Schiit Mini loko+

I think it’s an excellent idea. 

     I agree

Dear @hanshhh  : Any decent speaker normally  " flat "  in that frequency range .

If your speakers specs says is " flat " down there then changing room speaker position ( testing in different ways. ) and along changes in room treatment could be fixed your " problem ".

In the other side you already knew what this gentleman posted about your Audience speakers in your thread:

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

But that eq. is " no-brannier " as you said. Test it.

I had a Schiit Loki plus for a few weeks.....liked it a lot....so much so that I decided to get their best unit, the Loki MAX.....I hear no loss of resolution or transparency when you switch out the device, ( the Max version allows for instant compares with its remote control capabilities). 

Just try one out, if it doesn’t work out within 15 days send it back ( small 5 % restocking fee)

Cheers.....

@ozzy62  I'm here to point out stupidity and keep things fun.

There's also the Lokius which may give you more control over the bandwidth and a tighter curve over your problem area.

I had a Loki on loan from a friend in my system. My setup is pretty revealing and the Loki was transparent. I couldn't detect any added noise when engaged or in bypass. It will also accept a LPS if you desire.