replacement speaker for gorilla gb70 bass amp

[heavenorlasvegas]

the original speaker in my gorilla amp is going bad. what should i be looking for in a replacement speaker? I have no idea what to look for as far as impedance and wattage go. Please help!

[Folderol]

At the risk of stating the obvious, are you sure it's the speaker and not the amp?

[heavenorlasvegas]

yep, thats what the tech told me.

it seems as though the difference between guitar and bass speaker for use in amp is vague. "bass speaker can handle lower frequencies" "dont use bass guitar on a guitar speaker!" etc...

i'm not finding alot of technical data that seperates the two. at least when i search online anyhow..

[resistorman]

There’s some talk here about Gorilla amps:

https://www.talkbass.com/threads/rebuil ... 0.1281945/

[Wonks]

It is a cheap 'bass' amp, though with an open back, it really isn't designed for bass.

You can spend more replacing the speaker than the amps worth. You could spend a similar amount getting a better sounding used bass amp.

I believe it's a 12" speaker (you can measure and check) and will probably be 8 ohms (it's a solid state amp so will be either 4 or 8, but 8 will be a safer choice).

The amp is 70W peak, so about a normal 35W rating.

Because of the open back and low power, you'd want something efficient and with a high power rating to provide mechanical robustness.

For a Celestion speaker, I'd go for this

https://www.lean-business.co.uk/eshop/c ... p-330.html

For Eminence

https://www.lean-business.co.uk/eshop/e ... p-864.html

There are slightly cheaper speakers but they have much lower efficiencies and you could end up with a very quiet amp.

12" isn't a popular bass speaker size (compared to 10" or 15"), so there's not a huge choice.

Do not use a guitar speaker. The manufacturers designate speakers for guitar or bass use for various reasons, but the ability to accommodate large speaker travel excursions from bass notes is one of the requisites for bass speakers.

If you really like the amp that much, how about looking for a used 100W 12" or 15" closed or ported bass cab and converting the Gorilla to just a head? Or would that be beyond what you are comfortable with?

[heavenorlasvegas]

It is a cheap 'bass' amp, though with an open back, it really isn't designed for bass.

You can spend more replacing the speaker than the amps worth. You could spend a similar amount getting a better sounding used bass amp.

I believe it's a 12" speaker (you can measure and check) and will probably be 8 ohms (it's a solid state amp so will be either 4 or 8, but 8 will be a safer choice).

The amp is 70W peak, so about a normal 35W rating.

Because of the open back and low power, you'd want something efficient and with a high power rating to provide mechanical robustness.

For a Celestion speaker, I'd go for this

https://www.lean-business.co.uk/eshop/c ... p-330.html

For Eminence

https://www.lean-business.co.uk/eshop/e ... p-864.html

There are slightly cheaper speakers but they have much lower efficiencies and you could end up with a very quiet amp.

12" isn't a popular bass speaker size (compared to 10" or 15"), so there's not a huge choice.

Do not use a guitar speaker. The manufacturers designate speakers for guitar or bass use for various reasons, but the ability to accommodate large speaker travel excursions from bass notes is one of the requisites for bass speakers.

If you really like the amp that much, how about looking for a used 100W 12" or 15" closed or ported bass cab and converting the Gorilla to just a head? Or would that be beyond what you are comfortable with?

thanks for your reply and useful info. If i upload a soundclip of the offending speaker would you be able to give me your opinion on what you think is wrong with it?

edit: i'm not sure it's even possible to upload sound clips

[Wonks]

You can’t upload anything here. Always have to host pictures, videos and sound files elsewhere and link.

[resistorman]

When a speaker is going bad, a typical thing that happens is the voice coil starts coming apart and expanding in the magnetic structures’ slot. If you take the speaker out and tap the cone gently, it should be a pure tone like a drum. Any overtones is bad. Also, applying equal pressure, gently move the cone in and out, there should be no sound. Rubbing noise is bad. Not likely this is the case with an open back cabinet, but if there’s a foam surround for the cone, sometimes they are rotted.