Size vs Power | Marshall stanmore bluetooth vs Regular guitar amps

[mpfig]

Hello,

I understand that these items serve completely different purposes.
Nevertheless, I've been searching online for an explanation on why are regular guitar amps bigger in size and with less power, when compared to this trendy Marshall bluetooth speaker. However I couldn't find any answer on this matter online.

I'll elaborate my question:

The marshall stanmore bluetooth claims 80 watts of power and it is a relatively small sized speaker, considering the power it has.
On the other hand, I own a line6 spider V30 which has a lot less power (30 watts) and it is way bigger in size.

Is the marshal speaker a smaller device with greater power simply because it is built with better / smaller / more expensive pieces of technology/electronics?
Or maybe my spider v30 has less power and a bigger size because it has additional components (guitar amp specific components) that are not present in a regular bluetooth speaker such as the Marshall one?

Thanks for your time in advance.
Cheers,
Manel

[Chuck H]

Well, for one thing I wonder if your Line6 isn't actually louder than your MS Bluetooth. I'll wager it is. Such devices as your MSB are often rated at peak power rather than RMS. Further, that peak power is fudged by selecting the highest peak performance frequency isolated from full bandwidth music performance. That's how things like 5 way speaker systems can claim 150W per channel from a little 3" x 3" box that weighs five ounces

Another consideration is that actual guitar amps have the dual purpose requirement of providing audio to an audience as well as just bedroom practice. For that you need to move a volume of air for spread and LF reproduction. You can't get that from a small box and little speakers. New tech in the recording industry is largely doing away with big boxes, but actual guitar amps still have to perform the function of handling a gig. For that most players agree that the 1X12" combo is just about the minimum requirement. Some will go as small as a single 10" combo, but even that almost always requires a mic or a PA assisted output to be heard even at small gigs.

[The Dude]

^^^^^^ What Chuck said. I'll add that a guitar amp only has to efficiently reproduce roughly 150Hz-5kHz, which requires less power than producing full musical bandwidth. Reproducing low frequency content requires more power, especially when you're trying to do so with limited woofer and cabinet size. For example: If you took the same power amp used for a guitar amp and used it to drive subwoofers for a P.A. system, a guitar amp that might deafen you would woefully under power the subs.

[J M Fahey]

Power is just one factor among many.
You are ignoring the speakers and their efficiency or sensitivity.

The Bluetooth music player has, if I donīt remember wrong, a 4" woofer and two 2" tweeters or something similar, I estimate efficiency in the low 80īs, thing 84 dB or less ... the Spider has a 12" Seventy/Eighty Celestion with 96 to 98 dB efficiency, so it sounds WAY louder even with less power input.
Just consider that rising efficiency by 3 dB is equivalent to *doubling* amp power ... here we have 12 to 14 dB ... do the Math.

You will find both "loud" in a bedroom .. but on a Club stage the Spider will work fine (if not awesome) and the Bluetooth one, if fed a Guitar signal (say, from a Pedalboard) will fail miserably when trying to match a real Drummer ... which are VERY loud.