Audio DiffMaker 
Some Example DYF Files

These "dyf" files can be downloaded and played within Audio DiffMaker.  Each "dyf" contains a set of related audio WAV files that you can play side-by-side and simultaneously to compare by ear, and then to listen to just the extracted Difference signal.  

Each download is a result of an experiment that tests for audible differences when different processes or changes are applied to audio systems. For all except the "listener challenge" files, the alignment and extraction (and EQ when needed)have already been done -- you only need to download and listen.

Series coupling capacitors (new updated version)

A musical track played through a good quality polypropylene capacitor; and through a Z5U ceramic disk capacitor.  Each compared to the sound of it playing through a direct connection (no capacitor)

Polypropylene vs. No capacitor

Z5U vs. No capacitor


The green felt marker CD tweak!

This famous CD tweak is said to improve CD playback by absorbing light waves at the edges.  Does it do anything?

Green Pen test


Power amplifiers

Three power amplifiers (one class D type, two class AB types) are each compared to their input signals (ahead of a preamp that drives the amps).  Amplifiers are driving a 4 ohm ribbon loudspeaker system.

IcePower 200ASC amplifier modules

Hafler DH200 (modified with servo and cascode input stage)

Home theater moderate cost 100W monophonic amplifier

24/88 and 16/44 format

A short musical clip recorded at 24bit/88.2kHz is compared to a version that was only CD quality (but has been upconverted to 24/88 for the comparison).  These are from digital files (not played back through any analog system before differencing).

HD vs. CD playback

MP3 compression

Compare the sound of an CD track to the same info after it has been run through MP2 compression (and back to CD format for the comparison).  Done at 128kbit and 256kbit).

MP3 128kbit

MP3 256kbit

(these are golden ears) ...and a listener challenge

So, your ears are more sensitive than Audio DiffMaker in telling differences between sounds?  Are you sure?  

Here's your chance to show it! -- 7 "dyf" sets of music. 

In each set, both tracks (A and B) contain the same choir music (Brahm's "Lullaby").  But one of the tracks in each has something else mixed in. Download the files, and have DiffMaker do the Difference extraction in each to convince yourself that there is some distinctly different music mixed into one of the tracks from each pair. (you'll have to change to "All Functions" mode in DiffMaker to do the extraction).

Then use your sensitive ears to tell which from each pair of tracks includes the marching  band playing in the background! Seven sets,  a 1 in 128 chance to guess all correctly.  Otherwise, you'll have to have ears that can tell a choir from a marching band.  (Correct answers to be provided at a later date!).

Test 1

Test 2

Test 3

Test 4

Test 5

Test 6

Test 7

Internet Explorer users!  For some reason IE sometimes will  save the DYF files as HTML files (it will change the extension to ".htm" -- we have no idea why)!  During or after saving the file, you  may have to change the file extension back to ".dyf" to listen to it in DiffMaker.  The Firefox browser doesn't have this problem.