ST600 Rockford Fosgate Motorcycle Amplifier

Can this amp be placed inside of the saddle bag?

Yes, the saddlebag is one of our recommended locations.

What is the recommended gain setting for the ST600 speakers

We like to push our speakers to their full capability, so typically around 9 or 10 with crossover set to HP or AP.

How much is a Bluetooth controller for this amp?

We offer 2 Bluetooth controller options for the Rockford amplifier.  They are priced at $39.99 and $99.95 depending on what features you want.  You can see them both here:  https://www.steelhorseaudio.com/collections/bluetooth

Does this amp come with the wiring hardware or do you have to buy that separately?

All wiring hardware is included standard with the amplifier.  This product also includes the wiring kit for power, remote and ground connections.

Can 2 of these amps be used from the same bluetooth device simultaneously ? I would like to run 2 amps from the same bluetooth source that you sell.

Yes, you could use a headphone splitter from the Bluetooth controller and connect to 2 seperate amplifiers.

Is this a 4 channel amp or 2 channel amp?

It is a 4-channel amplifier.