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Post by Quint on Nov 3, 2020 11:54:45 GMT -6
I'm thinking about getting something like this: www.amazon.com/Monoprice-Extension-Repeater-PlayStation-Keyboard/dp/B004HJDUW0#:~:text=Due%20to%20its%20design%2C%20USB,USB%20extension%20cable%20from%20Monoprice! I've never used an active USB cable before. The distance I need to go between my Akai keyboard (midi controller) and the computer is longer than the max length of a passive USB cable, hence why I'm looking into an active USB cable. Is there any additional latency that would be incurred by using an active cable? I don't know what all takes place inside of an active USB cable, so I was worried about that. Maybe active USB cables don't add any latency at all. I don't know. I just need to make sure of that, since it will be used to transmit midi to the computer, real time. |
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Post by svart on Nov 3, 2020 12:26:18 GMT -6
I'm thinking about getting something like this: www.amazon.com/Monoprice-Extension-Repeater-PlayStation-Keyboard/dp/B004HJDUW0#:~:text=Due%20to%20its%20design%2C%20USB,USB%20extension%20cable%20from%20Monoprice! I've never used an active USB cable before. The distance I need to go between my Akai keyboard (midi controller) and the computer is longer than the max length of a passive USB cable, hence why I'm looking into an active USB cable. Is there any additional latency that would be incurred by using an active cable? I don't know what all takes place inside of an active USB cable, so I was worried about that. Maybe active USB cables don't add any latency at all. I don't know. I just need to make sure of that, since it will be used to transmit midi to the computer, real time. Latency is generally thought of as digital "processing time". The term you're looking for is "propagation delay" which is the time it takes a signal to travel from one end to the other of an analog conductor, including delays through active buffering, and this of course is longer for the length of cable. Generally this shouldn't be an issue since USB is a non real-time protocol anyway, which could have highly variable and non-deterministic latency in-the-box due to process interrupts, drivers, CPU time priority, etc., and requires buffering of data anyway. The propagation delay of the USB cable itself will be deterministic/repeatable and the length won't overtly affect the latency of the system. |
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Post by Quint on Nov 3, 2020 13:10:45 GMT -6
I'm thinking about getting something like this: www.amazon.com/Monoprice-Extension-Repeater-PlayStation-Keyboard/dp/B004HJDUW0#:~:text=Due%20to%20its%20design%2C%20USB,USB%20extension%20cable%20from%20Monoprice! I've never used an active USB cable before. The distance I need to go between my Akai keyboard (midi controller) and the computer is longer than the max length of a passive USB cable, hence why I'm looking into an active USB cable. Is there any additional latency that would be incurred by using an active cable? I don't know what all takes place inside of an active USB cable, so I was worried about that. Maybe active USB cables don't add any latency at all. I don't know. I just need to make sure of that, since it will be used to transmit midi to the computer, real time. Latency is generally thought of as digital "processing time". The term you're looking for is "propagation delay" which is the time it takes a signal to travel from one end to the other of an analog conductor, including delays through active buffering, and this of course is longer for the length of cable. Generally this shouldn't be an issue since USB is a non real-time protocol anyway, which could have highly variable and non-deterministic latency in-the-box due to process interrupts, drivers, CPU time priority, etc., and requires buffering of data anyway. The propagation delay of the USB cable itself will be deterministic/repeatable and the length won't overtly affect the latency of the system. Yes, it's the active buffers in the active USB cable that I'm worried about. So, basically, if you had two cables of equal length, one passive and one active, the active cable shouldn't be any slower than the passive one, correct? If so, then I'll get an active USB cable and not worry about it causing any timing issues for transmitting midi between the keyboard controller and the PC . |
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Post by svart on Nov 3, 2020 14:01:27 GMT -6
Latency is generally thought of as digital "processing time". The term you're looking for is "propagation delay" which is the time it takes a signal to travel from one end to the other of an analog conductor, including delays through active buffering, and this of course is longer for the length of cable. Generally this shouldn't be an issue since USB is a non real-time protocol anyway, which could have highly variable and non-deterministic latency in-the-box due to process interrupts, drivers, CPU time priority, etc., and requires buffering of data anyway. The propagation delay of the USB cable itself will be deterministic/repeatable and the length won't overtly affect the latency of the system. Yes, it's the active buffers in the active USB cable that I'm worried about. So, basically, if you had two cables of equal length, one passive and one active, the active cable shouldn't be any slower than the passive one, correct? If so, then I'll get an active USB cable and not worry about it causing any timing issues for transmitting midi between the keyboard controller and the PC . The buffers would effectively have the same delay for every digital bit, so it shouldn't affect overall timing at all. They're likely just transistors set up as digital switches to add higher current drive, which we typically call "accelerators" in the design world. |
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Post by Quint on Nov 3, 2020 14:19:21 GMT -6
Yes, it's the active buffers in the active USB cable that I'm worried about. So, basically, if you had two cables of equal length, one passive and one active, the active cable shouldn't be any slower than the passive one, correct? If so, then I'll get an active USB cable and not worry about it causing any timing issues for transmitting midi between the keyboard controller and the PC . The buffers would effectively have the same delay for every digital bit, so it shouldn't affect overall timing at all. They're likely just transistors set up as digital switches to add higher current drive, which we typically call "accelerators" in the design world. Ok. Well I'll just get an active USB cable and use it without worrying about it slowing anything down then. Thanks. |
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Post by christopher on Jun 6, 2023 14:07:24 GMT -6
I’m curious if this worked out? I want to put a monitor and midi keyboard far from my PC. Im looking at 50ft HDMI and USB so I can go through the attic. I already have a wireless typing keyboard with trackpad (logitech) that has been so awesome for self tracking.
I’m thinking next: setup a little soft synth spot by where I track other stuff, no more back and forth.. my hope anyway. And then if I want to work at the main desk, simple to take the midi keys over where the short usb ready to patch.
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Post by Ward on Jun 7, 2023 7:40:20 GMT -6
I’m curious if this worked out? I want to put a monitor and midi keyboard far from my PC. Im looking at 50ft HDMI and USB so I can go through the attic. I already have a wireless typing keyboard with trackpad (logitech) that has been so awesome for self tracking. I’m thinking next: setup a little soft synth spot by where I track other stuff, no more back and forth.. my hope anyway. And then if I want to work at the main desk, simple to take the midi keys over where the short usb ready to patch. If you're going to run any more than 25' HDMI out of the Mini-DV or HDMI port from a computer, use a splitter/booster to help power the signal run. As for USB? If it's for peripherals like a keyboard or mouse/trackpad/ball consider sticking with bluetooth. The long cable runs can be a nightmare - personal experience. if it's just a long USB cable for a midi keyboard, you should also use the separate power supply that most have the facility for. USB power drains are a pain. |
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Post by drbill on Jun 7, 2023 8:41:55 GMT -6
On the USB - I've used those. I felt no discernible difference between a 6' USB and a 50' active. I only had keyboards, trackball, MIDI interfaces, etc. off them though. No audio interfaces.
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Post by svart on Jun 7, 2023 8:52:11 GMT -6
I used a 25ft HDMI cable many times. Haven't tried a 50ft one yet personally but I've seen it done without a repeater.
I bought a cheap (100$) wireless HDMI system for a handheld monitor so I can monitor my camera in real time from a distance without cables. It works well but any kind of door/wall/obstruction seems to really reduce the distance it works. A more expensive version with antennas might work better.
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Post by the other mark williams on Jun 7, 2023 14:55:33 GMT -6
I’m curious if this worked out? I want to put a monitor and midi keyboard far from my PC. Im looking at 50ft HDMI and USB so I can go through the attic. I already have a wireless typing keyboard with trackpad (logitech) that has been so awesome for self tracking. I’m thinking next: setup a little soft synth spot by where I track other stuff, no more back and forth.. my hope anyway. And then if I want to work at the main desk, simple to take the midi keys over where the short usb ready to patch. While you may have no problem using an active USB cable for your MIDI keyboard for this, I'd still recommend using a MIDI cable instead and running that to your MIDI interface nearby the computer. You can run MIDI cables a long way without issue. For HDMI, there are several ways to do it. You may have no problem running 50' in your use case. I have seen HDMI cables of that length not work in certain situations, though (like running 4k 60fps to a recorder). If you do run into a problem, you could always convert the HDMI to SDI, which can be run a long, long way without problems. Blackmagic makes an affordable HDMI-to-SDI converter box (and SDI back to HDMI if your monitor can't handle SDI). |
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Post by BenjaminAshlin on Jun 7, 2023 15:49:18 GMT -6
I have done 50Ft hdmi runs with a good quality cable.
The cheaper solution that I have used may times is HDMI to RJ45 extenders. They will do over 50 meters easily (164 ft for people still in the dark ages /jk)
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