Axiom Home Page Forums General Discussion Advice from Axiom Owners EP175 Hum

Greetings programs!

Yesterday I received my new EP175 to complement my old M3's and VP100. Unfortunately after I connected the sub to my AVR, I heard the dreaded hum. The hum appears to be intermittent. If I touch the ground loop screw, it goes away, but eventually returns. This morning I removed the screw after the hum started. It stayed away until I touched the TV with a dust cloth. After reading how the hum can sometimes be caused by the cable TV, I disconnected it from my cable box. The hum stopped. I then reattached the cable, and the hum returned. The hum also stopped if I left the cable attached, but unplugged the HDMI cable between the box and the AVR. Looks like I need a round-isolating transformer. Unfortunately it appears like the one offered by Axiom is no longer for sale. Does anyone have any alternative suggestions?

I found an Isolation Transformer from Bluejeans Cables, but this one attaches to the analog cables between your sub and AVR. Any idea if this would work?

By the way, Shaw Cable was of no help, and the hum is not present on any of the speakers connected to the TV, or the 7.1 Axiom system in my home theatre. My EP500 there is dead quiet until it goes boom.

I had the same problem some time ago with my Velodyne Subs - caused by my Cable TV Box - Shaw as well. This is a common problem & Shaw normally will not acknowledge it.

I made a jumper cable of zip wire with alligator clips on each end. Attached one clip to the outside barrel of an audio jack on the sub & did the same with the other end on the TV. Some experimenting was required to find out what connection worked best, but in the end the hum was gone.

When I replaced the Velos with my EP800s the hum was back but screwing 'out' the chassis ground screw cured it...

TAM

you could try a two prong cheater AC plug for your sub where it is plugged into the wall.

I briefly used an old two-prong plug while testing to see what would and wouldn't work and it eliminated the hum. But since those cheater plugs are illegal in Canada, I don't want to use one for fear of voiding my house insurance.

To quote Tweeter and the Monkey Man

It was Jan who'd told him many times
"It was you to me who'd taught
In Kingston everything's legal, Jan
As long as you don't get caught"

use the cheater plug. Or buy a new cord and take a hacksaw and cut off the top ground prong.

Just an update. After speaking to one of the techs from Axiom, I decided to purchase a ground loop isolator off Amazon. It completely eliminated the hum. The sub is a nice addition to my system. The isolator may have cost $100, but thanks to Axiom's Black Friday sale, I still came out ahead.

May you could share with us which isolator you chose.

It's the Viewsonics VSIS-EU Cable TV Ground Loop Isolator. Similar is design to what Axiom once offered.

Hope you are able to enjoy that sub without the HUMMM

It's great. A really nice bass extension there. The hum got better when we replaced a 21 year old fridge, but it showed up every now and then. Now there's nothing.