replacing guitar amp speakers

[sky]

hi, i have a peavey bravo 112 combo that i use to practice with, i was just wondering if i swapped the speaker in it to a bass range speaker id basically be changing it to a bass amp, so was wondering if anyone could recommend a good 12 inch speaker to go into it, i really know very little about speakers.

thanks, leo

[Phil Starr]

Hi Leo, it's a bit more complex than that, though quite possible. Bass stresses speakers much more than guitar so you have to be a bit more careful in design. You'd need the cab to be at least closed back/sealed and possibly ported to get the best bass you can. If you give us the internal dimensions of the cab we might be able to find something.

[Bill Fitzmaurice]

The Bravo 112 cabinet volume is perhaps half that required for good results with electric bass.

[kwmlondon]

I just looked up the Bravo 112 and it's actually quite a desirable little amp. If you want a better practise amp for bass use I'd suggest selling it and buying a proper little bass amp - I used a Hartke 75w recently and it was brilliant, a Fender Rumble 40 would also be great. 

 

If you want one amp to do bass AND guitar just for practise then what I would do is get a small full frequency range speaker, or monitor, and then use the modelling on my laptop - I use a Mac so for me it'd be Garage Band. It's free and it has AMAZING modelling. You can experience an AC30, Marshall Stack, Fender Twin on guitar, and try an Ampeg 8x10 or whatnot on bass. Anyway. That's my suggestion.

[Beer of the Bass]

It's an open back cabinet too, which are risky for bass use. And closing the back would cut off the ventilation around the valves, which will almost certainly cause you heat problems.

[BigRedX]

Open back is only risky for bass use if you want lots of bass and/or lots of volume.

 

For the first two years of playing bass I used my Carlsbro Wasp 10W guitar amp which had a 10" speaker and an open back design. My band was mostly a recording project so we didn't need to play very loud (and most of the time I was channeling my inner Peter Hook), and if we did need to use it live, it was mic'd up through the PA.

 

In the days when I ran a bi-amped rig the top end was supplied by a 2x8" cab which I had made myself based on the dimensions a guitar combo I used to own.

 

And if it's not real, open back can sound great with bass guitar. At the moment my favourite amp/cab combination on the Helix is their emulation of the Roland Jazz Chorus Combo, something that you would never use for bass in real life, but which sounds surprisingly good for the type of music I play.

[sky]

ok, looks a bit more complicated than i may have thought then, i guess ill just leave it as is, i can use it for quiet volumes as is with it seems the speaker only gets stressed past around 5 on the volume, might just maybe look for a really cheap bass cab and plug that into it, might work fine?

[Dan Dare]

11 minutes ago, sky said:

maybe look for a really cheap bass cab and plug that into it, might work fine?

 

That would probably work, but best to bypass the combo speaker.

[Lfalex v1.1]

2 hours ago, sky said:

 might just maybe look for a really cheap bass cab and plug that into it, might work fine?

 

On the face of it, that should work,  but do be aware that the tone controls in the amp stage will still be optimised for guitar rather than bass. 

 

It might be best to leave these "flat" if possible an introduce EQ from another device- multi fx, an EQ pedal, or a pre-amp of some sort. 

[Matt P]

if you do decide to use a seperate bass speaker make sure that the Impedance is matched to the original one, 

 

 

I'd suggest that if it's for home use then the best option would actually be to look for a small cheap bass combo instead, there are plenty of cheap options for home practice amps (although personally i use headphones and a pc interface) compared to the cost of a separate speaker cabinet or a decent bass driver to go in an existing amp then a small bass combo should be able to be found for a similar price.

 

Matt

[Matt P]

EDIT- stupidly double posted!

Edited March 28, 2023 by Matt P

[sky]

yeah i know its just i really like using channel 2 for a distortion sound its better than any pedals i have!

[Phil Starr]

A lot depends upon your attitude to a project. If you fancy a bit of DIY then building a bass cab to match your combo and uses the combo amp would be fun and could sit under the combo so not take up a lot of space. Who knows the right speaker might take you up to 11.

[Baloney Balderdash]

8 hours ago, BigRedX said:

Open back is only risky for bass use if you want lots of bass and/or lots of volume.

 

For the first two years of playing bass I used my Carlsbro Wasp 10W guitar amp which had a 10" speaker and an open back design. My band was mostly a recording project so we didn't need to play very loud (and most of the time I was channeling my inner Peter Hook), and if we did need to use it live, it was mic'd up through the PA.

 

In the days when I ran a bi-amped rig the top end was supplied by a 2x8" cab which I had made myself based on the dimensions a guitar combo I used to own.

 

And if it's not real, open back can sound great with bass guitar. At the moment my favourite amp/cab combination on the Helix is their emulation of the Roland Jazz Chorus Combo, something that you would never use for bass in real life, but which sounds surprisingly good for the type of music I play.

It might work on a modeler.

 

Since a modeler will only replicate the EQ of the speakers not the actual excursion of them.

 

And your small 10W combo amp might had been different too.

 

But as someone who actually tried to play bass, and not very loud even, and not even a very bassy bass, for a recoding, through the Roland JC120 Jazz Chorus amp I once owned, I wouldn't recommend it.

 

The speakers didn't like it that's for sure the way they behaved and violently moved about, and sounded pretty donkey too.

 

 

To OP:

 

As someone else has already pointed out I would hook up the actual amp part of your combo to an external cab made with bass being played through it in mind instead, that is unless you want to build the amp into a completely new combo cabinet with a design and dimensions fitting an actual bass speaker.

 

Guitar amps can make great bass amps, guitar cabs and guitar speakers not so much.

 

Edited March 28, 2023 by Baloney Balderdash

[sky]

59 minutes ago, Baloney Balderdash said:

It might work on a modeler.

 

Since a modeler will only replicate the EQ of the speakers not the actual excursion of them.

 

And your small 10W combo amp might had been different too.

 

But as someone who actually tried to play bass, and not very loud even, and not even a very bassy bass, for a recoding, through the Roland JC120 Jazz Chorus amp I once owned, I wouldn't recommend it.

 

The speakers didn't like it that's for sure the way they behaved and violently moved about, and sounded pretty donkey too.

 

 

To OP:

 

As someone else has already pointed out I would hook up the actual amp part of your combo to an external cab made with bass being played through it in mind instead, that is unless you want to build the amp into a completely new combo cabinet with a design and dimensions fitting an actual bass speaker.

 

Guitar amps can make great bass amps, guitar cabs and guitar speakers not so much.

 

yep think ill just keep a look out on facebook, ive seen some decent looking cabs come up for the £60, £70 mark, so theres definately something i could do

[Downunderwonder]

If you're going down that road you need to get routine that involves always having one or the other connected to the amp.

 

Failure means you turn on and no sound comes out. If you keep playing trying to figure it out you will be frying your precious tube amp.

[sky]

35 minutes ago, Downunderwonder said:

If you're going down that road you need to get routine that involves always having one or the other connected to the amp.

 

Failure means you turn on and no sound comes out. If you keep playing trying to figure it out you will be frying your precious tube amp.

oh didnt know that, ill have to keep that in mind. it is my only amp at the moment but it isnt particularly precious, just something i found really cheap on facebook, does sound pretty good though to be fair

[Phil Starr]

8 hours ago, sky said:

oh didnt know that, ill have to keep that in mind. it is my only amp at the moment but it isnt particularly precious, just something i found really cheap on facebook, does sound pretty good though to be fair

You've been lucky in that you've bought a little gem at a good price. You probably paid a lot less than it is worth so look after it

 

Because it is a valve amp you just need to be careful about connecting other speakers. It has a transformer which matches the amps output to the speaker exactly and switching it on with no speaker connected will probably damage the amp. It would be possible to mod the amp with a jack socket which switches out the internal speaker when you connect an external one but you'd need to do that properly or you could end up accidentally switching on with no speaker connected. You'll get lots of advice here if you need it 

[BigRedX]

14 hours ago, Baloney Balderdash said:

It might work on a modeler.

 

Since a modeler will only replicate the EQ of the speakers not the actual excursion of them.

 

And your small 10W combo amp might had been different too.

 

But as someone who actually tried to play bass, and not very loud even, and not even a very bassy bass, for a recoding, through the Roland JC120 Jazz Chorus amp I once owned, I wouldn't recommend it.

 

The speakers didn't like it that's for sure the way they behaved and violently moved about, and sounded pretty donkey too.

 

My definition of lots of bass and/or lots of volume is obviously different yours.

 

AFAIAC home practice means that the sound coming out of the speaker is just loud enough to mask the acoustic sound of the bass, nothing more. Also I don't want lots of bass because most of the time I want to be able to properly hear the pitch of the notes.

 

You obviously have different goals when practicing at home.

[Downunderwonder]

If you got an 8 ohm cab a simple rule to have would be "1 in 1 out", in that order. That way there is always at least one cab connected and impedance is always in the range. No problem being interrupted mid process.

 

Actually, not sure that works as the second jack is labelled extension with no switch. There could be internal switching on the jack itself so equally possible there is already self shorting on the main one, which would make it all a non issue. Schematic time.