piano sounds great going in, lousy in Audacity

[Jim Robbins]

Good idea, Steve. I'll see if I can sample the piano sound by itself. I'll post it when it's done.

[Jim Robbins]

Here's a sample piano. http://www.snapdrive.net/files/372235/s ... 0piano.mp3 No added EQ. I even tried just going from the L/mono by itself, out from the keyboard. That sounded even weaker.

The 1/4 inch cables are going out from the keyboard into the line-in on the mixer. One of the line-in's is a guitar/high-imped. channel. I've even tried that high and low. No difference. It's a mystery.

[steve]

That sounds pretty good to me, though I don't know what sound you are expecting. It may be that the difference/lack of quality is simply that when you are listening to the piano "direct" you are listening in stereo, but when you record, you are recording in mono.

There's a few things that I do notice, but I don't know if they are due to the piano, the recording, or the MP3 encoding:
1) there appears to be some sort of gating of high frequencies (above 13.8kHz) while the notes are initially sounding. When the note has decayed sufficiently, frequencies above 13.8kHz are "switched" back on.
2) There is a whistle at 4.5 kHz whenever notes are being played. (there are other harmonics present, but this sound the most prominent to me).
3) There are prominent whistles at 8800Hz and 16300Hz during the "silence" before and after the piano is playing.
4) This is not a "dry" piano sound - there is quite noticeable room ambiance - I'd guess this is due to the piano sound that you are using.
These are all pretty subtle and I find the overall tonal quality very pleasant.

In this sample I've notched out the whistle from 1.5 seconds to 3 seconds. I've exported it as a single channel mono WAV file.

sample solo piano.wav

(360.49 KiB) Downloaded 207 times

In this second sample, the first few seconds is the original and the second half has had the 4.5kHz whistle removed, the treble pushed up a little, and has been "spacialised" with a bit of reverb to make it stereo. You should notice that the stereo section sounds a lot more lively.

sample solo piano2.wav

(1.5 MiB) Downloaded 169 times

[kozikowski]

To recap, it sounds perfect, punchy and clear when you're listening to the headphones, but anything downstream sounds flat and lifeless.

Is it in stereo at the mixer and mono in Audacity -- I mean there may be two channels, but they're identical?

You can get into serious trouble if you plug a mono performance in a stereo plug into a connection expecting full tilt boogie stereo. The production echo and flavor of the performance may go flat. Really odd things happen, but not if you hear the performance at the mixer and it's OK. This can still get you into trouble if the show in Audacity is mono. Depending on how it got mixed to mono, you get get odd distortions.

Until this gets resolved, I would avoid oddball sample rates and bit depths. 44100,16-bit, Stereo is good enough for billions of Music CD listeners and 48000, 16-bit, Stereo is holding up digital television sound all over the world. Obvious problems like what you have are far worse than the difference between 48000 and 96000.

Are you on a PC? Do you like to record internet audio, YouTube, etc. Do you have Mix-Out or What-U-Hear selected in your Windows Control Panels. That can create a very slight echo and seriously change the character of stereo instruments.

Audacity applies no effects or damage on recording. It doesn't do anything in real time except straight recording and play back. It's a complete slave to the computer running it.

Set Audacity Preferences for Hardware or Software Playthrough, whichever is supported. Click inside one of the red recording meters and they will wake up and monitor the show without going into record. It will also send the show out the headphones for you to listen while you troubleshoot and experiment.

Koz

[kozikowski]

<<<There's a few things that I do notice>>>

And all that could be subtle feedback problems from having Mix-Out on by accident. Or leaving the microphone and speakers running together. The computer, I think by now it's clear, is Doing Something Wrong.

Koz

[Trebor]

The original piano solo has very little high frequency content and sounds dull (muffled).

I added extra high frequencies using Steve's vocal exciter ...

Solo Piano Before -After tweaking..mp3

(798.75 KiB) Downloaded 344 times

Audacity frequency analyses - Before (blue) After (purple).png (78.13 KiB) Viewed 3359 times

BTW Jim expect a writ from Bruce Hornsby for breach of copyright

[steve]

Is it in stereo at the mixer and mono in Audacity -- I mean there may be two channels, but they're identical?
.... The production echo and flavor of the performance may go flat.

I suspect that is exactly what is happening - now waiting for Jim to confirm.

Until this gets resolved, I would avoid oddball sample rates and bit depths. 44100,16-bit, Stereo is good enough for billions of Music CD listeners and 48000, 16-bit, Stereo is holding up digital television sound all over the world.

I'd go for 32bit 44100 (the Audacity default), or perhaps 32bit 48000 if that suited my sound card better. There's no point going above 48kHz as the keyboard cuts off before 20kHz. 32 bit has advantages with processing and Audacity 1.3 will automatically do a nice job downsampling on Export.

[steve]

I cheated : I added extra high frequencies using Steve's vocal exciter ...

It's nice to know that someone is using it, but I don't know that I would really recommend it - to my ear it's a bit rough - written more as a "proof of concept" than a high quality effect.

And all that could be subtle feedback problems from having Mix-Out on by accident. Or leaving the microphone and speakers running together.

Personally I doubt that is the problem on this occasion (though no harm in checking) - I think you were right the first time koz re. the sound becoming dull/lifeless as a result of going mono.

[Jim Robbins]

Hey Steve -- that second sample with the contrasts really helps. Did you add that spacialization/verb in Audacity? Also, is there a tool in Audacity that you used to identify the noise and the way the sound spectrum should sound? Thanks. I've been a musician for decades, but have very little experience in audio engineering.

[Jim Robbins]

Thanks, Koz. The sound out from the keyboard is stereo, but is only showing up mono in Audacity. Here's a top image of the Alesis mixer I'm using. I'm running the outs from the keys into channels 1 and 2 on the mixer. P.S. I turned off all other programs but Audacity when I recorded. I've also got it set at 32bit 44100HZ.