Wall Wart RFI Noise Filter

Home Theater System RFI Kit for AC Powered Sub-Woofers Only - 5 filters

SKU RFI-HTS-SW
$29.95
On Sale
List price $35.80
Save 16%
Bulk pricing available for quantities of 2 units or more
1
Buy more, save more
QuantityPrice per itemDiscount
2 items$26.9510% off
10 items$24.9517% off
Save this product for later
Customer reviews
No reviews yet. Only signed-in customers who bought this product can leave reviews. To leave a review, sign in
Share this product with your friends
Home Theater System RFI Kit for AC Powered Sub-Woofers Only - 5 filters
Product Details
MPN: RFI-HTS-SW
Type: NEW
Country/Region of Manufacture: USA
Filter Power Rating (PEP watts): not applicable
RFI Suppression Range (MHz): 1-300 MHz

This sub-woofer RFi kit is specifically designed to suppress audio interference triggered by Radio Frequency Interference problems from AM, FM, CB and Ham radio stations AND to minimize the interference to nearby electronics caused by a sub-woofer without magnetic shielding (Velodyne, Hartley, Hsu, etc). The ferrite filters are selected to suppress RFI from 1 to 300 MHz. The filters are easy to install, don’t require modification of the protected equipment and work in almost all cases.

What is included in the kit?

The RFI-HTS-SW kit contains a a ring filter for the AC power cord to the sub-woofer and 4 snap-on filters for the speaker wires (either for audio pass through to main speakers or direct line out to the sub-woofer).

Tech Note: This kit is INCLUDED in the full home theater RFI Kit (part #RFI-HTS) and you do not have to purchase a separate RFI kit for the sub-woofer.

Wall Wart switching DC power supplies that plug into the AC power line plug and provide DC power to laptops, routers, battery chargers, cell phone chargers, etc are a known source of broadband RFI (a.k.a dirty electricity) that effects many electrical devices including computers, radio receivers, HDTV systems, etc.  In many cases this extra RFI noise effects computer I/O speeds since they have to error correct the information packets many more times due to the noise interference causing packet errors.  A ferrite ring can often increase data throughput by reducing the error correction to normal rates.

A simple ferrite ring filter on the DC power line can help suppress the RFI noise affecting the victim device or keep the DC power cord from acting as an antenna and radiating RFI into other victim devices. This kit is also useful on laptop computer supplies, routers, cable modems, wireless phone charges, etc.

RFI WW Installation 300x288 - Wall Wart RFI Noise Filter

Installation is quick and easy: Just wrap the DC power cord through the center of the ring filter as many times as you can and reinstall.  For best results with long DC power lines, use one at the ring filter at the wall wart end (to prevent the wall wart power supply from using the DC line as an antenna) and another at the DC plug end (to prevent the electronics in the powered device from using the DC power cord as an antenna).  Typical installation is shown below:

The filter suppresses RFI in from .1-100 MHz.   Inside diameter is 3/4 inch/19 mm.

Since most households and office environments have multiple wall warts we offer the Wall Wart RFI Filter kit in bulk quantity packages.

Known RFI Generators include Roku/Sling-TV power adapter - Interference heard in the AM broadcast band
 and harmonics.
Also many ethernet Cable/DSL modems, cell phone chargers, computer power adapters have the same issue:
using the AC or DC side of the power supply as a radiating antenna.

RFI solution is to use a linear power supply, change adapters or wall wart ferrite filters