This type of amplifier has 75W x 4, V12 High Power Amplifier, MOSFET Power Supply, Non-Fading Pre-Amp Output, and Bass Engine.
Thats really an opinion both brands are good amps and both are tested to show their correct wattage if not more than
Alpine by far.
2x20 Watts
The Alpine V12 DC Straight amplifier typically comes in different models with varying power outputs. It can range from around 300 watts to 1200 watts, depending on the specific model. It's best to check the specific model number or specifications to determine the exact wattage.
At least 1000
Alpine amplifiers are used to amplify sound of digital equipment such as Subwoofers. You can purchase Alphine amplifiers online from retailers such as Amazon.
Alpine offered up until last year the PDX-1000 wich is a 1000 Watts RMS amplifier designed with the type X subwoofer series in mind. Now the best match would be the PDX-M12. Set the amplifier gain carefully as this amplifier is a bit strong for this subwoofer.
The Alpine v12 MRV-F505 amplifier puts out up to 200 watts of RMS power at 4 Ohms and using 12 volts. At 14 volts, it puts out up to 400 watts of RMS power with a bridged 4 Ohms ratio.
To parpahrase Henry Ford the Alpine V-Power MRP-F300 comes in any color you want so long as it's black.
According to Alpine's website the dimensions are (WxHxD) in: 10-15/16'' x 2-23/64'' x 9-27/32''
The Alpine MRV is an amplifier that is used in car stereo's. There are many different models in the MRV line. On ebay you see prices from $50.00 for older units, on up to $1250 for current new-in-the-box models.
You could use any amp size over 100 watts for great sound production.