Lumagen Pro HDMI switching delays

MyronAub

Active Member
Since resolving the annoying squeal and hiss from my projector and amp respectively I'm now more aware of the annoying delays I get when switching HDMI sources - first world problems I know! :)

I have a Sky HD box, Sony UHD player and Nvidia Pro media player feeding a Lumagen Pro 4242+ which outputs the signal to a Denon AVC-X6700H amp and Sony VPL-VW590ES projector.

I've just ran three tests which show that it can take up to 18 seconds of blank screen before the image switches from one source to another:

Nvidia -> Sky 9 seconds
Sky -> UHD Player 13 seconds
UHD Player -> Nvidia 18 seconds

Do these delays sound typical and I'm just being impatient and picky? Or does anyone think I may have something set up not quite right? Eighteen seconds may not sound long but it feels like an age when you're essentially just changing channels!

I thought I'd read something somewhere about a Lumagen setting that speeds up source switching but I'm blowed if I can find it now...
 

Gordon @ Convergent AV

Distinguished Member
AVForums Sponsor
The 18GHz input module has one HDMI receiver chip and two sockets attached to it. The 9GHz card on inputs 3 and 4 has a single HDMI chip for each socket. Once the source on 3 and 4 has chatted to the lumagen they are essentially locked and loaded and ready to go. Switching between inputs 1 and 2 the HDMI receiver chip has to renegotiate everytime so takes about 1.5-2 seconds longer.

Everytime there is a format change, ie different incoming signal resolution, colourspace, dynamic range change, refresh rate, the display and the av receiver will renegotiate HDCP etc. The bulk of your delay is in the av and display resyncing to the signal. With some displays this is so bad that it could take up to a minute for the image to re-appear. This is one of the reasons that Radiance Pro's are bundled with many hi-end projection displays. It is possible to get switching times down to 3 seconds...but this involves a compromise in image fidelity that most enthusiasts would not want to put up with either. You do it by telling the scaler to always output the same resolution, refresh rate, colourspace and dynamic range for all content...and you use the calibration tools in the scaler to "fix" everything so it looks correct.

Without this fix you would want to put your most used sources on 3 and 4 if they will work well in to a 9GHz input. Also make sure Genlock is OFF. Lastly make sure you are using quality certified cables on input and output side.
 

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