Is my MicPort broken?

[A.J. Hamler]

I'm having issues with my MicPort, and I'm starting to wonder if I got a bad one.

I purchased it in mid-May, and from the first time I used it, it has emitted a one-second blast of noise whenever I plug it in. This happens no matter how I plug it in -- Mic first, then the USB; USB first and then the mic; or plug it all in before turning the computer on. If I do that last, then it makes the one-second blast immediately upon powering up. This has been consistent since day one, although it hasn't seemed to affect any recording I've made. I've just taken it as a quirk of the thing.

Then, for some reason I suddenly can no longer use it to listen to playback through my headphones. I always edit with headphones to best hear noises and other imperfections, but can no longer do so. Now, when selecting playback through the MicPort (using Audacity) it does one of two things: It either gives you no signal at all through the phones, or it runs a string of extremely loud -- very, very loud -- static and noise through the headphones instead of the recorded audio. Playback through my computer and speakers is normal, and none of this seems to appear on the recorded audio. The headphone signal and volume is not affected while recording, only on playback.

I'm using Audacity on a Mac. What I've tried --- I've swapped out USB cables, with no difference. I've tried using different USB ports, but the problems persist. I've changed nothing on my Mac -- either software or hardware. I've uninstalled and reinstalled Audacity with no difference. Again, I've done nothing of which I'm aware to cause these issues; they just appeared on their own. The original issue has existed since day one, and the issue with not being able to listen to playback popped up just last.

Thanks in advance for any insights.

A.J.

[david]

Hi A.J.,

I'll assume the problems you describe are on Mac only. If not, please let me know.

1) If the headphone volume is off, do you still hear the noise?

2a) Is Audacity's Project rate the same as the sample rate of your MicPort? The project rate should be the same as the Default Sample Rate in Audacity's Preferences, and the same in Mac's "Audio MIDI Setup" for MicPort. If sample rates are not the same, then this could be an issue. Granted, I am not familiar with the Mac version of Audacity, so I don't know how these settings are used in Mac.

2b) How does your MicPort sound with iTunes? (or whichever music player you use)

Kudos for swapping cables, the weakest link of all audio gear.

David

[A.J. Hamler]

David...

Thanks for the reply. Yes, these problems are on Mac only. I've never used my MicPort with a PC. I really have two issues. The first is the MicPort making a blast of noise on power-up, which it's done since the day I took it out of the box. It does this whether Audacity is running or not, so I'm not sure I see how a difference in sample rate between Audacity and the MicPort would make a difference there. To be honest, that noise blast on power-up hasn't interfered with any recording; it's just been an odd, annoying thing. (And I make sure never to have the headphones on when I power the MicPort up, lest my ears be ringing for 15 minutes. Don't ask me how I know this....) The second issue is the new one -- and the more serious of the two -- where I've suddenly lost last week the ability to listen to Audacity playbacks through headphones through the MicPort. Still, both issues concern me greatly, as my MicPort is basically brand new.

1) If the headphone volume is off, do you still hear the noise?

No, the noise isn't there if the volume is off, or if I unplug the headphones. At least, I don't hear it. Which I guess makes sense if it's turned all the way down or unplugged. (g)

2a) Is Audacity's Project rate the same as the sample rate of your MicPort? The project rate should be the same as the Default Sample Rate in Audacity's Preferences, and the same in Mac's "Audio MIDI Setup" for MicPort. If sample rates are not the same, then this could be an issue. Granted, I am not familiar with the Mac version of Audacity, so I don't know how these settings are used in Mac.

Well, the sample rate in Audacity is the same as when I installed it, the default of 44100. Unfortunately, I have no idea where to find or check or reset the sample rate on the MicPort. I assume it's set at whatever it came as. I've certainly not changed it. Again, I've changed nothing before or after I stopped being able to hear playback through the MicPort. Playback through headphones worked fine from when I bought it in May till last week when it just stopped.

2b) How does your MicPort sound with iTunes? (or whichever music player you use)

I'd never played iTunes through the MicPort, so I gave it a quick test and tried a dozen or so times. The result was the same as listening to playback through Audacity -- either no sound at all, or just loud harsh crackle and noise. Perhaps a snippet of music a second or two in length, but then back to either silence or loud noise. Mostly, what I heard was just silence. By the way, I had Audacity shut down when I tried to listen to iTunes, so again I can't see how a mismatch in sample rates between Audacity and the MicPort would come into play there.

I wish I was more savvy on this stuff to better answer your questions. Thanks for bearing with me.

A.J.

[david]

A.J.,

Question 1) was only for your 1st (original) problem.

On to the playback issue...

What version of Mac?

As for sample rates, let's just be absolutely sure...

1. Plug in your MicPort.
2. Open one of your Audacity projects.
3. Open Finder, and type in "Audio MIDI Setup". Open the application "Audio MIDI Setup".
4. select MicPort in the "Properties For" box.
5. What does the "Format" box say for Input and Output? 44100, 48000, 88200, or 96000? Are the Input and Output numbers the same? Do they match your Audacity project sample rate?

David

[A.J. Hamler]

Hi David...

Following your instructions I checked the sample rates at both places. In Audacity the sample rate is 44100. For the MicPort, it's 96000 for both input and output. Obviously different from Audacity, although that's the way they've been since I got it, I assume, since I've not changed anything, and I only recently lost ability to listen to Audacity playback. Would having those settings for MicPort both at 96000 also cause me not to being able to hear playback from iTunes through headphones on the MicPort?

Again, thanks.

A.J.

[david]

Hi A.J.,

Change the format (i.e., the sample rate) in Audio MIDI Setup from 96000 to 44100, and then report the results.

David

[A.J. Hamler]

David....

You're a wizard. I still get that little blast of noise on power-up, but everything with the headphones is working just fine now.

I still have no idea how this issue suddenly developed -- The headphones worked fine till last week, and I certainly didn't change those values -- but it's a moot point now. Not only is the problem fixed, but I now know where to look if it repeats itself. Can't thank you enough.

I guess that little blast of noise on power-up is normal? If so, I'll ignore it since it doesn't seem to affect anything.

Again, my sincerest thanks.

A.J.

[david]

A.J.,

Glad to hear we fixed the playback issue! Agreed, I too am perplexed as to how it happened. The only "change" I can think of is a Mac update "changed" something. Typically, Mac is very good at automatically telling the hardware (e.g., MicPort) what sample rate it should use, based on the sample rate in the software application you are using (e.g., iTunes, etc.). So, I don't know why there was a problem.

I think the burst of noise is Mac-only, to the best of my knowledge. Regardless, it is good practice to have the volume down whenever speakers are attached to a device when power is turned on or off (just ask anybody who runs live sound).

Cheers,
David