So now that all is well with my issue previously discussed in this forum (just random resonating in my house) I have a new concern that my Ampeg Micro VR might not be loud enough for a live/rehearsal situation. I´m running it through an Ashdown 115 at 8 ohms or 150 watts as Ampeg specifies. The volume seems decent but I don't know if it could stack up in a full band situation. If another cab may be needed, then no biggie once I feel like I truly need it. Maybe I don't need another cab at all and im just out of touch? I mainly play an odd mix of hard/prog rock and post punk/new wave so please let me know if you think I need to add anything else if I ever hope to gig medium places.
If you don't want to buy another amp a couple of years down the road, get an amp that will do 500-watts into 4Ω. That will give you 250 to ~300-watts rms into one speaker cab which will work fine for small and medium sized rooms Then buy a second cab to unleash the rest of the amps power to be split between the two cabs (250-watts into each) when you need it. Be sure that any cabs you buy can handle about 300-watts rms just in case you really need to get loud. If you add a second 210 or 115 giving you a 500-watt 410 rig or 215 rig, that will take care of just about anything.
An 800-watt amp is even better than a 500-watt one because you can use it anywhere and will give you greater flexibility in what cabs can be used with it. Good idea to use cabs that will handle 400-watts rms each with the 800-watt amp.
I'd be looking at a 210 ideally but a 115 should work OK for you. I played a lot of small and medium sized gigs with a 115 cab by itself and back in the early 70's I toured with a nightclub group for 3-years with a 215 cab that I never could max out because it got too loud long before it topped out the amp's power. Was a great amp right until somebody stole it along with my '65 Jazz Bass in 1976.
Don't expect a 112 cab to fill up a medium-sized venue though. It will do small venues such as brew pubs just fine but won't be able to keep up with guitars and keys in a medium-sized club. I use a 225-watt into 4Ω class D, Eden amp into an Eden EX-112 that will handle 300-watt rms for small venues because it's loud enough for small venues. A big plus with that small rig is that I can carry the amp in its shoulder bag over one shoulder, the gig bag over the other shoulder; grab the 112 cab by its handle in one hand, and my bass in its case with the other hand and then load in or out all in just one trip. AND, it sounds good.
That single 112 cab won't handle a medium sized venue though. A 212 cab or 2x112 cabs will work fine for small and medium venues, but may be too little for a large or outdoor venue. Adding a second 212 cab will certainly handle the large and outdoor venues. If you go the multiple 112 cabs direction, be sure you get an amp that will handle a 2Ω load so you can use all 4 of them if you need to.
I personally think getting a 210 that will handle at 400-watts is a good choice and then adding a second one as needed is the best choice. I wish that I had done that myself. I did it backwards though. In 2015 bought a DNS-410 cab by DNA (handles 1400-watts rms) and truly thought I would never have to buy another cab. Then found out I can't use my 410 it at small clubs like just about any of the 400+ brewpubs in Washington state. It would freak out the owners when I rolled my 410 cab in and they'd make me use some small 112 combo they had - virtually never sounded good. So I bought a 112 cab for that and soon after bought a small and low-powered class D amp to run it. That works great for small venues.
If I had bought a 210 cab first, I would not have needed to buy a 112 rig for the small venues. Nobody looks twice at a bass player bringing in a 210, so certainly could play small and medium venues with that. Then I could have bought a second 210 when I needed a 410 rig to play large or outdoor venues. I did actually buy a DNS-210 cab (handles 700-watts rms) when I got my DNA endorsement in 2019. It is such a loud cabinet that I actually use if for all my indoor venues and only use my 410 for outdoor venues and Music Festivals. I don't stack my 210 on top of it for music festivals because just running my Eden 800-watt amp into my DNS-410 is loud enough by itself. If I turn the master on that 800-watt amp up to 10:30, the sound techs make me turn it down. So no need to bring both and no need to ever worry about hauling a 165-lb 810 cab around with me either.
So there are lots of choices there for you, but I'd recommend getting at least a 500-watt rms into 4Ω amp instead of going to a 300 or 400-watt amp or you're liable to find yourself going down this upgrade path again in a year or two.. And if you have the $$, get an 800-watt amp so you don't have to worry about upgrading it somewhere down the road.
