Sound Proof... is very important, in fact every little thing in audio is important in order to sing well...
So we start with the basic: Sound Proof
The following pictures shall help you to identify whether the audio shop is skillful:
The first issue is, soundproof sheets were not applied properly, they only paste on easy spot to save their time, quick money.
The second issue is, wrong spec of sheet were used, thin layer SP normally don't apply there, it doesn't strengthen the door.
This is the biggest problem which directly tells you the shop who carry out this work is bunch of dumb/liar
Picture was taken while my tuner taking off the old sheet, ever wonder why is it so clean? (no gum stains in the center part of panel)
Its because the previous shop only press the SP on panel side, covering all wiring inside...(how to repair if got wiring problem
)
with only four corner were pressed, the center part was made a hollow space which create more noise,
totally forfeited the purpose of SP
A proper SP work takes around half day to complete 2 doors
Some experience to share:
a) Local SP product can achieve good result too
b) Using imported stuff like STP but completed without skill serve no purpose
c) Different metal part requires different type of SP sheet, if the shop you are going says no different?? GO
Refer below for a fine SP work picture:
