I just bought a brand new Scarlett 4i4 3rd Gen. All installed OK, but one problem:

I have a Line 6 Helix LT guitar digital modeller which I want to connect to the Scarlett. The Helix is set to provide Line level output on stereo XLR balanced outputs, and I am using balanced cables, XLR to TRS, to plug into the back of the Scarlett, line in 3 & 4.

The Helix is turned up full, and hard thrashing is producing peak signals of -18dB. My Helix presets are made to be about the same volume as a bypassed signal.

As a sanity check, I plugged the Helix into the front panel line ins, and I had to turn them down to about 3 or 4 out of 10 (11 o'clock).

Is this normal? Are the rear line ins set for low sensitivity compared to the front ones? There are no gain controls for these rear inputs. Surely we're not expected to record such a low signal, or have to add extra hardware to up the gain?