+4 or +10 ?

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+4 or -10 ?

I am using the E-MU 1212m soundcard. In the patchmix settings, I am using the +4 input and output settings. What is the difference between the two settings as far as the overall sound quality, or does it even make any difference? Thanks!
 
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I think you mean +4 and -10.

I'm not the best to answer this, but +4 is usually considered to be a hotter signal and used more so in professional equipment. -10 is usually consumer...unbalanced too I believe. If your equipment that you're running into the card will put a +4 signal out, definitely use that.

That is the general gist of it.
 
Thanks, but does the sound differ from one setting to the other?
 
+4dBu and -10dBu are two different levels of a Line Level signal. You may hear someone say something like "Line Level referenced to +4dBu (or -10 dBu). Basically +4dBu is considered "professional" level and is a hotter signal, than -10dBu which is considered "consumer" level.

There shouldn't be any difference in sound quality at all, just level. The important thing is to have your levels matched up. For example if you are feeding a -10dBu signal (lower level) to a device that is looking for a +4dBu signal, then you might not be getting enough gain. On the flip side, if you are sending a +4dBu signal to a device looking for a -10dBu signal, then you might be overgaining the signal.

So the only thing you should notice when you change your settings is the level of your signal changes.

Balanced/Unbalanced if a different issue from +4dBu/-10dBu

For those not offended by Wikipedia:
http://en.wikipedia.org/wiki/Line_level
This makes for some good reinforcement of the information
 
they're just two different ways of comparing voltage levels.
Back in the day dBu (used with the +4 you're seeing) was the only designation professionals had to work with. When consumer audio products started being made, the dBV level was created and so they started putting -10dBV on the consumer gear...+4dBu just kinda stuck in the professional world (if it ain't broke, don't fix it).
Both designations just reference different voltage levels. There is no "better" sounding level. One references 1V and the other .775V, so there is going to be a slight difference between the two. In fact it's an 11.79dB difference.

Basically, just plug a +4dBu output into a +4dBu input. And vice versa.
 
bennychico11 said:
they're just two different ways of comparing voltage levels.
Back in the day dBu (used with the +4 you're seeing) was the only designation professionals had to work with. When consumer audio products started being made, the dBV level was created and so they started putting -10dBV on the consumer gear...+4dBu just kinda stuck in the professional world (if it ain't broke, don't fix it).
Both designations just reference different voltage levels. There is no "better" sounding level. One references 1V and the other .775V, so there is going to be a slight difference between the two. In fact it's an 11.79dB difference.

Basically, just plug a +4dBu output into a +4dBu input. And vice versa.
Click to expand...

According to Wikipedia, and this is them, not me, I didn't know this, -10dBV has a voltage level of .3162 V RMS, and +4dBu has a voltage level of 1.228 V RMS. You're right that -10 is dbV, not dBu, that was my mistake in my first post.

dBu or dBv references .775 Volts. dBV references 1 Volt.

But don't get bogged down in all this dB stuff, the point is, as bennychico stated, just plug one output into the same input, and you're good.
 
RAK said:
According to Wikipedia, and this is them, not me, I didn't know this, -10dBV has a voltage level of .3162 V RMS, and +4dBu has a voltage level of 1.228 V RMS.
Click to expand...

Yep, the equation for those are:
dBV = 20 * log (voltage / 1V)
dBu = 20 * log (voltage / .775 V)

Doing the math for the correct decibel numbers you'll get your output voltage.
Here's a great link giving pretty much a 101 on dB
 
bennychico11 said:
Yep, the equation for those are:
dBV = 20 * log (voltage / 1V)
dBu = 20 * log (voltage / .775 V)

Doing the math for the correct decibel numbers you'll get your output voltage.
Here's a great link giving pretty much a 101 on dB
Click to expand...

I'm hip to all that, I guess I just let Wikipedia do the calculations. 20logVout/Vin for voltage, or 10logVout/Vin for power. dBm being the referenced to 1 mW of power.
Maybe you know this, but my understanding is that a Bel is .002 Dynes/cm2. My question is, what's a Dyne?

Word.
 
RAK said:
Maybe you know this, but my understanding is that a Bel is .002 Dynes/cm2. My question is, what's a Dyne?
Click to expand...

A unit of force. In this case, it's the amount of force needed to produce a given SPL.
 
RAK said:
I'm hip to all that, I guess I just let Wikipedia do the calculations. 20logVout/Vin for voltage, or 10logVout/Vin for power. dBm being the referenced to 1 mW of power.
Click to expand...


be careful, it's not really Vin (or voltage in)...it's a reference voltage. Basically in our world it's just how much voltage it takes for your meter to read 0dBVU. Your gear just remembers this reference and says "anything coming in at this voltage level = 0dB.
And think of the 20 log equation as an equation to use for PRESSURE...not just voltage. This is how we measure SPL (sound pressure levels) too.

Maybe you know this, but my understanding is that a Bel is .002 Dynes/cm2. My question is, what's a Dyne?
Click to expand...

Well, the bel and decibel are just ratios. They don't really equal anything until you have a reference point. So saying that a Bel = .002 Dynes/cm2...would depend on what you're talking about I guess. But I think the Bel was mainly used for telephone companies in trying to figure out telephone cables.

However, a dyne is equal to 10^-5 newtons. As the dictionary defines it:
"the force required to accelerate a mass of one gram at a rate of one centimeter per second squared"
But this gets WAY too far into physics...and is way too confusing for this conversation. For practical concerns (since you'll probably never want to use the Bel in audio), just think that the decibel (dB)= .1B (Bel).
 
boingoman said:
A unit of force. In this case, it's the amount of force needed to produce a given SPL.
Click to expand...

okay, so if we're talking about SPL then I think your referencing the smallest possible sound (which we call 0dBSPL). The math gets confusing for me when trying to convert it, but I think once you get all the way down to the end
.002 Dynes/cm^2 = .00002 Pa (or .00002 N/m^2)

...which ends up being the smallest threshold of human hearing. Our reference level for 0dBSPL.
 
bennychico11 said:
But this gets WAY too far into physics...and is way too confusing for this conversation. For practical concerns (since you'll probably never want to use the Bel in audio), just think that the decibel (dB)= .1B (Bel).
Click to expand...

Oh for sure, I just thought that's where we were taking this. :)

At some point I learned Vout/Vin, but I see what you're saying about the reference voltage.

Basically we use the same formula for Voltage/Power/Intensity/SPL.
20(or 10)log(X/Xo)
 
bennychico11 said:
...which ends up being the smallest threshold of human hearing. Our reference level for 0dBSPL.
Click to expand...


Yeah, that sounds familiar. It's all coming back now. That's where the .002 dynes/cm2 came from.
 
RAK said:
Basically we use the same formula for Voltage/Power/Intensity/SPL.
20(or 10)log(X/Xo)
Click to expand...

yes. If we're talking about Power (watts) or Intensity (watts per meter squared) we're going to use the 10 log formula.
But know that voltage, however, is similar to Pressure...and in fact is sometimes called electrical pressure. When talking about pressure in relationship to intensity, it's defined as I = P^2/r....(where r is air impedance) And when we use this formula, intensity and pressure do not vary directly. In other words when you double in pressure, intensity is going to quadruple. So that 10 log formula doesn't work anymore. After substituting the expression for intensity in place of X, Y...and then simplifying we get 20 log (Px / Py). So we use this formula.
 
bennychico11 said:
yes. If we're talking about Power (watts) or Intensity (watts per meter squared) we're going to use the 10 log formula.
But know that voltage, however, is similar to Pressure...and in fact is sometimes called electrical pressure. When talking about pressure in relationship to intensity, it's defined as I = P^2/r. And when we use this formula, intensity and pressure do not vary directly. In other words when you double in pressure, intensity is going to quadruple. So that 10 log formula doesn't work anymore. After substituting the expression for intensity in place of X, Y...and then simplifying we get 20 log (Px / Py). So we use this formula.
Click to expand...


No, I know, the 10log is only for Power/Intensity, the 20Log is for Voltage/SPL.

But if I is current and P is power, then I=Root(P/R). Talk about mixing metaphors. I just like equations.
 
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