[Replied]USB Extension issues

I have been trying to setup my 5k+ but because the the normal cord length isn’t quite as long as I need I tried out a extension cables. I picked up a 10ft display port extension for it, that hasnt been a issue. The Issue seems to be with the USB side of this.

I first tried out a 25ft usb 2.0 cable i had laying around, It didn’t seem to work at all so I switched down to a 10ft usb 3.0 cable. This worked for tracking but the audio is filled with distortion in the form of crackling. I then tried a 15ft usb 3.0 active usb cable. This won’t even get tracking working so finally I went down to a 6ft usb 3.0 cable. The audio is a little better but I can still hear the hissing and popping.

Figuring it might be the ports through this entire process I switched through all the usb 2.0, 3.0 and 3.1 ports on the computer but still had no luck. As a last ditch effort I bought a Via usb 3.0 controller that supports 4W of power. This unfortunately didn’t improve anything.

Any ideas of what I might be doing wrong here?

Usb 3.0 active 15ft cable https://www.amazon.ca/gp/product/B0179MXKU8/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
Usb 3.0 6ft https://www.amazon.ca/gp/product/B00NH134L6/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

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You’ve already tried the things I would have suggested. One thing concerns me: Is it true that the “normal” usb cable still had bad audio? If all cables have a similar problem, the problem might not be the cables. You might try plugging a usb adapter card into your motherboard and see if that is an improvement. (Someone on this forum mentioned that fixed his problem.)

If I just plug the pimax into the usb its fine but as soon as I try any additional extension cables I start having issues that only compound as the distance gets further.

I have also tried a usb 3.0 card from vantek. This has the same issues as the other ports on the computer.

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Hmmm… This sounds like it might be a power issue, but you’ve already tried a “usb 3.0 controller that supports 4W of power”.

I can’t think of anything else to try. Does anyone have some suggestions? Otherwise, you can contact @Pimax-Support.

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Have a read of this thread:

https://community.openmr.ai/t/extension-cables-pls-share-experiences/10541

Hope it helps.

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They appear to talk about usb cables for the odyssey. From the gist of it, it was ok with a 10m cable. I am using cables 1/2 and 1/3rd the length but having no success with the pimax.

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My guess is that the pimax is already on the high end of drawing power from usb and the ac/dc brick that comes with it.

This would explain the many connection issues and also the few problems with the power brick stop working.

The extension cable does not only decrease the available usb power but also the available power to the headset.

So you could switch the brightness in pitools down to low and then try the extension cable again. Brightness setting has imho a quite big influence in power needed by the headset.

Edit: therefore I think a stronger power brick (delivering more mA and maybe even better a few more Volts because the resistance of the cable reduces the voltage available for the headset) would solve extension cable issues

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Or try the vive extension and use only the usb connection of it. Advantage: it powers the lighthouses on/off via Bluetooth if steamVR is running.

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in general usb is limited to 5m, anything above will need a hub or repeater, even something like 2,5m cable plus 2,5m extension (passive cable) is not guaranteed to work as there are additional connectors in between, so depending of how long the cable delivered with the hmd is it might not be possible to extend it securely
i’'d suggest to just test with more usb length and leave anything else to standard length
so the usb-a connector from the standard cable of the hmd to a active (powered) usb hub and from the usb hub to computer, if that works it can be tested to replace the usb hub and its connection to the computer with a repeater cable

there are other solutions too but more expansive

  1. using special adapters that use cat5/6 ethernet cable (or more expansive optical fiber) often used together with a video link like hdmi, can be any protocol, it just uses the cable, also often seen for KVM solutions over ethernet cable
  2. using software and network (copper, optical, wifi) to get around the length problem, tpcast does use wifi for this in its little black box where the powerbank is attatched, same is done in the open tpcast solution with a different software, you can call this virtual usb port over network

people who wanted to bridge >10m with vive and rift have already tried this stuff, main problem is the added latency, even if it works the added latency can be a no go for VR as there is the need for low “motion to photon”

you can search reddit vive and rift for more information

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@Living_Dead

Just like @IG88 said, 5m is a limited length for USB cable, and we do not recommend you use extended cable to extend, or the connection can not be guaranteed.

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As I posted my results of the 10m extension (for the OD+) I found out that the choice of the USB cable is cruicial. (The choice of the HDMI or DP cable as well of course) But the USB cable needs! to be powered by an additional DC adaptor. The one that I found even fowarded some juice to the middle of the cable where it had a 2nd repeater. I can say it works flawlessly.
I also checked all of my external HDDs if they are loosing a single megabyte in transferrate which was not the case. I also already tested it to use my soundinterface on stage in order to leave it there and put my recording Laptop in front of stage.

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There are some threads here on extensions used.

@EarlyBackers

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there is a need of clear definition, a cable (just some copper cable with connectors) won’t do it, it has to be a active component like a hub (imho a repeater is just the same only for one device to connect), it can be passive (bus powered), drawing its power from the host usb (aka from the computer) witch will reduce the power for device(s) on the other side, if the computer delivers 500mA and the Hub/Repeater consumes 70mA then only max. 430mA will be available (for all devices on the Hub/Repeater), for USB 3.0/3.1 the max. is 900mA
so to be on the save side its better to have a powered one so all connected devices will get the max. possible current

in theory (usb spec) the max. distance is 30m (6x5m with hubs every 5m), but thats only if you keep within the normal limits defined in base standards, its possible to do more when mixing in other technologies

also as a “fun” fact with usb 3.0 you can have all components within the standard and resulting in a system thats not within the specs (in theory that should have been corrected with usb 3.1) but in most cases usb 3 problems come from crappy implementation/hardware
those crappy hardware can also result into wifi and BT problems when not properly shielded

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So this is bugging me a little then. I tried a active usb cable but that failed. Makes sense seeing how long the usb extension was but today I tried a dlink usb powered hug. I tried everything down to a 1ft cable to see if I could make anything work. At the end of testing I was never successful with any of the solutions.

It appears from the testing that there isn’t much hope for extending past the length we have right now. Either that or I am really having issues with my setup. This is going to make it hard to setup my VR play area.

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Good info @IG88
I almost ordered an extension cable, but going for a powered 3.1 hub now :+1::beers:

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When you try yours out Ill be interested in hearing if it works for you.

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It’ll take a few months, but sure :smile:

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What is your system setup including psu? @SweViver has gottten extensions to work & others had a trial & error to find a cable that worked

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one thing to keep in mind with such solution, the power plugin port on the hub/repeater is at least ~5m away from the socket, for what we have in mind here this means to also extend the cable from the power plug (usually 1,5m) to 5m, there are ready made cable for this (i’m using such extensions in white with the lighthouses mounted to the white walls to make it a little less appeared)
so in addition to the DP and USB cable you will have to “bundle” a power cable (5V) for the 5m in question

btw. a usb hub is meant for testing, king of not practical to have such massive thing to drag around when runnig around in room scale vr
(i think i will miss my tpcast when the 5k comes in e few weeks)

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I7 6700k, 12gb ddr3 ram, Asus z170-a motherboard, 1000w psu, 1080 gpu and ssds of assorted sizes and makes.

I added a additional USB 3.0 vantec pci-e card that claims 4w output to see if it was a power issue.

Cables I have tried are a 6ft Amazon basic usb3 card, 10ft cable matters USB 3 extension and 15ft cable creations active USB 3 cable.

I have confied my drivers are up to date and tried all USB ports on the computer.

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