SPDIF channel duplication

[ppataki]

I would like to split digital coax (RCA) SPDIF in the following way:

I have one cable that has Left and Right channels (standard digit coax output from my miniDSP U-DIO8). I would like to split it to have one cable that has the Left and Left channel and another cable that will have the Right and Right channel
Is that possible somehow?

Many thanks

 

[MarsianC#]

Why would you want to have the same digital signal per side twice? Active crossover and DAC/amplifier in speaker?
If not I'd set the output volume for the left side to out1 100%, out2 0% and for the right out3 0%, out4 100%.

Isn't there some kind of input matrix to choose?
In case of using a computer as source check Voicemeter Banana to reroute the audio channels.

 

[MaxwellsEq]

I would like to split digital coax (RCA) SPDIF in the following way:

I have one cable that has Left and Right channels (standard digit coax output from my miniDSP U-DIO8). I would like to split it to have one cable that has the Left and Left channel and another cable that will have the Right and Right channel
Is that possible somehow?

Many thanks

I'm not sure I understand your requirement. However, you can't use a cable to do this. The left and right channels are interleaved in the bitstream. You could use a processor chain to cut all the left channel on one S/PDIF output and another processor chain to cut all of the right channel etc. Years ago I used an AES/EBU test device to do something similar so there may be something in the professional audio world.

 

[ppataki]

you can't use a cable to do this. The left and right channels are interleaved in the bitstream

Yes, that is what I was afraid of

The use-case is the following:
I have two subs, with two pairs of banana plugs each (2*4 ohm)
I have two stereo full digital amps with SPDIF inputs and want to drive the subs with those
But I cannot sacrifice 4 SPDIF channels to make that happen
So ideally I would feed the 'left' channel to one sub and the 'right' channel to the other, hence I asked if I can split the SPDIF signal by channel
So one amp would get the left channel only (left-left) and the other the right only (right-right) - if that makes sense

 

[MCH]

The few SPDIF transceiver chips I know cannot do it, they always work with the pairs as they receive them. Even multichannel ones (i.e. ES9080q DAC's SPDIF outs). I can imagine it isn't that straightforward. The only practical way I see is to have a SBC in the middle, running something like camilladsp. If you have the u-dio8, that should solve the output hardware requirement, I can imagine. Doesn't the minidsp software allow to mix channels?

 

[MaxwellsEq]

Yes, that is what I was afraid of

The use-case is the following:
I have two subs, with two pairs of banana plugs each (2*4 ohm)
I have two stereo full digital amps with SPDIF inputs and want to drive the subs with those
But I cannot sacrifice 4 SPDIF channels to make that happen
So ideally I would feed the 'left' channel to one sub and the 'right' channel to the other, hence I asked if I can split the SPDIF signal by channel
So one amp would get the left channel only (left-left) and the other the right only (right-right) - if that makes sense

I've had a look in the pro world and it's not a feature there unless you use a mixer with digital ins and outs or a DSP processor.

 

[ppataki]

I've had a look in the pro world and it's not a feature there unless you use a mixer with digital ins and outs or a DSP processor.

Thank you for checking, appreciated

 

[mdsimon2]

But I cannot sacrifice 4 SPDIF channels to make that happen

I think I understand what you are trying to do and your limitations but want to confirm.

You have a U-DIO8 but only have one free stereo SPDIF output for the subs. Is this correct? So, any sort of software DSP channel routing solution upstream of the U-DIO8 isn't a viable option.

Cheapest off the shelf option I can think of is a used miniDSP nanodigi but these are a bit hard to find. I wouldn't want to have any sort of software DSP downstream of the U-DIO8 due to inconsistent delay. You could also use a miniDSP option that has I2S output, like a 2x4HD or miniSHARC which might be easier to obtain than a nanodigi.

Michael

 

[ppataki]

Thanks @mdsimon2 , probably I will ditch this idea since it seems to be pretty cumbersome to make it happen