Originally Posted by trevorlj
I've been working with him on a hum issue with my new 4000ULF-ST and I haven't heard anything back since the 13th.
Have you guys experienced an incurable 60Hz hum with the 4000 series subs? My 4000ULF is a Sofa Table and I sit about 2.5 feet in front of it. It's not to the level that the hum is obvious while actively watching content but go to switch a movie and you cant miss it when you're within about 8-10 feet (the low hum like being in a high current electrical room). If the amp goes into standby it becomes very apparent how much hum was being introduced to the mix when you hear the amp click and the room goes dead silent.
- The hum is there even without the signal wire connected
- It is gain, crossover, and LFE boost independent (zero change - even with the gain at minimum)
- I've changed the power wire (always 14 AWG), rerouted the power wire (away from all others), plugged the amp direct to the wall (vs my power conditioners), and even tried a "cheater" plug as a last ditch (also zero change)
My APC H15 Power Conditioners have ID'ed faulty wiring in a different home (they can pick up a missing ground or overloaded neutral) but this house shows no issues.
Do you think this is a faulty plate amp or just a function of how much power it has combined with how close I'm sitting to it. The noise floor on this thing is pretty high but the power potential is insane too.
I have experienced hums with my subs off/on last 20+ yrs in various subs and homes and connections etc... problem always solved without reason to sub itself...knock on wood.
Power: Marantz sr7008, NAD C 275Bee x 2, Video: Oppo 103, Samsung 75un6300 LG oled c9 77
Speakers: Focal aria 948, Focal cc900, Klipsch synergy KSF 10.5, Magnepan LRS, Audioengine A2+
Subs: Rythmik FV25HP, Rythmik FV15HP, Velodyne HGS 12, Velodyne VA1512