This review has been a long time coming, for myself included. But I finally decided to take the plunge and pick up a pair of these puppies (and a lovely case to hold them.) Now I can provide you the review and information I was looking for, incase you're looking as well (or just like to read about more DJ gear.) I don't quite have the verbal dexterity or photographical mastery as our fearless leader, but I will do my best in humble service to the DJ community.
In a nutshell, the X² is the CDX and TTX combined in a neat and good-looking package with a few key differences: the CD section has no built-in effects, the vinyl section has no key lock or 78RPM (Who uses that anyway, right? But you can still do it with 45RPM +73% pitch.) And there's no digital output or MIDI at all. It's basically a no-nonsense, professional-quality CD, MP3, and vinyl player in one unit. I like to think of it as the ultimate transition device, since it can play everything from the oldest vinyl to the newest computer-based DJ software (using control records and/or CDs, preferably the latter.)
Getting all the basics out of the way, you've got dual start-stop buttons, 6/12/25/100% pitch ranges, adjustable braking & starting torque (0-6s,) adjustable scratch modes as on the CDX (for crossfader-less scratching,) CD program mode (to pre-select tracks to play in order,) key lock (for CD & MP3 only,) interchangeable straight & S-shaped tone arms, reverse & bleep switch, 45RPM adapter holder, BPM counter with beat LEDs, single ("auto cue" on CDJs) & continuous play modes.
Let me first mention that if vinyl is your main thing and you're looking for the best vinyl deck, you should really go with the Stanton STR8-150 or ST-150, as I consider those to be the best 'tables ever made. (They use the same floating magnetic drive system as the Technics only with higher torque, and they have key lock, digital out, 78RPM, etc. and are very heavy and rock-solid. Plus they come with a pre-mounted cartridge.) Don't get me wrong: the X² is a very good vinyl deck and you'll be very happy with its performance, it just lacks those couple of features to make it a great vinyl deck. (I ended up deciding to take the vinyl feature hit in exchange for more CD control in an all-in-one unit which cuts down on my load by two cases.) That said, the X² does feature interchangeable (straight & S-shaped) tonearms like its brethren, so it does have that advantage over the Stantons.
The X² has a CD-only drive (i.e. no DVDs.) It plays CD-Rs, CD-RWs (with difficulty, after warming up for a couple minutes) and of course pressed (store-bought) CDs. It accepts standard 12cm CDs as well as 8cm "mini" CDs (just insert them at the center of the drive by the LED.) Avoid non-round discs as they could get stuck. The discs can be regular (Red Book) audio CDs or MP3 data CDs. Numark says to avoid variable bit-rate (VBR) MP3 files but they seem to play just fine. (I only saw weird glitches when searching a long way through one.) It's always good practice to burn CDs you're going to use at a gig at the slowest speed possible no matter what it says on the disc. This causes a greater optical difference between the 1s and 0s on the media and makes it much easier for any drive (especially older ones) to read reliably. (It also increases the longevity of the data when exposed to light.) With MP3s, the X² will display the file name but no ID3 tag info, unfortunately. There's no folder navigation either: the X² just goes through all the folders on the disc and numbers each playable file as it encounters them. You simply rotate the select knob to the file number/name you're looking for. You're limited to +50% pitch control while using MP3s, but can still go to -100%. Seeking/searching is a bit sketchy with MP3s of either type (compared to audio CD tracks) in that it'll take half a second to respond to a button press, play a bit of audio, then silence for a quarter second as it seeks, then a bit of audio, etc. (This is due to the fact that MP3s need to be decoded in "chunks" (especially with VBR files) and it takes a fair bit of computing power.) But scratching, backcueing, etc. all work just as well with MP3s as CDs (thanks to buffering.) You don't want to backcue too far though or you'll run out of buffer and just hear silence until the unit catches up.
A nice feature of the X² (and the CDX from whence it came) is the ability to change the key of the music (on CD & MP3 only) independent of the tempo. This lets you create harmonically-correct mixes, which are more pleasing to listen to. (Unless you're doing a Halloween party or something and dissonance is desired. ;) ) You do this just by holding down the Key Lock button and rotating the select knob to the desired key, relative to the original. Each click of the knob (and number in the display) is a half-tone. E.g. C to C#, E to F, Ab to G, etc. The selectable range is -64 down to +24 up.) When you release the button, the key change takes effect. Another good time to use this is if you're playing an overly repetitive song (or running a loop) and want to make it a bit less monotonous: change the key 3 half-tones up to increase the apparent energy but still be in harmony with the original. This new key can also be locked just by pressing & releasing the key lock button (a lock symbol shows in the display.) Then the pitch slider only changes the tempo. A word on scratching with the key lock: it locks the key of the back scratch as well! Normally this isn't want you want (so make sure key lock is off before you bust out the moves,) but it can be used as an interesting variation.
You can mix from CD to vinyl (or scratch vinyl over a CD track) on one unit by connecting the CD out and Phono out to separate channels on your mixer. Once the CD is playing, you switch to TT mode which effectively disconnects the platter from the CD player, allowing you to pretty much treat it like a vinyl-only deck. Change pitch, stop the platter, scratch cue, go nuts; the CD will keep on playing. When you're ready to mix or scratch, just operate your cross-fader as usual. Beat-mixing from vinyl to CD is close to impossible though because you can't change the pitch of the CD player without affecting the vinyl. You can, however still operate the CD player from the transport buttons (including looping & key changes,) so it's still possible to stutter play a cue, create/recall a loop, or cut to a new song on CD. Kind of like a CDJ without the pitch slider. (See the second video below for more on this.)
The X² supports fader start and relay play (CD only for both. Though you could use them with vinyl too with the unit in CD mode since the platter spins even if there's no disc in the drive.) The fader start can be configured through the menu to work with different mixers or foot switches. Relay play just means that one unit will send a pulse when it's finished playing and the second one will start automatically at that point. You use this as an "auto play" function to have a second song start playing on the other deck when the current one finishes so you can spend more time dancing with that cutie. This isn't specific to Numark gear, so you could connect any other piece of gear that supported relay play to it if you so chose.
The X² will save cues if you explicitly ask it to via the menus before you eject the disc in question. (I imagine it keys the cues to the unique disc ID present on all CD media.) It can store up to 3,000 of these cues apparently.
I can't fairly compare the X² to Gemini's CDT-05 because I've never seen the Gemini "in person" nor used it. But from what I read here and on Gemini's site, the CD control mechanism on the X² is much more elegant: it has a special semi-rectangular center spindle [PIC] which the control record fits exactly and just lifts off like a regular record when you want to play vinyl (unlike the CDT-05's permanently-attached CD control vinyl which you cover with a special slipmat then your record.) Since the X²'s control vinyl is just another record with a special hole, you can use your own slipmat and/or slikmat as usual for the CD control record as well as regular records. (And you can change mats mid-show if that's your thing. Or change the CD control record every song if you want to pretend like you're playing all vinyl. :) You can also attach the CD control hub to your own record if you want to customize.) The only slight disadvantage to the X²'s arrangement is the reduced surface area on the center of a regular record, [PIC] which may affect heavy scratching. This is only a minor annoyance though and can be solved with a trusty piece of tape over the record hole, a technique with which seasoned vinyl jocks are well-familiar. Other differences: the X² has up to 100% pitch control, the CDT-05 has only 50%; X² has no DSP effects, the CDT-05 has three; the CDT-05 has digital coax (RCA) output, the X² doesn't have any digital output; the X² has vinyl-only (phono level,) CD-only (line level,) and switched (line level) outputs [PIC] and the CDT-05 has just vinyl (phono) and CD (line) outputs (which can be used at the same time as well.) This means that if you don't intend to play both at once or mix between them, you can just use one pair of cables to connect the X² to a mixer's line-level input and switch between the sources on the deck. (And if you need line-level output from vinyl, as when digitizing your records, you're SOL on the Gemini.) As for looks, of course beauty is in the eye of the beholder, but many people seem to prefer the X²'s appearance (and all-blue LEDs) to that of the Gemini. (The X² looks great paired with Stanton Trackmaster II-RS carts as well. [PIC]) Remember though that these are tools, and the only people that care what they look like is you and other DJs. Your chick-charming abilities will not be affected by the aesthetics of your DJ gear, I assure you. (Unless it's pink, or you have cute dogs or bunnies on your slipmats...)
I have made some demo videos if you want to see the units in action:
Mixing from CD to vinyl on one unit:
Please forgive the audio lag that gets worse as the videos progress...my FLV encoder was screwed up. I discovered the problem after I deleted the source video! (DOH!)
And if you end up picking up one or more of these and want a case, check out Marathon's line made for the CDT-05 but fits the X2 perfectly.
Single case: http://marathonpro.com/mamacatoho1x.html
(I have the coffin and it's very well-made. One of the slot covers was machined incorrectly but they replaced it under warranty quickly.)
Well there you have it. I hope this information is useful or at least interesting to you all!
Hailing from the USA with much love for the Skratchworx crew & readership, (and all the great dance music coming from Europe!)