ChrisPFuchs
New member
Thanks for taking your time to look for me.
By "AI" I assume you're talking about the interface. What does this stand for exactly?
Basic Gain Staging
- Thread starter ChrisPFuchs
- Start date
Thanks for taking your time to look for me.
By "AI" I assume you're talking about the interface. What does this stand for exactly?
ChrisPFuchs
New member
Oh, wow. Don't know how I didn't connect the dots there
Farview
Well-known member
-10dbV isn't -10 volts. 0dbV is one volt, a negative number dbV would be a fraction of a volt.
0dbu is 0.7746 volts, which is why dbV and dbu don't relate to each other. The reference voltage is different and since db is a logarithmic scale, the db value doesn't have a one to one relationship with the voltage.
What you thought was happening was correct, the Mackie is working at a line level that is much higher than the line level the interface is expecting. That's why the Mackie is making the interface clip.
Now, if that wasn't confusing enough, different manufacturers will calibrate their converters to different levels. The -18dbfs thing is a rule of thumb that is safe to use at any time, but some interfaces are calibrated so that -15dbfs is line level, other at -12dbfs, others at -20dbfs...
The bottom line is that all you need to do is turn down the Mackie to get the appropriate recording levels in the DAW and not worry too much about it.
In fairness, 'don't worry is easier after you understand and get this stuff behind you.
Farview
Well-known member
Of course. When dealing with inexpensive equipment, you will always run into issues with calibration, metering and differing standards being used.
Also, different companies choose different ballistics for their meters, so even if everything uses the same line level standard, the meters might read differently anyway.
Luckily, with digital you don't have to be terribly exact with the recording levels.
Also, different companies choose different ballistics for their meters, so even if everything uses the same line level standard, the meters might read differently anyway.
Luckily, with digital you don't have to be terribly exact with the recording levels.
"I guess ultimately the fix is to set the gain on my mixer to a much lower level and simply read the digital metering. I don't really feel satisfied with that though for some reason,"
You have my sympathy Chris! "We" did try to rationalize things many years ago (had bumber stickers "600 Ohms is dead!") but around a century later dBu (was dBm) is still with us and the 0.775V reference comes from the telephone industry when, AFAIK, there were no amplifiers even!
There IS a downside to working at -10dBV, the signal exchange system, cables, are more prone to picking up interference but for the short runs in domestic surroundings this is rarely a problem*.
The signal levels inside and going to and from gear is related to and determined by the DC supply voltages inside said gear. "Pro" kit will have effectively 36volt supplies (tho' 34V is better for reliability) whereas your domestics will be 30V or even as low as 24V.
Running higher internal supplies is more expensive. Transformers, capacitors all cost more and the gear will run warmer and maybe need to be bigger and metal costs!
Manufacturers for the most part do not help us with specifications. What we REALLY need to know is what input voltage (in millivolts/dB) produces -18dBFS in the software or any other dBFS level we can get a handle on.
But if just backing off the mixer output bugs you Chris and you intend to keep on with this recording game. Learn to Solder! You will find as you progress that mic cables ALWAYS fail at 16:30 of a wet Sunday and there is no shop open! Then you can and will want to experiment with connecting gear or even just need to connect something with a non-standard connector, having some electronics smarts can be of enormous use.
I am not suggesting you build a synth or something! No, just passive stuff (for now but the PP3 is always with us!) The attenuator box I referred to earlier is very simple, will post a set of drawings if you like?
*Tis a little known fact, a BALANCED line input will always be considerably noisier (hiss) than a simple unbalanced one unless VERY carefully and expensively made!
Dave.
You have my sympathy Chris! "We" did try to rationalize things many years ago (had bumber stickers "600 Ohms is dead!") but around a century later dBu (was dBm) is still with us and the 0.775V reference comes from the telephone industry when, AFAIK, there were no amplifiers even!
There IS a downside to working at -10dBV, the signal exchange system, cables, are more prone to picking up interference but for the short runs in domestic surroundings this is rarely a problem*.
The signal levels inside and going to and from gear is related to and determined by the DC supply voltages inside said gear. "Pro" kit will have effectively 36volt supplies (tho' 34V is better for reliability) whereas your domestics will be 30V or even as low as 24V.
Running higher internal supplies is more expensive. Transformers, capacitors all cost more and the gear will run warmer and maybe need to be bigger and metal costs!
Manufacturers for the most part do not help us with specifications. What we REALLY need to know is what input voltage (in millivolts/dB) produces -18dBFS in the software or any other dBFS level we can get a handle on.
But if just backing off the mixer output bugs you Chris and you intend to keep on with this recording game. Learn to Solder! You will find as you progress that mic cables ALWAYS fail at 16:30 of a wet Sunday and there is no shop open! Then you can and will want to experiment with connecting gear or even just need to connect something with a non-standard connector, having some electronics smarts can be of enormous use.
I am not suggesting you build a synth or something! No, just passive stuff (for now but the PP3 is always with us!) The attenuator box I referred to earlier is very simple, will post a set of drawings if you like?
*Tis a little known fact, a BALANCED line input will always be considerably noisier (hiss) than a simple unbalanced one unless VERY carefully and expensively made!
Dave.
Still can't edit.
I gave the impression that "I" was a century old! Not quite, coming up to 70% of that. No I meant that the dB reff 0.775V was at least that old.
It is interesting that the (relatively young) guitar electronics industry is based around dBV? It is still however quite hard to find test gear calibrated in other than dBu.
Dave.
I gave the impression that "I" was a century old! Not quite, coming up to 70% of that. No I meant that the dB reff 0.775V was at least that old.
It is interesting that the (relatively young) guitar electronics industry is based around dBV? It is still however quite hard to find test gear calibrated in other than dBu.
Dave.
ChrisPFuchs
New member
That seems like a fun and useful project! If you wouldn't mind, sure, I'd appreciate that.
That's interesting, I wouldn't have expected that. For short distances and most locations, like you said about the downside to working at -10dBV, balanced cables and inputs aren't necessary anyways are they?
That makes sense. Good to know!
Bobbsy
Boring Old Git
Now you're just playing "confuse the newbies" Dave.
Yeah, in a wonderful theoretical world, a simple, unbalanced circuit would be ideal. We don't live in a wonderful, theoretical world and the advantages of balanced circuits outweigh this theoretical benefit by a huge margin.
Add to this that balanced ins and outs tend to be on gear designed to be better quality than low end domestic (i.e. unbalanced) stuff and I'd much rather work in a world where I never see another unbalanced line or phono jack again. It would be unfortunate if anyone trying to learn from this forum took your statement literally and assumed unbalanced was "better" than balanced.
(Part of my baldness stems from designing patch bays--and I'm talking big ones with hundreds of rows--to keep the few unbalanced circuits we had to handle away from everything else--and build in lots of transformers for isolation.)
ChrisPFuchs
New member
Ah, I see. That is interesting though.
I consider myself well and truly admonished Bobbs!
You are quite right, the Newb section was NOT the place to drop in that particular snippet of information.
Right! Noobs, listen up! BALANCED connections between pieces of audio gear are almost always preferable to unbalanced. For microphone circuits do not consider anything else. Short, under 10mtrs say, line level unbalanced runs will USUALLY give no problems but even so, balance if you can.
But baldness Bob is just down to luck. I have lots more hair at 70 than my son does at 43! He has mind you turned both me and Wife very grey!
Dave.
You are quite right, the Newb section was NOT the place to drop in that particular snippet of information.
Right! Noobs, listen up! BALANCED connections between pieces of audio gear are almost always preferable to unbalanced. For microphone circuits do not consider anything else. Short, under 10mtrs say, line level unbalanced runs will USUALLY give no problems but even so, balance if you can.
But baldness Bob is just down to luck. I have lots more hair at 70 than my son does at 43! He has mind you turned both me and Wife very grey!
Dave.