ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1] 2 3 ... 5   Go Down

Author Topic: Industrial quality CDJ connections  (Read 9877 times)

Tony Rivieras

  • Newbie
  • *
  • Offline Offline
  • Posts: 23
Industrial quality CDJ connections
« on: January 22, 2015, 06:31:30 pm »

Greetings all, i recently was having a conversation on what connection options provide the best quality when connecting CDJ 2K Nexus's to a DJM 900 Mixer. My associate and i both agree that SPIDIF into the mixer and out of the mixer is most likely the best option provided the DJ plays .wav files. As we got into it more i had the idea of using high end BNC cables with RCA adapters. My reason for that is in this foto http://i.imgur.com/2j0k6L8.jpg It seems like they are using BNC. My question is if money was no object would using BNC cables be the best option?

For reference the PA would be a Line Array system such as a D&B or Meyer system and going digital via spidif into the sound desk.




Best.

Tony
Logged

Corey Scogin

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1066
  • Birmingham, AL, US
Re: Industrial quality CDJ connections
« Reply #1 on: January 22, 2015, 06:49:59 pm »

Greetings all, i recently was having a conversation on what connection options provide the best quality when connecting CDJ 2K Nexus's to a DJM 900 Mixer. My associate and i both agree that SPIDIF into the mixer and out of the mixer is most likely the best option provided the DJ plays .wav files. As we got into it more i had the idea of using high end BNC cables with RCA adapters. My reason for that is in this foto http://i.imgur.com/2j0k6L8.jpg It seems like they are using BNC. My question is if money was no object would using BNC cables be the best option?

For reference the PA would be a Line Array system such as a D&B or Meyer system and going digital via spidif into the sound desk.

BNC is a connector not a cable.  There should be no difference between any two analog audio cables especially at short distances.

It's typically better to keep things in the digital domain as long as possible to minimize A/D and D/A conversion so if the SPDIF works and proves to be reliable enough then use it.  It's likely there won't be any noticeable difference either way.

The file type being played should not affect whether SPDIF or analog sounds better.
Logged

Tony Rivieras

  • Newbie
  • *
  • Offline Offline
  • Posts: 23
Re: Industrial quality CDJ connections
« Reply #2 on: January 22, 2015, 07:04:13 pm »

Yep sorry i meant to say BNC cable, the only reason i thought of it was because of its use that that picture. at least i think it's BNC
Logged

Mac Kerr

  • Old enough to know better
  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 6264
  • Audio Plumber
Re: Industrial quality CDJ connections
« Reply #3 on: January 22, 2015, 07:37:19 pm »

Greetings all, i recently was having a conversation on what connection options provide the best quality when connecting CDJ 2K Nexus's to a DJM 900 Mixer. My associate and i both agree that SPIDIF into the mixer and out of the mixer is most likely the best option provided the DJ plays .wav files. As we got into it more i had the idea of using high end BNC cables with RCA adapters. My reason for that is in this foto http://i.imgur.com/2j0k6L8.jpg It seems like they are using BNC. My question is if money was no object would using BNC cables be the best option?

For reference the PA would be a Line Array system such as a D&B or Meyer system and going digital via spidif into the sound desk.

I would be curious how the mixer manages to be clocked to 2 different sources unless there is a wordclock distro.

Mac
Logged

Tony Rivieras

  • Newbie
  • *
  • Offline Offline
  • Posts: 23
Re: Industrial quality CDJ connections
« Reply #4 on: January 22, 2015, 07:59:41 pm »

I would be curious how the mixer manages to be clocked to 2 different sources unless there is a wordclock distro.

Mac

Mac

I am not exactly sure what you mean when you mention a "wordclock". The way i thought it worked was i connect the CDJ's to the DJ Mixer via Spidif and then go spidif to AES into the PA mixer which would most likely be a Avid Venue profile.

Tony

Logged

Mac Kerr

  • Old enough to know better
  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 6264
  • Audio Plumber
Re: Industrial quality CDJ connections
« Reply #5 on: January 22, 2015, 08:16:42 pm »

Mac

I am not exactly sure what you mean when you mention a "wordclock". The way i thought it worked was i connect the CDJ's to the DJ Mixer via Spidif and then go spidif to AES into the PA mixer which would most likely be a Avid Venue profile.

Tony

SPDIF is digital. For a digital source (CD player) to work with a digital input, the digital input has to be clocked from the source, or be clocked from a separate clock source that goes to all digital devices (wordclock). If the mixer clocks to 1 of the CD players, how does it stay in clock sync with the other one, it can only sync to 1 clock.

Mac
Logged

Corey Scogin

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1066
  • Birmingham, AL, US
Re: Industrial quality CDJ connections
« Reply #6 on: January 23, 2015, 12:04:29 am »

Yep sorry i meant to say BNC cable, the only reason i thought of it was because of its use that that picture. at least i think it's BNC

Those look like standard RCA to me.

I would be curious how the mixer manages to be clocked to 2 different sources unless there is a wordclock distro.

Would it be possible / feasible for it to resample each input to its own internal clock?  Just guessing.  Out of curiosity, I looked over the manual and it doesn't say anything about wordclock sync issues.
Logged

Tony Rivieras

  • Newbie
  • *
  • Offline Offline
  • Posts: 23
Re: Industrial quality CDJ connections
« Reply #7 on: January 23, 2015, 12:32:02 am »

Those look like standard RCA to me.

Would it be possible / feasible for it to resample each input to its own internal clock?  Just guessing.  Out of curiosity, I looked over the manual and it doesn't say anything about wordclock sync issues.

I Must be starting to go blind i thought those connectors seem a bit wider than normal. As for the wordclock i still dont see how that would be a problem i have used the Spidif set up i mentioned about 2 times and it was quite plug and play with zero issues at all
Logged

TJ (Tom) Cornish

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 4166
  • St. Paul, MN
Re: Industrial quality CDJ connections
« Reply #8 on: January 23, 2015, 08:50:40 am »

I Must be starting to go blind i thought those connectors seem a bit wider than normal. As for the wordclock i still dont see how that would be a problem i have used the Spidif set up i mentioned about 2 times and it was quite plug and play with zero issues at all
Generally speaking, connecting multiple digital outputs - i.e. several playback decks to a mixer requires some external mechanism (wordclock) to keep the input devices exactly in sync, or a Sample Rate Converter (SRC) that uses a bit of memory to buffer the sound to absorb timing issues.  Without either of these two functions, you will hear clicks and pops in the audio as samples are lost between devices that aren't clocked together.  If this is the case, the Analog inputs will definitely provide better quality.

I looked in the manual: (gasp!)
http://www.pioneerelectronics.com/StaticFiles/Manuals/DJ/DJM-900nexus_OperatingInstructions070511.pdf

and it appears in the block diagram on pg 25 that this device actually has SRCs on every digital input, which should solve the problem.  There's no external wordclock feature, so you can't connect it even if you wanted to.

The theoretical advantages of digital vs analog are unlikely to be consequential over 3' of cable, so if it were me, I would use whatever connection method is more convenient.  Sp/Dif is one cable rather than a pair of RCA analogs, so that's a bit less work, however you should be using a 120Ω digital coax cable for Sp/Dif rather than a normal analog RCA cable (though even that isn't likely to matter with very short cables).
Logged

Tony Rivieras

  • Newbie
  • *
  • Offline Offline
  • Posts: 23
Re: Industrial quality CDJ connections
« Reply #9 on: January 23, 2015, 02:10:59 pm »

Generally speaking, connecting multiple digital outputs - i.e. several playback decks to a mixer requires some external mechanism (wordclock) to keep the input devices exactly in sync, or a Sample Rate Converter (SRC) that uses a bit of memory to buffer the sound to absorb timing issues.  Without either of these two functions, you will hear clicks and pops in the audio as samples are lost between devices that aren't clocked together.  If this is the case, the Analog inputs will definitely provide better quality.

I looked in the manual: (gasp!)
http://www.pioneerelectronics.com/StaticFiles/Manuals/DJ/DJM-900nexus_OperatingInstructions070511.pdf

and it appears in the block diagram on pg 25 that this device actually has SRCs on every digital input, which should solve the problem.  There's no external wordclock feature, so you can't connect it even if you wanted to.

The theoretical advantages of digital vs analog are unlikely to be consequential over 3' of cable, so if it were me, I would use whatever connection method is more convenient.  Sp/Dif is one cable rather than a pair of RCA analogs, so that's a bit less work, however you should be using a 120Ω digital coax cable for Sp/Dif rather than a normal analog RCA cable (though even that isn't likely to matter with very short cables).

It would be a 10 foot cable, not sure if that makes any difference. However since you mentioned 120-ohm cable. I noticed i have only 75-ohm cable (this one http://zaolla.com/products/zae-100 ) Of course i ask this question to see what people would recommend most for when using such a large PA.

Also again not sure if it matters to much but the DJ Mixer would be set to 96kHz

Logged
Pages: [1] 2 3 ... 5   Go Up
 


Page created in 0.082 seconds with 22 queries.