Be careful here though, what kind of bass do you want? The Sony XB series REALLY is a MONSTER of bass. I found them to be really overpowering. What kind of bass do you want? Do you want the kind of bass that "can shake your head around like a ragdoll while listening to just an acoustic guitar" or "a nice touch of bass just to hear some raw power"? Be careful, the XB series are a powerful creature that some bassheads even have a hard time bearing in some cases. If what you want is the first kind of bass, then the XBs are your #1s, if not, please continue your search.
LODs and DACs? Explain them? Okay let me try.
I'll do LODs first, and try in the simplest terms.
So imagine a street, just a one-way street with one lane, no shoulders or sidewalks, and a speed limit. This is the equivalent to your 3.5mm audio jack. Now this highway is fine, it handles power sufficiently, can deliver clarity and volume, and it really is "good enough" for most cases, but once you get to a certain point, the cars might be all clogged up and accidents may happen if too much is demanded of the road. Now imagine a street with 4 or 5 lanes with sidewalks and all, no speed limit, now this street can handle LOTS more power, LOTS more clarity, and lots more EVERYTHING WITHOUT having the same stress issues as the first street. They really do help you out a lot if you want more than "good enough" and they really are quite cheap. Also, LOD stands for (Line-Out Device)
DAC? Okay this is going to be hard, if you dont understand the explanation then dont worry, just know that DACs help your music sound better
But let me try anyway.
So speakers are an analog device. It relies on amounts of power varying from 0% to 100% to run and perform. What your speaker is in essence is a material diaphragm with a magnetic base infront of a magnet (cobalt or neodynium in most cases), and this magnet takes the electrical signal from your cables (whether that electrical signal is 0-100%) and magnetizes itself, pulling back the diapghram, moving air, and your brain interprets that air as frequencies, many frequencies are sounds, many sounds are songs. So anyway, analog is 0%-100%, but digital is 0% OR 100%. No in between. Your iPod or whatever is containing your music is a digital device, and it cant power your speakers without something to convert it's digital signals into analog signals for your speakers to read.
Now your iPod or comptuer or whatever has a DAC (which, for future reference, is Digital to Analog Converter) built in, this is usually referred to as a "sound/audio card" in computer terms. And it takes the music files from your digital computer, reads them, determines what frequencies of the song require what speaker power and output and colour, and throws it through the wires of your headphones into your speakers which end up as music. Now, the DAC your computer or iPod has is fine, theres nothing wrong with it, but lets make another comparison like I did with the LODs.
Imagine two artists. One is a new artist with few techniques and one paint brush and a limited palette of colours. He paints nice work, and its "good enough". Now imagine another artist. This artist is a master artist with many tools and palettes and hundreds of techniques, his art is astonishingly beautiful! Now lets say your music is an art piece (which it is! Aha how coincidental!) and your speakers are the canvas for this art piece to be painted onto. Now, the first artist can paint it all just fine, he gets the main idea in and even some details, but with only one paint brush and a limited palette, its slow and sortof a boring piece of work. The first artist is in proportion to the stock sound card of your iPod or computer or whatever. Now the second artist can make your art piece into absolutely magnificient work on the canvas! Always entertaining and beautiful! This second artist is in proportion to a purpose-built DAC. The first artist can do the job fine, and is "good enough", but the clarity and life isnt anywhere near on the level of the master artist.
So thats my explanation xD Hope you understood it!
EDIT: LIZARD YOU BEAT ME TO IT >W< !!!!