Dual monitor not working on M3 Air. Do I need new monitors?

[Dellfanboy]

So, I purchased a 24GB/ 2TB M3 Macbook Air and can't for the life of me figure out how to get dual monitor with the lid closed. I'm using the following two monitors:

1. Samsung C24F390: https://www.amazon.com/Samsung-LC24F390FHNXZA-24-inch-Monitor-FreeSync/dp/B01CX26WPY
2. HP M27FW: https://www.hp.com/us-en/shop/pdp/hp-m27fw-fhd-monitor

Any clue how I can get them to work with my new Macbook air? I tried the following: Connected the Samsung HDMI into the HP HDMI (in the back) then pluged the HP HDMI into a usb-c adapter to my mac. Only the HP monitor works when I close the lid. My macbook air and HP works with the lid open.

This is killing me. Any help needed. Do I need to buy new monitors?

 

[bradman83]

So, I purchased a 24GB/ 2TB M3 Macbook Air and can't for the life of me figure out how to get dual monitor with the lid closed. I'm using the following two monitors:

1. Samsung C24F390: https://www.amazon.com/Samsung-LC24F390FHNXZA-24-inch-Monitor-FreeSync/dp/B01CX26WPY
2. HP M27FW: https://www.hp.com/us-en/shop/pdp/hp-m27fw-fhd-monitor

Any clue how I can get them to work with my new Macbook air? I tried the following: Connected the Samsung HDMI into the HP HDMI (in the back) then pluged the HP HDMI into a usb-c adapter to my mac. Only the HP monitor works when I close the lid. My macbook air and HP works with the lid open.

This is killing me. Any help needed. Do I need to buy new monitors?

Couple issues here:

Are you sure the HP monitor supports daisy chaining? Typically daisy chaining displays is done via DisplayPort Multi-Stream Transport (MST) which as the name implies requires DisplayPort; to my knowledge HDMI doesn't support daisy chaining.

Even if you had the right hardware macOS doesn't support MST.

You need to do one of two things - either connect both displays to the Mac directly or connect the displays to a USB-C hub and then connect the hub to the Mac. (Both displays are FHD so a standard inexpensive USB-C hub that supports dual HDMI should work fine here, but you'd need to go Thunderbolt if you go higher than FHD).

 

[Dellfanboy]

Couple issues here:

Are you sure the HP monitor supports daisy chaining? Typically daisy chaining displays is done via DisplayPort Multi-Stream Transport (MST) which as the name implies requires DisplayPort; to my knowledge HDMI doesn't support daisy chaining.

Even if you had the right hardware macOS doesn't support MST.

You need to do one of two things - either connect both displays to the Mac directly or connect the displays to a USB-C hub and then connect the hub to the Mac. (Both displays are FHD so a standard inexpensive USB-C hub that supports dual HDMI should work fine here, but you'd need to go Thunderbolt if you go higher than FHD).

First thank you for taking the time to help me.This makes total sense. I think the "USB-C hub" makes the most sense. Do you have any recommendations? I'm trying to find one on amazon or Best buy but so many include "instant view" or something similar which doesn't allow me to stream DRM content. This is such a headache.

 

[joevt]

You need a Thunderbolt hub or Thunderbolt dock or Thunderbolt to Dual DisplayPort adapter or Thunderbolt to Dual HDMI adapter to connect two displays to a single Thunderbolt port of a Mac.

Or you can use a USB hub with DisplayLink but you don't want to use DisplayLink if there's an alternative that allows a direct connection to the GPU such as Thunderbolt since DisplayLink must use video that is compressed (from 16 Gbps for 4K60) by the CPU and transmitted over USB at < 4 Gbps.

 

[bradman83]

You need a Thunderbolt hub or Thunderbolt dock or Thunderbolt to Dual DisplayPort adapter or Thunderbolt to Dual HDMI adapter to connect two displays to a single Thunderbolt port of a Mac.

Or you can use a USB hub with DisplayLink but you don't want to use DisplayLink if there's an alternative that allows a direct connection to the GPU such as Thunderbolt since DisplayLink must use video that is compressed (from 16 Gbps for 4K60) by the CPU and transmitted over USB at < 4 Gbps.

Thunderbolt is only necessary if you're trying to do dual 4K. The monitors the original poster referenced are full HD so a standard USB-C hub with dual HDMI can handle that without an issue (or resorting to DisplayLink) for much cheaper.

 

[joevt]

Thunderbolt is only necessary if you're trying to do dual 4K. The monitors the original poster referenced are full HD so a standard USB-C hub with dual HDMI can handle that without an issue (or resorting to DisplayLink) for much cheaper.

USB-C (non-Thunderbolt) hubs or docks can support more than one display only if they use MST or DisplayLink. macOS doesn't support MST for multiple displays (except mirroring).