Echo sound on DAB

[ehsanspicedigital]

Hi, Lads, Hope everyone’s well, Enjoying the weather (while it lasted )

I’ve got a Optimod 6200s going into a Sonifex PS-SEND, When listening to the output of the station from a DAB receiver i can hear some sort of double playing / echo sound on the audio, Which isn’t apparent on the Webstream being sent to the MUX. has anyone ever come across this issue? what could the possibilities be? So far i’ve:
Checked cables to ensure correct connection for phase
Used both a Digital and Analog audio path to the encoder,
Checked cable phase from sound card to Mixing Desk,
Checked sample rate match between Encoder&Processor,
Checked my stream provider isn’t doing something dodgy on their end,


I’m out of ideas, This is happening on 2 stations of ours, both on different MUX’s with seperate equipment in different locations, but the equipment itself is the same.

Again, It’s not apparent on the Stream going from here, It sounds clean, When On-air it’s sounds like echo / Double-play.

Another thing to mention is that the double playing reduces a lot when feeding Mono audio to the processor.

Extreme thanks for your help in advance! Thanks Lads!

[Albert H]

Your first mistake is using any Orban Clipper / Distorter. It's really instructive to connect an Optimod (any model) to a distortion analyser, and put in a few tones. You'll find that when it goes into "Limiting", the percentage distortion goes through the roof! Don't believe the hype about "distortion cancellation"!

Can you locally decode your outgoing stream after the processing / abuse? You may find that it's some bizarre digital artefact from the Optimod.

[ehsanspicedigital]

Hi, Albert, Thanks for the reply, I didn't know that the Optimod was so bad?

What ill do is ill share a audio clip from the mixing desk, without any processing, and then a recording of the audio stream, playing the same track and a jingle on each end. If you can have a look it would be great! Thanks!

[mpx]

Stereo reverb?

[ehsanspicedigital]

https://fromsmash.com/c.RgfMkUmN-bt

Here’s 2 recordings

No processing.wav is output from the mixing desk
Stream recording.wav is the webstream after processing and mp1l3 encoding.

Please can you check if there’s any noticeable artifacts?

I’m working of getting 3 recordings, Studio side, Webstream side, DAB Side, they would be great to compare and might give a better understanding

[radionortheast]

Sounds like the kind of thing that happens when you’ve got monitoring on through a soundcard, you’ve got two signals instead of one, echo happens because theres a delay between the two, check you’ve not got two duplicate versions of software going.

[ehsanspicedigital]

That is what I was first inclined to check, but this sound is happening on both of my stations, And its the same sound, and the audio chain is basically mirrored on both of them, same equipment etc. Does anyone know if the Optimod 6200s has some sort of stereo enhancer that can be disabled or turned off, might be something like a stereo enhancer doing something to the audio that isn't apparent on the webstream, but when it gets DAB+'d and audio basically gets destroyed it might be bringing out them artifacts in the audio, is that something that makes sense or am i just blabbling on

[ehsanspicedigital]

Here, I’ve got a recording from the Studio side & the output of the DAB Mux from Digris, You can hear the problem on the jingle inbetween the tracks. Can someone please have a listen and let me know what they think could possibly be going wrong!

https://fromsmash.com/cZd92vdaBn-bt - Link created via Smash, the super alternative to WeTransfer.

[jvok]

Can you bypass the 6200 (temporarily) and send input straight to the ps-send? Its got to be coming from one piece of gear of the other (or I guess something the mux operator is doing downstream) so if you can rule one out it should be easier to track down