MRA Reticulated IR

I have a customer that wants a minimalistic look and does not want to see an amplifier (even in a cupboard) but does want to use the local audio input. I was going to install a wallplate with RCA audio connectors (red & white) in each room and run screened audio cable back to a central point about 25m away where there would be other similarly arranged amplifiers.

I also want to extend the figure 8 cable for a tube target (probably in the ceiling) the same distance for reticulated IR.

Is it ok to run the cables over this length?

If I use the desktop amplifier, will the IR target plugged into it allow volume control of that amp? If not, can I assume the only way is to use a DLT (which will be in the room anyway) and not have IR volume control in this case?

Cheers

Colin

 

I would strongly suggest running Balanced audio cabling over that kind of distance, rather than RCA (unbalanced).

Whether that means you put in XLR (Cannon) plugs in the wall plates instead of RCA's, or if you install unbalanced to balanced "convertors" behind the RCA wall plates, it's still a better option than plain shielded unbalanced cables.

You could also use Cat5 as the cabling and put convertors/baluns/blah in behind the wall plates if you want a cheaper option.

Otherwise you're running the risk of having all manner of interference being introduced into the cabling, especially in this day and age where there are so many electrical devices around emitting RFI/EMI interference.

Just my 2c

Darpa

 

Thanks for that - that makes sense.

Has anyone extended the IR target cable over this kind of distance??

Colin

 

I can't see why you wouldn't be able to extend it to around 25m, just make sure you use decent quality/thickness fig8, don't use the 30c/m cheap bell wire crap.
You might almost be better using Cat5, as the cost would probably be around the same mark as decent fig8.

Darpa

 

IR on Cat5 over that distance won't be a problem.

 

I have a project which does not have power supplies for Amplifiels (x8 amps). Sound and C-Bus work fine, but IR extention does not work. Could it be because of no power supplies?

dynamic buttons IR commands work fine

 

The lack of power supplies makes no difference to the operation of the IR, power comes from either external supplies or over the CAT5 from the matrix Switcher.

The reticulated IR port only goes to the IR transmitters connected to the Matrix Switcher. No signal processing is done on it and it does not interact with the MRA system. Only the IR port on The Desktop amps can control the system. The reticulated IR is just there to control third party equipment through that equipments IR remote control.

If the reticulated IR is not responding try repositioning the sensor (other IR sources in the room usually lower the sensitivity). It is also fairly sensitive to EMI, so try to keep it away from sources of interference. There will be some signal degredation over the cable with higher frequency IR remotes, but your normal 38kHz ones should be fine.

A handy little jig for testing reticulated IR is to make up an IR emitter with an ordinary visible LED instead of the IR LED. From this you can often tell if the system is being swamped with noise (LED on all the time) or if it is picking up the IR signal (brief flashes).

Cheers
RDS