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CAD U37 USB microphone multi-tracking on windows, latency fix

March 17, 2012

Latency, if you’ve ever tried to multi track on this usb microphone you probably noticed this annoying problem, if not, lucky you.

A quick test to show you why out-of-the-box the CAD u37 fails at muti-track recording…

Ladies and Gentlemen, start your DAW,

Arm an audio track and record a few 10’s seconds of finger clicks (this is a mechanical process, you click your fingers and feel like a real hip cat) with the U37..

Arm another track and while playing back the first track of finger clicks (the sound comes from your speakers), record the playback with the microphone on the second track.

In a real recording situation when you play these two recordings back they *should* be in sync (maybe a little phasing), but wait a minute, what the…

Adobe Audition - CAD U37 Latency

Adobe Audition – CAD U37 Latency

That is some damn horrible latency… CAD completely suck for not mentioning this fundamental flaw, yes I know it’s a prosumer microphone, but for demo’s on a laptop this could have been a killer mic… this is where most recording musicians give up on the mic, and rightly so.

The sample size has very little effect on this, as it is set to the lowest setting – 512 samples, still a whopping amount latency.

Well it turns out that http://www.asio4all.com/ works really well with this microphone.

I had to use the super advanced settings to have my nasty internal sound card handle playback while the usb mic also gets handled via ASIO.

Realtek *High definition Audio* my arse!

Redo the test above, now that’s actually fairly usable, there is still a little bit of latency but good enough for a demo or two.

The extra noise on the first track? I opened a door, it is wind noise, I live in Wellington, It’s expected phenomena for this locale.

To use Asio4All you actually have to select it as a driver (in Audition, probably the same in other DAWs), the writer of this bit of software Michael Tippach doesn’t have a donate option on his site so if you ever bump into him buy that man a beer.

I’m not addressing monitoring, for me when I want to make a demo I don’t really care about hearing the live room in the headphones, I’m sure you can work it out.

Why didn’t CAD put a jack on the side of the microphone for monitoring? I mean it’s got a full c-media sound card in that plastic case, I might see if I can hack-a-day one into this so that I don’t have to have a mix of sound cards (internal and USB)

The sound quality of the microphone at the price and portability is good to very good, can’t beat that bus powering… don’t even attempt to compare it to a real pre-amp and microphone though, they are totally different contexts, if you can’t use the u37 because it isn’t Neumann into Neve then you are missing the point.

The driver for the microphone being PnP installed is pretty stable and that c-media is about as well established as a sound card can get. At the price – zZounds have them for $47 USD, although no international shipping – 3.5 out of 5 stars from me, because you must cock around getting it to go properly and because CAD has no obvious forum/support or ASIO drivers for it. Still not as bad an experience as when I brought a Lexicon Core 2 new just before Windows XP came out, but that’s another story!

Try it out yourselves, results may vary

 

*UPDATE –nearly two years later*

So one of the commentators hit me up this week about my loose hack-a-day comment (adding a jack)

pin 30 & 32 are lineout of the CM119 chip

wire

jack

 

 

 

 

 

 

 

I know the wire is not shielded and about a million times too big… it’ll test your soldering skills, it is fiddly-freakn’-diddley..

top blue in picture is the earth, bottom blue is the left channel (pin 30), (right channel pin 32 is not in photo), soldered directly to the jack…

Now there is no problem with the playback audio (via the mic sound card) syncing with recorded audio, finger clicks below are all good enough for government work. It is a mod that I’d highly suggest if you have the soldering chops, I can imagine times when the tripod might take a topple due to the headphone lead, but really this should have been baked in at the factory, it would have put about 50 cents on the BOM… maybe CAD thought it was less ‘pro’ to have an audio out on the mic, maybe the idea of tripod topples and warranty??

Capture

 

 

 

 

 

 

 

 

Almost wasn’t going to do this mod, currently for demos I use iPhone 5 and the AudioTools app –more than enough for demos.. then again an iPhone is horrifically expensive.. ‘AudioTools’ can remove the HPF and help with the in built compressor/limiter, just needs a pad :)

 

 

 

10 Comments
  1. Hi there. This is very helpful. I bought the CAD U37 to use for recording in garageband. As you can imagine, the latency problem is out of control. I thought about upgrading to Logic Pro but I don’t believe that will actually fix the problem. I’ve tried to download the asio4all driver as you suggested, but I can’t get it to open even after I compress the file. If you have any suggestions, they would be greatly appreciated. I’d love to find a solution to this without having to return the microphone, because that is unfortunately the next step. Or maybe you could suggest a better microphone for multi-tracking that is still under $100?

    Thanks,
    L

    • Sorry for taking so long to reply ( that’s like a year and a half) * insert excuse here * I’m not too much of a mac user, the mic works ok on Linux, maybe you can use Alsa on a mac? But, to even comment I’d be getting into areas that I know very little about, sorry

  2. Dmitri permalink

    Hey, very interesting! And what about your hack-a-day for putting a jack on the side of the microphone for monitoring? I would like to do that….

    • I’m probably the worst blogger in history :) too many projects… I’ll get back to you about the mods.. Looks fairly straight forward enough but as the mic proves, you can never really tell about latency

    • ok, I opened the case to have a squiz…

      CAD U37

      it looks like there is enough room to mod, here is a nasty fuzzy photo of the chip:

      The Chip

      That’s a CM119, here is the datasheet -> here

      The chip has ‘modes’, it is most likely in ‘L:Headset Mode: Playback & Recording’, the other mode is speaker mode.. pin 30 and 32 are L/R Line Out Channel.. I’d say you could whack a jack on those pins for an experiment. If you attach the mic to other equipment i’d add a blocking cap for any DC. Check how much power is being used on the USB bus too..

      looks like the chip can do volume up/down HID and spdif… no big thing really..

      looking at the graphs of the playback it’s no good after about 10k, but the other specs on that chip aren’t too bad for a cheap ic.

      • Dmitriy permalink

        thanks for the information dude, unfortunetely know nothing about the electrinics, if you know how to do that in pictures, than it would be perfect, if you do not- than dont bother….

      • I think I’d need a better camera for the photos, phone and macro shooting is the pits.. It really is as simple as what I’ve said at the end of the main article, the soldering skills! That’s the tricky bit, well tricky for me at least, I’m no surface mount guru

      • Dmitriy permalink

        good, if you finnaly make this jack, please let me know… i really need to hear my voice while recording… it is convenient.. if there is no way out, than I have to collect money for the new mic … by the way, could you advice me hardware and software for producing voice over? i try to voice over movies from english into russian

  3. I am about to give this mod a shot. From the datasheet, pin 30 looks like it’s in a different spot than where you soldered your wire. Am I looking at the chip in the wrong orientation?

    • When I hacked that wire onto the chip it worked pretty much as expected, there is a small possibility that things change between revisions but, like I say it’s a small likelihood. In terms of pinouts the chip has a little dot in one corner that you can align to the illustration in the specs, normally the dot is by pin 1 (not always)

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