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.

This thing is rock solid and works as expected.

Good

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 nice and small perfect and easy to install

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.

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.