Reviewing Digital Music

Posted by: Mr Underhill on 17 October 2011

 

Thought I might start posting some more in-depth reviews of my HiDef files, and decided to start by publishing my methodology.

My hope is that we, the Naim Forum community, might be able to agree a standard system that is repeatable by any person.

With this is mind I have chosen to use Audacity, as:

1. It is free;
2. It can run on Windoze and Linux, and so I would think it will run on a Mac.

I am thinking of producing three graphs showing:

1. The waveform, does it breach 0db?
2. The spectrum, does the file use the whole available frequency spectrum, and how often?
3. Plot the spectrum, as 2 in another way.

1. Is the standard file representation shown in Audacity when a file is opened, click on VIEW and select 'Show Clipping' to display a red line where 0db is breached.
2. With the waveform being displayed look at the upper panel to the left, click the downward facing arrow, and select spectrum.
   Right click the scale on the right to increase the available values to the maximum, e.g. 24k for a 48Khz file. Nyquist rules OK.
3. Select ANALYZE. Select PLOT SPECTRUM. Set: Size = 512; Axis = Log Frequency; Function = Blackman-Harris Window.


Can you suggest better software? Better settings?

I will shortly post a file review on the basis of these settings. Let me know what you think.

M

Posted on: 17 October 2011 by BigH47

M

When you open a file with Audacity does it show the recorded file sampling and bit rate?   

Posted on: 17 October 2011 by Guido Fawkes

>:  It can run on Windoze and Linux, and so I would think it will run on a Mac.

 

Audacity  runs under Mac OS X - great bit of software; knew it ran under Linux, but didn't know it ran under Windows too.  


All the best, Guy



> When you open a file with Audacity does it show the recorded file sampling and bit rate?   

 

Audacity definitely tells you the sample rate .... 96 or 44.1, but it says it is setting the sample rate to 32 bit float rather than 24 bit or 16 bit PCM on my Power-Mac - you can set this to 16 or 24 bit PCM. iTunes get info does give both these data.  


Audacity is a very good editor and a more than decent player. 


All the best, Guy

Posted on: 17 October 2011 by Mr Underhill

Hi BigH47,

 

Depends.

 

For a 16 bit file that is what is shown, together with the sampling rate.

 

For 24 bit files, as Guido says, when you open the file it shows the sampling rate, and the bit rate is  shown as 32 bit float.

 

Personally I double check this via the operating system.

 

M

 

Guido,

 

I agree, it is a great bit of FREE kit.

 

M