Audio quality drops plugging mixer into mic [SOLVED]

Hi everyone,

I am using Windows 7 and Audacity 2.05 and I obtained the zip installer

I’m recording my DJ mixes with Audacity 2.05 from my Numark Mixdeck Express, and sometimes during the mix the sound quality will change and drop in quality, forcing me to do the mix again. It doesn’t happen often, but I was wondering what the cause is so that I can hopefully prevent it.

I’ve attached a sample where the change in audio quality occurs.

To record my mix, I connect my Numark Mixdeck Express with a standard audio cable, RCA to 3.5mm stereo jack (Phono to jack), I plug the jack into the microphone port of my laptop (which is a Compaq Presario CQ57 model) and connect the ends of the cable (one red and one white) into the “Master 2” ports of the Mixdeck Express. To record my mixes into audacity I go to preferences - to which the Audio Host is MME, the Output Device is Speakers, and the Input Device is Microphone - and I change the Input Channels to 2 (Stereo), I also turn the input volume in Audacity to 0.01 then record my mix.

I can’t seem to figure out why this change happens, at first I thought it was because of me playing with the bass too much during the mix, but I’ve learnt this isn’t the cause. Any help is welcome.

That is probably the problem.
The output signal from a mixer is MASSIVELY bigger than a microphone signal, so there is a very bad mismatch between the signal that you are sending from the mixer and the microphone input. Although this will sometimes work to greater or lesser degree, there is also the consideration that “on-board” sound cards are generally poor quality - built for a few cents and design for nothing more that “telephone” quality recording (for Skype and similar).

An inexpensive alternative to using the mic input is to use a USB “line level” input. (I use a Behringer UCA 202 for this purpose, which cost around $25 and the sound quality is very much better than using the mic input. Other makes/models are available at a range of prices).

Oh okay, (sorry I forgot to attach the sound clip in my first message but the message isn’t sending when I attach it)

So I’ll get one of these:

and I connect a RCA to RCA (Phono to Phono) to the ports on the UCA222, then connect the interface via it’s USB, and record my mix, which should hopefully sort out the issue, but won’t I still need to plug my RCA to 3.5mm stereo jack (Phono to jack) into the microphone port of my laptop?

As near as I can tell, the only difference between the two is the paint job.

The UCA device provides a very good quality stereo connection to your computer. Both directions. That illustration is from the overdubbing tutorial and features the UCA running both ways, playing the existing track for rhythm and monitoring the new, live performance.

You don’t need any analog connections to your computer.

You might check if your Windows is set up for conferencing processing. That can seriously mess with music.


Thanks for the picture, I’m surprised that’s all I need to record the mix once I have the UCA. Do I keep the same settings on my laptop and Audacity too when the UCA is connected?

I couldn’t find out what conferencing processing is, but I followed the help link you sent and just disabled all the sound effects in my recording and playback, and my god the improvement is already drastic.

Plug the USB plug into your laptop.
Connect the line-out connections of your mixer to the line-in connections of the UCA 22.
Launch Audacity (the USB should be connected before you open Audacity).
Select the USB option as the recording input in the device toolbar.

If you plug your headphones into the UCA 222 (usually recommended), then you will also need to set the playback output in the device toolbar to the USB option so that Audacity plays out through the UCA 222.

Thanks alot for the the tips and advice guys, it’s helped so much! :smiley: My mixes are so much clearer now.

Thanks again.