For Bass, What 12" Speaker in Guitar Tube Combo Amp?

[xsogol]

I bought an old JMF Spectra 120-7 tube amp for guitar like the one seen in the picture below about a year ago and it is a GREAT sounding amp, especially when I play through it with basses with P-style pickups.



The amp has a switch on it to switch between 60 watts and 120 watts which is very nice!

Here's my dilemma...

It has a good sounding, vintagey 12" speaker in it, but I am worried about turning the bass up beyond 2 or the volume up as I don't want to blow the speaker (and it feels like I might when I try to turn it up slightly)....

SO...

Should I replace the 12" speaker with a speaker more suited to bass?...

I want to keep the vintage tone, but would like to use a neodymium speaker, only if possible, to decrease weight...also, I would still like to occasionally use this amp for guitar.

If I replace the speaker, based on what I said above, what brands/types of 12" speakers should I be looking at? Thanks!

[BurningSkies]

That's an open backed combo, right?

There's really no driver for bass that wants to work in an open backed cab. Also, it sounds like you're looking for something that does everything...bass, guitar, etc., which is a bit much to expect. Keep it the way it is and if you need something for louder play, get a dedicated bass amp.

[anonymous02282011]

It's about more than just changing the speaker ...

it's about how the speaker will perform inside the size of the box that it's in.

You'll want a driver that performs optimally in the cabinet that you've already got. You'd want to take measurements of the cabinet and run a bunch of drivers through WinISD (free dowload). You'll also want to add some damping material to the inside of the cab if it doesn't have some already. Finally, if the cab is an open back design, you're probably not going to have any optimal use with it for bass unless you close it up.

In short, what you're after is a little more complicated than it seems and you're probably better off just buying a bass cabinet.

With some of the old Fender tube combos and the Ampeg VT-22, people have removed the amp section from the cab, built a new housing for the amp and used it with other cabs.