I got this amp/box ... sounds good in my friends car ... just asking bc i dont know ... Is there a best/certain type of speaker for this setup?

 

Heres the box

 

Ones that fit and match the specs of the box and amp will be best. I don't get it...your photo shows speakers...so why do you need speakers?

 

sorry, i meant speakers within the car. I am looking to upgrade but if the stock ones r good enough, i only have to replace passenger speaker.

 

It's gonna be loud that's all I know. Set the gains on your subs appropriately so they don't overpower your interior speakers.

 

Depends on what you want, your budget, the level of effort you want, and if your existing head unit, amp, and speakers are all still functional. What is "good enough" for me, may not be good enough for you. You have to figure that out. My stereo is bone stock and will stay that way. It is good enough....for me.