I have the answer for you! Look at the specification on the amp (particularly the speakers) that you currently have. Specifically the frequency response. NOT the frequency range, mind you, it's the FREQUENCY RESPONSE that is your real problem. The chances are that your amp or speaker system only deliver's a frequency response down to a minimum of 40 Hz. Many hig quality systems I hae looked at recently, only provide a low-end response of 45 Hz to 55 Hz. So, what is wrong with that? Well, it's all physics, my firend. The sound produced by the low E-string on a 4 or 5-string bass produces a sound vibation of 41.2035 Hz. To really hear that sound will, your amp & speaker system need to provide head room (or bottom room as the case may be) below that 41 Hz frequency inorder to give you the best quality of sound. The low 40 Hz you probably have is not really adequate to give you a quality low E. So, what about the 5-string, that even lower B vibration? Well, I'll tell you. The low B vibrates at 30.8677 Hz. You see what I mean? It's almost like no one in the bass amplifier/speaker market thought is was necessary to change anything when they came out with the 5-sting bass. Here is how I solved that problem and you can too. First, forget about buying a bass amplifier. There is NO bass amplifier on the market today that can accomodate a 5-string bass. I know, I've looked at all of them. Instead, go and get yourself a really good 500 watt Power Amp like the QSC GX5. Then buy a pair of JBL JRX115 speaker cabinets to go with that. You can ad any pedal effects you might need for your bass on the front end of this configuration but, you're not done yet. Why? Because those really high quality JBL speakers you just bought only give you a low-end response of 35 Hz. You will need to add a subwoofer to your configuration to get that low-end quality of sound. So, go out and buy a JBL ES250PB powered subwoofer. I know, it's home theater equipment not stage equipment, so just be carefull with it and don't bang it around too much but, it's powered by a 400 watts built in amp and it will give you to 24 Hz low-end response and it will absolutely blow away any bass amp on the market. How would you like to be on a gig and have other bass players come up and ask you how you get that really deep rich sound out of your 5-string? They do it all the time to me. The other question I always get is: "Where's your bass amp?" You see the QSC QX5 / JBL JRX115 doubles an a PA amplifier when you front end it with an Alesis 16-channel mixer. You will even be the perceived as the best bass player in town once your secret it out! So what is the cost of all this? Much less than you would expect. Depending on what discounts you can get on the equipment, You ar probably looking at less than $1400 for the Amp, speakers & subwoofer and a good mixer will run about $500 to $600 if you need one. I use a mixer in my configurattion because I also sing and play the guitar and keyboard and that allows me to be versatile on the fly. So, now you know my SECRET of the 5-string bass sound. Good luck to you!