Audacity Forum

Hello,
Recently I started to record my old vinil records to burn them on a cd.
Attached the record player into the "Line-in" socket of the pc, (strait from the record player), started "Audacity" (2.1.3), set source to Line-in, pressed the record button than started the player, and started the recording.
While recording, could not hear any audio from the loudspeakers.
The audio "pattern' was not on the program's center line (as on attached screenshot), and when I opened the finished file to listes, there was an annoying 'click' at the begining and at the end. I tried to cut a segment out and saved it , there were also these 'clicks' at both ends. However, the recording was played ok (as expected from old records).
When I make a recording from the speakers, the audio "pattern" is on the center-line and there are not those 'clicks' at both ends.
My questions:
1. Why no audio from loudspeakers while recording ?
2. Why audio 'pattern' was not on the center-line ?
3. Why the clicks at both ends - even when I started the play anywhere in the middle ?
Attached also an audio sample taken from the middle of some recording.
Os is win 10 pro.
Answers will be appreciated.
Thanks
Motim

Motim wrote:1. Why no audio from loudspeakers while recording ?

Because Windows disables "playthrough" by default, and for good reason. If your input was a microphone, and playthrough was enabled, then the sound from the speakers would go back into the microphone and cause howling feedback.

As you are not using a microphone, you can enable playthrough by going into the Windows Sound Control Panel, find the recording device (your sound card in the Recording setting), then find and enable the "listen to this device" option. Alternatively you can enable "Software Playthrough" in Audacity (near the bottom of the Transport menu), though this may give a bit more delay than the "listen to this device" option.

Motim wrote:Why audio 'pattern' was not on the center-line ?

That's called "DC offset", and it is a common problem with poor quality sound cards.
The best solution is to upgrade your sound card (possibly with a USB device).
Alternatively, you can use the Normalize effect to re-centre the waveform by using the "Remove DC offset" option. (http://manual.audacityteam.org/man/normalize.html)

Motim wrote:Why the clicks at both ends

That's probably because the output has to jump suddenly from the 'normal' zero position to the 'offset' position.

If you still have a slight click after using Remove DC Offset just make a short fade-in and fade-out (maybe 10 milliseconds or more) and that will silence it.

You can't hear DC offset (it's zero Hz) but you can hear when it kicks-in and kicks-out.

The biggest issue with offset is that it limits headroom and you can get clipping at the top (with a positive offset) or the bottom (with negative offset). The sample you posted is nowhere the 0dB limit (+1 or -1) and if all your waveforms look like that you should be OK. If you've got "louder" records you may have to watch for clipping.

Motim wrote:Attached the record player into the "Line-in" socket of the pc, (strait from the record player), started "Audacity" (2.1.3), set source to Line-in, pressed the record button than started the player, and started the recording.

I hope you mean that this is a boom box or music centre and that you connected from that to the "Line-in".

If you are directly connecting the leads from a standalone turntable then I guess you are connecting to the microphone in, otherwise the low level phono signals would record at an extremely low level. Direct connection also means there will be no RIAA equalization applied, so the recording will sound tinny with too much high frequency. If that is the case, apply the RIAA curve in Audacity's Equalization effect.

If you are recording into the microphone port, there may be a setting for that input in Windows Sound to cancel the DC offset at the recording stage.


Gale

Hello and thanks for the answer.
As I wrote in my question: The record player was connected strait into the line-in socket, nothing in between.
The recording was acceptable, only the sound patterns were not on the program's center-line, and the strange 'clicks' when starting the playback of the audio file at the begining and at the end.
And another thing - while recording there was no sound from the speakers.
Note: When I use audacity to record sound coming from the speakers, the patterns are on the program's center-line and no clicks at both ends.
Thanks again
Motim

Motim wrote:As I wrote in my question: The record player was connected strait into the line-in socket, nothing in between

I read what you wrote, but many users say "line-in" when they mean the mic in. If you only have one audio input like most computers these days, then almost certainly you do not have a proper Line-In for strong signals. Some rare computers with only one input have a switch to toggle that input between mic level (amplification is applied) and line level (no amplification is applied). Your turntable signals are low level and normally would need amplifying.

If you are connecting straight from the turntable output cables into mic-in or line-in then you are recording without RIAA equalization. If you don't care that it won't sound like the record that is fine, but it is our job to point this out for the sake of other users who may read this.

Motim wrote:while recording there was no sound from the speakers

To correct that, enable Transport > Software Playthrough.

Motim wrote:When I use audacity to record sound coming from the speakers, the patterns are on the program's center-line and no clicks at both ends.

As I wrote, you can look for settings in Windows to cancel DC offset. The sound card is adding offset, not Audacity.

When you record the speakers you are no longer recording from a physical input, hence no offset.


Gale

and the strange 'clicks' when starting the playback of the audio file at the begining and at the end.

When you have an offset, the signal suddenly jumps-up from zero when you start playback. That causes a click. There's another click when playback ends and the signal suddenly jumps-back to zero again.

...When you play the music (through a speaker) the speaker vibrates in & out following the waveform... If the waveform suddenly jumps, your speaker will suddenly jump, making a sound. Although the DC will probably be filtered-out somewhere along the path, through the electronics, the clicks will remain.

Note: When I use audacity to record sound coming from the speakers, the patterns are on the program's center-line and no clicks at both ends.

When you record streaming digital audio the sound isn't coming-in through your soundcard. The offset comes from the analog side of your soundcard. (Sometimes the offset on the mic input is worse than the offset on line-in, but your line-in is pretty bad.)