Routing USB-B hub via USB-C to MacBook Pro

Is it possible to configure it such that the USB-B hub can be active at the same time as the USB-C hub, so that I can route the USB-B hub via the USB-C hub which can then be communicated directly to my MacBook Pro via the one USB-C cable?

In other words, is it possible to route the USB-B hub via the USB-C cable to my MacBook Pro (with only one USB-C port on its right side)?

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I’m sorry @JacobCXDev I don’t quite understand what you are saying.

You have a Macbook pro with 1 USB-Type-C that cable is connected to the data port on the Spectrum (port 5) - is this correct? Then the Spectrum has a USB type-B cable (port 6) but I’m not certain what it is plugged into. I assume that there are other devices plugged into the Spectrum usb ports (ports 7 and 8) that you want the MacBook to recognize and use but they are not available.


Can you explain what is plugged into which ports and what you want to happen (i.e. I want the the USB headset plugged into the upper USB type-A port 8 to be available to play the sound from my MacBook) and what isn’t working (The head set isn’t recognized by my MacBook).

The following is the cable layout which I have been using with my old MacBook Pro:

Keyboard ➡ ⑧ ➡ ⑥ ➡ Sabrent USB-A Sharing Switch USB-A Port ➡ Anker USB-C Hub USB-A Port ➡ MacBook Pro USB-C Port.
             ↗                                               ↘
   Mouse ➡ ⑧                                                  PC USB-A Port.

Unfortunately, my new MacBook Pro only has one USB-C port on its right side — the only side I can cleanly connect my cables to, due to constraints with my setup and cable lengths. When connected to my Spectrum 4K, this single USB-C port is occupied by a Thunderbolt 4 USB-C cable which is plugged into ⑤; is it possible to connect the devices connected to ⑧ to my MacBook Pro via ⑤? If not directly, is it possible to enable both ⑥ and ⑦ so that I can connect the devices connected to ⑧ to my MacBook Pro via ⑤ by connecting ⑥ and ⑦ with an external USB-B to USB-C cable?


Ah… I see what you have going on there now. I think we can help you get this going for you without having to live the dongle life.

You had the PC and MacBook sharing the keyboard and mouse via the sharing switch. But adding the Spectrum and/or new MacBook complicated things with cable management.

I just need to confirm with @MarvyMarvz what setting to use on the Spectrum to make this configuration work. I believe you can connect as you described - keyboard and mouse into ports 8, PC into the USB Type-B and the MacBook into USB Type-c port 5. I believe there is an auto select for the USB so that when you switch the input form the PC to the Mac it will switch the hub from the USB Type-B to the USB Type-C for the hub.


Hi @JacobCXDev,

Just like Shane said, you should be able to switch hub sources depending on the input you select. However, I’ve been doing some tests to confirm if this is the case and what settings should be used to achieve this.

According to my findings, the last hub source selected before changing to “select automatically”, will be the hub source that stays active.

In simpler terms, the “select automatically” function does not work as intended.

This will be something we will have to look into but for now please use the presets as an alternative temporarily. Apologies for this, I will carry doing some tests to see if there is a way to bypass it.


And, as an update, not only is this being fixed (we’re currently testing it now), we’ve also assigned the functionality to the Up position on the joystick - so that, regardless of whether you have an active video signal or not, pressing up on the joystick will let you cycle through USB Hub Source. In a similar manner, pressing down will let you cycle through video inputs - again, regardless of if there is an active signal or not. In my testing, it mostly - still a couple of minor issues - so we’re almost assured that it will be in the next release.

The upgrade to assign any hub source with any video signal is still in the works, but should be out with the final release of fw v106.


That’s great to hear; thanks for the update. Are you able to provide any loose estimation of when firmware version 106 may be ready for (early access) release? If it’s in the distant future, I’ll likely invest in an alternative configuration for use in the meantime.

Also, on a slightly unrelated note, do you have any plans for open-sourcing Spectrum’s firmware? I should have liked to try add that functionality myself :smile:.

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Not currently.It has to go through the fw dev team’s QRE process after we sign off on it, and there are a couple of things I need to ascertain by this week’s meeting to see if they can make it in or not. But I’m really hoping we can have it out soon , before the end of February, if possible.


Good news! The ability to assign any USB Hub source to any video is working on our test build. Furthermore, the ability to change video input via User Presets is also working now (it’s been broken for a while).

So, using User presets, you effectively now have a 2 USB Input / 3 Video input KVM (emulator) built into your Spectrum - or, well, you will once v106 is officially released.


I have the same question too. I connect my MacBook Pro to my monitor via port 5 and would like to then access USB devices like a webcam in port 8, yet I can’t get this to work. Any suggestions please?

There are a couple of settings in the Spectrum you’ll want to check if the webcam isn’t working.

The first is the USB hub source, which is the second line in the Input / Output section of the on-screen controls. Try setting this to USB Type-C, which should then force the Spectrum to act as a hub for the MacBook Pro connected via port 5.

When firmware 106 comes out, you’ll be able to use the Select automatically setting. This will automatically select USB Type-C as the hub source when video is coming over USB-C.

The second is the USB-C bandwidth priority, which is the second-to-last settings in the Input / Output section. There are 2 settings here:

  • High refresh rate. This allows the Spectrum to do up to 144Hz, but restricts the USB connection to USB 2.0 only (480Mbps).
  • High USB data speed. This restricts the Spectrum to around 60Hz, but allows USB 3.0 data which means higher speeds (5Gbps or more).

Some webcams will only work on USB 3.0, so you might need to play with this setting and see if it helps.


With firmware version 106 successfully installed (finally!), this issue is resolved.