b26i with dual 12's and 350w amp

I'm putting in two Memphis Power Reference 12in subs with an alpine 350 watt amp. Will I need to change the alternator out for a bigger one? If so, what's the best amperage to get?

I don't think so. Back in the day I had a Phoenix Gold M50 and a M25. The M50 was in 2ohm bridge and the M25 was 1ohm stero. I also had a Phoenix Gold x-over borrowed epicenter. I ran a 2 farad cap and no probems.

I just got a Phoenix Gold M50, and 2x12 JL box. I've been wondering if I was gonna need a bigger alternator. (Also running a Nitro 4 channel amp)

Tell me more of the 2 farad cap.

That would help to store energy. Like a capacitor, which would cut down the potential need for a bigger alternator. I think that's right?

Yup, that's the idea. Under $50, and easy install. Still, I wonder if I need one.

As bass heavy as some of the classic D&B I listen to is, I wonder when the cap would have a chance to recharge.

i think it can recharge when the truck is off... not entirely sure though

The one I was looking at, in addition to battery + & -, had a lead to hook up to the head unit's remote wire. In this case, at least, no charge with truck off. Anyway the recharge/ discharge is much faster, than that.

The cap is like another battery. you can connect them in series as well. I highly recomend one! They will help with "disco" headlights if you have that issue.

dont waste ur money on a cap there junk if ur thinkin ur needing extra power just get another battery and battery isolator isolator acts as a switch charges ur main batt. and then switches to charge ur auxiliary batt

me personally i would just go to walmart due to the easy exchange get the biggest batt. for ur truck im running just one in mine everstart max 3 yr warranty have to check the cca but im runnin a clarion cheap-0 DHD 1000 watt amp on 4 midbass drivers (loudspeakers) with a 7inch indash i got a separate battery for my air ride

Takes power to make power. If you add a second battery you will be able to play the stereo longer with the key off but that's it. The extra battery is going to need more amperage to keep it charged and the stock Mazda alt is already being taxed.

Stiffening capacitors are a band aid too. The biggest gain will be from putting in a higher output alternator. The Ford V6 alt or a Chevy one wire will help.
The stock Mazda alt is like 60 amps maybe. Let's say your truck draws 50 amps with the headlights, heater, wipers, ect now you install a stereo that pulls 40 amps now you are in the negatives and are gonna work the stock alt overtime.