I just love this lil box.
When I was modding mine to light the display,
I noticed there is a resistor in series with the tweeter.
It is not a capacitor to act as a type of crossover,
so I decided to bypass it to see if more sound out put would come out of the tweeter.
This really help bring out the "presence" in music, as the tweeters produced sound much higher range but was always low in sound.
It did not change like the "treble boost", rather it gave a noticeable increase of the highest range, maybe like 1db boost, like the "hiss" sound range,
maybe around 11k
Definitely increased quality in my opinion.
My assumption is that with age this tweeter diminished slightly so bypassing that resistor helped bring it back to "new" sound.
Also I am not shure if my unit's woofers are acting normal, they are producing bass without usual limit and are trying to reproduce low sounds making them flutter, or bottom out at higher volumes.
Not shure if it is from old age or if the change is partially due to change in impedance to the amp from bypassing tweeter resistor.
Can't complain because the sound is so huge from this tiny box as it tries to mimic 6" woofers.
I posted it on youtube a while ago, you can notice the bass just from the singing voice I do not believe this is normal:
Looky Here:
https://www.youtube.com/watch?v=OZeIg4RYddY&feature=plcp