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Passive Summing Mixer Myth
Old 4 weeks ago
  #1
Here for the gear
 
🎧 5 years
Passive Summing Mixer Myth

Guys,

I know those passive summing boxes like Fulcrum, DIY-RE SB2 or Little Lab. We use mic pres after those devices to regain the signal we've lost in those boxes right? As I was digging up, I 've learned all those devices use only resistors on their input channels and later sum all the signal to their stereo output. This made me wonder the aim of this design?

If the aim is to send 2bus into a pair of mic preamp, why do we place a passive box between the output of the interface and mic preamp, seperate and then gather channels again? I mean are these tiny and cheap input resistors all responsible for that seperation and depth people call, really?

Ok, I know what a summing mixer is, and the process. I hope you get my question right, I'm just wondering, what is responsible for the seperation and depth. Resistors? Audio seperated to stems and gathered back again? A 2bus signal hitting to preamps low beacuse of the resistors?

My 2nd question would be like, in reality if active summing mixers are basically combination of passive summig box (with pan and faders maybe) + some sort of microphone preamplifier on the last stage ?

Thanks!
Old 4 weeks ago
  #2
Lives for gear
 
🎧 10 years
"Analog summing" is the magic pixie dust du jour. There's a market for boxes of resistors at the moment, so they exist. I don't own one.
Old 4 weeks ago
  #3
Lives for gear
 
🎧 15 years
I have the diyre and return to a pair of inexpensive “neve type” 500 preamps and a big brand ssl comp clone. I like what it does, so whatever anyone else thinks of it is ok by me as long as they like their workflow.
Old 4 weeks ago
  #4
Gear Guru
 
Karloff70's Avatar
 
🎧 10 years
One thing that it does that people mostly don't think about is give you the opportunity to split the mix over several converter OUTPUTS....before the summing. Running everything out of one analog stage or select things per output is different.
Old 4 weeks ago | Show parent
  #5
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GYMusic's Avatar
 
🎧 15 years
Quote:
Originally Posted by Whoopysnorp ➡️
There's a market for boxes of resistors at the moment, so they exist. I don't own one.
I don't either. The reason why? Run some white noise or a frequency sweep through one and look what starts happening around 8k and above.
Old 4 weeks ago | Show parent
  #6
Lives for gear
 
🎧 15 years
Quote:
Originally Posted by GYMusic ➡️
I don't either. The reason why? Run some white noise or a frequency sweep through one and look what starts happening around 8k and above.
I may try it so I can increase my knowledge, but what I do know is that whatever is going on that a scope, graph, meter, or other analysis tool can measure is resulting in a sound that is pleasing to my ears. But I don’t consider a test readout to be a reason to avoid or recommend using something if it helps someone achieve something they like.
Old 4 weeks ago | Show parent
  #7
Lives for gear
 
🎧 10 years
Quote:
Originally Posted by GYMusic ➡️
I don't either. The reason why? Run some white noise or a frequency sweep through one and look what starts happening around 8k and above.
What does it to do 8k+?

I always thought we were beating some bad sounding smushing that DAW bounces get you. The comparisons I've heard do sound good, so the question is if my current converters + the DIYRE box + two preamps I own or would buy

= sounds good.
Old 4 weeks ago
  #8
Gear Guru
 
theblue1's Avatar
 
🎧 15 years
There's no question that, all else equal, a 'straight wire' delivers the cleanest signal. There's no question that most passive mixer designs tend to change frequency balance, diminishing HF response relative to lower.

But if one genuinely likes the effect of a given box, there you go. Use it and don't obsess. But do be aware of what is happening to your signal to get it to where you like it. It might not be the right hammer for every nail. Stay flexible. And do your colleagues and those coming up (and maybe even yourself) a favor and be realistic when publicly extolling the benefits you perceived.
Old 4 weeks ago | Show parent
  #9
Lives for gear
 
🎧 15 years
Quote:
Originally Posted by bangbang ➡️
What does it to do 8k+?

I always thought we were beating some bad sounding smushing that DAW bounces get you. The comparisons I've heard do sound good, so the question is if my current converters + the DIYRE box + two preamps I own or would buy

= sounds good.
I have the experience that the DIYRE box plus my two preamps and my current converters do give a pleasing sound.
Old 4 weeks ago
  #10
I used to work at a studio with a Shadow Hills summing mixer and while it has the fancy transformer selection and great preamp built in, I seem to recall the summing section itself looking quite a bit like the diyre sb2.
Old 4 weeks ago
  #11
Lives for gear
 
zvukofor's Avatar
 
🎧 10 years
Just compare it with summing ITB and putting the same preamps for resulting stereo pair. Most benefits comes from nonlinearities of a preamp, anyway. Crosstalk? No way. Stereo imbalance? Maybe, but very subtle if using matched resistors. Nonlinearities, and little more noise (which could be pleasing too), that’s all.
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