I've been having a rather vexing issue over the last few days that I'm hoping someone here could shed some light on.
My setup is Shure wireless PG58 mic, with the mic output on the base station connected to an Audio Buddy mic pre-amp, which is then connected to the Mic/Line-In jack on my PC.
The PC is a Dell OptiPlex 755 with on-board audio (currently disabled in the BIOS), an ATI video card with HDMI-out connected to a TV (sound output to TV), and now an additional sound card I've added, an Asus Xonar D1 PCI sound card (probably seems like an odd choice, but I needed a low-profile card for the workstation, this was one of the few I could find). The mic setup is currently hooked up to the sound card's line in/mic jack.
Originally my mic setup was connected to a Dell OptiPlex GX620 and I had no issues with recording. Upon hooking it up to the OptiPlex 755, suddenly I was getting almost no sound when recording the mic in Audacity, and what sound I did get was heavily distorted. My first thought was that there was a problem with the on-board sound, so I added the Asus Xonar D1 card to see if that would make a difference. It did not.
Today I figured out that if I switched to stereo for the mic input in the Audacity settings, everything recorded fine and came through with no issues. This lead me to wonder if it was an issue with the cable running between the PC and the Audio Buddy mic pre-amp. It's a 1/4" to 1/8" stereo audio cable. I realize that my mic is a mono mic, and thus a stereo cable is probably not necessary (I'm assuming?) between the pre-amp and the PC, but like I said, it worked fine on a previous PC with a very similar sound card with no problems.
I tried adding a stereo-to-mono adapter on the end connecting to the PC, and that did nothing. However, swapping out the stereo cable for a mono cable did seem to partially solve the problem. The only thing I'm noticing now is that the sound seems to get clipped at the +/-0.5 level instead of 1.0 when I record in Audacity, and I'm having to boost the signal much more than I did before to get it to come through clearly. I did see a previous thread regarding clipping at 0.5, but I think there may be more to this situation than just the clipping issue.
Anyway, since I can now record without distortion and everything sounds clean on the PC, I could just leave the setup as-is and consider it fixed, but I still feel like there is more going on here that I don't understand. I realize this is probably more of an audio setup question than an Audacity question, but I'm hopeful that someone here can point me in the right direction.
Thanks to any and all for your help and your time!
Issues Recording Mic via Pre-Amp
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kozikowski
- Forum Staff
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- Joined: Thu Aug 02, 2007 5:57 pm
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Re: Issues Recording Mic via Pre-Amp
<<<connected to the Mic/Line-In jack on my PC.>>>
Promise you'll stop using that phrase. You can have a Mic-In or a Line-In, rarely both in the same connector (although that has happened). They're very different.
http://www.kozco.com/tech/audioconnecto ... ctors.html
The top connector is expecting a massive powerful stereo audio signal. The bottom connector is expecting a tiny, wispy, delicate mono microphone signal. They're really different.
Most computers fog the issue by forcing the one single mono microphone signal to appear both left and right leading everybody to think they're connecting in stereo, when in fact, they're doing nothing of the sort. It's a trick.
The microphone connection is easily overloaded. A common complaint after somebody crosses the cables by accident is the inability to reduce the volume of the show to a usable level and that the signal never gets over 0.5 on the waveforms. Any of this starting to sound familiar?
There's nothing wrong with wanting to do your tasks, you just need to connect your stereo plug into the blue Line-In connector of your sound card (it's usually blue), or connect to the computer with one of the fine USB external sound cards we reviewed and take your sound cards out of service completely.
http://forum.audacityteam.org/viewtopic.php?f=27&t=9477
As I said earlier, there are sound cards that can switch between the two services on one connector, but they're very rare and we suspect don't actually work particularly well. It's hard to do. Stereo line signals can be a thousand times louder than a microphone. The silly analogy is the difference between a flashlight battery (1.5v) and the high voltage power lines going over your house (1500 volts). It's rough to get a piece of electronics to manage both without damage somewhere.
Koz
Promise you'll stop using that phrase. You can have a Mic-In or a Line-In, rarely both in the same connector (although that has happened). They're very different.
http://www.kozco.com/tech/audioconnecto ... ctors.html
The top connector is expecting a massive powerful stereo audio signal. The bottom connector is expecting a tiny, wispy, delicate mono microphone signal. They're really different.
Most computers fog the issue by forcing the one single mono microphone signal to appear both left and right leading everybody to think they're connecting in stereo, when in fact, they're doing nothing of the sort. It's a trick.
The microphone connection is easily overloaded. A common complaint after somebody crosses the cables by accident is the inability to reduce the volume of the show to a usable level and that the signal never gets over 0.5 on the waveforms. Any of this starting to sound familiar?
There's nothing wrong with wanting to do your tasks, you just need to connect your stereo plug into the blue Line-In connector of your sound card (it's usually blue), or connect to the computer with one of the fine USB external sound cards we reviewed and take your sound cards out of service completely.
http://forum.audacityteam.org/viewtopic.php?f=27&t=9477
As I said earlier, there are sound cards that can switch between the two services on one connector, but they're very rare and we suspect don't actually work particularly well. It's hard to do. Stereo line signals can be a thousand times louder than a microphone. The silly analogy is the difference between a flashlight battery (1.5v) and the high voltage power lines going over your house (1500 volts). It's rough to get a piece of electronics to manage both without damage somewhere.
Koz
Re: Issues Recording Mic via Pre-Amp
In this case the jack really *is* a mic/line in jack (all in one). You can select in the driver settings which one you have connected to it-- I've also noticed that the card actually makes a clicking sound anytime you change it. I realize the tendency would be to suggest that it's a bad card or it's not doing what it says it is, but I'd also refer back to the fact that when I had it plugged into an older machine, with only on-board sound, everything sounded fine. It wasn't until I tried connecting it up to a newer machine on-board line-in jack (and then the sound card, after that failed) that I started having this problem.
Supposedly the Audio Buddy outputs a line-level signal, and thus I tried setting the jack on the sound card to a "line-in" setting. However, the mic was not loud enough and it wasn't until I switched it both back to the "Microphone" setting *and* added the "Microphone Boost" that it was loud enough again. Before I made that change, I actually had the pre-amp volume cranked all the way to the max, the line-in volume cranked to the max, and the mic was barely loud enough. It really confuses me, especially because the mic is going through a pre-amp!
My first thought was that there was something wrong with the pre-amp, but when I connect my headphones to the audio-out on the Audio Buddy (disconnecting it from the PC), everything sounds great and is loud enough with no issues. And again, when I used the "stereo" setting in Audacity, everything was ok.
I'd like to try other equipment if I thought it would help, I'm just still troubled by the fact that A.) it works on the old PC just fine and B.) when I plug headphones into the output jack on the Audio Buddy, everything sounds perfect. The only other thing I can think of that might have some bearing is the fact that the PC's audio output is being routed through the video card/HDMI connector to a TV, but even when I disabled it, I still had the same problems.
Anyway, I really appreciate your help, and I welcome any further suggestions you or anyone else can provide. Normally I can work through these types of problems without much trouble, but this particular instance really has me stumped.
Supposedly the Audio Buddy outputs a line-level signal, and thus I tried setting the jack on the sound card to a "line-in" setting. However, the mic was not loud enough and it wasn't until I switched it both back to the "Microphone" setting *and* added the "Microphone Boost" that it was loud enough again. Before I made that change, I actually had the pre-amp volume cranked all the way to the max, the line-in volume cranked to the max, and the mic was barely loud enough. It really confuses me, especially because the mic is going through a pre-amp!
My first thought was that there was something wrong with the pre-amp, but when I connect my headphones to the audio-out on the Audio Buddy (disconnecting it from the PC), everything sounds great and is loud enough with no issues. And again, when I used the "stereo" setting in Audacity, everything was ok.
I'd like to try other equipment if I thought it would help, I'm just still troubled by the fact that A.) it works on the old PC just fine and B.) when I plug headphones into the output jack on the Audio Buddy, everything sounds perfect. The only other thing I can think of that might have some bearing is the fact that the PC's audio output is being routed through the video card/HDMI connector to a TV, but even when I disabled it, I still had the same problems.
Anyway, I really appreciate your help, and I welcome any further suggestions you or anyone else can provide. Normally I can work through these types of problems without much trouble, but this particular instance really has me stumped.
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kozikowski
- Forum Staff
- Posts: 69384
- Joined: Thu Aug 02, 2007 5:57 pm
- Operating System: macOS 10.13 High Sierra
Re: Issues Recording Mic via Pre-Amp
So you're the one! <g>
Excellent.
You have an electronic celebrity and yes, if someone with a gun said I had to design a board that did that, I would totally be using mechanical relays which is the tiny ticking sound you hear.
The down side of doing a special sound board is the requirement of special software to tell the relays when to switch. Regular sound card drivers and conventional sound software will have no idea at all what to do and you will be left with a board that does whatever the default or relaxed relay mode is.
The +20dB microphone boost too, is a function of the sound board design (OK so far), and the software knowing when and how to turn it on. The fact that the connection service seems to be reversed in the new computer would tell me that the software is no longer up to the task or is conflicting with something in the machine.
Put the Buddy aside for a second and plug your iPod or Portable Music Player into the sound card with a stereo mini plug to plug cable. Turn everything on at normal listening volume and see if the sound card can capture the close to line level performance. If that fails, too, then the software/PC combination is hostile to your board.
The Windows elves never tire of telling people to try to find updated drivers for their device or system.
Koz
Excellent.
You have an electronic celebrity and yes, if someone with a gun said I had to design a board that did that, I would totally be using mechanical relays which is the tiny ticking sound you hear.
The down side of doing a special sound board is the requirement of special software to tell the relays when to switch. Regular sound card drivers and conventional sound software will have no idea at all what to do and you will be left with a board that does whatever the default or relaxed relay mode is.
The +20dB microphone boost too, is a function of the sound board design (OK so far), and the software knowing when and how to turn it on. The fact that the connection service seems to be reversed in the new computer would tell me that the software is no longer up to the task or is conflicting with something in the machine.
Put the Buddy aside for a second and plug your iPod or Portable Music Player into the sound card with a stereo mini plug to plug cable. Turn everything on at normal listening volume and see if the sound card can capture the close to line level performance. If that fails, too, then the software/PC combination is hostile to your board.
The Windows elves never tire of telling people to try to find updated drivers for their device or system.
Koz
Re: Issues Recording Mic via Pre-Amp
It is most likely a weird sound card driver issue. When you have the input set to "Line" the driver is expecting a stereo line level input. If you then set Audacity to record mono, the soundcard driver is in some way merging the two channels but appears to be making a very bad job of it. Updating the sound card driver may improve or fix the issue, but otherwise you will need to use your current workaround.JJimmy wrote:since I can now record without distortion and everything sounds clean on the PC, I could just leave the setup as-is and consider it fixed, but I still feel like there is more going on here that I don't understand.
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