I once knew an (absolute top notch) engineer who mastered everything through a cheap stereo as well - his argument being that's what most people will listen to the thing on!ME's use very nice monitors in very nice rooms with very nice outboard to polish your finished mix and make it sound as good as possible.
Had a listen to content synth - not bad! Two main comments I'd have would be the drum beat coming in at ~1:45 sounds a bit rushed personally - and perhaps the minimalist section at the beginning could build up a bit quicker?
Just a couple of thoughts I was brought up in the classical realm of music though so I may be coming from a bit of a different angle!