Choosing a Bass Amplifier/Speaker Cabinet definitely comes with ALOT of factors to consider. Here are a few general tips to consider. Some may seem obvious but are sometimes overlooked. 

Application-What will you be using the amp for? 

     If your amp is going to be used for live playing you will need to consider the type of venues you will be performing at. Coffee houses typically won't require an 8x10 cabinet for example while a theater size room may be more appropriate for a larger cabinet and amplifier. The smaller the venue or stage, the smaller the footprint will need to be for you. Also, how will you transport the amplifier to your local gigs? With the implementation of In Ear monitoring even down on the consumer level and profiling amplifiers that only require a stage monitor, it's a whole new landscape for Bass Players with many more viable options. Our goal should be quick and efficient with tone and volume that works well with the jobs we are hired for. Remember, equipment does not supersede your ability to play accurately and to the requirements of the gig. 

Ensemble Type-What is the instrumentation in the group?

     If you have a loud drummer in say a rock type ensemble, a single 1x12 cabinet will not cut the mustard. Conversely in a small venue playing Jazz, it will most likely work perfectly! Two guitar players a keyboard player take up ALOT of sonic space. This will most definitely require a little more wattage and cabinet to cut thru the dense frequencies these instruments produce. 

Understanding Frequencies as it pertains to your Instrument 

     Most bass cabinets are GENERALLY designed to reproduce standard 4 string basses just fine. With the advent of multiple stringed instruments, the frequencies they produce changes the requirements that your cabinet must produce. 5 String basses produce lower fundamentals so it's a good idea to look for a cabinet design that goes down a little lower in frequency than the standard bass cabinet to accurately reproduce those low notes. 6-7-8-9-10-12 String instruments also produce higher frequency ranges so you would most likely benefit from a cabinet with a tweeter or horn.  

Wattage does not necessarily equal louder

     1000 watts sounds impressive, but if you boost the low end on the equalizer, you can eat up the watts fast. Learning how to eq conservatively based on your instrument, in the room you're in and the ensemble you are playing with is much more important than wattage. Wattage IS important for headroom in bass guitar land to produce good, clean fundamentals, very similar to Pro Audio in that regard. The equalizer on your amp is the single most important feature to be aware of.