i listen to EBM/industrial, which shares alot of similarities with Trance/Techno, so that's what my system is geared most to. i can play Trance with great clarity (even standing a good distance outside my car), and it gets loud enough to where i can't sit inside my car if i turn it almost all the way up, or the flesh will begin to slough off of my body from the sheer volume. j/k
sooo.... first and foremost, you need to amp your speakers. most headunits do not put out anywhere near what they advertise (at least, not RMS). your HU (45w x 4) is more realistically pushing about 12-15 watts per channel, and noisily at that. the reason being, when you turn up your stereo, the headunit begins to clip as it reaches max volume. when this happens, your speakers will distort, and sound skank. adding an amp will provide your spkrs with a nice, FAT and clean signal, and allow you to raise your volume considerably! i didn't think it would either (sounds silly), but my lowly 60w Sony speakers are capable of getting extremely loud, while maintaining their clarity.
another factor is bass. your speakers are not intended to play massive amounts of loud bass. that's where a new sub comes in, with an amp. you connect your front speakers to a couple of the channels, and set the amp's "crossover" accordingly, so the smaller, interior speakers play only the high frequencies. your sub will be set to a much lower crossover, and thus, will only play the low frequencies. again, the amp is required to send a clean and powerful signal to your subwoofer, so it can run smoothly.
Delco's speakers are generally very subpar, when compared to average aftermarket companies. you seem pretty pleased with yours. why not just buy the amp, and sub (and box, and wiring, etc...) and hook that up first? no matter what, you will not be disappointed. a subwoofer on its own can do a lot to improve your sound, if you're content with your current interior speakers, since most folks looking to upgrade are most interested in loud, clean bass frequencies.
i suggest a multichannel amp so that you may add a couple nice speakers up front, when you can afford to do so. that way, you don't have to go and purchase another amp. i warn you, though, that at some point you will want some tasty new speakers, so keep it in mind (and start saving!).
i agree with SubXero, that good speakers are a huge portion of your SQ, and if your Delcos aren't keeping up with the subwoofer, you may be a bit disappointed. however, i personally chose to install a subwoofer, and worried about my interior speakers later. i'm glad i did it that way -- i got to enjoy some big, boomy bass before i beefed up the rest of my system to match.
abe m.
