Hartke A70 speaker problem

[sii.pepenk]

i got a Hartke A70 for a few days, but something coming up. there's a 'brrrrrrrr' sound when i play some low note, then i check the speaker on the surface (front cone) and find no cut or broken at all. then i check behind speaker from a hole to make sure that there is no spider web, dust or something else and i found it is pretty clean

i'm afraid that something going on inside the speaker cone, any suggestion for this?

for the worst possiblity, if i replace the speaker (for a better one maybe) is it worthed? the speaker spec is 12" with 8ohm, so what kind of speaker will fit for this amp?

 

[JimmyM]

What's your bass knob set at? How loud? Could be you're just asking more from it than it can give you...?

 

[RickenBoogie]

+1 pushing the low eq eats your power, and is hard on spkrs. CUT the lows.

 

[sii.pepenk]

What's your bass knob set at? How loud? Could be you're just asking more from it than it can give you...?

+1 pushing the low eq eats your power, and is hard on spkrs. CUT the lows.

i use all the knob to flat seting, even the volume knob only on 9