well at first i wanna thank you for having alisten to my tunes. i had some experimental times some years ago with kinda psycore project. i rejected after first releases and locked myself into studio to work some further. the 148bpm is the more recent stuff i did ^^
had some trancy EP i worked on which is not uploaded. i dont give anything about that genre thingy. music is who i am, i try to not control whats coming out there.
anyways, according to your questions, a dsp is a signal processor right. i.e. used for processing audio and videomaterial in mostly any way. for synthesis this i.e. means the dsp calculates by 0 and 1 any given waveform. you can see that in any daw if you take a real analog waveform like a pure sine and put a digital sine next to it. now if you zoom in, you´ll clearly see the digital sine becoming edgy and more steppy. theres the difference between analog and digital visible. the analog signal will always stay smooth roundish, as it´s controlled voltage. a digital signal is nothing more than an approach to an analog signal, calculated by a dsp
yeah dsp use to run in common audio interfaces for emulating D/A<->A/D conversion i.e. they just operate like any processor calculating the math behind. for interfaces this means they take the process your pc would need to calculate, i.e. any conversions and good ones even offer external dsp processed fx, which allows even more cpu usage beeing taken off your pc system. this gets pretty handy sometime....
anyways, getting deeper here. the reason i mentioned those two dsp in my xstation is simply because they can run seperate. thus the xstation runs easily as midi controlling device with external fx section that may be added to the output by one button, and that easily i can switch it to synth mode, which allows me to use it as synth. any midi routing keeps for sure, just this one button decides wther my knobs and such are used for the synth or for midi controlling. to me this is just perfect and that time i bought it, the suspended clavia g2 was the only machine offering similiar even better.
now they both suspended but are worth their money. you will never leave them thats for sure. just some sincere words according the g2. its fkkn worth every single penny, and this is the reason why its not that easy to find. sometimes there are one or two on ebay n such. but often i had no chance finding one. if i find it, i dont have the money xD
thing is, you can create your own synth. pretty easy, you learn damnin lot and you can try this here:
any patch you create there is uploaded to the g2. now imagine you got kinda synth where you dont switch patches as sounds but switch patches as synths. you will learn everything i told you here just by giving this demo a go and trying to get a sound out of it. you learn how a signal path works and really lots of basics and advance stuff. if you understand that demo, you wont have problems understanding any synth there is.
so, to me a synth was really beneficial. i bought a blofeld too when it came out and that time i learned really lot of that. its much more comfortable to have it infront of you for real and not only on screen.
been a lot, excuse the novel pls. keeping things short, an audio interface does the in/out stuff, usually cheap ones doing nothing more. so that does not have to mean your keyboard has a synth. and surely ONLY synths have soundbanks. you need an audio interface, def.! you need higher samplerates, lower latency rates , dsp power to get the calculating process off your computer. sounds weired, just easy. usually, midi keyboards DONT have built in audio interfaces. now if you want a synth too, its up to you buying three to four devices or one. while there are for sure better sound interfaces than the one built into my xstation, its way better than most 100 bucks interfaces on the market and def. way more than enough to work with.
to the clavia, that machine beeing anywhere like 1600€-2000€, which sounds a lot. but some simple math shows that a cheap synth with similiar options is min. 400€ (while similiar beeing not really that realistic, as the g2 is a modular synth), a similiar midi device somewhere 300€-400€, an similiar interface 500€-600€..... sooo, those few bucks left you pay for the extraordinary quality clavia delivers (in terms of sound and technology) and the cult status of the g2 ^^
so, for those 400€ for the xstation, i was able to solve the synth, the midi AND the interface issue.... without that beeing chaotic struggling through thousands of small menues on even smaller screen. i.e. it was really one of the best deals i ever did
but i wanted to keep things hand luggage size first and go for studio equipment later on. so, a 25keys version of a keyboard beeing my synth, midicontroller and interface was just fkkn what i needed ^^ so for a gig just my laptop was needed + usb cable and power supply. adding the blofeld was still hand luggage.... neat
if i had the bucks i anyways would def. ANY TIME go for the g2 .... but thats my humble opinion. im a modular nerd and love the analog style emulation of this synth. matter of taste.
how you go for these things is really up to you. if you want rock hard candys and solid state of the art material you dont need to replace i would at least go for good midi keys (you need to feel them, go to any music store and compare, try really expensive ones and feel the difference. if a knob feels not comfortable, leave that shit, if a fader is not running 200% smooth as you want it to move, leave it).
for the interface, if bought seperate, i´d def. go AT LEAST for a rme or motu interface. as for the synth i´d go for what suits me most. just listen to them, make the local or neaby music store your girlfriend. get kinda hobnob with it ^^
mac/pc optimized for audio
rme/motu interface (if things mobile, getting deeper if analog gear is preferred)
synth matter of choice (already got one to thousands with the g2)
monitoring beeing matter of choice too and depending on the size of the room, 8" woofers needed for really lowend mixing and mastering purposes.... like event, genelec, k&h etc. (for active....differs if passive preferred) id go for three way instead of two way and get small 2way nearfielders next to the bigboys.
the best equipment is useless if you cant use it.... hope it was kinda helpful. you asked some tough questions which are hard to be answered short. so pls excuse the novel. have fun between and fiddle around with the g2 demo. ^^
thats beeing my 2 cents. but this is really up to you. what you need. if you want to set up home basement and solidify things or keeping things mobile first.... sure for a studio setup id go for different things. if money and room not beeing an issue ....