Don’t sound “clean”? All their digital mixers have about as low a noise floor as the X1800. The Nexus had a slightly worse S/N ratio than the DJM800 and NXS2, but has darn good transient response. Lot of people complain about that first DJM900, but it does some stuff well, IMO.
I find most of the warmth people are hearing on the analog A&H mixers is actually caused by the EQs. It’s funny on the DB4 how you can mimic them (iso like a 92, eq kinda like a 62), but if you switch it to filter/bypass mode it sounds more like a brand new Mackie! When you have properly-functioning outputs on the DB4, it’s pretty darn amazing. They have some goofy grounding issues on their master outs. Oh, hey, that’s another mixer other than the X-9 with noise issues, hah hah. I really like the DB4 compared to the 62, 92, and even 4D.
Here’s my subjective take on the X1800:
I think the X1800 is more forgiving-sounding than the DJM800 but darker, mushier, and more furry than the DJM900NXS2. Sorta reminds me of the old Numark DM905 tone. Wish it was more the DM900EX tone
Might be the opamps or analog output topology.
X1800 seems like a little less low-level detail than the NXS2, leading to a sense of lower in-the-blend transparency (weird because digital summing math is supposed to be settled science) and less ambience retrieval, particularly in spatial depth reproduction. The in-the-blend stuff is probably just the overall tonal character and low-level detail reproduction rather than bad summing math.
X1800 is more cohesive-sounding to my old ears than any of the digital Pioneers, though, even the NXS2 that while the smoothest and most refined Pioneer mixer yet and not quite as bloated in the lows, glassy in the mids, and crunchy in highs as the DJM800 still sounds like three separate, synthetic bands that don’t quite gel. Synthetic is the operative word there even if it’s smooth and has that warm lower midrange. The NXS2 highs are like artificially delicate or something without being quieter.
So X1800 sounds a little less clear & open and sounds less dimensional in its imaging, but does sound more real and organic to me even if its separation of instruments within a song or blending of layered channels isn’t as good. X1800’s got more grunt and palpability to it than the NXS2 at the expense of clarity, spaciousness, and freedom from added processing texture, but the NXS2’s smoothness, clarity, and openness is at the expense of realism.
I do think for some weird reason the X1800 might sound better at lower sampling rates. The X1700 is more transparent to the original signal at the sample rate you pipe into it if you match rates, but does really nifty stuff to upsample… musical processing to the mids & highs at 96khz. I definitely am not hearing anything beneficial to upsampling lower input rates on the X1800, possibly the reverse, but hard to tell. There might be some benefit to running the X1800 right now even lower than the sample rate you pipe into it! You don’t have that option on any of the Pioneers, though.
It’s not a bad sound. Perfectly functional and all. I mean, it’s no MP2015 but it’s a valid sort of flavor compared to all the other digital mixers out there on the market. There also might be some way for Denon DJ to improve the processing on the X1800 even more.