Bass Cab Power to Weight Ratio ???

[leftybassman392]

12 minutes ago, tauzero said:

What are these lb things that people speak of?

Don't worry about it. You'll never need it (unless of course certain events develop in a certain way come March 29th, in which case you'll need to mug up on it a bit; and while you're at it you might want to check out gills, groats and chains too).

Edited January 17, 2019 by leftybassman392

[tauzero]

4 minutes ago, leftybassman392 said:

Don't worry about it. You'll never need it (unless of course certains events develop in a certain way come March 29th, in which case you'll need to mug up on it a bit; and while you're at it you might want to check out gills, groats and chains too).

Ah yes, the things we moved away from when I was 15, in 1972. How quaint.

[Phil Starr]

On ‎10‎/‎01‎/‎2019 at 10:08, Nostromo said:

Hi,

Does anyone know which Bass Cabs have the best "Power to Weight" Ratio . . . ie High Output sound wise but low weight lifting about wise ???

Thanks

Nostromo

There are actually two questions hidden in here. One is simply about shopping; I need a loud light cab, tell me which ones I should be looking at. The second question is about power to weight ratio and you are spot on, it is about sound output and not about how many watts the speaker can soak up.

Sound output is a tricky concept as it is about frequency as much as absolute output. Our ears are much more sensitive in the frequencies of the human voice, one hundred times more sensitive more or less, that's why guitarists are so damn noisy A lot of bass cabs have some mid boost baked in, they are going to sound louder than other cabs without the baked in sound. The other thing is how much bass do you want and where do you want it. There isn't much bass in the output from a bass guitar surprisingly and very little at all below 50Hz, in fact you can generally filter it out without the audience noticing, in fact in a live situation you can usually filter it out without the bassist noticing. In terms of lightweight cabs that means you can reduce the size of the cab if you sacrifice deep bass. There's an added bonus too, you could lighten the cone if you know up front your design won't do really deep bass and that can raise the efficiency of the speaker.

All I'm really trying to say here is that some cabs sound louder because of the tonal balance of the cab, if you don't want or like that tone it isn't a sensible buy for you. Always buy a cab that sounds good to you.

Power handling isn't a sensible way to look at power to weight ratio. Some cabs are easily 10x better at converting watts into decibels compared to others, and decibels are what you want. Typically bass cabs vary by less than that and though there are exceptions youd expect most cabs to vary within a 94-100dB/watt range. that simply means the better cabs might give you 100dB across most of the frequency range for a 1W input and a lower efficiency cab might only give you 94dB. This is all standing straight in front of the cab and just a metre away. That 6dB is significantly louder, you'll absolutely hear a marked difference but it's not going to be twice as loud, just louder. That's at one watt, you an add more decibels by turning the tap up at the amp, at 100w they will both be a lot louder but there will still be a 6dB difference. The loudest sound they make will depend upon the power handling and the efficiency combined, how you hear it on the tonal balance as well.

So lightweight? Small cabs, lightweight cab materials, complex bracing and lightweight neodymium based speakers. All adding to the cost (OK except the smaller cab) 

Efficient cabs, big cabs, large cone speakers or lots of speakers, large speaker magnets.

Ultimately you can have light and loud but not light loud and cheap. If you are contemplating shopping though the best bet is a shortlist and then trying them

[Nostromo]

Thank you Phil . . . excellent reply and you are right there are lots of variables to take into consideration . . . to the point that I now realise my initial question was a bit of a dumb question !!!

 

In the end I settled down with a second hand Epifani 3 x 10" cab, not sure of its power handling but it goes well with my 300W head and it has served me well as "loud enough" backline performer and certainly is light enough to haul about without breaking my back.

 

Cheers.

[dclaassen]

Nice thread resurrection! I still lug a fender 4x12 cabinet around, and have been known to use an 18. Do you folks who use a 1 x 10 or 2 x 10 with your 5 string notice a lack of low end? IIRC, an open B is around 30 hz.

[Downunderwonder]

37 minutes ago, dclaassen said:

Nice thread resurrection! I still lug a fender 4x12 cabinet around, and have been known to use an 18. Do you folks who use a 1 x 10 or 2 x 10 with your 5 string notice a lack of low end? IIRC, an open B is around 30 hz.

The fundamental is 30hz and you need a really excellent subwoofer to make any heard. Sending a 30hz sine to your cabs will make a feeble noise that is distortion at 60hz.

 

If you 1st send a 60hz send at just audible volume you will hear nothing at all when you change to 30hz.

[Lfalex v1.1]

On 10/01/2019 at 10:48, warwickhunt said:

TBH once you get into the realms of declared ratings they are written on snakeoil paper by Mickey Mouse. 

 

And then there's the quoted efficiency figures... which are relevant,  but only if they're accurate and measured to the same standard.

Generally, they're even greater flights of fantasy than power ratings.