DJM800 - Digital vs RCA

[mostapha]

There would be 1 less digital audio conversion taking place so it's going to be a higher quality signal at the mixers master out regardless of if you're using mp3's or wav's.…Wether or not you can actually notice the quality increase is subjective though.

2. The CDJ converts D->A, then the mixer immediately converts A->D. That means more places for distortion, jitter, artifacts or phase shifting from the anti-aliasing filter, and line noise on the analog signal…which all probably adds up to fuck all. But still…the signal degradation is there.

It's also one more place to clip the signal that's partially mitigated by using the digital connection, which does matter because of the loudness wars. If the signal hits digital zero but doesn't actually clip, using the analog cables will have the mixer sampling a signal that was distorted (from intersample modulation distortion) and using the digital cables would possibly preserve the just-barely-not-distorted signal a little farther so the DJ can either screw it up or not based on how hot he runs his master.

fyi it's digital, it doesn't matter about the quality of the cabling

That's not entirely correct. There are things that can be wrong with a cable that would fuck up a digital signal but not an analog one, mostly because the signal is such higher frequency. It has to block different kinds of RF and electrical interference…at least, that's what they told us at GC, and it seemed to make sense with my limited knowledge of physics.

It might be worth trying different cables.

If that seems to make a difference, don't buy Monster. Digital cables are just as cheap as normal ones, they just take a slightly different kind of shielding. At $1/each, I'd probably buy them just for peace of mind.

[react]

That's not entirely correct. There are things that can be wrong with a cable that would fuck up a digital signal but not an analog one, mostly because the signal is such higher frequency. It has to block different kinds of RF and electrical interference…at least, that's what they told us at GC, and it seemed to make sense with my limited knowledge of physics.

It might be worth trying different cables.

I'm going to have to disagree. In common usage with the cable lengths we're talking when hooking up DJ equipment I don't think it's going to be an issue. It's binary, either the signal exists or it doesn't. The quality of cable isn't going to matter unless it's actually broken inside the sleeve or something is blocking the signal from reaching the other end (which would affect plain line signal too).

There was a thing a couple of years ago where someone hooked up some Monster cables and a coat hanger and people couldn't tell the difference.

Regardless the problem he's having is saying that the EQ sounds weird with digital, I don't think cables are coming into it. They wouldn't alter the sound when you're talking digital, it would sound crackly/staticy.

The OP should try this:

Connect phono RCA's and digital into the same channel on the DJM 800 and then use the input selector at the top of the channel strip to quickly A/B the sound.

Do the EQ's sound different when they are left at 12 o`clock?

Perhaps there's some psychoacoustics going on here.

[react]

You should be able to run a DJ mixer Flat - everything 12 o' Clock or almost, I'd be looking at maybe getting a post mixer EQ TBH.

Not following...so you buy a DJ mixer to not use the EQ's?

[mostapha]

I'm going to have to disagree. In common usage with the cable lengths we're talking when hooking up DJ equipment I don't think it's going to be an issue. It's binary, either the signal exists or it doesn't. The quality of cable isn't going to matter unless it's actually broken inside the sleeve or something is blocking the signal from reaching the other end (which would affect plain line signal too).

There was a thing a couple of years ago where someone hooked up some Monster cables and a coat hanger and people couldn't tell the difference.

Regardless the problem he's having is saying that the EQ sounds weird with digital, I don't think cables are coming into it. They wouldn't alter the sound when you're talking digital, it would sound crackly/staticy.

The OP should try this:

Connect phono RCA's and digital into the same channel on the DJM 800 and then use the input selector at the top of the channel strip to quickly A/B the sound.

Do the EQ's sound different when they are left at 12 o`clock?

Perhaps there's some psychoacoustics going on here.

Good points. And a good test. I hope he does it.

Not following...so you buy a DJ mixer to not use the EQ's?

EQs on a DJ mixer are an effect. They're neither precise enough nor quiet enough to really tune tracks whether you're targeting another track or a room. They're useful, certainly. But that's not what deevey was talking about. The OP mentioned setting up EQs which doesn't make any sense with that mixer based on the information I've been given…and his comment might have been related to what the OP was trying to do.

[react]

EQs on a DJ mixer are an effect. They're neither precise enough nor quiet enough to really tune tracks whether you're targeting another track or a room. They're useful, certainly. But that's not what deevey was talking about. The OP mentioned setting up EQs which doesn't make any sense with that mixer based on the information I've been given…and his comment might have been related to what the OP was trying to do.

Fair enough, seems to be some confusion as to what the OP is actually trying to do.

[Ryan Leo]

Seems like he just got a bad case of bad speakers.

How far up do you have the DJM up on the master out?

Try reducing your gain and your master volume.. You might be pushing the speakers harder than they can handle... and the speakers might not even be capable of providing you with the frequencies you feel without.

Make sure you get a sub with your new monitors when you get them.

[rgtb]

when you hook up cdjs to a DJM-800 by means of rca rather than s/pdif, an additional DA and an additional AD conversion have to take place.

theoretically, these conversions deteriorate the signal. (a central problem during the DA conversion is quantization error and a central problem during the AD conversion is aliasing.) however, nowadays, you can consider these conversions as practically lossless. ADCs and DACs have gotten pretty good.

maybe you might hear a difference with top stuff in the entire chain. so basically, OP's problem most likely lies elsewhere.

[mostapha]

Seems like he just got a bad case of bad speakers.

How far up do you have the DJM up on the master out?

Try reducing your gain and your master volume.. You might be pushing the speakers harder than they can handle... and the speakers might not even be capable of providing you with the frequencies you feel without.

Make sure you get a sub with your new monitors when you get them.

a mixer is not a volume knob.

amplifiers and powered speakers have gain knobs on them for this purpose.

For those of you that know that a lot of live venues run amps wide open and rely on the mixer and DSP stack to control level…true. I accept this point as both true and valid. There's no reason to take that shortcut to simplicity in a bedroom.

[ToS]

Digital RCA cable is 50ohm.
Also, there is a theory that you loose up to 1ms in each A/D conversion so connecting via SPDIF should lower the latency just a bit.
(that is probably one of the marketing tricks NI used when they say that A6/A10 has improved latency)

[rgtb]

digital rca cable is 75 ohm.

fyp

(that is probably one of the marketing tricks NI used when they say that A6/A10 has improved latency)

this doesn't make sense to me as neither the TA6 nor the TA10 features s/pdif