Welcome To the Hoffman Amplifiers Forum

September 06, 2025, 10:42:58 pm
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: Fender Rumble 25 bass amp speaker buzz  (Read 911 times)

0 Members and 1 Guest are viewing this topic.

Offline GuitarPilot65

  • Level 2
  • **
  • Posts: 141
  • Music by Lee/Lifeson; Lyrics by Peart
Hoffman Amps Forum image
Fender Rumble 25 bass amp speaker buzz
« on: January 17, 2025, 11:23:03 am »
Seeking help with speaker repair or recommendations for replacement


Stock speaker in subject amp buzzes when played; buzzing stops when I dampen the speaker with my hand on the cone.


Other info:
  • "R25" and "S1804" black stamps on back of magnet.
  • 8-in nominal diameter
  • 8Ω (verified with meter)
  • Cloth surround (can't tell how "doped" it is; see photo)
  • Paper cone with cloth domed voice coil cover
  • 3-in diameter magnet
  • Looks to be 1-in dia. voice coil.


No visible separation of surround/cone, no cone tears, no loose wires, etc. Based on physical appearance, this speaker seems more applicable as a home stereo woofer.

Before replying with admonishment about buying this amp, budgetary constraints governed its selection at the time of purchase. I paid about $100 for it new. Preliminary research shows 8-in replacements are scarce; Eminence Alpha-8A currently listing for $80.


Any help and guidance would be appreciated. Photos attached.
1993 Brown Fender '63 Vibroverb RI (6G16)
1994 Blonde Fender '65 Deluxe Reverb RI (AB763, modified [by me])

Offline shooter

  • Level 5
  • *******
  • Posts: 11014
  • Karma Loves haters
Hoffman Amps Forum image
Re: Fender Rumble 25 bass amp speaker buzz
« Reply #1 on: January 17, 2025, 01:30:03 pm »
guessing, the voice coil is dragging, or the "rubber edges" have lost "tension"
speakers are replacement parts, by the time you "repair" you're in 70% of a replacement with no guarantee


Quote
speaker seems more applicable as a home stereo woofer.
they basically are one in the same.  double the amps Wattage and throw in any 8" about that wattage and test drive.
(AMP = 25W   speaker ~~~ 50W)



Went Class C for efficiency

Offline GuitarPilot65

  • Level 2
  • **
  • Posts: 141
  • Music by Lee/Lifeson; Lyrics by Peart
Hoffman Amps Forum image
Re: Fender Rumble 25 bass amp speaker buzz
« Reply #2 on: January 17, 2025, 03:07:05 pm »
Thanks, Shooter. Agree with your cost analysis re: repair.

The voice coil may indeed be dragging. All of my amps, guitars and regular stereo speakers reside in a corner room in our house, whose temperature has likely hovered between 65 and 70 deg F this winter. Perhaps not so coincidentally, the voice coil of one of my Dayton Audio Classic Series 8-in woofers was dragging the other night when I played a CD. Being that our house has central HVAC (we're in NW FL), it may be time for a space heater in that room.
1993 Brown Fender '63 Vibroverb RI (6G16)
1994 Blonde Fender '65 Deluxe Reverb RI (AB763, modified [by me])

 


Choose a link from the
Hoffman Amplifiers parts catalog
Mobile Device
Catalog Link
Yard Sale
Discontinued
Misc. Hardware
What's New Board Building
 Parts
Amp trim
Handles
Lamps
Diodes
Hoffman Turret
 Boards
Channel
Switching
Resistors Fender Eyelet
 Boards
Screws/Nuts
Washers
Jacks/Plugs
Connectors
Misc Eyelet
Boards
Tools
Capacitors Custom Boards
Tubes
Valves
Pots
Knobs
Fuses/Cords Chassis
Tube
Sockets
Switches Wire
Cable


Handy Links
Tube Amp Library
Tube Amp
Schematics library
Design a custom Eyelet or
Turret Board
DIY Layout Creator
File analyzer program
DIY Layout Creator
File library
Transformer Wiring
Diagrams
Hoffmanamps
Facebook page
Hoffman Amplifiers
Discount Program