Help with a wiring/config setup

Hi Guys,

Wonder if you could help me with this; it’s doing my head in!

I’m going to be hosting a web radio show shortly and I’m having a little trouble thinking about how to do the “wiring”, if I can call it that.

Basically I’ll be sending an audio feed via Skype and listening to the show on the BlogTalkRadio web-site using WMP.

The audio feed will go into my audiophile soundcard from my mixer but one of the channels, going into the mixer (apart from the voice mic) will be recorded material fed into the mixer from another media player on the same PC.

I’ve checked that the recorded stuff will actually get out of the PC to the mixer and back in again and go off via Skype to the phone call’s destination, but…

Methinks, wont that set up a feedback loop?

I’ve been trying to figure out how to break the loop but that’s when my brain started hurting.

Does anyone have any suggestions. I know this is probably pretty basic but I just can’t think it through.



If you run all signals mono then I think that the following scheme would work. If you want to run stereo signals, obviously the number of channels needed would be doubled, and I am not sure that routing of WMP output would be up to the task. Anyway, this should work for mono feeds.

All inputs in signal chain 1 are panned completely left. All inputs in signal chain 2 are panned completeley right. This scheme depends on being able to pan WMP completely right at the software level. I don’t remember trying this myself but I assume that it can be done.

Signal chain 1:

(mic + other audio feed) -> mixer input ch1 and input ch2 -> mixer output ch1 -> audiophile ch1-> Skype -> BlogTalkRadio

Signal chain 2:

internet -> WMP -> audiophile ch2 -> mixer input ch3 -> mixer output ch2 -> external audio amp -> your ear


Thanks T,

Yup, you got it. You could even add an extra instance of “mixer” as the penultimate item in the list (not that it matters - lol.

I see what you mean about the delay and I guess they’ll probably be mixing all the other input signals (5 additional callers are allowed at once) and compressing it all to 32kbps plus whatever else they have to do, before we can listen to it.

Hard to see how there wont be a significant delay. And as host you can’t not listen to the output 'cos then you can’t hear guests and callers talking.

I’ve tried talking with my voice echoing back with some international calls; it’s very disconcerting, I don’t think I’d like to try to conduct a radio broadcast under such conditions.

Anyway, back to my original problem. So, apart from providing an external feed for the recorded stuff, I take it it’s not possible to break this feedback loop in some way. Could it be done by using different soundcard channels for different tasks do you think?




Mike - I accidentally edited my first posting instead of putting up a new posting. So look back at it to see one approach to solving your feedback loop problem.


Thanks T,

I think you have it!

The only thing (well probably not the ONLY thing) I got wrong in my explanation of the scheme of things is that the output of the Radio show comes back to me (from BlogTalkRadio) via Skype - WMP only gets involved when streaming archived shows (if I ever get that far - hehe). But I think your idea still holds good none the less.

Anyway, I’ll try it out in the morning as it’s time for bed here.

Will let you know how I get on.


Ok, think it’s working now. I found I couldn’t get it work in mono for some reason but remembered that the audiophile soundcard has stereo spdif ins and outs and Skype is happy to oblige by sending it’s output to spdif.

I still have to test it in a “live” radio environment and the “delay” issue is still outstanding but at least I don’t have the feedback I had before so it’s a step forward.

Planning to do a test show tomorrow afternoon - hopefully only listened to by me and BTR’s liason guy as I’m not a natural presenter type. My good lady, who is very much a natural, still thinks I’m running before I can walk (which of course is true) so I’ll be using taped material off her web-site and hope that the archive of the resulting “show” goes some way to convincing her that we might make a go of it.

Anyway, sorry to be so long-winded but it helps no end to chat about all this stuff. Will let you know how I get on.



Good luck with your web “show”.