not certain
True in absolute value, but the speakers are not the same depending on the amp. Higher range amps tends to have higher quality speakers, with higher sensitivity.
Not sure about the Rumble range tho, that’s why I haven’t bought a Rumble 100 at some time. (great amp overall, but the speaker is really really bad)
But yeah, definitly, It’s nice to have a little practice amp.
Yeah definitely true. This kind of comparison is only valid for some of the variables remaining similar between the amps.
The Rumble 25 apparently uses a “Fender Special Design”, which I assume means the most cost effective thing they could find. The 100 uses an “Eminence-Designed” speaker, which again indicates an inexpensive aftermarket speaker manufactured based on basic specs from Eminence.
Exactly. A 10” speaker reproduces bass tones better than an 8”. And better perceived sound makes the 40 a better choice for many, as @JoshFossgreen stated in his beginner bass/gear video.
Again, everyone’s need/desire for an amp can be wildly different, depending on the intended goal. But for a really solid practice amp, I gotta agree with our Trusty Bass Teacher. 
That’s it. Both low end speakers but the Rumble 100 is still a bit better. But still crappy to be honest.
Now I am wondering what one would sound like if you dropped a Celestion Pulse12 in one 
Still not too expensive but probably sounds a lot better.
Most probably, yeah. I’m quite sure that a speaker swap would make a Rumble 100 an absolute beast.
The Pulse looks interesting. Resonant peak right at 40Hz. I bet it sounds awesome, if I had a Rumble 100 I would be tempted to drop one in.
isn’t the sensitivity too low ?
Maybe, might get a volume hit? 94dB sensitivity isn’t bad, even if it isn’t the absolute best.
Response curve looks ok (but not great):
Celestion rates its low end response at 45Hz, which doesn’t make sense to me from that graph (as it is flat there and from that graph either already rolled off up around 150, which is not how I would describe it, or hasn’t yet and does at about 25, depending on how you interpret it - I would call that 25-30Hz based on the graph, myself).
not so good 
I’d like at least 96 or 97 db/w/m. On my guitar amps, I have speakers over 100 db/w/m. (maybe a little bit expensive …)
My experience is that, the only objective data is the sensitivity. For the frequency response, you have to try the speaker in person and judge by yourself.
Yeah it’s not the best but important to remember this is still a relatively inexpensive speaker - less than $100 new for the one I was looking at. And very likely much better than the “Eminence-Designed” 
Yeah I can’t disagree
well yeah, a Rumble 100 with a “relatively good” replacement speaker could be a serious bargain sleeper amp.
Agree, I’d be tempted if I owned one. And I am not just GAS-enabling here, this seems like a cool DIY upgrade.
This has been a serious option for me, at some point. But then, SVT, 4x10 and all that … 
Not really sure why a Rumble 25 is inadequate.
I have one for my practice and it never gets above a 1/4 turn for volume.
I was using it for our jams (not gigs) and it kept up with the PA the keys and drums were using.
Now for jams I use the big Laney amp that lives where we play but that is mainly for convenience.
So in terms of practice and small area use I think it is pretty good, no problems with sound quality or volume.
Having said that I may get a much bigger and more expensive Orange or something at some point, but I am not tripping over myself right now.
Could also do the same math with some of the nice new Ampeg combos, the Rocket seemed really interesting. Not that I’m amp shopping (I already know what I would get then).
It’s not, at all. It’s a fine little practice amp. I liked mine.
Actually yes. Will see about the reliability … you know I had a lot of issues with my BA 115 HPT 
I hope they solved all that. As you know I bought a BA V2 so we’ll see if it’s reliable.
Yeah, nice practice amp. Nothing wrong.
I just need to make it another 2 weeks. There’s been a RB-210 for $450 at one of the local Music Go Round’s. The biggest drawback to it that I can find is someone replaced the front grill with a neon green cover.
Partly GAS, partly motivation. I’ve basically decided that I’m going to hold off on any significant gear purchases until I wrap up B2B. Then I’m going to do a bit of shopping to at least test drive some new toys.
(If a killer dealer pops up on something, I’ll snag it up.)