DJM USB vs RCAs vs Digital

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11-29-2017, 11:53 AM
Mark T

2 Attachment(s)

DJM USB vs RCAs vs Digital

Hello All ,
Am Facing something strange for those different connection

I Do usually play through my laptop using Traktor
I Use USB port form my mixer to get the Sound instead of using the CDJs as soundcard

But Noticed if am playing with a USB stick, connected via RCAs and the other deck having the same track on laptop having its sound through USB to the mixer , there is a Massive difference is sound Level Output.

I connected to Digital instead of RCAs , I Found that they are typically the same , but a very little noticeable sound difference from usb to digital channel

Attachment 28017
In this photo , CH1 uses Digital Input , CH2 uses USB Signal , Almost same gain but appears that USB is slightly Higher thats why I Had to decrease the Gain a very unnoticeable move to make them both same limit to reach almost 0 dB

Attachment 28016
In this photo , CH1 Connected through RCAs , CH2 remains USB with same previous setup for the gain as noticed .

Kindly help with your info :)
11-29-2017, 12:17 PM
SlayForMoney

What exactly are you trying to do? Or better yet, what is the problem here (that gain/trim knob cannot fix)?
11-29-2017, 01:49 PM
Mark T

Quote:

Originally Posted by SlayForMoney

What exactly are you trying to do? Or better yet, what is the problem here (that gain/trim knob cannot fix)?

I Am asking why The Signal Coming Through Digital or USB is Less than the one By RCAs ?

In the First Photo You will see almost same signal and just little difference in gain to maintain both 0dB , CH1 is connected to the first CDJ by Digital ports , And CH2 receiving the second signal from USB from the 2nd CDJ and same track is played on both.

Second Photo , CH1 Receives the Signal from RCA Cables from the First CDJ , and the Second still USB .
11-29-2017, 08:00 PM
Mastah Kyler

check page 2 of this thread, idk if it will answer your question exactly but it might help http://forum.djtechtools.com/showthread.php?t=94269
11-30-2017, 02:01 PM
SlayForMoney

Quote:

Originally Posted by Mark T

I Am asking why The Signal Coming Through Digital or USB is Less than the one By RCAs ?

Because higher-end CDJ's have digital and analog outputs and.... because of tehnical differences they have different output volumes. :blink:
Is this really something that needs to be explained? Thats why there's that trim knob...so you can adjust the volume when mixing from different sources.

PS output from the internal USB interface can be adjusted in the DJ software preferences
12-08-2017, 05:50 AM
Mark T

Quote:

Originally Posted by Mastah Kyler

check page 2 of this thread, idk if it will answer your question exactly but it might help http://forum.djtechtools.com/showthread.php?t=94269

Thanks a lot :)
12-08-2017, 05:51 AM
Mark T

Quote:

Originally Posted by SlayForMoney

Because higher-end CDJ's have digital and analog outputs and.... because of tehnical differences they have different output volumes. :blink:
Is this really something that needs to be explained? Thats why there's that trim knob...so you can adjust the volume when mixing from different sources.

PS output from the internal USB interface can be adjusted in the DJ software preferences

Excuse my lack of knowledge , I think none knows everything , we keep up learning dude ;)
12-08-2017, 12:01 PM
SlayForMoney

Quote:

Originally Posted by Mark T

Excuse my lack of knowledge , I think none knows everything , we keep up learning dude ;)

I did not mean to be condoscending, of course nobody knows everything and we were all at one point beginners. But to be honest, because of the equipment in question I expected a complicated question/problem so it kinda threw me off. The function of trim/gain knob on a dj mixer is something that I would explain in a first DJ lesson to a beginner.
12-09-2017, 10:41 AM
Mark T

Quote:

Originally Posted by SlayForMoney

I did not mean to be condoscending, of course nobody knows everything and we were all at one point beginners. But to be honest, because of the equipment in question I expected a complicated question/problem so it kinda threw me off. The function of trim/gain knob on a dj mixer is something that I would explain in a first DJ lesson to a beginner.

Am DJying since 10years , and frankly didnt get the occasion to try digital vs rca , casue never used Digitals , I Began to notice the difference between USB and RCAs when i started a year ago Connecting the mixa VIA USB instead of RCAs from the CDJs , thats why am asking :)

Thanks !
12-09-2017, 12:14 PM
Moostapha

Quote:

Originally Posted by Mark T

Am DJying since 10years , and frankly didnt get the occasion to try digital vs rca , casue never used Digitals , I Began to notice the difference between USB and RCAs when i started a year ago Connecting the mixa VIA USB instead of RCAs from the CDJs , thats why am asking :)

Thanks !

So...the longer version of this is that different kinds of audio connections have different reference levels. Depening on whether you're talking analog or digital and the mix of speific gear...it's a huge can of worms to open. There's a lot of information about it all over the place. Gearslutz, wavemusic, and other recording forums present a wealth of knowledge mixed with old wives tales and flat out lies

The details of this topic (gain staging) and a lot of the rules of thumb come from analog mixers, in which adding gain (amplifying/boosting a signal) anywhere amplifies both the signal (e.g., the song) and the noise (e.g., hum, pops, clicks, background electronic interference, etc.). A large part of how good something sounded was how loud the signal was compared to the noise floor (the quiet noise inherent in all electronics), and a lot of the techniques we still follow come from a time when the noise floor was around -60dB (compared to 0dB peaks). With modern digital stuff, like what appears to be a DJM-2000, the noise floor of the mixer is a lot quieter....quiet enough to be basically nonexistant.

Part of what a mixer does is accounting for these reference levels so that you can mix a very quiet record played with a very weak cartridge to a modern digital track played from an insanely hot audio interface without a huge shift in volume.

It's actually more complicated in analog mixers due to a much louder noise floor, very different amounts of headroom (above 0dBu), and a few different ways of both cutting and boosting a signal.

There's a lot more to go into it if you care to learn the details. But from playing with Pioneer mixers and spending way too much time reading, it boils down to a few simple facts.

1. The position of the gain/trim knob is irrelevant. It has to be right for what you're playing, but the actual position doesn't matter.

2. The numbers on the meter are arbitrary and kind of "fudged" to fit how the majority of DJs play, which is to say that 0dB (top of the green) seems to have nothing directly to do with 0dBFS (which is where digital audio clips) or 0VU or 0dBU or any other sensible standard.

3. All of the internals of that mixer seem to work best with your tacks peaking somewhere in the yellow. If you hit red, it's too hot. If you actually clip it internally or clip the output DAC, you'll hear it, and it sound's horrible.

I haven't played extensively with a DJM-2000, but every other Pioneer mixer (including the all-in-ones) that I've played with since they switched from analog to digital works like that.

....and a few guidelines...

1. Turn the trim control so your tracks, at their loudest points, are reading into the yellow. In that digital mixer, it's not about noise, it's about getting the right response from the EQs, filters, internal effects, and the "magic" that happens in their summing algorithm.

2. When a channel is open, playing by itself, the channel fader should be all the way up.

3. Adjust the master out so that the master meter is peaking in the yellow and never hits red, unless you're playing somewhere with a FOH guy that tells you to do something different (he probably has a reason).

This is the way the vast majority of modern mixers are made to work.

Other things work differently.

Most DAWs aim for completely clean summing and use digital math internally that make the noise floor even more nonexistant than most DJ mixers. They don't really care whether your channels are peaking at -5 or -200 as long as it gets turned up enough at the end that you can actually hear things. Plugins and processors do, but that's a different story.

Traktor itself seems to be set up to sound terrible. Everything runs hot as hell for literally no reason. A few years ago, I dove into experimenting with it's gain staging and figured out that it's almost impossible to clip traktor internally (again, because of digital math), that it basically doesn't have a noise floor, and that everything works a good bit better if you turn all of the channel gains down. All of NI's software that I've played with seems to work like that. I don't know if they're trying to keep recording engineers in business or just figure that people wanting warmth, punch, and subtlety will get it right eventually...or if they actually think it sounds good set to it's defaults.

Sorry for the long-winded explanation for a very simple issue. But...it's actually not all that simple. It's just that companies like Pioneer have figured out what DJs are probably going to do anyway and designed their gear to match that instead of actually requiring people to learn the finer points of what they're doing.