The electric bass guitar replaced the double bass in the early 1950s. The bass guitar sound requires the use of a bass amp. There are many differences in a bass amp and an electric guitar amp. A bass guitar amp can double as an acoustic amp but not as an electric amp.
Examine the frequencies of the amp. Bass guitar amps produce a wider variety of frequencies than an electric amp.
Look at the controls on the amp. Bass amps have fewer controls than electric guitar amps. Bass amps have basic controls such as volume, low, mids and highs. Some bass amps have gains but bass amps do not have distortion or reverb.
Check the wattage on the amp. Bass amps normally come in watts of 300 and up. Electric and acoustic amps range from 50 to 250 watts.
Inspect the speaker in the amp. Bass amps have larger speakers that produce a low end sound. Electric and acoustic amps have a smaller speaker for a higher range.
Plug an electric guitar into the amp and play a few bars. An electric guitar plugged into a bass amp produces a dull sound.