BOSS Audio SystemsGround Loop Isolator B25N noise Filter for Car Audio Systems

Listening to music is probably my favorite hobby. I went through three different home built PC's (have been building my own systems for a while now) to get rid of noise emanating from these builds i.e. Home entertainment PC based systems. This little box cleared up the noise completely. It does exactly what is was designed to do, i.e. get rid of input noise. For more details read on.I'm a PC enthusiast with audiophile taste but not their pocket. My previous system was an Amd FX-6350 CPU and a Sound Blaster X-Fi Platinum sound card for a 5.1 sound system. Two power amplifiers and 15" and 12" speakers for sub's and front and other smaller speakers for rear and centre. My FX-6350 System had no noise problems but I was dissatisfied with it's performance. I messed up my system striving to extract more performance from it. The system froze during a bios upgrade ending my MOBO's life hence the need for my new build, an FX-9590 PC. I went for an upgrade of my sound card as well.The first new system an AMD FX-9590 with a sabertooth 990fx and an upgraded Soundblaster Z sound card was working well with the exception of noise coming from the sub-woofers and to a lesser degree from the front full range speakers connected to the pyramid PA-1800X and PA-800X power amplifiers respectively. The whining static like in and out white noise morhed with a high pitched sound of a few kilohertz was unbearable especially since my new sound card was rated @ 116db S/N ratio.I tried a different power supply and video card which helped a little but the noise was still there. Bought another MOBO but the thermals of that board was too low for my new 220w tpd processor, but worked well my FX-6350. I then sold the first MOBO the sabertooth 990fx which locked up on the boot screen. I thus gave up the second MOBO which according to my research had a few successful builds with a FX9590 CPU. I sold it along with the FX-6350. I'm now down three MOBO's I have a powerful new CPU and no working system. I then purchase my final MOBO a Crosshair V formula Z and guess what the noise is back.I researched the problem on-line and tried sheilding the sound card with foil and cardboard - no significant difference. With my MOBO bios one could save various bios setting profiles, so I underclocked the machine significantly from 5.0ghz to 1.5 or 1.8 ghz. It helped but noise was still there but more tolerable but the machine's performance was significantly diminished.. Frustrated with performance I went back up in clock speed and turned off two of the eight cores, it helped but not enough. I was convinced that the problem was processor based I had no intentions of buying another MOBO. SInce Sub-woofer output is mono I used two ten band equalizers in series i.e. channel into channel and then equalizer into equalizer and attenuated everything from 300 hz and above. total attenuation 12db per channel times 4 - 48db this yielded the largest reduction in noise and I used this system for a while but in a quiet room, anyone with a keen ear could still hear the faint noise.While searching for a better solution on-line I came across a number of possible solutions and one of them took me to a device similar to this one on amazon. I reviewed the specs and especially the reviews of devices similar to this one and despite a few negative reviews after careful consideration I decided on this one.That is a decision I will not regret. My noise problem persisted for several months and could be detected in a room from a distance of twenty feet or more feet even with the volume muted on my PC. I tried a number of possible solutions which had limited to no success at all. I went through three different motherboard at a cost of a couple hundred dollars and guess what the solution was this device available right there on Amazon for less than 10 bucks.I highly recommend this product it works. I experienced no audible signal loss as some reviewers claimed but I did experience full noise loss. I think it was designed for car audio but it certainly works for home audio. Now I can put my ear to the grill of my 15's and hear no noise whatsoever with the PC soundcard volume at one hundred percent while nothing is playing. Thanks Boss audio for a great product.

This was something my man wanted so I got it for his car. I guess it was what he wanted and needed. He didn't have to pay for it and he had it installed so overall I got what I ordered.

When connected my aux input stop working, my connection was as follows, Android head unit RCA out to isolator to factory AUX RCA input. When connected the factory unit disable the AUX option.It won’t work on 2008 Acura MDX

I had an annoying 60Hz hum from a ground loop with my Buttkicker amplifier, feeding into my home theater subwoofer. I could not solve it with an ac isolation transformer, so I tried this filter, and it solved the problem. Easily installed in line with the Buttkicker RCA input. It does distort the signal, which I deemed acceptable as it's just feeding a tactile transducer, but I would not use this in series with any audio signal where I cared about the signal quality.

Since I hooked up all my new Boss radio, amp 4 speakers, and subwoofer, worked great but had that awful whine from the alternate. 2 of these ground loop eliminators, front channels and back, the speakers are whisper quiet between songs. Well worth the $15 apiece!

Large plastic box encloses the isolation transformers.

The Boss converter is a transformer with two primary windings, that accept the right and left stereo loudspeaker output from f.ex. a radio, a TV, or a cd-player, and with two corresponding secondary windings with line level signals for e.g. active speakers. The resistance of each of the primary windings is 17ohm, and energy dissipation in these resistances is no problem at the manufacturer's sensitivity setting, irrespective of the max. output of your amplifier. The relative size of each output signal - the sensitivity - is adjustable by an attenuator from zero to about 38% of the input signal. The converter is set a cautious 33% sensitivity by the manufacturer, and as an exersize I changed it downwards to 20%, (within 0.2%), a bit more suitable for the Dynaudio BM5A active speakers, that the converter is to serve. My primary signal is from a Pure Sirocco 550 radio/cd unit designed for 8 ohms speakers.The resistance of the output circuits of the converter, when set to 20%, was 3.3kohm and 2.1kohm respectively for the two output channels, as measured with a multimeter. This difference in resistance may carry over to the resulting signals for the two active speakers, but this I could not tell with mine.The frequency response of the Boss converter is perfectly linear from 20kHz to around 100Hz with a very gradual fall off, and 50Hz being only 4% down in output, 30Hz 7-8% down, and 20Hz about 50% down compared to the (100%) 20kHz to 100Hz range. This diminishment is not noticeable with the Dynaudio speakers, but the converter is less suited below 30Hz.The sensitivity adjustment of each output is through a 3/4 turn of a set-screw, clockwise for higher gain. I used a sine-wave generator and an oscilloscope + a multimeter for the measurements and settings, but a 1volt 50 or 60Hz signal plus an ac multimeter with a 1000mV range would suffice for setting the sensitivity, because the setting at 50Hz is valid throughout the frequency range.You will appreciate, that replacing passive speakers with active counterparts in your home stereo system is quite manageable. Simply leave the old cables in place (or replace them with lighter ones), swop the passive and active speakers, and affix a converter to the back of each of the active speakers, with the loudspeaker cables providing the primary input. To feed the converter's unbalanced output to the balanced input of my active speakers, I used an extra 4 inch mono phono cable (with a male plug) and soldered the center conductor to nr. 2 pin and the shield to the nr. 3 AND to the nr. 1 pin of an XLR connector for the input. The remaining hassle is to connect the active speakers to the mains supply.The Boss converter, exemplary in low cost and simplicity, is a perfect Hi-Fi level converter with no noise and no distortion in my listening experience. It may contribute to powerful Hi-Fi home stereo sound from a modestly priced radio/cd-player, via active, analogue speakers. One might argue for one star down, because, if not using the converter with the factory settings, accurate sensitivity adjustment is a bit cumbersome, as described, and documentation is very limited. The factory setting of 33% is perfectly sensible though, the only possible drawback being lower than usual nominal volume settings.

Worked like a charm. Great product.