Most useful tweaks that are sensible and really make a noticeable improvement

Cryogenics works, at least on metals. Here’s detailed research showing exactly how it profoundly changes metallic grain structure

https://www.researchgate.net/publication/257142195_Cryogenic_Processing_of_Materials_for_Enhanced_Pr...

Another vote for speaker placement.

Some sound better closer to boundaries some don't - it just depends upon the room and what the designer wanted.

For me, it's tweeter aimed at ear level before anything else. Then it's proximity to rear wall, as very few speakers sound best placed flat against it.

@mauriceminor, the ultimate DIY tweak?

In the UK many of us live in older houses which have suspended wooden floors. In these houses bass vibration is a real problem.

The solution is:
1. Put your speakers onto cheap granite/stone slabs. I use two cheap kitchen counter top chopping boards.

2. Remove the spikes from the speakers and replace them with feet that absorb vibration. Isoacoustic Gaia feet are excellent as are Townshend Seismic bars or feet or platforms.

Maybe this also works on solid floors, I have not tested it. Isoacoustic do demos of their feet on solid floors so I suspect it works here too.


Other tweaks that worked for me:

- For the rack sit the spiked rack feet into Townshend Seismic corners. These fully suspend the whole rack so that it ‘floats’. By doing this then I have found that individual component isolation on the rack is no longer necessary.   

- separate AC power circuit for the Hi-Fi, and do not plug any components powered by switch-mode power supplies into these sockets.

- use a network switch between your router and your streamer. Cheap second hand Cisco switches are good, maybe due to good shielded mains power supplies? Although Hi-Fi companies have started manufacturing expensive equivalents Cisco seem as good. Do avoid ‘noisy’ cheap low voltage network switches.


- without wanting to open up a cable debate I will say that if you use usb cable to connect a streamer to a DAC then use as short as possible. It makes a difference.

- and finally, whilst I have not tried expensive Hi-Fi Ethernet cable I can say that Cat 7E is better than Cat 5E. There is good reason as it has better shielding. However I really did not want this to be true as I have Cat 5E cable under the floorboards to my streamer, installed years ago when we renovated the house. But unfortunately the Cat 7E is so much better that I have to have above-floor cables again. Not ideal.

If you get bored and can’t think of anything else to do there’s always the water bowl tweak. Place three medium size bowls filled with ice cold water about a foot or two out in front of the speakers, one bowl in front of each speaker and one between the speakers in line with the other two bowls.

Free tweak for the first person to correctly explain how the water bowl tweak works.

I wonder why no one mentions Master Setting speakers.  I went to a Denver audio store and they demonstrated master set.  He had his speaker location taped on the floor so after moving them out of position they would go back into sync.  He demonstrated how everything sounds better when you can not detect either right or left speakers.  When he moved the right speaker about a foot out of position, we suddenly had to raise our voices in order to hear each other.  The moment he moved the right position, we were able speak at normal conversational volume levels.  I also noticed how my shoulders dropped.  Everything sounded relaxing and the sound came from between the speakers to create a really nice sounding sound stage.  However, when he demonstrated the REL S3 subwoofer, I was not able to detect a great deal of difference.  I think this is because REL designs their subs to act more like woofers than subwoofers to allow them to play down slightly lower.  This is probably why they blend so well.  However if the specs for the S3 say they play down to 21 Hz at -6 db, they are most likely playing down to maybe 30 Hz.  The problem is if a recording contains frequencies that play down to 14 to 20 Hz, you are not going to hear them.  The trick is finding a subwoofer that doesn't pound you out of the room.