Reducing high latency when recording music on a laptop

February 16, 2010 3:39 PM

What factors cause high latency when recording music using a laptop, and what can I do to decrease it?

I've been recording music onto an old laptop (HP Pavilion running Reaper on WinXP, ~1.2GHz processor, around 300MB RAM, about 6 years old now) through a Behringer UCA202 USB interface. This has been generally fine just for recording, particularly as I'm not recording more than one track at a time, but there's the odd pop or skip in the recorded music, and the latency in the signal coming back from Reaper is completely useless for anything live.

I'd like to get the latency down to manageable levels for live music, if that's even possible (and I recognise this may mean getting a newer laptop, something I've been considering doing anyway). What are the main steps I can take, which bits of a computer are likely to be providing the bottlenecks, and what are the limiting factors in terms of hardware/software/drivers that I should be concentrating on?

(One extra detail: the audio interface shows up in Reaper as a DirectSound object, called "USB Audio Codec". I've heard that ASIO drivers are faster, but nothing shows up in the list of ASIO devices.)

posted by ZsigE to technology (6 answers total)

Did you install a driver for it? You can get that on the website.
posted by AlsoMike at 3:44 PM on February 16, 2010

Reducing your audio buffer size should reduce latency, but may introduce artifacts if taken too low. But this may be an ASIO only solution.
posted by sourwookie at 3:52 PM on February 16, 2010

Naturally, it could be that despite all your tweaking, it won't be powerful enough.

However! I own a Dell Inspiron 1501 - it is about 3 years old. I could hardly get it to do jack without latency... when I used an interface like the one you're using. I think mine was emu. I forget. Which is not to say that cheap does not = good enough, often, BUT. I purchased the Kore 1, which has a built in 24/96 interface along with all of its other bells and whistles - and it is specifically designed only for USB 2.0 Now I can use the Kore software, and or record stuff with it, and or use softsynths with very little latency. (Not all at the same time, mind you).

So

1. the interface could potentially be too junky, no matter how 'low latency' they advertise it as.
2. If you are using usb 1.1, that might be a problem.

There may also be the option of attempting to use a cardbus card if your notebook has slots for those... dunno who makes them right now that are any good. In any case, if you didn't want to buy a whole new notebook right now, I'd see if maybe you could find devices you could try out (and then return) if they didn't do the job any better than what you already have.

Finally: you can try disabling a whole bunch of Windows services that you don't need in XP, via Black Viper's damn thorough 'which services can I disable for performance gains?' pages. I have been disabling services in XP like crazy for years, and it makes a signficant difference, especially on older machines.
posted by bitterkitten at 4:02 PM on February 16, 2010

At the bottom of this page Behringer supplies ASIO drivers. It's not a stellar interface, but they do work.

There are a ton of articles out there on tuning XP for audio performance. Be sure to kill any apps not absolutely necessary when you're recording.

Audio recording doesn't require a ton of horsepower, and reaper has very low requirements. I use an ancient Shuttle PC, a little older than your laptop, with Reaper to record 8 tracks at high bit/sample rates without any issues, albeit not using USB.
posted by jjb at 4:40 PM on February 16, 2010

The driver is the single most important factor.

You should select the ASIO or WDM style of driver in the recording program. Then the driver itself must be good. As noted above, try what native drivers Behringer offer. Then the universal low-latency driver ASIO4ALL is pretty good too. Try it and see.

The program you use has some impact too. Native Instruments' apps are very good for latency, some are less well programmed. Might want to experiment with different apps to see where the culprit is hiding.

You WILL be able to get the latency down to very reasonable low levels if you spend some time on it.

And I must say that Macs generally have less problems with latency. 10ms or less on the built-in interface, which even sounds OK.
posted by krilli at 4:53 PM on February 16, 2010

Installing the ASIO divers from Behringer made a massive difference - that's easily good enough to use the laptop as an effects box with Reaper. Thanks, guys! Now my only complaint is that I don't have much excuse to buy a new laptop...

Mobius still has very high latency (and can't get the levels right either), so live looping is still out, but I suspect that might be Mobius being a bit rubbish. On the whole, that's much much better, so thanks again.
posted by ZsigE at 3:49 PM on February 17, 2010