Ok so when I got this Tahoe the po had added an amp for all the door speakers I guess the factory one quit. Also have a nice pioneer head unit. Well I found that I had a sub i the back but it was blown and nothing going to it. So I looked at replacement subs. Being ann8 inch I wasn't expecting much but after some searching I got a planet audio ac8d. Its rated for 1200 watts has dual voice coils and is a direct fit in the stock box. I hooked it up to a 1000 watt amp. My first impression was WTF. how could an 8 inch sub produce so much bass and so clearly. I only have the gain up a little over half. Dialed in my x over and got my door speaker amp dialed in with the head unit. Omg. This sub was only 32 bucks on Amazon. Best bang for the buck ever. If anyone is looking to replace there factory sub in a Tahoe that is like mine. This is absolutely the best option. Performs great and is super cheap. Get a 12 out of 10 on my list