Mid Side - does cable length affect the phase/delay of stereo result?

[JohnRoberts]

It is the nature of internet discussions for people to tell you what they know rather than what you need.

The OP's query was asked and answered....

JR

 

[pucho812]

The original poster was, I just used your reply as an easy jumping point to respond to the original question.

Sounds good to me boss.

 

[capacitorless]

@ccaudle and others, I for one really appreciate the detailed insights. I like to learn the truth about things and be a better and better person every day, so information related to the question at hand (in whatever context) are very much welcome. Pedantry be damned, haha!

 

[ccaudle]

The OP's query was asked and answered....

Yes, but to me the question seemed so far fetched that it seemed worthwhile to try to pull the OP up a level in how to think about questions like that.
It just didn't seem very satisfying that if someone else asked the OP the same question, and questioned how he came to that conclusion, his answer would just be "John said so" without any understanding of why that was the case.

 

[JohnRoberts]

Yes, but to me the question seemed so far fetched that it seemed worthwhile to try to pull the OP up a level in how to think about questions like that.
It just didn't seem very satisfying that if someone else asked the OP the same question, and questioned how he came to that conclusion, his answer would just be "John said so" without any understanding of why that was the case.

It was a good question from the OP ignoring the speed of electrical signal propagation through wires being extremely fast compared to the relatively pedantic audio wavelength/periods.

In other slower mediums sum and difference combinations of audio traveling over different path lengths (like through air) can interfere..... and for much higher frequencies than audio the propagation speed through wires can result in constructive or destructive interference (and more).

"No" was just my succinct answer to the original question. There is nothing wrong with more information but at some point it can get confusing "Blinding them with science".

Why is it though that I get a delay on my midi cable, that is 6 meters long when I play keyboard to my DAW? A 1 meter cable is unnoticeable when playing but when I used a 6 meter cable, there is a noticeable delay?

Just to be clear you are comparing the speed of an analog audio signal passing through wire vs, MIDI digital bit stream passing through wire. Apples and Grapefruit... not the same. There is propagation delay in both the midi send end and midi receive end.

The delay has nothing to do with the length of the midi cable. I recall experimenting with sending MIDI signals through 100' long audio snakes with no appreciable delay (while I wasn't measuring for that, I just wanted to see if it worked).

JR

 

[sahib]

....... Electrons in a wire move at somewhere closer to a few millimeters per second.....

Drift velocity.
Approximately 10^-4 meter per second, or about one tenth of a millimetre.

 

[k brown]

Drift velocity.
Approximately 10^-4 meter per second, or about one tenth of a millimetre.

No wonder I never liked the sound of MS; drift freakin' velocity!

 

[radardoug]

Yes, but to me the question seemed so far fetched that it seemed worthwhile to try to pull the OP up a level in how to think about questions like that.
It just didn't seem very satisfying that if someone else asked the OP the same question, and questioned how he came to that conclusion, his answer would just be "John said so" without any understanding of why that was the case.

As we have seen, the OP doesn't want to research it for himself. He just wants to waste our time. And we all fell for it!

 

[pucho812]

Drift velocity.
Approximately 10^-4 meter per second, or about one tenth of a millimetre.

Can you say that in American please

 

[Chrisfromthepast]

Can you say that in American please

Roughly the speed of light, only a lil slower?

 

[Chrisfromthepast]

Roughly the speed of light, only a lil slower?

**** thats the propagation delay

 

[k brown]

**** thats the propagation delay

One of the more effective forms of birth control.

 

[canidoit]

True but doesn't account for the perceived delay with a longer MIDI cable. I suspect it's something in the DAW / computer setup being different. I suggest to OP to try with a hardware sound module if wishing to investigate this. Plus is it a real MIDI cable or MIDI over USB ?

Its old school midi interface to midi cable.
Mac > Midi interface > Midi cable > Sound Module

I never thought that 6 meters would cause a delay but it did, so I had to make a short midi cable run in the middle of the room than around the edges of the room.

As we have seen, the OP doesn't want to research it for himself. He just wants to waste our time. And we all fell for it!

I don't think it was a waste of time. I now have confirmation about M/S and cable length and whether I am hearing any difference as my hearing is not what they were, and also found some new information that I was not aware of.

There may be people that may find this post and it's responses useful

 

[JohnRoberts]

Its old school midi interface to midi cable.
Mac > Midi interface > Midi cable > Sound Module

I never thought that 6 meters would cause a delay but it did, so I had to make a short midi cable run in the middle of the room than around the edges of the room.

again please clarify... are you experiencing a signal delay related to the length of your midi cable? i.e. short midi cable passes signal faster than long cable?

IIRC midi uses RS-485 serial data protocol that is supposed to be good for thousands of feet (at least for slower data rates).

JR

I don't think it was a waste of time. I now have confirmation about M/S and cable length and whether I am hearing any difference as my hearing is not what they were, and also found some new information that I was not aware of.

There may be people that may find this post and it's responses useful

 

[canidoit]

Its old school midi interface to midi cable.
Mac > Midi interface > Midi cable > Sound Module

I never thought that 6 meters would cause a delay but it did, so I had to make a short midi cable run in the middle of the room than around the edges of the room.

again please clarify... are you experiencing a signal delay related to the length of your midi cable? i.e. short midi cable passes signal faster than long cable?

IIRC midi uses RS-485 serial data protocol that is supposed to be good for thousands of feet (at least for slower data rates).

JR

Hi JR,

Wow, RS-485 is even more old school than 5 pin DIN, isn't that with the old Atari or Commodore computers for sequencing?

I am using the 5 pin din for midi. From recollection I thought their limits were 6 meters before signal loss, as that is what the stores suggested but based on my research they are suppose to have 50 feet, but most people find after 20 feet, signal drop outs can occur but what I was experiencing was delay.

 

[JohnRoberts]

We did testing on a couple of pieces of gear, figuring you could test all day and get similar but different results. We tested what we thought was a fair and reasonable length of 250ft using our top-grade MIDI cable, Mogami 2948, and a long length 100ft of Mogami 2-pair snake wire (W2930). With both attempts, the MIDI continued to work flawlessly.
https://eventhorizon-srv.com/shop/long-length-midi-cables-t-4

IIRC I tested sending midi down a 100' audio snake. But this was last century.

JR

 

[sahib]

Can you say that in American please

Ok. As an info.

I know it is useless and call me the clerk of useless info of the forum.

It says that the electrons do not move all that fast. Hence for the electric current to flow in a conductor it does not need the electrons marching from one end of the conductor to the other. The current flow is actually the transmission of forces on electrons.

 

[JohnRoberts]

Ok. As an info.

I know it is useless and call me the clerk of useless info of the forum.

It says that the electrons do not move all that fast. Hence for the electric current to flow in a conductor it des not need the electrons marching from one end of the conductor to the other. The current flow is actually the transmission of forces on electrons.

Like waves in the ocean are not moving the water which remains mostly in place.

JR

 

[Voyager10]

I am using the 5 pin din for midi. From recollection I thought their limits were 6 meters before signal loss, as that is what the stores suggested but based on my research they are suppose to have 50 feet, but most people find after 20 feet, signal drop outs can occur but what I was experiencing was delay.

Do you have a DAW with a Midi output, and a synth or similar with a Midi input?

If so, you could measure it.

Make a simple Midi track with repeated notes, a hi-hat every quarter-note would be perfect. Connect the DAW out to the synth via the first Midi cable, then loop the analog output into your audio interface. Play the Midi track and record the audio to one track in the DAW.

Now change to the other Midi cable and do the same, recording the audio to a second track in the DAW. You can now compare the two tracks, audibly and visually. If there is a delay between the tracks, bring up the waveforms side by side, and post us a photo!

 

[Nele]

From the midi specification:

"Cables shall have a maximum length of fifty feet (15 meters), and shall be terminated on each end by a
corresponding 5-pin DIN male plug, such as the SWITCHCRAFT 05GM5M. The cable shall be shielded
twisted pair, with the shield connected to pin 2 at both ends."