Impedance and Power Ratings
One extremely important thing when looking for a replacement speaker for your guitar amp is the impedance and the power ratings of it. Of course, you’re going to need guitar speakers that operate at the same impedance and wattage rating as your original speakers were operating at.
Size
Next, you’ll need to think about the size of the speakers you’re going to get. 12-inch speakers are fairly popular in guitar combo amp(s) as well as speaker cabinets. They are great if you’re playing music that has a lot of low-mid frequencies and a lot of bass.
On the other hand, some guitarists prefer 10-inch speakers due to their overall punchier and brighter sound.
You can also try smaller 8-inch speakers. They are typically found in practice combo amp(s) and can definitely produce a competent sound if that’s the tone you’re looking for.
Design
The fiber that makes up the speaker, as well as its design, plays a huge role in what the speaker will sound like.
Most speakers are made of paper-like material like hemp, etc.
In general, thinner cones tend to break up at lower volumes as compared to thicker tones.
British vs American Tone
If you’re looking for a more distorted and heavier sound, then you should go for a speaker that produces a British tone. As it’s influenced by British Invasion bands that wanted to play heavier, wilder sounds.
On the other hand, American tone is characterized by bright and clean sounds with genres such as Country.