Some clarification needed, and additional info.

..."bring two stereo signals from a Soundcraft....into the two (line) inputs of a Xone:23".

I am assuming you are running TWO sets of stereo signals (4 cables, or two paired stereo cables), one set coming from the "record out" of the Soundcraft, with RCA jacks on both ends, that pair going to a "Line In" (not "Phono") of the Xone? The other pair must be 1/4" TS plugs one end (at Soundcraft "Monitor Out") to RCA plugs on other end, at XOne "Line in", opposite the other "Line In"?

I assumed that from your statement of "Going out from the record and monitor outputs of EPM to the left and right of Xone gives a good signal from Xone's record output.'

I'm sure this next question doesn't exactly have anything to do with the problem you state, but is the mix from both the "Record Out" and the "Monitor Out" of the Soundcraft the same? Panning, instrumentation, etc.? If so, might it be a little less work dealing with trying to match levels into the XOne by just using two RCA "Y" cables coming from the Soundcraft into the XOne? Both "Line Inputs" would see the exact same level, and the signal SHOULD be strong enough to not get degraded?
IF that is the case, and you want both sides the same, I assume you have a need for that, like having whatever is running from the Souncraft to go into both sides of the XOne, and then fading two different signals mixed in from the "Phono Inputs" at will? That's all I can imagine you are trying to do. I may be wrong, but my first inclination to get the same exact signal into the left-mixed and right-mixed channels of the XOne would be to simply "Y" the L/R RCA outputs from the Soundcraft "Record Out" to each XOne "Line In" input? Then, the Input attenuators on the XOne should pretty closely match, more easily?

Anyway...your actual problem. Have you listened, also, in headphones? You say the signal is fine through the XOne's "Record Output", but funky through the Main XLR outputs? Is it also fine with headphones? Knowing these things will help isolate the problem area. To what are you running each set of outputs? You didn't mention that, and that's a definite "need to know".

Are you running the output of the XOne into powered studio monitors or PA speakers? If so, do these speakers have the RCA inputs, the XLR inputs, or both? Do they also have a 1/4" input, and are they combo 1/4" TRS/XLR, etc.? If powered speakers, do they have any input controls that could affect levels, or anything else?

OR, are you using a separate power amp, running into unpowered studio monitors, or PA speakers? If so, are you sure it's working properly at its inputs, whatever inputs you are using? have you tried running, for instance, the XLR outs of the Soundcraft into them (or into WHATEVER you are using) to eliminate the speakers or power amp XLR ins as the problem? (Must be SOMETHING about the XLR, since those are the outputs of the XOne you say are giving you the problem.)

OR...since we don't know. Are you, perhaps, running the XLR outputs of the XOne into, say, a "powered mixer/amp PA head", and trying to run them through, say, Input Channel 1 and 2 XLR inputs, where the signal will be taking a long journey through many more gain stages and EQ stages, etc.?

THAT could present a problem, if so. IF using a "mixer/amp PA head", probably best to figure out a path directly to "Amp Section", and it likely won't be through an XLR input. Though, it MAY be possible that that it could take balanced inputs through 1/4" TRS jacks. AND, to have "stereo" it would have to be a stereo head (or dual channel head, some will let you run stereo, or let you use one internal amp for mains, one for stage monitors, etc.) AND, it would have to have TWO "Amp Input" jacks, one going to each amp section, to keep "stereo". Unfortunately, in a PA "mixer/amp head", a balanced "Amp In" for both amp sections are not all too common. And, many may only have an "unbalanced" TS "Amp In". It depends on the design.

ANYWAY! Elaborate on the exact connections to and from EVERYTHING, and the make and models of ANYTHING else connected. Knowing all that can lead to people possibly spotting a problem right away, and avoid further long-winded posts...like I have just written!

One more thing. Make sure NONE of the "extra stuff" on that XOne is engaged, and start with the input levels at minimum, then bring up as signal is output from the Soundcraft. Not sure if there are "levels" problems, grounding problems, connection problems, equipment malfunctions...whatever...with too little info.

Good luck!

Kapt.Krunch

Hey Kapt.Krunch, I'm delighted to see your reply!

Yes, your interpretation of my statement regarding the connections is absolutely correct. But No, the mixes on the two sides are not the same, in which case I would have also used a Y-cable!

I've solved the problem this morning: the XLR outs of the Xone go to XLR ins of a Tascam recorder. The same problem existed when connecting them to an active speaker. The XLR's on the Tascam rate the input at -14 dBu. I changed the cable to a XLR to TRS and that solved the problem, as the TRS input is rated at +4 dBu. It is the huge headroom Xone makes available that was the source of the curse (it puts out an unbelievable max of +28 dBu from its XLR outs! With a nominal +4 dBu, which is the max input level of an XLR input of the Tascam.), even though otherwise and in itself an amazing feature.

It was the different context of a DJ mixer that led me to this problem. I'm used to mixers which only MIX and put out a nice 0 dBu (with the possibility to add some "manual" gain for the day it's needed) for everyone to do their thing with it. DJ mixers seem to feel themselves more responsible in that respect, so I think people should be actually calling them Mixer/Amplifiers, or perhaps Mixifires. And this Xone, I must admit, is really a golden Mixifire!

Anyways, many thanks for the time you took to analyse the problem... It speaks for the quality of this platform (recording.org). I'm happy to be a part of it now!

Cheers, Pouzi