USB Microphone behaving differently depending on what port it is plugged into?!

I use a humble Samson C01U USB Condenser microphone to record my humble Youtube recordings. I have had this mic for years.

When I first got it, I recall it being a highly sensitive mic capable of making recordings with high volume levels into my recording software (Audacity). I used it on my laptop.

Over the years, I got a new laptop and noticed that on this particular laptop, that the recording levels are not as loud as on the old laptop. Even when all the settings are at 100% in Windows Audio settings, etc and in Audacity recording program..

It feels like the recording level is capped at around 20%.

This did not make the mic unusable though. It just meant that my audio tracks would not be recorded at particularly high levels. It was quite a nuisance though not being able to record softer sounds.


Tonight just for kicks, I plugged the mic into a different USB port on my laptop (strangely enough, first time I did in all the years).

The problem is gone! The recording levels are high. The Mic level set at 100% is actually what you would expect at 100% - super sensitive with a bit of clipping. I dial it down to around 50%, and the mic responds as it should!

I plug the mic back into the old USB port, and the problem is back.

I tried uninstalling the mic driver while it was plugged into the problematic USB port and reinstalling the drivers again.. but it did not help.

Why does the mic behave this way in one particular USB port but not in the others?! I tried the other 3 USB ports and the mic works fine in it.

The USB port causing the low-mic-volume does not seem to be faulty with other devices. I plugged in USB sticks, my mouse and connected my phone into it - only to see that it functions perfectly and recharges my phone. Any clues? Do some USB ports give out more power than others? What is it?

It's just bloody computers innit ? I swear that they have a mind of their own !!!

USB ports can act a little differently if they are sharing hubs, however I believe CeeJay's answer is scientifically sound except that he failed to mention bad Mojo!

Planned obstreperousness.

kissing said:

... The USB port causing the low-mic-volume does not seem to be faulty with other devices. I plugged in USB sticks, my mouse and connected my phone into it - only to see that it functions perfectly and recharges my phone. Any clues? Do some USB ports give out more power than others? What is it?

Click to expand...

USB specifications do change over time. Because of this some computers come with ports that have different specs (one ports with an older spec, and two with a new spec) for compatibility and cost reasons. Depending on how old your computer is, and what updates have been applied, it is possible to have a ports act differently than others.

Older USB ports used to put out lower power. Newer ports can put out more power.

What you are seeing could very well be related to what USB specs the port is based upon.

Thanks everyone for clearing that up! Makes more sense now.

The funny thing is that the mic still has been functioning on the "weak" usb port.. but has been recording with less power?

That'll be the Mojo chip, (thanks Doug W) it sclerates the overdriven checksum point on the dopplerised duplex dongle and basically strangles the little bugger as it tries to do its job.


Have you tried switching it off and switching it on again ....but in a skip...twenty miles away ...that'll give it something to think about ...Jumped up bloody clock.

Having been in IT for 30 years, I can vouch for two of the answers already posted. Older laptops had ports compaitble with the old and near USB 1 & 2 specs. And also voltage levels at such low.levels can make USB ports act slightly differently.

And then there is the variability of the multitude of hardware vendors of wimdows pcs.... Which is why I now prefer Apple products at home. Narrowing the set of hardware specs makes things more stable overall.

Olarte said:

Having been in IT for 30 years, I can vouch for two of the answers already posted. Older laptops had ports compaitble with the old and near USB 1 & 2 specs. And also voltage levels at such low.levels can make USB ports act slightly differently.

And then there is the variability of the multitude of hardware vendors of wimdows pcs.... Which is why I now prefer Apple products at home. Narrowing the set of hardware specs makes things more stable overall.

Click to expand...

Which is Teckernicle Speak for All Compooters Are Ba*****s.

There are a lot of reasons why USB ports will give out variable voltage. One of the USB ports could be damaged or slightly corroded. Or, there could be a problem from the motherboard. The USB specification actually allows for fairly wide variability in voltage between ports. You can try testing the port with a multimeter. Based on what you say - it's some kind of hardware issue. I'd bet the one port is probably faulty in some way.

On some desktop PCs the USB ports on the front of the case are not on the same bus as the ports on the back of the case. It's very common that some peripherals will work on the back but not the front - kind of like some things won't work through a hub. Usually when the voltage is deliberately different from the manufacturer it is because one port is set up as a continuous power port for charging cell phones or one port is a USB 2.0 and the others are USB 3.0 or one port is a dual USB/SATA port. If one of the ports isn't a specialized port if the voltage is different enough to affect the volume from the microphone - it is probably that the USB port is faulty or damaged in some way.

Thanks for the informative answers... maybe the port is a bit faulty.

It is not a new model laptop.
I'm pretty sure it's pre-USB 3.0.

It's a Dell Studio with Centrino 2 processor from Windows Vista days (currently have Windows 7 on it).

Maybe that USB port has worn out or something....


I guess the good news is that when I plug the mic into any of the other ports, I get sufficient microphone gain.

But I am rather irritated at the situation, because I have been recording all my videos for the last few YEARS using the "faulty" USB port.
The low signal level made me want to invest in a more expensive recording setup involving an interface + XLR microphones... solely to have higher gains..

But now I don't know what to do. After years of adapting, making do and familiarising myself with this "low power" microphone... all of a sudden its giving me higher gain levels again. This inflames my OCD.. I was looking forward to buying this setup:

http://www.shure.com/americas/products/microphones/sm/sm58-x2u-usb-digital-bundle

But now I don't think I'll need to. I'm kinda disappointed that I found that my mic is ok through other ports.. I was sorta excited at getting new equipment >_<

kissing said:

Thanks for the informative answers...

But now I don't know what to do. After years of adapting, making do and familiarising myself with this "low power" microphone... all of a sudden its giving me higher gain levels again. This inflames my OCD.. I was looking forward to buying this setup:

http://www.shure.com/americas/products/microphones/sm/sm58-x2u-usb-digital-bundle

But now I don't think I'll need to. I'm kinda disappointed that I found that my mic is ok through other ports.. I was sorta excited at getting new equipment >_<

Click to expand...

Purchase this:

http://www.rme-audio.de/en_products_fireface_ucx.php

It's a great system. Then you can purchase some mics.