That's a nice garage system. Is that your main high end listening system or do you have another primary listening system elsewhere? If I was to try and venture a guess as to why you and your family aren't hearing differences it would be the following:
- A garage is a very reflective environment acoustically
- A garage is probably noisier than a typical listening room
- The speakers are not necessarily placed ideally due to a lack of symmetry to barriers and the closeness to one side wall
- Most people don't know what to listen for and/or don't want to hear a difference which can make it easy to dismiss the differences that are in fact there (These differences are subtle, which is why Lossy compression works).
I find the difference between the uncompressed FLAC from Tidal HiFi and the compressed version (as well as the more compressed versions from Amazon, Pandora, and Spotify) to be easily heard, but not in all scenarios nor is the difference necessarily night and day. That makes sense, these compressed algorithms are lossy in a manner that takes advantage of our auditory systems masking and limitations. Under many circumstances it shouldn't be obvious (or even audible), but that isn't the same as saying that they are audibly equal. I have a few test tracks I've used that help highlight the differences. One is Gun's and Roses "Welcome to the Jungle." That song's drum beat sounds audibly compressed (less dynamic) through lossy services than it does through Tidal HiFi and if you know what to listen for, is pretty easy to spot.
The primary differences are typically going to be in slightly reduced dynamics and removal of some harmonic information that is otherwise masked. Occasionally some portion of the fundamental is removed as well if the harmonic would take up less space and is known to fool the ear into hearing the fundamental. A great example is that a 20hz tone's harmonics can fool us into thinking we hear the 20hz fundamental even if it isn't there. A lossy track might reduce the dynamic peak of the 20hz tone and rely on the harmonic to maintain the perception of that dynamic. Lossy compression doesn't typically reduce the frequency range of the music to save space nor does it actually reduce the true dynamic range all that much (I've seen anything from 0 to 2db's loss), it just removes portions of the signal that take up a lot of space and can still be perceived through other means. That means that you need a fairly resolving and capable system, a quiet room, and to listen carefully to hear differences. Studies looking at the audibility have shown that under the right conditions such differences are easily perceived, but many companies researching their own compression algorithms have drawn different conclusions (which is in their best interest, so I tend to take their conclusions with a grain of salt).
If you would like to hear what is being removed, what you can do is take a CD track in wav or flac format and then convert it to an MP3 (or similar compressed format) at various compression levels. Then using
http://www.libinst.com/Audio DiffMaker.htm diffmaker you can listen to a new track that contains just the difference information. The noise you hear is the information from the original music that was removed by the compression. It is sometimes helpful to listen to these when doing tests (if you really care to do them) on both headphones and on your speakers. If you hear something through the headphones and not the speakers, then you know right away that your speakers aren't able to resolve whatever was removed (My experience is that even really bad speakers can resolve this, but a noisy room might mask it).
