Why doesn't my subwoofer handle max settings?

First things first: hardware can’t solve a problem if it exists in the recording itself, and things like subwoofers will bring out qualities in the audio that are hidden without them. Usually that’s a good thing (obviously, the whole point of bass boosters is to augment frequencies that can get lost without them), but sometimes it brings out flaws (such as when the bass was recorded or imprinted already dirty). So if whatever you are listening to doesn’t have a clean bass sound, no technological fix will get it for you.

But it’s more likely that the issue is your setup. Low frequencies have more overtones, so it’s not easy to boost them without getting distortion unless you also change the sound in other ways. Basically, you need to do three things at once: boost the bass, reduce the treble, and apply dynamic range compression to the whole signal. That can be complicated, so I’ll PM you a link to a site that might be able to give you more specific help.

Spec sheets are all lies for one. Max settings are what can be handled without causing damage, it will sound cappy long before those levels.

Wait help me okay, you are using a sub-woofer on a PC with Corsair VS450Power Supply and not a stereo or A-V receiver? ? ?

@Tropical_Willie and @ARE_you_kidding_me have good points. If you max out the system, you will get clipping: https://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/clipping/page1.html
that results in a DC signal going to the speaker, which will cause distorted sound or burnout.

PC’s don’t have audio like receiver.

Maybe this isn’t important…
Make sure the speaker can handle more watts that the unit can put out.

Sub-woofers control the their own amps, I think he is getting a “dirty signal” from the Computer.

“it seems that if I bump bass to max it distorts sound. I have no idea why.”

Keyword there, bump any sound system to max and it will sound bad, especially sub woofers. They deflect a lot and low frequency harmonics come into play when cranked on max settings like that. Makes a tight punch sound like a windy fart.
Also T.W. has a good point, if your source audio maxes out you distort the signal. Pre-outs from computers are still usually just fancy op-amp circuits. Once over-driven they “clip” just like @RocketGuy mentioned. solid state amplifiers have a hard cutoff also known as “hitting the rails”
Bottom line is….back off on the volume and don’t turn the bass up to max.

So depending on your specific setup, you might have to stick to either of those two guidelines. Most surround sound receivers incorporate bass management, and can assist in setting up a sub that has a 20–120 Hz response, in a THX system, for instance.

Generally-speaking, the eardrum doesn’t respond to frequencies below approximately 80Hz, so I always felt that 80 Hz was a better choice for a crossover frequency.