TOPIC:

I'm putting together an active HT system, trying to figure out how to set it up. I'm considering this:

Digital transport > Emotiva Surround processor > DSP > Power amps > Speakers

Main speakers
Active 3 way (possible expand to 4 way) ... high pass required
Note stereo subs with powered plate amps are included here

No centre

Surrounds
Active 2 way

LFE sub

The main issue I'm having is with volume control and digital/analogue inputs. The simple solution would be analogue outputs from the processor so that it controls volume, but this adds another DAC and will mean low input level when the volume is low.

Digital inputs seems ideal, assuming it's possible for multi channel, but how then do I control volume? Do I end up with a whole lot of volume pots? I'd like to sit back with the remote and have a master volume control.

Paul,

In answer to your question about Digital volume:

Digital inputs seems ideal, assuming it's possible for multi channel, but how then do I control volume?

not sure what you mean by "multi-channel" but if you're asking for Dolby decoding from an SPDIF signal, that's not going to happen. (need a decoder).

If your receiver can output digital audio for front and another SPDIF out for rear, then you could do that project with:

Front:
- 2 x miniDSP processing the 3/4 way signal.
- 1 x miniDIGI getting the digital signal

Rear
- 1 x miniDSP processing stereo 2way
- 1 x miniDIGI getting the rear signal.

As for volume control, have a look at the user manual which describes how to connect a 10k pot to the board to provide master volume control (can control multiple boards). That topic has been discussed already a couple of times on the forum. There are even some users using remote. DIY though and out of our support structure, but not so hard...

Hope this makes sense.

What do I mean by multi channel? I'd be using a dedicated surround processor (the Emotiva) which does surround decoding, then ideally running digital outputs from that - 4 channels. Last night I scanned through the entire forum and previosly downloaded about 10 datasheets, but didn't realise that the master digital volume could be done for more than 2 channels. I would have 4 and they would have already passed through surround decoding.

When set up this way, would the outputs be adequate to drive the power amps? It seems that in running everything digital that I would have bypassed all preamps. Just wondering if this would then be an issue.

Paul,

Yes indeed, it's what we refer as a "Master volume control" (see p10 of the miniDSP Kit user manual). I.e. affecting volume of all 4 channels at once.
In your configuration, I don't know your gear so to make sure there are no misunderstanding, on the type of signals coming out of your surround processor to get these 4 channels Digital out. It could be 2 types:
- 2 x SPDIF out (2 channels each = 4ch out) -> 1 SPDIF going to the front, 1 SPDIF going to the rear. See configuration explained earlier.
- 1 x SPDIF out (4ch still encoded) - That wouldn't work since we can't decode that signal to 4 channel.

Hope this is clear.

Thanks for the response. I'm waiting to hear back from Emotiva about this. I know I can get SPDIF out with 2 channel downmix, but whether I can get the surround channels out at the same time is another matter. Seems I would probably have to use pre outs for the rear channels.

Would the output be adequate to drive a typical power amp without a preamp in the middle?

I can't answer whether the miniDSP would be able to correctly drive your amp without knowing its sensitivity. Most of users are running it straight to an amp and not having issues, but it all depend on your sound chain. You can always start without and see later if you need a buffer or not.

I have a number of different power amps in mind, but just to know it's not generally required is enough for now.