there is no definit answer to this question.
the problem:
I have been going trough an ongoing PM-hell with members from various forums and also friends who desperatly seek the ultimate compressor (hardware).
case-study:
it seems that these days, testing is not the answer for everyone. Practical example: guy gets 3 totally different compressors, wants to use em for bus-compression, tracking and other stuff I don’t know. Must be the best compressor for vocals, percussion, 2 bus “add warmth” thing, squash it, transparent.. he tests all compressors for 2 weeks and finds compressor 2 the best. he calls me, to ask what my opinion is on his decision.
I tell him, I don’t use compressor 2 for all this, only used it for compressing the final master of the white album back in the day. He revise his decision to buy compressor 2 and buys compressor 3, just because I mentioned that I use it on most stuff.
solution:
there is no solution. we are confrontated with so many products, it’s scary. Most people in the industry do not have
A: the experience
B: the environement
C: the material
to judge differences (what is better, what is worse).
I include myself in this equation. After testing gear for 10 years, I still hear dragons roaring trough this new wonderfully praised “to be the next 1176” unit in onlineforums. After the dragons have gone, mostly you go back to what you have used the day before and sell this new wonderful product on ebay.
testing:
you get a new compressor. put it on everything. Vocals, kick, snare, guitars. Smash the shit out of the signal with the new compressor. Hear how it behaves. Listen to the release envelope, screw with the attack. How fast can it compress, how much is the transient loss? Do you like the recovery envelope of the release? After the extreme settings, put it back to normal (4:1, reduce max 2 to 5dBs). Is there any signal change you can hear? Does it make the sound fuller, smaller, wider, deeper?
Try it in a mix. Put your favourite plugin on the bass and then change back and forth with the new compressor. Can you hear a difference? What is the difference? Does it make the bass more “solid”?
Conclusion:
accept, that there is no best compressor for everything. accept, that you might not get what you want, because you don’t know what you want, altough people online have told you what you need/want. If a compressor is cheap, probably the material used to build it are cheap. That means, the PCB doesn’t get the current it needs, the whole curcuit starts to get flaky, which mostly results in distortion and/or making the signal a lot smaller.
Most important: do not trust marketing. Hit-albums have been made with the classic stuff (UREI LA2a, 1176/78, dbx160…) and we can not invent the weel again. Imagine that there have been dozens of people involved back in the day to develop such a piece of gear, while today they operate mostly out of a garage, beeing a one man show (which is not a bad thing but you get the picture).
There are geniuses out there, building smart stuff. Dave Hill, Avenson, Avedis, Weiss and others. I trust them.