PAC SNI-15 Speaker Level to Preamp Adapter

Installed in a 2008 Mazda3 with the stock radio to add a sub and it works flawlessly. Before hooking it up I ran a simple frequency response sweep and this thing is perfectly flat from 20-20,000 Hz just like it says. The input impedance is just about 20 ohms per channel, so you can connect it in parallel with the stock speakers and it will not put excessive extra load on your head unit. I wired it in parallel to the rear speakers and it worked out great. Uses an isolation transformer and is completely passive for zero added noise. No need to connect power to it like other units. There is no reason this type of device should need power. There is no hum or distortion being added by this device that I can tell. And the 10:1 ratio is fixed, which is probably perfect for most stock radios. My amp gain is set to about 2 o'clock and there's plenty of bass. Device is beefy and not super small, but still fit behind the radio without any issues. There are two brown ground wires that you do not need to connect. The instructions say to connect them to ground if you get no sound from your amp. I ohmed them out and they are connected to the ground on the RCA connectors. I'm not sure in what scenario you would have to hook those up, but leaving them unconnected worked fine for my setup. No noise, no hum, and now I've got some bass with my factory head unit. This device made it possible. Can easily recommend. 5 stars.

Have a couple subwoofers that were used on desk top computers so decided to experiment and hook one up to a book shelf system . Used this to piggy back to the speaker outputs at the amp. Wasn't sure a sub designed for computer use would work but it's flawless, clean and clear bass with plenty oomph and no distortion. Guess any line converter would work but this on has a 10 to 1 reduction and is doing its job very well.

Works great to convert my high level factory sub inputs to low level. Make sure to hook up the brown ground wires. It will give you a stronger signal.

This line converter was exactly what I needed to add my subwoofer to my Jeep Wrangler. This was a much cheaper option than buying an aftermarket headunit and the adapter that would have been required to hookup said aftermarket headunit to the factory Jeep JK harness. Plus I have the extra benefit of keeping the factory radio in place and not having a nice aftermarket unit to tempt would-be thieves into taking. Installation was very simple with the included instructions. You do need to find which wires on your specific make and model of vehicle to tap into but that information is pretty easy to find. I personally followed a write-up on a Jeep forum about my application and like I said before, installation was a breeze. Quality of the unit seemed to be good. The wires come pre-stripped and ready for connections. The unit came in a simple blister type of package and did not require the jaws of life to open. The instructions were in layman's terms and very easy to understand (printed in English). While the instructions did say how to orient the device to properly distinguish the Left and Right RCA outputs, I feel it would be worth marking them on the device itself just to avoid any confusion and potential problems. Even though that was not an issue for me, it is my absolute only complaint about the unit and I am overall extremely satisfied with my purchase of this item and certainly would recommend it to others.

Works great nice and small perfect and easy to install

I rarely write reviews, but felt compelled due to how much this unit helped with my setup, and hope it might be of use to someone else. I have a 1990's-era Teac subwoofer that only has an RCA input, and a 1980's Akai receiver that doesn't include a sub out jack. I used this adapter to connect my subwoofer to the B speaker wire level out on the Akai. It enables the Teac to add on some nice low end heft to the regular A stereo speakers that are connected, when I run both A and B at the same time. I'm definitely not an audiophile, but the end result sounds really good to my ears.

As expected, fast shipping.

Good