The geographical distance is short, but you should try to use the same provider wherever possible. Otherwise, the geographical distance between the providers’ peering points might result in an increased RTT. RTT is the "Round Trip Time", the latency for "ping packets" (ICMP) to the destination and back.
When I use my provider’s speed test, I get the following RTTs - with VDSL 250/40 Mbps - to servers of the same ISP.
For a server 230 km away from me, RTT is 8 ms; for a server 560 km away, it is already 16 ms.
Converter latencies for RME reference converters and current recording interfaces – such as the BBF Pro FS – are around 5–7 samples for A/D and D/A. That is no more than 0.11–0.16 ms; you can read about this in any RME manual in the ‘Latency and Monitoring’ chapter.
The latencies for transport via USB are significantly higher. You can read about this in my blog article: https://www.tonstudio-forum.de/blog/ent … cts-en-de/
The so-called RTL (Round Trip Latency, i.e. A/D, transport via USB, PC processing, transport via USB, D/A) for the UFX III is 2.9 ms with ASIO buffer sizes of 32 samples (@44.1 kHz); at 512 samples, it is already 24.7 ms.
If your PC hardware is suitable for audio processing and has low DPC latency, it should be possible to use a very low ASIO buffer size of 32 samples. I recommend not using the lowest setting to have a little bit headroom to prevent audio gaps.
The Babyface Pro FS's USB driver allows buffer sizes starting with 48 samples. I would try whether 48 samples work and then use 96 samples to get a little more headroom on top.
I would use the combination of Babyface Pro FS and ADI-2 Pro to also have TotalMix FX for more flexible routing.
The ADAT connection between the two devices will introduce a little latency of 1 or 2 samples; this is a little nothing.
WAN / ISP
|
Internet Router
|
| LAN
|
PC
|
| USB2
|
Babyface Pro FS [cs]---ADAT OUT--------->ADAT IN---ADI-2 Pro---1/2 + 3/4 "monitoring"
\---ADAT IN<---------ADAT OUT---/
Another advantage, you can work with up to 3 headphones on your side.
In your LAN, I would take care, that your internet router - usually a combination of router and switch- are in the same subnet to avoid any additional latency in your LAN due to routing.
Also - as already mentioned by KaiS - avoid wireless, which introduces latency and which is a half-duplex connection, which means that WLAN participants can't send and receive at the same time. Its a must for you to use cabled connections!
To be on the very safe side check that you links are using full-duplex connections.
Usually auto-detection on both sides of a link, e.g. between your PC and the switch port, should result in a fulll-duplex connection. This means, both sides can send and receive packets at the same time.
To keep a long story short: it should work, but autodetection can fail if you have it enabled only on one side.
A mix of autodetection and static settings for speed and duplex can lead to a half-duplex connection.
Then both parties can not send and receive at the same time, instead of this you get a shared network connection, where only one party can send and if the other side sends at the same time, you get a network collision, the sending process is interrupted and needs to be repeated until the shared medium is free. This kills performance in terms of throughput significantly.
What can also be of help, depending on the capabilties of your WAN/LAN router, to prioritize the traffic of this particular PC.
QoS configuration makes most sense end-to-end but is in your case most likely not applicable if you do not have a WAN product that allows for QoS or a LAN structure with multiple switches allowing QOS configuration and other internet user.
BR Ramses - HDSPe MADI FX, M-1620 Pro D, 12Mic, UFX III, ADI-2 Pro FS R BE, Nuendo 15, Win10 IoT Ent