Sundown AudioSA-6.5 SW D4 6.5" 200W Dual 4-Ohm SA Series Subwoofer

I'm building a bluetooth 2.1 boom box (my 4th one). The previous one used Tang Band 5.25inch sub or 6.5 inch sub but they require 720 cubic inch to get down to F3 of 35Hz. This Sundown 6.5 sub will allow me to get down to 38 Hz in a 520 cubic box and 16 inch long port of 2 inch inside dia. (according to Bassbox Pro). It isn't "musical" meaning that above 100 Hz it drops off very quickly compared to the TangBand which could go all the way to 1000 HZ. The power handling was great too.In fact, I bought two, one for my son and one for myself.Make sure your amp can deliver 250W rms into 2 ohms otherwise it will cause your amp to clip.

These little subs really pound, especially when you put them in the right box. Sundown's website says you can put it in a sealed box, but I tried that and it was super weak, and had a light slapping noise under tight bass, like a kick drum. Very annoying. I put it in a ported box built to the exact recommended specs and it is super loud and surprising. If all I listened to was hip hop, breakbeat, dubstep or drum and bass, I'd be happy.But in the end, I want a more musical sub. This fills out the deep bass decently, but there's a hole around 150-300hz in the music. I have it in a wagon with 4 polk 6.5" components and those don't go low enough, and this sub doesn't go high enough. And to be honest when I really crank it, I hear distortion and noise that is only coming from the sub. They've tried to replace big subs but I can't do it. A sealed 8" will be the same box size as this ported 6.5" and likely be way more powerful with a flatter response.Since I have a 12" sealed box already built I just went with a 12" designed for a sealed box and I'm much happier with the sound, even though it's 3x larger. In the end if I haul stuff in my wagon I have to pull the sub anyway, so smaller isn't worth the compromise.I really wanted to love this sub, and I was very impressed with its volume and depth of bass, but physics are physics. If you have a tiny car or truck and this is all you can fit in it, you'll be able to enjoy very deep bass with it that you can feel.

That blew second I got

Update: 9/13/2020I figured out why the speaker was rattling at all volume levels. The gel silica pack that keeps moisture from the product was inside the woofer. When the speaker was playing the silica pack would bounce around like a small bing bag causing the speaker to rattle.So out of 3 speaker I have only had one be defective. I have changed my review from 1 star to 4 stars. I can not give this speaker 5 stars because I still think the quality control needs improving. I still have one speaker go bad in less than 2 weeks. These speakers cost too much money to go out in that short amount of time.Than being said I think Sun Down Audio is on the right track of producing some good audio equipment.The concept of Sun Down audio is awesome but the quality control is just not there. The parts they use are quality but the assembly of the parts are not good. So far I have had 3 of these speakers and had to return 2 of them. The one that works plays really well. The speakers that I had to return one had some soldering issues near the voice coil and the other one rattled on all volume level right out of the box. Either the seller sent me a used speaker or it was defective at the time of manufacturing.Until Sun Down gets its act together I would suggest buying Skar woofers. The quality is just abut as good as Sun Down and the price is much cheaper. Skar has been around a little longer so the quality control on their speakers is much better.Sun Down gives a 2 year and 1 year warranty on their speakers which is good. But it is not good when you have take the speaker out of the box a few weeks after install because of problems. Sun Down needs to make a better product so their warranty actually means something.