MIDI interface

if u use separate midi connections u have the full 16 channels free 2 use. If u chain say more than 4 midi devices u also can get timing problems because midi isnt that fast (its a serial protocol)
 
A midi interface is what ties your midi devices to your computer.
Chaining midi devices will allow for control of all modules at once without reconfiguring your wiring. You will transmit & recieve data from a specific channel for each device.
 
struberg said:
If u chain say more than 4 midi devices u also can get timing problems because midi isnt that fast (its a serial protocol)
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Im not sure what you mean by this as midi is just data and it is quite fast. If you use a specific channel for each device, it does a very effecient job.
 
Stealthtech said:

Im not sure what you mean by this as midi is just data and it is quite fast. If you use a specific channel for each device, it does a very effecient job.
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Everytime you pass midi from one device thru another you will get some latency. Usually it's not a big problem with only 2 or 3 devices.

As Struberg said, the main advantage of a mulit port interface is that you get 16Channels per port/cable and it can make complicated routing/patching much easier.
 
MIDI isn't really very fast at all, especially by today's standards. The spec only calls for a baud rate of 31.5k, which tranlates to 3937.5 BYTES per second; each midi message is at least two and sometimes three bytes long, so each note on/off message takes approximately 1/2 millisecond. Play a 4-note chord, and the data takes 2 milliseconds to stream. Do that on 3 instruments, each on only ONE channel, and you have a 6 millisecond delay total. 20 milliseconds is a fair "elvis" slap echo, and even 2-3 milliseconds can cause serious phasing between stereo tracks.

At 6 kHz, one complete cycle takes .000166 seconds, or .166 milliseconds, for a 360 degree phase shift. even a 5 degree phase shift will cause comb filtering, so 5/360 = .01388 x .166 ms, or .0023 MILLISECONDS . This shows that a few MICROSECONDS can negatively affect your sound under some circumstances.

In practical applications, normally a single note on command causes BOTH channels of a stereo keyboard to sound that note, so the above scenario almost NEVER causes the problems it could if given worst case circumstances.

Depending on how picky you are about timing, and how fast your particular sound modules respond to MIDI information, sometimes even ONE device is too slow.

Generally, Tex's ballpark of 2-3 devices per port will keep you from noticing lag and timing errors, even if you DO "got rhythm" - Beyond that, it's time for a multi-port interface. Besides, as Tex pointed out, it's much easier to set up a system with dedicated ports/wiring/channels... Steve
 
I didn't realize midi had that limited of a bandwidth. I remember them talking about a newer midi protocol 10yrs ago but I guess it never took off. You'd think they would at least replace the jacks/cables with USB or something with higher bandwidth. Even the 128 step resolution of midi is horribly outdated.
 
Yeah, we need version 2 bad - When MIDI first came out, it was faster than any serial port - serial ports at that time topped out at 28.8k, and MIDI had to have a parallel or plug-in card interface so it could run at its "blazing" 31.5 K... Now, windows typically configures serial ports at 115,200 and MIDI is still slogging along at 31.5 -

I'm not sure, but possibly newer multiport interfaces, by going with USB and parallel ports, might have gotten around that limitation. I don't really think so though, because the spec hasn't changed as far as I know - Each MIDI port is still limited to 31.5 kBaud AFAIK.

The safest way for larger systems is still brute force, and if you ever think you will expand your system very much an 8 x 8 interface makes a lot of sense... Steve
 
knightfly said:
About what?
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:)
The link I posted leads to many customable MIDI thru device. I didn't use it, nor know anything about it's ability, but by reading their explanations, these devices will solve many MIDI connection problems. Do you think it's good idea using these devices ? One more thing, you said fastest MIDI bandwith was 31.5 kBaud. One of my module (Korg O5R/W) connected to PC thru serial port using special cable (AG001), and they communicate up to 38.4 kBaud. How come ? The only message they "talk" is MIDI... so ain't it break your theory ? ;)
 
Sorry about the "about what" comment James, I was being a smart-ass at the time.

The MIDI spec spells out all sorts of things, one of which is that a standard MIDI device must be able to communicate over a MIDI port at 31.5 kBaud. If your Korg can do it faster over a "to host" port directly to a computer, it doesn't break my theory for two reasons - one, it's not my theory. It's the MIDI 1.0 specification. and two, that's technically NOT a MIDI port, it's a direct interface using MIDI protocols. A technicality, to be sure, but a defensible one. As near as I can recall, the MIDI 1.0 spec states that a device must be able to sustain 31.5 kBaud. I don't remember it stating that devices couldn't go any FASTER than that, and you're right about my not mentioning that earlier.

The thing is, any time you start mixing and matching devices within a certain specification, you have to assume that at least one of those devices will BARELY meet spec, or perhaps even FAIL to meet the spec. Therefore, in order to predict what kind of performance the system as a whole will have, you have to be pessimistic or expect to be dis-appointed.

As far as the link you posted, these devices can come in handy if you have the particular problem they solve. The thing to remember is that any electronic device has a finite amount of propagation delay by it's very design, and if you put too many of them in series those delays can get large enough to be noticeable. Still, if all you need is for one output to go to three different places, or for three different MIDI streams to go to the same input, then a simple box can be the best solution.

Midi solutions has been around for quite some time, and I don't recall ever hearing any negative feedback about them. I haven't personally used any of their gear, but wouldn't hesitate to do so if I needed a particular function that they could do... Steve
 
Sorry about the "about what" comment James, I was being a smart-ass at the time.

The MIDI spec spells out all sorts of things, one of which is that a standard MIDI device must be able to communicate over a MIDI port at 31.5 kBaud. If your Korg can do it faster over a "to host" port directly to a computer, it doesn't break my theory for two reasons - one, it's not my theory. It's the MIDI 1.0 specification. and two, that's technically NOT a MIDI port, it's a direct interface using MIDI protocols. A technicality, to be sure, but a defensible one. As near as I can recall, the MIDI 1.0 spec states that a device must be able to sustain 31.5 kBaud. I don't remember it stating that devices couldn't go any FASTER than that, and you're right about my not mentioning that earlier.

The thing is, any time you start mixing and matching devices within a certain specification, you have to assume that at least one of those devices will BARELY meet spec, or perhaps even FAIL to meet the spec. Therefore, in order to predict what kind of performance the system as a whole will have, you have to be pessimistic or expect to be dis-appointed.

As far as the link you posted, these devices can come in handy if you have the particular problem they solve. The thing to remember is that any electronic device has a finite amount of propagation delay by it's very design, and if you put too many of them in series those delays can get large enough to be noticeable. Still, if all you need is for one output to go to three different places, or for three different MIDI streams to go to the same input, then a simple box can be the best solution.

Midi solutions has been around for quite some time, and I don't recall ever hearing any negative feedback about them. I haven't personally used any of their gear, but wouldn't hesitate to do so if I needed a particular function that they could do... Steve
 
That's okay buddy... I'm cool. You're right, the more the device in the chain, the more the problem probably might ocur. I never put more than two devices in a link, instead I used to put a MIDI patchbay. Nowdays, I don't do MIDI that much anymore. Not jest like when the first time it hit me. Rather working with sampling / real audio by now. MIDI ain't developed much since then. Two things I am pissed off about DAW :

1. They don't develop MIDI. It needs new standard more than just introducing GM level 2. :(

2. They don't develop the 1.44" Floppy disk.

The same two esential tools we use since early '80es. I mean, people just love compatibility issue when they excepting a new technology. Change the place of floppy with CD is not the answer. See ? How many manufacturer support it. I realize USB pocket drive bringing a new hope (fast, small, reliable, mobile), but still it takes long time untill it has it's place to be implemented as standard. I didn't see any hype when they invent it. Not many instrument plant it. Look at those brand new Triton, still use the same old floppy. Same old MIDI... Somebody must make the breakthrough... :rolleyes: anyone ?
:cool:
 
WARNING - SMART-ASS MODE IS ON -

To quote some un-remembered but equally smart-ass person,
"The great thing about standards is that there are so fucking many of them..."

SMART-ASS MODE OFF -

Although MIDI is archaic by today's standards, it is still probably the single most important development in electronic music, for this reason(s)

With some study and thought, you can get most mid to High-level electronic music hardware to, at the very least, regurgitate ALL their settings into a common storage place, like the song file in your music software

You can control many effects processors with a MIDI fader box while mixing, and save the MIDI data to the songfile, so that the efx box re-plays the changes real-time

You can automate a mix in several different ways -

And a whole lot more, but I'm running out of time for now -

As to storage, I doubt that will EVER be solved - the minute someone makes one big enough, some turkey gets even sloppier with code because "now he has the space for it" - kinda like people and houses - we tend to expand to fit the environment.

Hopefully in the near future, one of the many schemes for total networking in the studio will actually work, get recognized as being workable, and proliferate. Til then, ain't it fun to bitch? I know it is for me... Steve
 
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