got The Dialog. I felt sick. What the fuck?

I borrowed another Macbook Pro for a session and saw it there too. Three computers?!? Maybe Cubase 4.5 was a dog, or RME’s drivers had somehow regressed. My gut, based on 20 years as a professional computer nerd, told me it was neither, but you never know.

Here are some suggestions I got from friends, the internet, Steinberg support, etc: Never record to the OS partition. Never record to an internal drive. That’s what you get for using Cubase. Try trashing your preferences. Try adjusting the pre-record time in Cubase. I was sure that none of these was my problem. Three computers and two OS’s? Something was just wrong.

I couldn’t repro the problem at home, ever. I was usually recording 18 inputs, which should be a piece of cake, but I also saw it with 2-3 tracks sometimes. In certain sessions it never happened. In fact it sure seemed like recording only crapped out while really loud things were going on nearby. Wait a minute…

I started googling with the “loud sounds” thing in mind, and found a few forum threads mentioning the same problem. Eventually I found this Apple support page: Apple Portables: Advanced tips for Sudden Motion Sensor. Here’s the money excerpt:

In some environments, such as live concert halls, recording studios, or dance clubs, external vibrations may be major enough to cause the module to unexpectedly park the hard drive heads, resulting in interrupted sound or video playback.

Bam. That would explain everything. The SMS is there to prevent your hard drive heads from bouncing on the drive platter if you drop your computer. High SPLs can trick the accelerometer into thinking that the machine is being dropped. The protection system parks the hard drive heads, and recording is in trouble.

It turns out that Thinkpads had a similar feature, though not all hard drives supported it. That would explain why I didn’t have any issues with my Thinkpad’s stock HD, but did after upgrading it.

Now, learn from my pain.

How To Disable the Sudden Motion Sensor on OSX 10.4 and up

  1. Start Terminal (in /Applications/Utilities)
  2. Type sudo pmset -a sms 0 and hit enter
  3. Enter your administrator password

To re-enable: sudo pmset -a sms 1

I let Steinberg support know about this; they hadn’t heard of it before. Avid’s optimization guide covers it: “If you’re recording in a loud environment, this optimization will prevent the Sudden Motion Sensor from kicking in and throwing a -9073 error in Pro Tools.”

It’s interesting, the “common sense” problems were not the problem. Recording to an external drive probably would have masked this problem, but also probably would have led me to wrongly conclude “yep, internal drives / OS partitions are no good for recording”. My personal feeling is that a lot of these well-known tweaks are folklore left over from the early days of digital recording. They may still matter if you’re trying to get 2ms latency with 80 inputs, but not for tracking 18 inputs of 44.1/24 with no plugins or latency concerns.

Anyways — if you always record in a control room, or if you use a desktop machine, this shouldn’t affect you. But if regularly have 500 watts of pissed-off tube amps pointed at your laptop, this may save your session. I’m still testing, to feel 100% sure that I have a fix, so please report back.

Here’s the last time it hit me. My laptop was three feet in front of the Marshall cab.

KWC TTJ pano

Bonus trivia: when the drums abruptly cut off at the end of “Yowie”… yeah. We said fuck it and left it.

2 Comments so far

  1. Vince Allen November 5th, 2011 8:39 am

    how would i go about fixing his on a windows/pc based laptop? thanks for any help.

  2. gse November 5th, 2011 7:17 pm

    Depends on the specific hardware. I mentioned the Thinkpad one: