RACKEYS Single Supply subwoofer Filter Board with inbuilt Phase Switch, Frequency selector and gain Control. Wide Input Voltage 9-24 Volts DC.

Excellent product.I really liked the sound quality.It works amazing.With frequency selector jumper, we can select the appropriate sound output.I really like low frequency base.I used it with mosfet 1943 and 5200 circuit and pioneer D4 12 inches subwoofer. It works great gives thundering base.

Good sound quality bass

I have exchanged with new one. But it shows another problem. Big humming noise. Very bad product.

I feel after long term use its best product in this range for best clarity. I feel I use crossover subwoofer base feature. In this price range.

Best Sound Quality ,Low Humming Created than other board,Build Quality is Best,Price is little high but ok,I have connected 60 Watt subwoofer with tda7265 ic board its working great.

The output is clean, but could be even cleaner. I really wanted a board on which I can change the crossover frequency and this one fits the bill perfectly.Note however that the output has a DC offset. When I plugged 12V to the board and input signal set to 0, the output is showing 6V DC. The input signal is coming on top of the DC offset. I was not sure if my active amplifier has an AC coupling capacitor. So just to be safe, I placed an AC coupling capacitor in series at the output before connecting to my subwoofer.

Adjustable Gain +Cutoff Frequency Selector +Same Audio Power Ground -Roll-off too sharp for normal music -Things to consider before buying:A separate power source required (same power source as amp will introduce noise).Bass seems slightly exaggerated ,not natural (Good for bass lovers , ear soar for audiophiles).

Sound quality is awesome. perfect value for money product. use above 12vdc power supply. i am using 14v dc and its working much better then it was with12v dc.