Sub does it's job quite well at $230, Pros: heavy hard hitting base that'll rumble your house and your burgular bars :); good for HTS. Cons: very inexpensive control knobs- scares me to make adjustments for it might just break any instance; cabinet vibrates becuz it's made of cheap thin particle wood-(not MDF); bass isn't accurate for music reproduction, too slow?? who knows? just doesn't blend well; Lastly, yes, the amplifier design, gets wayyyyy too hot, after playing Saving Private Ryan at not even full blast, it was almost 2 hot 2 touch.P.S.
Doesn't even have a freakin grille to cover the woofer?!

I give it 5 speakers at $230 bucks!
at 500bucks I'd have to give it 3speakers!

Bought my AV550s from OnSale, Inc. auction for $229, and all I can say is WOW! I'm using a Denon AVR 2700, three Paradigm atoms for front and center and two Energy Take 5's for surrounds, and this sub just kicks, yet can be quite subtle when dialed back.
When I first hooked it up (with my old pro-logic reciever using parallel speaker connections), it was hilarious to listen to a news report outdoors, because the lavalier microphone the reporter used had wind blowing across it, and the low level rumble (normally inaudible) it caused nearly knocked knick-knacks off the furniture. Of course, I then dialed the sub in properly, and it produces PHENOMENAL levels of low bass, even with the gain turned nearly to it's lowest position. Home theatre comes alive.

As to sound clarity and quality, I can say it compares favorably to the Velodyne 12" sub I've heard, and absolutely demolishes anything JBL. Only sub in the general price category (sub-$1000) I've heard better is Definitive Technology 18" system, but this comes close.

Kudos to Bob Carver and Advent....I feel like I stole this one.

Best $229 I've ever spent

After reading the other reviews on the Advent 550, I would have to say that they are pretty much right on. IT IS A MONSTER!!!! More deep bass than one could ever want, with a price that is fantastic!The reviews have said,the knobs are cheap, the sub is hard to blend and that the power turns off at low volumes.This is all TRUE and right on the money. They also say that the bass is so powerfull it will move furniture, this also is true! Everyone has taken into consideration the price and given it a 5 speaker rating. This sub is the real deal and the ultimate BANG FOR YOUR BUCK.

Just hooked this av550s up. Unbeleivable power and bass response. I have the gain down almost to nothing and I am still shaking all in the house. My wife thought there was an Earthquake. did some fine tuning on the crossover and phase control. This sub really comes alive. Who needs a Velodyne with this kind of performance for the price $275. Not using LFE, running inputs from preamp in stereo. A great complement to the rest of my home audio sustem. Maybe I will buy 2 more for the home Theater ? If your in the market for a powered sub don't miss this one before buying.

I just got this sub to round out the lows in my system and it sure does deliver! This thing is huge and heavy, take that into consideration if you have spatial limitations because you have been warned! It has a great build quality and the amp runs very cool. I can see where some people might not like the knobs for the adjustments. Personally, I have no problems with them. I actually like the knobs for certian reasons and in no way do I feel like they are going to break as some claim. Taking some time to adjust the sub will yeild excellent results. It is effeciently powered at all volumes and keeps up with music as well as home theater. Let me tell you this thing hits SMOOTH and LOW when adjusted properly. Being in the finished basement it resonates through out all 3 floors with ease, even only with modest power and conservative adjustments! Take this into consideration if you are living in an apartment, because you might get complaints/evicted no matter what the volume! So how does it sound? Easily like a 1000$ subwoofer. This subs' lows really shine on techno tracks and make you realize (giddy!) why you NEED a sub to hit 20hz. Also with traditional music it reproduces bass lines quite faithfully. I feel I stole this at an auction site for 221$. I suggest if you are in the market for a subwoofer and have a budget like most nomal people are limited to, you WILL NOT find anything better. I would of gladly payed more for something of this quality, but I am shocked that I didn't have to... Bravo!
Oh, one more note; no cables/wires (except powercord) are included so be sure you are prepared. It might save you a speeding ticket from all the excitement of rushing out to get one at the last minute!

Just wanted to update my previous review. I would definitely still rate this sub a five, after having a lot more time to test it with a very wide range of music and video. If you buy one and are not amazed with the sound, mess around with the crossover and the gain. I have found that this makes a huge difference in my system. If you take the time to blend the sub, I don't think you will find a better sub out there for even twice the price.

Just got my sub, after UPS delivered it to the wrong place. Got home plugged it in, NOTHING!.
I placed a call to Advent, and rather then ship it back to onsale where i got it from, i figured i could just get it serviced quicker.
Found a place near me, but being the tinkerer i am, i decided to open it myself.
I'm glad i did, there was obviously a missed step in the assembly process, the circuit board is suppose to be attached to the 3 pins where the plug goes into, and it wasn't.
the board was dangling, and it wasn't from shipping either.
There were 2 mounting holes for rivets to hold the circuit board on,and the holes weren't even poked through, so i drilled them out and i used small bolts with rubber washers to affix the board.
Then i soldered the tips of the pins, so they can't be jarred loose.
This was all steps that should have been done in the first place, and there is nothing rigged about it.
So, now it works.
I agree the knobs are a little low buck, but then again, so is the sub.
The Xover was the hardest to turn also.
But set it once, get it right, and forget it.
The overall design now that i have seen it, inside and out, is average, the sub has a huge looking magnet, the inside chamber has insulation on the walls, the port is cardboard, i didn't see anything different about it, compared to other ported boxes i have seen.
The construction is solid, although i don't think it's MDF,but some sort of heavy rigid wood. The outside is a black laminate and looks appealing.
The Amp, sits inside a plastic tray, completely sealed from the sub chamber, i saw no heatsinks, and i am wondering how this thing dissipates heat.
The only thing i can think of is that the access panel to the amp is metal, and may act as the heatsink itself.
Gain, control varies, with different sound input, seems that there is a sudden boost of power the last fraction of a turn.
So anyway, i woke the baby, my wife is screaming, the picture on the wall is rattling, and i only have begun to play.
If a low budget earth shaking sub is on your list, and you can deal with some potential problems that might come up, then this sub is for you.

Performance versus cost *****
design (knobs) **
actual sound performance ****
appearance ****

Good subwoofer for a great price.

I am terribly sorry for posting negatively here a few days ago. I asked my vendor to change the defective sub and the new one sounds great! It can simply blow away my Velodyne CT-120 at the low Hz. I'd like to give it four and half stars, because I think it can be a little bit more musical. Without such an option, five stars. Thanks a million for those who helped me set up the cute fat boy.

Good price, yes. Quality? well... mediocre. Cheap knobs, especially for the crossover, which requires effort to turn, and feels like it's gonna snap off... The port tube is flimsy, with black paper covering. Part of the paper was peeling, which was a resonant annoyance until removed. The tube also gives trouble on tracks like Stabbing Westward's "Drowning," with a constant low-freq signal (it may be sub 20hz, i don't have an oscilliscope). Haven't had any "automatic switching poppings," though it does snap when you turn it on.
2.5 stars for build quality

Yes, it's 20Hz. Yes, i can make the whole freakin' dorm shake, at low gain even. (my front speakers have 15" drivers too. 3x15" = lots of air motion.)

5 stars for bang/buck

Musicality? Not great, not bad. I don't do HT, so. Run the crossover low, and it should be okay. Take time to blend it.

4 stars "Musicality"


Big, loud, cheap (biggest complaint is the construction)
4 stars overall


P.S. If someone posts a negative review, it is _NOT_ necessary to paste a fake followup positive review. Don't get upset just 'cos someone doesn't like your spiffy sub.