Power Supply for Sony XM GS4 (temporarily) in a Home Stereo 2.1 set-up

[Gensonic]

Hello everyone !

I recently purchased a car amplifier Sony XM GS4 (4/3/2 channel, class AB amplifier). I plan to use it my up-coming car. For time being, I thought why not to put it into action in a 2.1 channel setup.

Manual suggest the following wiring design for a 2.1 setup:

The amplifier's specs mention as under:

Speaking about the details of speakers, I'm using Q Acoustics Concept 20 (2 x25 to 75W) with a custom passive sub-woofer (1x 250W RMS 4 ohm), totaling to max. 400W (not sure if I'm correct on this).

Considering the 12V DC power supply, I found it confusing to calculate the current requirement while deciding the specification of the PSU. Though I'm considering following factors will play role in deciding the current, but not sure how to use them:

1. Efficiency (40-60%) of the AB class amplifier
2. (Assuming) 400W output
3. Relating the average DC input power supply with RMS power of amplifier and the output power of the speakers

Looking forward to the experts in understanding these factors and the specs of PSU to go with.

Thanks,

 

[wwenze]

It has 2 * 30A fuses presumably in parallel so prepare 30A to 60A worth of 12V

Or actually you won't actually need that much, it will just draw the amount that is required.

 

[AnalogSteph]

Given the substantial crest factor of typical music, it doesn't make sense to use a super massive power supply. Go with a decent-sized charger (10-15 amps maybe), a car battery (or equivalent lithium iron phosphate) and arguably a supercapacitor for automotive use.

Keep in mind that the amp would generally be tied to the same ground potential as the source inside a car via the chassis, you may need to replicate that connection.

 

[Gensonic]

It has 2 * 30A fuses presumably in parallel so prepare 30A to 60A worth of 12V

Or actually you won't actually need that much, it will just draw the amount that is required.

Thanks for the help.

While going through the manual, I found this diagram on two-fuse arrangement. I guess you're correct on their parallel connection, thereby, resulting 60 A as the fusing current.

Given the substantial crest factor of typical music, it doesn't make sense to use a super massive power supply. Go with a decent-sized charger (10-15 amps maybe), a car battery (or equivalent lithium iron phosphate) and arguably a supercapacitor for automotive use.

Keep in mind that the amp would generally be tied to the same ground potential as the source inside a car via the chassis, you may need to replicate that connection.

Thanks for the reply.

My another doubt lies with powering the sub (250 RMS), especially. Won't that be underpowered, if I go with 15 or 30A PSU? If yes, my sub might need more power to perform for its capacity. It means adding another powerful amplifier.

Kindly guide me on this.

Thanks,