Extension cab louder than internal speaker

What's the efficiency rating of the two speakers?

 

Speakers with different wattages will sound different. Your speakers are two different models too! GB's are known to be low efficiency. Cab type can make a more subtle difference. New speakers can be a bit more "in your face" until the paper softens up a bit.

 

Celestion G12H sensitivity is 100db.
https://celestion.com/product/141/g12h75_creamback/

Things to check / consider:
differences in sensitivity,
differences in impedance (and how they are wired -- series vs parallel)
break in time for new speakers,
etc.

If your amp has the G12M it's sensitivity is 98db. So, yes, the G12H would be noticeably louder. (given similar impedance ratings, wiring scheme, eg; comparing drivers 1:1)

 

It isn't because it's new, it's just a louder speaker and always will be. The M65 watt Creamback is more in line sensitivity wise with a Greenback.

 

What these guys are saying is right one. The volume will never match. You have a 98db speaker in the combo, and a 100db speaker in the extension cab. It won’t be a huge difference, but it will be noticeable.

 

Put the ext cab on the floor and the combo on top, then play standing up.

Which cab is louder now?

Nice speaker BTW!
Or I assume it's nice, never tried that one.
I run speakers with different efficiency pretty often, really isn't a problem and for example a louder Celestion Blue next to a less efficient G12H30 55hz is a mismatch, yet the warmer 30 certainly adds to the sound as well as the dispersion.

If you look at response charts, every speaker has more than 2db difference between 100hz and 1000hz, but you can still hear the entire frequency range.
IMO concerns about pairing speakers of different efficiency are somewhat exaggerated.
Only when they are way off is it really a "problem", but again, what exactly goes wrong?
In a room, there might be louder areas and less loud areas.
Point the louder cab where more volume is needed, like at the drummer!

 

Yep. I have an Origin 20, with a 10” Celestion
V Type. It’s a 96 db speaker. I use it with an Egnater ext cab that is loaded with a 12” Celestion “Elite 50” rated at 99 db. You don’t think you’re even hearing the V Type. But if you unplug it you sure notice a difference!

 

+1

Exactly. Having 'mismatched' (or just different) speakers available is not a limitation -- it's an opportunity to mix things up at the output end and test different combinations (hopefully, without having to install/uninstall and the rest of that hassle). I have found that speakers I considered mutually incompatible (for lack of a better term..) actually sounded quite good together. More speakers = more options. More options is usually a good problem to have.

 

Oh I see the combo is bigger and can't really sit on top of the cab.
When playing in a band context with a smaller amp or two, I really need to elevate at least one of the amps so I can hear myself without being too loud, because my hearing is pretty well shot.

I'd bet I need easily another 5-7db to hear an amp pointed at my ankles compared to an amp pointed at my guitar.

I've actually been thinking of making a really small 1x10 cab I can mount on a drum stand up near chest height just so I have a closer guitar monitor. It's that hard to hear myself in a band setting, and it sucks to be asked to turn down all the time.
I've considered buying a crappy 12" or so rack tom (drum) to make into a little speaker cab for that mounting.

Off topic but speaks to the fact that the location of the speaker is a huge factor in how we hear the volume, and some of the tech talk may not apply as much to practical stage situations.
Same as the back of a combo near a wall delivering the reflected sound, I doubt the measured dbs coming off the wall are as high as the front of the amp, yet that added sound fills out and adds to the room.
Likewise the focused louder closed cab sound has less dispersion so some get slammed while others can't hear your guitar at all.

I really like using two smaller amps, bit that does present some problems of its own too.
I guess I've never trusted sound guys and maybe that's not fair to them...

 

What model Gibson is that? I like it a lot!