Thanks for posting. I always thought Dirac would set a negative gain automatically to avoid clipping.
The post in the minidsp forum seems old though. Can any Dirac-minidsp user confirm it? Thanks
I've been speaking to a few of the people from that chat and it all still applies. The MiniDSP doesn't have an easy way to see how much boost Dirac puts on so you have to either set it at -10dB to be guaranteed no clipping, but that will reduce headroom on your amp. So if you want max headroom without clipping you need to measure how much boost Dirac has added in your room via one of the techniques in that thread and then attenuated your SHD master volume by that amount. It most likely won't be more than -6dB but there's no way to know for sure unless you measure.
I'm going to use this method:
[Thanks
@Tony_J for the detailed research. I've recently acquired an SHD, which I guess has more or less the same signal processing architecture, and this is the best description I've found so far about how it all fits together, and has clarified a couple of things I was confused about.
Something I learnt about recently is that you can use REW to directly measure what the SHD is doing, via USB. So the chain is:
REW -> USB Output -> SHD processing -> USB Input -> REW .
Obviously you don't see what's happening directly in the analogue domain, but I assume any clipping would show up in REW anyway.
Attached is a graph from this method using a measurement sweep that shows the frequency response of the Dirac filters in my setup. It looks like the maximum boost applied for me is around 5db.
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