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Title: Industrial quality CDJ connections
Post by: Tony Rivieras 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
Title: Re: Industrial quality CDJ connections
Post by: Corey Scogin 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.
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras 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
Title: Re: Industrial quality CDJ connections
Post by: Mac Kerr 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
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras 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

Title: Re: Industrial quality CDJ connections
Post by: Mac Kerr 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
Title: Re: Industrial quality CDJ connections
Post by: Corey Scogin 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.
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras 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
Title: Re: Industrial quality CDJ connections
Post by: TJ (Tom) Cornish 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 (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).
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras 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 (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

Title: Re: Industrial quality CDJ connections
Post by: TJ (Tom) Cornish on January 23, 2015, 02:19:55 pm
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
I'm incorrect - Sp/Dif is 75Ω, AES is 120Ω.  You're fine.  96Khz makes ZERO difference compared to 44.1Khz (it's arguably worse due to passing ultrasonic noise that speakers can't reproduce and ears can't hear anyway), and if it were me and I was actually spinning audio CDs, I'd leave the system at 44.1K to avoid one more unnecessary SRC.

Live audio is very different than being in a studio.  With playback, important factors are:
1.  Having enough rig for the gig
2.  Having quality speakers
3.  Room acoustics
4.  Having source material that isn't re-ripped three times to effectively 32kbps
5. ...
6. ...
...
8,791: interconnection settings between devices.

Not even the largest and/or most pro PA changes this; and in many cases, the larger the system, the poorer the fidelity.  The more elements in a system to get the output you need interfere with each other, not to mention severe loss of hearing fidelity due to threshold shift of your listeners at loud concert levels.

Enjoy your gear.
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 02:42:27 pm
I'm incorrect - Sp/Dif is 75Ω, AES is 120Ω.  You're fine.  96Khz makes ZERO difference compared to 44.1Khz (it's arguably worse due to passing ultrasonic noise that speakers can't reproduce and ears can't hear anyway), and if it were me and I was actually spinning audio CDs, I'd leave the system at 44.1K to avoid one more unnecessary SRC.

Live audio is very different than being in a studio.  With playback, important factors are:
1.  Having enough rig for the gig
2.  Having quality speakers
3.  Room acoustics
4.  Having source material that isn't re-ripped three times to effectively 32kbps
5. ...
6. ...
...
8,791: interconnection settings between devices.

Not even the largest and/or most pro PA changes this; and in many cases, the larger the system, the poorer the fidelity.  The more elements in a system to get the output you need interfere with each other, not to mention severe loss of hearing fidelity due to threshold shift of your listeners at loud concert levels.

Enjoy your gear.

Interesting you mentioned the AES's 120ohm Because i was planing on using a Spidif to AES cable on the digital out of the DJ mixer to go into the sound console. (this cable http://www.fullcompass.com/product/354649.html) is that something that would be an issue?

Title: Re: Industrial quality CDJ connections
Post by: TJ (Tom) Cornish on January 23, 2015, 02:46:57 pm
Interesting you mentioned the AES's 120ohm Because i was planing on using a Spidif to AES cable on the digital out of the DJ mixer to go into the sound console. (this cable http://www.fullcompass.com/product/354649.html) is that something that would be an issue?
For 10' it's going to be fine.  For 100', not so fine (though the bigger issue is that Sp/Dif is single-ended and not intended for long-distance transmission; AES is balanced and can go a couple hundred feet).

I would not plan on the system provider allowing you to connect digitally, however.  You will likely be handed a DI box and expected to provide a pair of analog RCAs or 1/4" plugs.

Digital interconnects are one of those things that seem great at first glance, but in practice it's almost always more work, more money, more compromises, and no benefit compared to plain-old analog cabling.
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 02:55:49 pm
For 10' it's going to be fine.  For 100', not so fine (though the bigger issue is that Sp/Dif is single-ended and not intended for long-distance transmission; AES is balanced and can go a couple hundred feet).


Yes i understand what Spidif is not made for long runs. What i had in mind was just using that 6 foot spidif to AES cable out of the mixer and then using a longer AES cable for the rest of the way to the sound desk
Title: Re: Industrial quality CDJ connections
Post by: TJ (Tom) Cornish on January 23, 2015, 02:59:44 pm
Yes i understand what Spidif is not made for long runs. What i had in mind was just using that 6 foot spidif to AES cable out of the mixer and then using a longer AES cable for the rest of the way to the sound desk
It doesn't work that way - Sp/Dif and AES are not the same thing.  To convert a Sp/Dif signal to a true AES signal requires an active box to re-transmit the signal in a balanced format.  Just changing the cable doesn't fix it.

This is moot anyway, as I will bet you any amount of money you like that you will not end up connecting to the system that way.  Not all desks have SRCs on the digital input, so the house system may have to clock to your mixer - something not likely to be popular with the system tech, and an analog connection via DI box provides material isolation benefits.

Once again, digital is not better than analog.
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 03:22:29 pm
It doesn't work that way - Sp/Dif and AES are not the same thing.  To convert a Sp/Dif signal to a true AES signal requires an active box to re-transmit the signal in a balanced format.  Just changing the cable doesn't fix it.

This is moot anyway, as I will bet you any amount of money you like that you will not end up connecting to the system that way.  Not all desks have SRCs on the digital input, so the house system may have to clock to your mixer - something not likely to be popular with the system tech, and an analog connection via DI box provides material isolation benefits.

Once again, digital is not better than analog.

Oh yes i have seen those boxes before when i searched for the cable.....was wondering what that was. As for the sound desk it would most likely be an Avid Venue profile from pictures i have seen it has AES inputs. Just to clarify and be 100% sure, if i used a Spidif to AES cable like the one i linked and plugged into one of those AES inputs on the profile  it would not work at all no matter the cable distance?

Title: Re: Industrial quality CDJ connections
Post by: TJ (Tom) Cornish on January 23, 2015, 03:28:22 pm
Oh yes i have seen those boxes before when i searched for the cable.....was wondering what that was. As for the sound desk it would most likely be an Avid Venue profile from pictures i have seen it has AES inputs. Just to clarify and be 100% sure, if i used a Spidif to AES cable like the one i linked and plugged into one of those AES inputs on the profile  it would not work at all no matter the cable distance?
It would likely work at less than 15' or so. 

Have you heard me say that digital is not better than analog?   Looking again at the mixer, it has balanced XLRs out.  If you are trying to be pro, use those.
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 03:34:41 pm
It would likely work at less than 15' or so. 

Have you heard me say that digital is not better than analog?   Looking again at the mixer, it has balanced XLRs out.  If you are trying to be pro, use those.

That is good to hear. I forgot to mention that I was also planing on using one of those cables to connect a CDJ directly to the sound console inside of FOH to play walk in music.

Thank you for your help
I am sure the sound engineers will look at me like im some kind of deranged lunatic when i tell them how i want to use SPIDIF out on the dj mixer.

Title: Re: Industrial quality CDJ connections
Post by: TJ (Tom) Cornish on January 23, 2015, 03:38:14 pm

I am sure the sound engineers will look at me like im some kind of deranged lunatic when i tell them how i want to use SPIDIF out on the dj mixer.
At best, they're going to ask you why (and you don't have any good reason); at worst you're going to seem either difficult to work with or a noobie.  This isn't a battle that I would choose to fight.
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 03:49:55 pm
At best, they're going to ask you why (and you don't have any good reason); at worst you're going to seem either difficult to work with or a noobie.  This isn't a battle that I would choose to fight.

My reason would be........."Digital less cables and sounds better" also forgot to mention that the audio is going to be recorded so that is another reason as to why i want the very highest sound quality possible
Title: Re: Industrial quality CDJ connections
Post by: TJ (Tom) Cornish on January 23, 2015, 03:57:02 pm
My reason would be........."Digital less cables and sounds better" also forgot to mention that the audio is going to be recorded so that is another reason as to why i want the very highest sound quality possible
And they're going to say "No it doesn't.  Here's a pair of XLRs."  And they will be right.

You seem to be very new at this, and I mean that in a non-condescending way.  I would suggest you invest your time practicing so you differentiate your craft by your musical skill, rather than chasing meaningless advantages- digital interconnects, which are really disadvantages.
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 04:04:44 pm
And they're going to say "No it doesn't.  Here's a pair of XLRs."  And they will be right.

You seem to be very new at this, and I mean that in a non-condescending way.  I would suggest you invest your time practicing so you differentiate your craft by your musical skill, rather than chasing meaningless advantages- digital interconnects, which are really disadvantages.

Lol at that first part. Yes i am very new to working with larger super high end PA's. In the past the largest PA i personally set up was 8 speakers all QSC and all Powered.

No offense taken and thank you again
Title: Re: Industrial quality CDJ connections
Post by: Mac Kerr on January 23, 2015, 04:33:41 pm
As for the sound desk it would most likely be an Avid Venue profile from pictures i have seen it has AES inputs.

Just to clarify a little more, your CD player is going to be putting out 44.KHz data, the Profile only runs at 48KHz, and the Profile does not have sample rate converters that I can find although I am admittedly not an Avid expert. In order to connect your CD player you will either need a fairly expensive external box to do the SRC, or you will go analog.

Take your 2 analog XLR cables to the system tech and say "Here is the stereo signal from my mixer".

Mac
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 04:43:58 pm
Just to clarify a little more, your CD player is going to be putting out 44.KHz data, the Profile only runs at 48KHz, and the Profile does not have sample rate converters that I can find although I am admittedly not an Avid expert. In order to connect your CD player you will either need a fairly expensive external box to do the SRC, or you will go analog.

Take your 2 analog XLR cables to the system tech and say "Here is the stereo signal from my mixer".

Mac

That that a unexpected problem. To solve it i decided that instead of using a CDJ for that i'll use a laptop with a Audio Interface ( this one http://www.musiciansfriend.com/pro-audio/tascam-us-1800-usb-2.0-audio-midi-interface) and just play the audio out of a DAW. Pretty complicated but oh well...... and thankfully the spec's on this audio interface seem to say that it can do 48khz

Tony



Title: Re: Industrial quality CDJ connections
Post by: TJ (Tom) Cornish on January 23, 2015, 04:53:54 pm
That that a unexpected problem. To solve it i decided that instead of using a CDJ for that i'll use a laptop with a Audio Interface ( this one http://www.musiciansfriend.com/pro-audio/tascam-us-1800-usb-2.0-audio-midi-interface) and just play the audio out of a DAW. Pretty complicated but oh well...... and thankfully the spec's on this audio interface seem to say that it can do 48khz

Tony
None of which will matter when you use the analog XLRs you're going to be using.
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 04:58:36 pm
None of which will matter when you use the analog XLRs you're going to be using.

Probably for the dj gear. but since the sound desk will be within 15 feet of the laptop it should be able to work with the Spidif to AES cable
Title: Re: Industrial quality CDJ connections
Post by: John L Nobile on January 23, 2015, 05:14:04 pm
That that a unexpected problem. To solve it i decided that instead of using a CDJ for that i'll use a laptop with a Audio Interface ( this one http://www.musiciansfriend.com/pro-audio/tascam-us-1800-usb-2.0-audio-midi-interface) and just play the audio out of a DAW. Pretty complicated but oh well...... and thankfully the spec's on this audio interface seem to say that it can do 48khz

Tony

Are you going to use this interface between your laptop and the sound board?
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 05:15:56 pm
Are you going to use this interface between your laptop and the sound board?

Yes i will use studio one as my DAW and route the output to the SPIDIF on the interface, going out of the spidif via a Spidif to AES cable into the sound board
Title: Re: Industrial quality CDJ connections
Post by: Mac Kerr on January 23, 2015, 05:29:25 pm
That that a unexpected problem. To solve it i decided that instead of using a CDJ for that i'll use a laptop with a Audio Interface ( this one http://www.musiciansfriend.com/pro-audio/tascam-us-1800-usb-2.0-audio-midi-interface) and just play the audio out of a DAW. Pretty complicated but oh well...... and thankfully the spec's on this audio interface seem to say that it can do 48khz

Tony

You seem determined to try this with a digital connection despite warning that it can be problematic, and the system provider may not let you do it anyway.

It will sound just as good analog and will be much more failure proof. Even with that Tascam interface you are going to have to clock it to the console and convert the SPDIF to AES. The only way to clock the interface to the console is to run an AES out from the console to the interface, where you will have to do an AES>SPDIF conversion into the digital input. To make the 2 protocol changes you will need 2 transformers, they are available from Canare (http://www.fullcompass.com/brand/CAN/AES-110-Ohm-Cable-Adapters-Transformers.html). Also read THIS (http://www.rane.com/note149.html).

Also be sure the files you want to play are 48KHz files.

Or... go analog.

Mac
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 05:50:15 pm
You seem determined to try this with a digital connection despite warning that it can be problematic, and the system provider may not let you do it anyway.

It will sound just as good analog and will be much more failure proof. Even with that Tascam interface you are going to have to clock it to the console and convert the SPDIF to AES. The only way to clock the interface to the console is to run an AES out from the console to the interface, where you will have to do an AES>SPDIF conversion into the digital input. To make the 2 protocol changes you will need 2 transformers, they are available from Canare (http://www.fullcompass.com/brand/CAN/AES-110-Ohm-Cable-Adapters-Transformers.html). Also read THIS (http://www.rane.com/note149.html).

Also be sure the files you want to play are 48KHz files.

Or... go analog.

Mac

I do indeed want to try to go Digital simply because it's being recorded and i want to have the highest quality possible recording. The steps you mentioned sound........rather complicated to say the least i can only hope the sound provider would have those items. Another reason is if i use SPIDIF to connect the cdj's to the dj mixer and go analog out that really defeats the purpose anyways


Title: Re: Industrial quality CDJ connections
Post by: Rob Spence on January 23, 2015, 06:02:00 pm
Yes i will use studio one as my DAW and route the output to the SPIDIF on the interface, going out of the spidif via a Spidif to AES cable into the sound board

You seemed to have missed that there is no SPIDF to AES cable. You can have an RCA to XLR but that doesn't convert the protocols.

You do not understand digital and clocking and you are not listening to the experts.


Sent from my iPad using Tapatalk HD
Title: Re: Industrial quality CDJ connections
Post by: g'bye, Dick Rees on January 23, 2015, 06:03:45 pm
I do indeed want to try to go Digital simply because it's being recorded and i want to have the highest quality possible recording. The steps you mentioned sound........rather complicated to say the least i can only hope the sound provider would have those items. Another reason is if i use SPIDIF to connect the cdj's to the dj mixer and go analog out that really defeats the purpose anyways

Re-inventing the wheel...
Title: Re: Industrial quality CDJ connections
Post by: Scott Holtzman on January 23, 2015, 06:13:59 pm
Another reason is if i use SPIDIF to connect the cdj's to the dj mixer and go analog out that really defeats the purpose anyways

It's not complicated, you are making it complicated.  You are making a recording of a recording so I get it you think if you send it digital you are going to get a better digital recording.  Maybe in theory but not in practice.

Is this recording something being done by a distributor to sell the content or for broadcast?  If so let them worry about it.  There are many issues, you don't want to record the FOH mix so if the folks paying for the recording care then they are going to split the input anyway and send it to the recording engineers equipment.

On the other hand if FOH is making you a recording you can only hope and pray and maybe bribe them to make you a clean mix. 

SPDIF is a consumer standard that is sometimes used in home studios.  It doesn't have a place in  pro audio.  I am not an Avid expert but I thought the I/O in the Profile (which is a series of console and I/O racks not a product I think) was all external.  In any case I further think you are mistaking ADAT connectors for SPDIF.  Just because a connector is the same doesn't mean the signal is the S/PDIF can be optical or electrical but is not the same as AES.  AES is balanced and like 8 volts P2P and S/PDIF is 1/2 volt designed for short distances and little noise immunity rejection.  The cable you found is odd, and not powered so it is a gimmick.  If you handed it to me I would put it in the trash. 

If you are hiring and paying the PA provider you could have a meeting, bring your gear and work out a digital interface if that is what you want and are willing to pay for.  If that is not the case, be a pro and hand them XLR's and move on.

 
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 06:28:08 pm
@Rob They make a cable that claims to do that http://www.fullcompass.com/product/354649.html i did ask and TJ said it would likely work. Note this is no longer about the longer run from the DJ Mixer but a shorter 15 foot cable from the laptop to the sound console in FOH. I don't 100% understand clocking it sounds like Timecode pretty much.

@Dick ??????>?>?>?>?>?>?.?.?.?

@Scott The Recording will not be for broadcast or commercial use, I personally want a copy to be able to listen back to it. It may be used to sync with videos that are recorded and uploaded on youtube of the dj sets. The photo i was using to reference the profile is http://www.gearsourcecdn.com/gearsource/v5/shared/image/listing/normal/d436e71b-68bd-442e-9bc0-34f92d47c422.jpg

I was never planing on going into the sound desk with a SPIDIF line but rather a SPIDIF to AES cable as i linked.

From what i was told a few hours ago it should work since the distance is very short if not i would need something like this http://www.bhphotovideo.com/c/product/395533-REG/Hosa_Technology_CDL_313_CDL_313_Data_Link.html

Title: Re: Industrial quality CDJ connections
Post by: Scott Holtzman on January 23, 2015, 06:38:51 pm
@Rob They make a cable that claims to do that http://www.fullcompass.com/product/354649.html i did ask and TJ said it would likely work. Note this is no longer about the longer run from the DJ Mixer but a shorter 15 foot cable from the laptop to the sound console in FOH. I don't 100% understand clocking it sounds like Timecode pretty much.

@Dick ??????>?>?>?>?>?>?.?.?.?

@Scott The Recording will not be for broadcast or commercial use, I personally want a copy to be able to listen back to it. It may be used to sync with videos that are recorded and uploaded on youtube of the dj sets. The photo i was using to reference the profile is http://www.gearsourcecdn.com/gearsource/v5/shared/image/listing/normal/d436e71b-68bd-442e-9bc0-34f92d47c422.jpg

I was never planing on going into the sound desk with a SPIDIF line but rather a SPIDIF to AES cable as i linked.

From what i was told a few hours ago it should work since the distance is very short if not i would need something like this http://www.bhphotovideo.com/c/product/395533-REG/Hosa_Technology_CDL_313_CDL_313_Data_Link.html

Timecode has nothing to do with clocking.  That picture is of the I/O box not the console.  You have no idea what I/O cards they will have installed nor what inputs they are going to be mapped to.  I really doubt the AES would be mapped to a main mix fader so you are asking the engineer to change his input list.  I don't think that is going to happen.

No matter what you do you are not going to hear the difference anyway.  I noticed you didn't even respond to my question about a dry mix?  Do you have the ability to contact the PA provider?  If you do ask them if you can use a digital input. 

Yes, the blue box think from Hosa is an active device and would properly convert from S/PDIF to AES.  External clock is the only issue you don't have to worry about, AES is plesiochronous in almost all practical applications for live sound.



Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 06:47:19 pm

Considering the entire show is 4 channels all stereo maybe he will be nice enough to change it. I most likely wont hear a difference live but it's the recording quality that im concerned about. The Dry mix...humm i mean how much could they change the sound? Some compression im sure perhaps a bit of EQ but i can't imagine it would really affect it that much
Title: Re: Industrial quality CDJ connections
Post by: Scott Holtzman on January 23, 2015, 07:00:36 pm
Considering the entire show is 4 channels all stereo maybe he will be nice enough to change it. I most likely wont hear a difference live but it's the recording quality that im concerned about. The Dry mix...humm i mean how much could they change the sound? Some compression im sure perhaps a bit of EQ but i can't imagine it would really affect it that much

 A bit of compression and a some EQ is going to change quite a bit compared to the inaudible difference between the balanced XLR's and the digital signal we just can't seem to talk you out of using.

Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 07:08:03 pm
A bit of compression and a some EQ is going to change quite a bit compared to the inaudible difference between the balanced XLR's and the digital signal we just can't seem to talk you out of using.

Im not sure how exactly i would get a "Dry mix" considering i need the master from the sound desk. As for the digital you may be happy to know that at least for the DJ Mixer's master out i guess i'll just use XLR's. Does it not defeat the propose of the CDJ's being plugged in via spidif?
Title: Re: Industrial quality CDJ connections
Post by: Scott Holtzman on January 23, 2015, 07:09:55 pm
Im not sure how exactly i would get a "Dry mix" considering i need the master from the sound desk. As for the digital you may be happy to know that at least for the DJ Mixer's master out i guess i'll just use XLR's. Does it not defeat the propose of the CDJ's being plugged in via spidif?

I won't be happy or sad.  I have no emotional attachment to what you are trying to achieve.

The dry mix would be done with an AUX send to answer that question.

Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 07:12:33 pm
I won't be happy or sad.  I have no emotional attachment to what you are trying to achieve.

The dry mix would be done with an AUX send to answer that question.

Alrighty then......well what about the CDJ's being connected via spidif only for the master to go out analog? does that not defeat the purpose of using Spidif on the CDJ connections?

And at least getting the recording actually recorded seems to be the easy part
Title: Re: Industrial quality CDJ connections
Post by: TJ (Tom) Cornish on January 23, 2015, 07:37:44 pm
I do indeed want to try to go Digital simply because it's being recorded and i want to have the highest quality possible recording. The steps you mentioned sound........rather complicated to say the least i can only hope the sound provider would have those items. Another reason is if i use SPIDIF to connect the cdj's to the dj mixer and go analog out that really defeats the purpose anyways
The only purpose being defeated in four pages of this thread is our time being wasted in trying to help you, since you clearly know better than probably 150 years of audio experience of the responders. For the eleventy-billionth time, digital does not sound better than analog. PERIOD.

There is nothing whatsoever you will gain other than pissing everybody off trying to do something uselessly complicated.

Either trust us, or take your superior knowledge off the thread and enjoy the fact that you are right in spite of reason and experience.
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 23, 2015, 07:55:51 pm
The only purpose being defeated in four pages of this thread is our time being wasted in trying to help you, since you clearly know better than probably 150 years of audio experience of the responders. For the eleventy-billionth time, digital does not sound better than analog. PERIOD.

There is nothing whatsoever you will gain other than pissing everybody off trying to do something uselessly complicated.

Either trust us, or take your superior knowledge off the thread and enjoy the fact that you are right in spite of reason and experience.

Okay i got it. Thank you very much for your answer. As some one mentioned perhaps i should meet with the sound provider and go over the options for this.
Title: Re: Industrial quality CDJ connections
Post by: Lee Buckalew on January 23, 2015, 08:25:58 pm
You seemed to have missed that there is no SPIDF to AES cable. You can have an RCA to XLR but that doesn't convert the protocols.


Sent from my iPad using Tapatalk HD

I am not suggesting the OP should use a digital rather than an analogue connection.  In this case the analogue will be a superior option but...

AES-3 balanced (120 Ohm) and SPDIF Coax can be interconnected (most successfully from SPDIF to AES3) with the use of a transformer.  I do this all the time for recording interfacing.  I have not tried an AES-3 BNC connection to SPDIF coax directly.  In theory this should also be fine because they are impedance matched.  There is a single bit difference between the two formats.  Modern chipsets generally work very well to send from the consumer based SPDIF to the pro AES3 by using a simple impedance conversion.  They don't work as well going from Pro to consumer.  As I said I have not tried direct SPDIF coax to AES-3 BNC connection but it should work in most cases with modern chips since it's already impedance matched.
Here's a link to a Rane publication on the topic. 

http://www.rane.com/note149.html

Lee
Title: Re: Industrial quality CDJ connections
Post by: Lee Buckalew on January 23, 2015, 08:45:35 pm
For 10' it's going to be fine.  For 100', not so fine (though the bigger issue is that Sp/Dif is single-ended and not intended for long-distance transmission; AES is balanced and can go a couple hundred feet).


SPDIF Coax has a maximum specified length limit of 10m.
AES-3 balanced on STP has a maximum specified limit of 100m.
AES-3 balanced via CAT5 has a maximum specified limit of 400m.
AES-3 id is unbalanced via 75 ohm coax and BNC connections.  It has a maximum specified limit of 1000m.

Balanced is not always better for long distance runs, lower impedance is.  For balanced AES-3 we often use baluns to convert to 75 ohm coax to gain a great advantage in transmission distance.

Lee

Title: Re: Industrial quality CDJ connections
Post by: Ray Aberle on January 27, 2015, 11:09:46 am

Okay i got it. Thank you very much for your answer. As some one mentioned perhaps i should meet with the sound provider and go over the options for this.

Is there a reason that you are involving the sound provider in this discussion at all? Why not just take either the digital out or the Master2 RCA output from the DJM-900nxs and take that straight into your computer for recording? Less fuss, the provider won't think you're being annoying, and it's going to give you the ability to have the best recording mix of the music.

-Ray
Title: Re: Industrial quality CDJ connections
Post by: Tony Rivieras on January 28, 2015, 12:01:53 am
Is there a reason that you are involving the sound provider in this discussion at all? Why not just take either the digital out or the Master2 RCA output from the DJM-900nxs and take that straight into your computer for recording? Less fuss, the provider won't think you're being annoying, and it's going to give you the ability to have the best recording mix of the music.

-Ray

There is no reason for not involving the sound provider. As for not going directly out of the mixer the reason for that is because there will be other audio played through the sound desk that comes from the laptop in FOH that i would like to be recorded.

 
Title: Re: Industrial quality CDJ connections
Post by: Ray Aberle on January 28, 2015, 10:56:10 am
There is no reason for not involving the sound provider. As for not going directly out of the mixer the reason for that is because there will be other audio played through the sound desk that comes from the laptop in FOH that i would like to be recorded.

 

Ah, ok, I didn't see that mentioned in the postings.

Your thought to meet with the soundco in advance is best, then. Let them know what you want to do, and they'll be able to help you to figure out the best solution available. They would *much rather* know about this in advance, then DOS. Haha.

-Ray
Title: Re: Industrial quality CDJ connections
Post by: Tim McCulloch on March 09, 2015, 09:12:26 am
That that a unexpected problem. To solve it i decided that instead of using a CDJ for that i'll use a laptop with a Audio Interface ( this one http://www.musiciansfriend.com/pro-audio/tascam-us-1800-usb-2.0-audio-midi-interface) and just play the audio out of a DAW. Pretty complicated but oh well...... and thankfully the spec's on this audio interface seem to say that it can do 48khz

Tony

The difference between 44.1 or 48k and 96k used for live DJ events is.... wait for it... zip... nada.... zero.  Don't obsess over this.

This is particularly true when the best commercial program sources are 44.1 or 48 and/or if anything being played is coming from a digitally compressed source.

Using digital inputs/outputs will result in greater complexity for everyone but you.  I can guarantee that if you showed up at an event intending to use digital-only signals, without advancing that with the PA provider, you'd be asked to provide analog Left/Right.

This isn't recording, it's providing entertainment for people in various forms of altered consciousness (psychological or chemical).  99.7% of them won't notice any difference between a 128kb MP3 or a 192kHz/24 bit studio recording.  I'm not suggesting that striving for good audio is a waste of time, it's not, but that if you're doing this for the masses you might get more return using the energy for other things the audience will notice and appreciate.

As for recording the event, again a 96k recording gains you nothing when the sources are 44.1/48kHz, or worse.

Have fun, good luck.

Tim Mc

edit ps... and then I looked at the date on this thread... oh well.
Title: Re: Industrial quality CDJ connections
Post by: Ray Aberle on March 11, 2015, 10:48:38 am
edit ps... and then I looked at the date on this thread... oh well.


… yeah, but it's not like you're hanging out in the DJ forum all the time anyways, right?

You'll see this thread was the last good action in here… six weeks ago! Heh.

-Ray